Migrate OSS up to d3b9a780d

.github/actions/spelling/allow/apis.txt

@@ -74,6 +74,7 @@ llu
 localtime
 lround
 LSHIFT
+mov
 msappx
 MULTIPLEUSE
 NCHITTEST
@@ -98,6 +99,7 @@ overridable
 PAGESCROLL
 PICKFOLDERS
 pmr
+rcx
 REGCLS
 RETURNCMD
 rfind
@@ -138,6 +140,7 @@ winmain
 wpc
 wsregex
 wwinmain
+xchg
 XDocument
 XElement
 xfacet

.github/actions/spelling/allow/microsoft.txt

@@ -33,6 +33,7 @@ MSVC
 muxc
 netcore
 osgvsowi
+PFILETIME
 pgc
 pgo
 pgosweep
@@ -40,10 +41,12 @@ powerrename
 powershell
 propkey
 pscustomobject
+QWORD
 robocopy
 SACLs
 Shobjidl
 Skype
+SRW
 sxs
 Sysinternals
 sysnative

.github/actions/spelling/expect/expect.txt

@@ -1443,6 +1443,7 @@ MSVCRTD
 MSVS
 msys
 msysgit
+MTSM
 mui
 Mul
 multiline
@@ -2416,7 +2417,6 @@ uapadmin
 UAX
 ubuntu
 ucd
-ucd
 ucdxml
 uch
 UCHAR
@@ -2780,7 +2780,6 @@ xml
 xmlns
 xor
 xorg
-xorg
 Xpath
 XPosition
 XResource

doc/cascadia/AddASetting.md

@@ -6,9 +6,9 @@ Adding a setting to Windows Terminal is fairly straightforward. This guide serve
 
 The Terminal Settings Model (`Microsoft.Terminal.Settings.Model`) is responsible for (de)serializing and exposing settings.
 
-### `GETSET_SETTING` macro
+### `INHERITABLE_SETTING` macro
 
-The `GETSET_SETTING` macro can be used to implement inheritance for your new setting and store the setting in the settings model. It takes three parameters:
+The `INHERITABLE_SETTING` macro can be used to implement inheritance for your new setting and store the setting in the settings model. It takes three parameters:
 - `type`: the type that the setting will be stored as
 - `name`: the name of the variable for storage
 - `defaultValue`: the value to use if the user does not define the setting anywhere
@@ -20,7 +20,7 @@ This tutorial will add `CloseOnExitMode CloseOnExit` as a profile setting.
 1. In `Profile.h`, declare/define the setting:
 
 ```c++
-GETSET_SETTING(CloseOnExitMode, CloseOnExit, CloseOnExitMode::Graceful)
+INHERITABLE_SETTING(CloseOnExitMode, CloseOnExit, CloseOnExitMode::Graceful)
 ```
 
 2. In `Profile.idl`, expose the setting via WinRT:
@@ -141,7 +141,7 @@ struct OpenSettingsArgs : public OpenSettingsArgsT<OpenSettingsArgs>
     OpenSettingsArgs() = default;
 
     // adds a getter/setter for your argument, and defines the json key
-    GETSET_PROPERTY(SettingsTarget, Target, SettingsTarget::SettingsFile);
+    WINRT_PROPERTY(SettingsTarget, Target, SettingsTarget::SettingsFile);
     static constexpr std::string_view TargetKey{ "target" };
 
     public:
@@ -213,9 +213,9 @@ Terminal-level settings are settings that affect a shell session. Generally, the
 - Declare the setting in `IControlSettings.idl` or `ICoreSettings.idl` (whichever is relevant to your setting). If your setting is an enum setting, declare the enum here instead of in the `TerminalSettingsModel` project.
 - In `TerminalSettings.h`, declare/define the setting...
 ```c++
-// The GETSET_PROPERTY macro declares/defines a getter setter for the setting.
-// Like GETSET_SETTING, it takes in a type, name, and defaultValue.
-GETSET_PROPERTY(bool, UseAcrylic, false);
+// The WINRT_PROPERTY macro declares/defines a getter setter for the setting.
+// Like INHERITABLE_SETTING, it takes in a type, name, and defaultValue.
+WINRT_PROPERTY(bool, UseAcrylic, false);
 ```
 - In `TerminalSettings.cpp`...
   - update `_ApplyProfileSettings` for profile settings

doc/cascadia/profiles.schema.json

@@ -165,6 +165,49 @@
       },
       "type": "object"
     },
+    "FontConfig": {
+      "properties": {
+        "face": {
+          "default": "Cascadia Mono",
+          "description": "Name of the font face used in the profile.",
+          "type": "string"
+        },
+        "size": {
+          "default": 12,
+          "description": "Size of the font in points.",
+          "minimum": 1,
+          "type": "integer"
+        },
+        "weight": {
+          "default": "normal",
+          "description": "Sets the weight (lightness or heaviness of the strokes) for the given font. Possible values:\n -\"thin\"\n -\"extra-light\"\n -\"light\"\n -\"semi-light\"\n -\"normal\" (default)\n -\"medium\"\n -\"semi-bold\"\n -\"bold\"\n -\"extra-bold\"\n -\"black\"\n -\"extra-black\"\n or the corresponding numeric representation of OpenType font weight.",
+          "oneOf": [
+            {
+              "enum": [
+                "thin",
+                "extra-light",
+                "light",
+                "semi-light",
+                "normal",
+                "medium",
+                "semi-bold",
+                "bold",
+                "extra-bold",
+                "black",
+                "extra-black"
+              ],
+              "type": "string"
+            },
+            {
+              "maximum": 990,
+              "minimum": 100,
+              "type": "integer"
+            }
+          ]
+        }
+      },
+      "type": "object"
+    },
     "ProfileGuid": {
       "default": "{}",
       "pattern": "^\\{[a-fA-F0-9]{8}-[a-fA-F0-9]{4}-[a-fA-F0-9]{4}-[a-fA-F0-9]{4}-[a-fA-F0-9]{12}\\}$",
@@ -546,12 +589,14 @@
             "action": { "type": "string", "pattern": "openSettings" },
             "target": {
               "type": "string",
-              "default": "settingsFile",
-              "description": "The settings file to open.",
+              "default": "settingsUI",
+              "description": "Opens Settings UI or settings file.",
               "enum": [
                 "settingsFile",
                 "defaultsFile",
-                "allFiles"
+                "allFiles",
+                "settingsUI"
+                
               ]
             }
           }
@@ -646,6 +691,25 @@
         }
       ]
     },
+    "CloseTabAction": {
+      "description": "Arguments for a closeTab action",
+      "allOf": [
+        { "$ref": "#/definitions/ShortcutAction" },
+        {
+          "properties": {
+            "action": { "type": "string", "pattern": "closeTab" },
+            "index": {
+              "oneOf": [
+                { "type": "integer" },
+                { "type": "null" }
+              ],
+              "default": null,
+              "description": "Close the tab at this index. If no index is provided, use the focused tab's index."
+            }
+          }
+        }
+      ]
+    },
     "ScrollUpAction": {
       "description": "Arguments for a scrollUp action",
       "allOf": [
@@ -897,6 +961,7 @@
               { "$ref": "#/definitions/WtAction" },
               { "$ref": "#/definitions/CloseOtherTabsAction" },
               { "$ref": "#/definitions/CloseTabsAfterAction" },
+              { "$ref": "#/definitions/CloseTabAction" },
               { "$ref": "#/definitions/ScrollUpAction" },
               { "$ref": "#/definitions/ScrollDownAction" },
               { "$ref": "#/definitions/MoveTabAction" },
@@ -1242,6 +1307,11 @@
           "description": "Sets the appearance of the terminal when it is unfocused.",
           "type": ["object", "null"]
         },
+        "font": {
+          "$ref": "#/definitions/FontConfig",
+          "description": "Sets the font options of the terminal.",
+          "type": ["object", "null"]
+        },
         "backgroundImage": {
           "description": "Sets the file location of the image to draw over the window background.",
           "oneOf": [
@@ -1358,18 +1428,20 @@
         },
         "fontFace": {
           "default": "Cascadia Mono",
-          "description": "Name of the font face used in the profile.",
-          "type": "string"
+          "description": "[deprecated] Define 'face' within the 'font' object instead.",
+          "type": "string",
+          "deprecated": true
         },
         "fontSize": {
           "default": 12,
-          "description": "Size of the font in points.",
+          "description": "[deprecated] Define 'size' within the 'font' object instead.",
           "minimum": 1,
-          "type": "integer"
+          "type": "integer",
+          "deprecated": true
         },
         "fontWeight": {
           "default": "normal",
-          "description": "Sets the weight (lightness or heaviness of the strokes) for the given font. Possible values:\n -\"thin\"\n -\"extra-light\"\n -\"light\"\n -\"semi-light\"\n -\"normal\" (default)\n -\"medium\"\n -\"semi-bold\"\n -\"bold\"\n -\"extra-bold\"\n -\"black\"\n -\"extra-black\"\n or the corresponding numeric representation of OpenType font weight.",
+          "description": "[deprecated] Define 'weight' within the 'font' object instead.",
           "oneOf": [
             {
               "enum": [
@@ -1392,7 +1464,8 @@
               "minimum": 100,
               "type": "integer"
             }
-          ]
+          ],
+          "deprecated": true
         },
         "foreground": {
           "$ref": "#/definitions/Color",

doc/terminal-v2-roadmap.md

@@ -28,7 +28,7 @@ Below is the schedule for when milestones will be included in release builds of
 | 2021-01-31 | [1.6] in Windows Terminal Preview<br>[1.5] in Windows Terminal | [Windows Terminal Preview 1.6 Release](https://devblogs.microsoft.com/commandline/windows-terminal-preview-1-6-release/) |
 | 2021-03-01 | [1.7] in Windows Terminal Preview<br>[1.6] in Windows Terminal | [Windows Terminal Preview 1.7 Release](https://devblogs.microsoft.com/commandline/windows-terminal-preview-1-7-release/) |
 | 2021-04-14 | [1.8] in Windows Terminal Preview<br>[1.7] in Windows Terminal | [Windows Terminal Preview 1.8 Release](https://devblogs.microsoft.com/commandline/windows-terminal-preview-1-8-release/) |
-| 2021-05-31 | [1.9] in Windows Terminal Preview<br>[1.8] in Windows Terminal | |
+| 2021-05-31 | [1.9] in Windows Terminal Preview<br>[1.8] in Windows Terminal | [Windows Terminal Preview 1.9 Release](https://devblogs.microsoft.com/commandline/windows-terminal-preview-1-9-release/) |
 | 2021-07-31 | 1.10 in Windows Terminal Preview<br>[1.9] in Windows Terminal | |
 | 2021-08-30 | 1.11 in Windows Terminal Preview<br>1.10 in Windows Terminal | |
 | 2021-10-31 | 1.12 in Windows Terminal Preview<br>1.11 in Windows Terminal | |

scratch/ScratchIslandApp/SampleApp/App.base.h

@@ -9,30 +9,22 @@ namespace winrt::SampleApp::implementation
 
         IXamlType GetXamlType(::winrt::Windows::UI::Xaml::Interop::TypeName const& type)
         {
-            return AppProvider()->GetXamlType(type);
+            return _appProvider.GetXamlType(type);
         }
 
         IXamlType GetXamlType(::winrt::hstring const& fullName)
         {
-            return AppProvider()->GetXamlType(fullName);
+            return _appProvider.GetXamlType(fullName);
         }
 
         ::winrt::com_array<::winrt::Windows::UI::Xaml::Markup::XmlnsDefinition> GetXmlnsDefinitions()
         {
-            return AppProvider()->GetXmlnsDefinitions();
+            return _appProvider.GetXmlnsDefinitions();
         }
 
     private:
         bool _contentLoaded{ false };
-        std::shared_ptr<XamlMetaDataProvider> _appProvider;
-        std::shared_ptr<XamlMetaDataProvider> AppProvider()
-        {
-            if (!_appProvider)
-            {
-                _appProvider = std::make_shared<XamlMetaDataProvider>();
-            }
-            return _appProvider;
-        }
+        winrt::SampleApp::XamlMetaDataProvider _appProvider;
     };
 
     template<typename D, typename... I>

scratch/ScratchIslandApp/WindowExe/WindowExe.manifest

@@ -6,7 +6,7 @@
         <!-- Windows 10 1903 -->
         <!-- See https://docs.microsoft.com/en-us/windows/apps/desktop/modernize/xaml-islands -->
         <!-- "maxversiontested" is CASE SENSITIVE. Do not change this.-->
-        <maxversiontested Id="10.0.19041.0"/>
+        <maxversiontested Id="10.0.18362.0"/>
         <supportedOS Id="{8e0f7a12-bfb3-4fe8-b9a5-48fd50a15a9a}" />
     </application>
   </compatibility>

src/cascadia/LocalTests_SettingsModel/SerializationTests.cpp

@@ -41,6 +41,7 @@ namespace SettingsModelLocalTests
         TEST_METHOD(ColorScheme);
         TEST_METHOD(Actions);
         TEST_METHOD(CascadiaSettings);
+        TEST_METHOD(LegacyFontSettings);
 
         TEST_CLASS_SETUP(ClassSetup)
         {
@@ -138,9 +139,11 @@ namespace SettingsModelLocalTests
                 "tabTitle": "Cool Tab",
                 "suppressApplicationTitle": false,
 
-                "fontFace": "Cascadia Mono",
-                "fontSize": 12,
-                "fontWeight": "normal",
+                "font": {
+                    "face": "Cascadia Mono",
+                    "size": 12,
+                    "weight": "normal"
+                },
                 "padding": "8, 8, 8, 8",
                 "antialiasingMode": "grayscale",
 
@@ -402,11 +405,13 @@ namespace SettingsModelLocalTests
 
                                                 "profiles": {
                                                     "defaults": {
-                                                        "fontFace": "Zamora Code"
+                                                        "font": {
+                                                            "face": "Zamora Code"
+                                                        }
                                                     },
                                                     "list": [
                                                         {
-                                                            "fontFace": "Cascadia Code",
+                                                            "font": { "face": "Cascadia Code" },
                                                             "guid": "{61c54bbd-1111-5271-96e7-009a87ff44bf}",
                                                             "name": "HowettShell"
                                                         },
@@ -464,4 +469,35 @@ namespace SettingsModelLocalTests
         const auto result{ settings->ToJson() };
         VERIFY_ARE_EQUAL(toString(settings->_userSettings), toString(result));
     }
+
+    void SerializationTests::LegacyFontSettings()
+    {
+        const std::string profileString{ R"(
+            {
+                "name": "Profile with legacy font settings",
+
+                "fontFace": "Cascadia Mono",
+                "fontSize": 12,
+                "fontWeight": "normal"
+            })" };
+
+        const std::string expectedOutput{ R"(
+            {
+                "name": "Profile with legacy font settings",
+
+                "font": {
+                    "face": "Cascadia Mono",
+                    "size": 12,
+                    "weight": "normal"
+                }
+            })" };
+
+        const auto json{ VerifyParseSucceeded(profileString) };
+        const auto settings{ implementation::Profile::FromJson(json) };
+        const auto result{ settings->ToJson() };
+
+        const auto jsonOutput{ VerifyParseSucceeded(expectedOutput) };
+
+        VERIFY_ARE_EQUAL(toString(jsonOutput), toString(result));
+    }
 }

src/cascadia/TerminalApp/AppActionHandlers.cpp

@@ -46,8 +46,26 @@ namespace winrt::TerminalApp::implementation
     void TerminalPage::_HandleCloseTab(const IInspectable& /*sender*/,
                                        const ActionEventArgs& args)
     {
-        _CloseFocusedTab();
-        args.Handled(true);
+        if (const auto realArgs = args.ActionArgs().try_as<CloseTabArgs>())
+        {
+            uint32_t index;
+            if (realArgs.Index())
+            {
+                index = realArgs.Index().Value();
+            }
+            else if (auto focusedTabIndex = _GetFocusedTabIndex())
+            {
+                index = *focusedTabIndex;
+            }
+            else
+            {
+                args.Handled(false);
+                return;
+            }
+
+            _CloseTabAtIndex(index);
+            args.Handled(true);
+        }
     }
 
     void TerminalPage::_HandleClosePane(const IInspectable& /*sender*/,

src/cascadia/TerminalApp/AppLogic.cpp

@@ -189,9 +189,7 @@ namespace winrt::TerminalApp::implementation
     }
 
     AppLogic::AppLogic() :
-        _dialogLock{},
-        _loadedInitialSettings{ false },
-        _settingsLoadedResult{ S_OK }
+        _reloadState{ std::chrono::milliseconds(100), []() { ApplicationState::SharedInstance().Reload(); } }
     {
         // For your own sanity, it's better to do setup outside the ctor.
         // If you do any setup in the ctor that ends up throwing an exception,
@@ -204,6 +202,13 @@ namespace winrt::TerminalApp::implementation
         // SetTitleBarContent
         _isElevated = _isUserAdmin();
         _root = winrt::make_self<TerminalPage>();
+
+        _reloadSettings = std::make_shared<ThrottledFuncTrailing<>>(_root->Dispatcher(), std::chrono::milliseconds(100), [weakSelf = get_weak()]() {
+            if (auto self{ weakSelf.get() })
+            {
+                self->_ReloadSettings();
+            }
+        });
     }
 
     // Method Description:
@@ -859,59 +864,29 @@ namespace winrt::TerminalApp::implementation
     // - <none>
     void AppLogic::_RegisterSettingsChange()
     {
-        // Get the containing folder.
         const std::filesystem::path settingsPath{ std::wstring_view{ CascadiaSettings::SettingsPath() } };
-        const auto folder = settingsPath.parent_path();
+        const std::filesystem::path statePath{ std::wstring_view{ ApplicationState::SharedInstance().FilePath() } };
 
-        _reader.create(folder.c_str(),
-                       false,
-                       wil::FolderChangeEvents::All,
-                       [this, settingsPath](wil::FolderChangeEvent event, PCWSTR fileModified) {
-                           // We want file modifications, AND when files are renamed to be
-                           // settings.json. This second case will oftentimes happen with text
-                           // editors, who will write a temp file, then rename it to be the
-                           // actual file you wrote. So listen for that too.
-                           if (!(event == wil::FolderChangeEvent::Modified ||
-                                 event == wil::FolderChangeEvent::RenameNewName ||
-                                 event == wil::FolderChangeEvent::Removed))
-                           {
-                               return;
-                           }
+        _reader.create(
+            settingsPath.parent_path().c_str(),
+            false,
+            // We want file modifications, AND when files are renamed to be
+            // settings.json. This second case will oftentimes happen with text
+            // editors, who will write a temp file, then rename it to be the
+            // actual file you wrote. So listen for that too.
+            wil::FolderChangeEvents::FileName | wil::FolderChangeEvents::LastWriteTime,
+            [this, settingsBasename = settingsPath.filename(), stateBasename = statePath.filename()](wil::FolderChangeEvent, PCWSTR fileModified) {
+                const auto modifiedBasename = std::filesystem::path{ fileModified }.filename();
 
-                           std::filesystem::path modifiedFilePath = fileModified;
-
-                           // Getting basename (filename.ext)
-                           const auto settingsBasename = settingsPath.filename();
-                           const auto modifiedBasename = modifiedFilePath.filename();
-
-                           if (settingsBasename == modifiedBasename)
-                           {
-                               this->_DispatchReloadSettings();
-                           }
-                       });
-    }
-
-    // Method Description:
-    // - Dispatches a settings reload with debounce.
-    //   Text editors implement Save in a bunch of different ways, so
-    //   this stops us from reloading too many times or too quickly.
-    fire_and_forget AppLogic::_DispatchReloadSettings()
-    {
-        if (_settingsReloadQueued.exchange(true))
-        {
-            co_return;
-        }
-
-        auto weakSelf = get_weak();
-
-        co_await winrt::resume_after(std::chrono::milliseconds(100));
-        co_await winrt::resume_foreground(_root->Dispatcher());
-
-        if (auto self{ weakSelf.get() })
-        {
-            _ReloadSettings();
-            _settingsReloadQueued.store(false);
-        }
+                if (modifiedBasename == settingsBasename)
+                {
+                    _reloadSettings->Run();
+                }
+                else if (modifiedBasename == stateBasename)
+                {
+                    _reloadState();
+                }
+            });
     }
 
     void AppLogic::_ApplyLanguageSettingChange() noexcept

src/cascadia/TerminalApp/AppLogic.h

@@ -7,7 +7,9 @@
 #include "FindTargetWindowResult.g.h"
 #include "TerminalPage.h"
 #include "Jumplist.h"
-#include "../../cascadia/inc/cppwinrt_utils.h"
+
+#include <inc/cppwinrt_utils.h>
+#include <ThrottledFunc.h>
 
 #ifdef UNIT_TESTING
 // fwdecl unittest classes
@@ -111,17 +113,15 @@ namespace winrt::TerminalApp::implementation
 
         Microsoft::Terminal::Settings::Model::CascadiaSettings _settings{ nullptr };
 
-        HRESULT _settingsLoadedResult;
-        winrt::hstring _settingsLoadExceptionText{};
-
-        bool _loadedInitialSettings;
-
         wil::unique_folder_change_reader_nothrow _reader;
+        std::shared_ptr<ThrottledFuncTrailing<>> _reloadSettings;
+        til::throttled_func_trailing<> _reloadState;
+        winrt::hstring _settingsLoadExceptionText;
+        HRESULT _settingsLoadedResult = S_OK;
+        bool _loadedInitialSettings = false;
 
         std::shared_mutex _dialogLock;
 
-        std::atomic<bool> _settingsReloadQueued{ false };
-
         ::TerminalApp::AppCommandlineArgs _appArgs;
         ::TerminalApp::AppCommandlineArgs _settingsAppArgs;
         static TerminalApp::FindTargetWindowResult _doFindTargetWindow(winrt::array_view<const hstring> args,

src/cascadia/TerminalApp/TabManagement.cpp

@@ -617,17 +617,6 @@ namespace winrt::TerminalApp::implementation
         }
     }
 
-    // Method Description:
-    // - Close the currently focused tab. Focus will move to the left, if possible.
-    void TerminalPage::_CloseFocusedTab()
-    {
-        if (auto index{ _GetFocusedTabIndex() })
-        {
-            auto tab{ _tabs.GetAt(*index) };
-            _HandleCloseTabRequested(tab);
-        }
-    }
-
     // Method Description:
     // - Close the currently focused pane. If the pane is the last pane in the
     //   tab, the tab will also be closed. This will happen when we handle the
@@ -675,6 +664,20 @@ namespace winrt::TerminalApp::implementation
         }
     }
 
+    // Method Description:
+    // - Close the tab at the given index.
+    void TerminalPage::_CloseTabAtIndex(uint32_t index)
+    {
+        if (index >= _tabs.Size())
+        {
+            return;
+        }
+        if (auto tab{ _tabs.GetAt(index) })
+        {
+            _HandleCloseTabRequested(tab);
+        }
+    }
+
     // Method Description:
     // - Closes provided tabs one by one
     // Arguments:

src/cascadia/TerminalApp/TerminalPage.h

@@ -216,6 +216,7 @@ namespace winrt::TerminalApp::implementation
         void _DuplicateTab(const TerminalTab& tab);
 
         winrt::Windows::Foundation::IAsyncAction _HandleCloseTabRequested(winrt::TerminalApp::TabBase tab);
+        void _CloseTabAtIndex(uint32_t index);
         void _RemoveTab(const winrt::TerminalApp::TabBase& tab);
         winrt::fire_and_forget _RemoveTabs(const std::vector<winrt::TerminalApp::TabBase> tabs);
 
@@ -238,7 +239,6 @@ namespace winrt::TerminalApp::implementation
         TerminalApp::TabBase _GetTabByTabViewItem(const Microsoft::UI::Xaml::Controls::TabViewItem& tabViewItem) const noexcept;
 
         winrt::fire_and_forget _SetFocusedTab(const winrt::TerminalApp::TabBase tab);
-        void _CloseFocusedTab();
         winrt::fire_and_forget _CloseFocusedPane();
 
         winrt::fire_and_forget _RemoveOnCloseRoutine(Microsoft::UI::Xaml::Controls::TabViewItem tabViewItem, winrt::com_ptr<TerminalPage> page);

src/cascadia/TerminalControl/ControlCore.h

@@ -23,7 +23,6 @@
 #include "../../cascadia/TerminalCore/Terminal.hpp"
 #include "../buffer/out/search.h"
 #include "cppwinrt_utils.h"
-#include "ThrottledFunc.h"
 
 namespace ControlUnitTests
 {

src/cascadia/TerminalControl/TermControl.h

@@ -13,7 +13,6 @@
 #include "../buffer/out/search.h"
 #include "cppwinrt_utils.h"
 #include "SearchBoxControl.h"
-#include "ThrottledFunc.h"
 
 #include "ControlInteractivity.h"
 

src/cascadia/TerminalControl/TerminalControlLib.vcxproj

@@ -52,7 +52,6 @@
     <ClInclude Include="TermControlAutomationPeer.h">
       <DependentUpon>TermControlAutomationPeer.idl</DependentUpon>
     </ClInclude>
-    <ClInclude Include="ThrottledFunc.h" />
     <ClInclude Include="TSFInputControl.h">
       <DependentUpon>TSFInputControl.xaml</DependentUpon>
     </ClInclude>

src/cascadia/TerminalControl/ThrottledFunc.h

@@ -1,186 +0,0 @@
-/*++
-Copyright (c) Microsoft Corporation
-Licensed under the MIT license.
-
-Module Name:
-- ThrottledFunc.h
---*/
-
-#pragma once
-#include "pch.h"
-
-template<typename... Args>
-class ThrottledFuncStorage
-{
-public:
-    template<typename... MakeArgs>
-    bool Emplace(MakeArgs&&... args)
-    {
-        std::scoped_lock guard{ _lock };
-
-        const bool hadValue = _pendingRunArgs.has_value();
-        _pendingRunArgs.emplace(std::forward<MakeArgs>(args)...);
-        return hadValue;
-    }
-
-    template<typename F>
-    void ModifyPending(F f)
-    {
-        std::scoped_lock guard{ _lock };
-
-        if (_pendingRunArgs.has_value())
-        {
-            std::apply(f, _pendingRunArgs.value());
-        }
-    }
-
-    std::tuple<Args...> Extract()
-    {
-        decltype(_pendingRunArgs) args;
-        std::scoped_lock guard{ _lock };
-        _pendingRunArgs.swap(args);
-        return args.value();
-    }
-
-private:
-    std::mutex _lock;
-    std::optional<std::tuple<Args...>> _pendingRunArgs;
-};
-
-template<>
-class ThrottledFuncStorage<>
-{
-public:
-    bool Emplace()
-    {
-        return _isRunPending.test_and_set(std::memory_order_relaxed);
-    }
-
-    std::tuple<> Extract()
-    {
-        Reset();
-        return {};
-    }
-
-    void Reset()
-    {
-        _isRunPending.clear(std::memory_order_relaxed);
-    }
-
-private:
-    std::atomic_flag _isRunPending;
-};
-
-// Class Description:
-// - Represents a function that takes arguments and whose invocation is
-//   delayed by a specified duration and rate-limited such that if the code
-//   tries to run the function while a call to the function is already
-//   pending, then the previous call with the previous arguments will be
-//   cancelled and the call will be made with the new arguments instead.
-// - The function will be run on the the specified dispatcher.
-template<bool leading, typename... Args>
-class ThrottledFunc : public std::enable_shared_from_this<ThrottledFunc<leading, Args...>>
-{
-public:
-    using Func = std::function<void(Args...)>;
-
-    ThrottledFunc(winrt::Windows::UI::Core::CoreDispatcher dispatcher, winrt::Windows::Foundation::TimeSpan delay, Func func) :
-        _dispatcher{ std::move(dispatcher) },
-        _delay{ std::move(delay) },
-        _func{ std::move(func) }
-    {
-    }
-
-    // Method Description:
-    // - Runs the function later with the specified arguments, except if `Run`
-    //   is called again before with new arguments, in which case the new
-    //   arguments will be used instead.
-    // - For more information, read the class' documentation.
-    // - This method is always thread-safe. It can be called multiple times on
-    //   different threads.
-    // Arguments:
-    // - args: the arguments to pass to the function
-    // Return Value:
-    // - <none>
-    template<typename... MakeArgs>
-    void Run(MakeArgs&&... args)
-    {
-        if (!_storage.Emplace(std::forward<MakeArgs>(args)...))
-        {
-            _Fire();
-        }
-    }
-
-    // Method Description:
-    // - Modifies the pending arguments for the next function invocation, if
-    //   there is one pending currently.
-    // - Let's say that you just called the `Run` method with some arguments.
-    //   After the delay specified in the constructor, the function specified
-    //   in the constructor will be called with these arguments.
-    // - By using this method, you can modify the arguments before the function
-    //   is called.
-    // - You pass a function to this method which will take references to
-    //   the arguments (one argument corresponds to one reference to an
-    //   argument) and will modify them.
-    // - When there is no pending invocation of the function, this method will
-    //   not do anything.
-    // - This method is always thread-safe. It can be called multiple times on
-    //   different threads.
-    // Arguments:
-    // - f: the function to call with references to the arguments
-    // Return Value:
-    // - <none>
-    template<typename F>
-    void ModifyPending(F f)
-    {
-        _storage.ModifyPending(f);
-    }
-
-private:
-    winrt::fire_and_forget _Fire()
-    {
-        const auto dispatcher = _dispatcher;
-        auto weakSelf = this->weak_from_this();
-
-        if constexpr (leading)
-        {
-            co_await winrt::resume_foreground(dispatcher);
-
-            if (auto self{ weakSelf.lock() })
-            {
-                self->_func();
-            }
-            else
-            {
-                co_return;
-            }
-
-            co_await winrt::resume_after(_delay);
-
-            if (auto self{ weakSelf.lock() })
-            {
-                self->_storage.Reset();
-            }
-        }
-        else
-        {
-            co_await winrt::resume_after(_delay);
-            co_await winrt::resume_foreground(dispatcher);
-
-            if (auto self{ weakSelf.lock() })
-            {
-                std::apply(self->_func, self->_storage.Extract());
-            }
-        }
-    }
-
-    winrt::Windows::UI::Core::CoreDispatcher _dispatcher;
-    winrt::Windows::Foundation::TimeSpan _delay;
-    Func _func;
-
-    ThrottledFuncStorage<Args...> _storage;
-};
-
-template<typename... Args>
-using ThrottledFuncTrailing = ThrottledFunc<false, Args...>;
-using ThrottledFuncLeading = ThrottledFunc<true>;

src/cascadia/TerminalControl/pch.h

@@ -58,3 +58,5 @@ TRACELOGGING_DECLARE_PROVIDER(g_hTerminalControlProvider);
 #include <telemetry/ProjectTelemetry.h>
 
 #include "til.h"
+
+#include "ThrottledFunc.h"

src/cascadia/TerminalSettingsEditor/Actions.cpp

@@ -7,6 +7,7 @@
 #include "KeyBindingViewModel.g.cpp"
 #include "ActionsPageNavigationState.g.cpp"
 #include "LibraryResources.h"
+#include "../TerminalSettingsModel/AllShortcutActions.h"
 
 using namespace winrt::Windows::Foundation;
 using namespace winrt::Windows::Foundation::Collections;
@@ -20,10 +21,12 @@ using namespace winrt::Microsoft::Terminal::Settings::Model;
 
 namespace winrt::Microsoft::Terminal::Settings::Editor::implementation
 {
-    KeyBindingViewModel::KeyBindingViewModel(const Control::KeyChord& keys, const Model::Command& cmd) :
+    KeyBindingViewModel::KeyBindingViewModel(const Control::KeyChord& keys, const hstring& actionName, const IObservableVector<hstring>& availableActions) :
         _Keys{ keys },
         _KeyChordText{ Model::KeyChordSerialization::ToString(keys) },
-        _Command{ cmd }
+        _CurrentAction{ actionName },
+        _ProposedAction{ box_value(actionName) },
+        _AvailableActions{ availableActions }
     {
         // Add a property changed handler to our own property changed event.
         // This propagates changes from the settings model to anybody listening to our
@@ -43,6 +46,10 @@ namespace winrt::Microsoft::Terminal::Settings::Editor::implementation
             {
                 _NotifyChanges(L"ShowEditButton");
             }
+            else if (viewModelProperty == L"CurrentAction")
+            {
+                _NotifyChanges(L"Name");
+            }
         });
     }
 
@@ -63,8 +70,10 @@ namespace winrt::Microsoft::Terminal::Settings::Editor::implementation
         if (_IsInEditMode)
         {
             // if we're in edit mode,
-            // pre-populate the text box with the current keys
+            // - pre-populate the text box with the current keys
+            // - reset the combo box with the current action
             ProposedKeys(KeyChordText());
+            ProposedAction(box_value(CurrentAction()));
         }
     }
 
@@ -75,13 +84,14 @@ namespace winrt::Microsoft::Terminal::Settings::Editor::implementation
 
     void KeyBindingViewModel::AttemptAcceptChanges(hstring newKeyChordText)
     {
-        auto args{ make_self<RebindKeysEventArgs>(_Keys, _Keys) };
+        auto args{ make_self<ModifyKeyBindingEventArgs>(_Keys, _Keys, _CurrentAction, unbox_value<hstring>(_ProposedAction)) };
+
+        // Key Chord Text
         try
         {
             // Attempt to convert the provided key chord text
             const auto newKeyChord{ KeyChordSerialization::FromString(newKeyChordText) };
             args->NewKeys(newKeyChord);
-            _RebindKeysRequestedHandlers(*this, *args);
         }
         catch (hresult_invalid_argument)
         {
@@ -94,6 +104,8 @@ namespace winrt::Microsoft::Terminal::Settings::Editor::implementation
             //  Alternatively, we want a full key chord editor/listener.
             //  If we implement that, we won't need this validation or error message.
         }
+
+        _ModifyKeyBindingRequestedHandlers(*this, *args);
     }
 
     Actions::Actions()
@@ -118,16 +130,28 @@ namespace winrt::Microsoft::Terminal::Settings::Editor::implementation
     {
         _State = e.Parameter().as<Editor::ActionsPageNavigationState>();
 
+        // Populate AvailableActionAndArgs
+        _AvailableActionMap = single_threaded_map<hstring, Model::ActionAndArgs>();
+        std::vector<hstring> availableActionAndArgs;
+        for (const auto& [name, actionAndArgs] : _State.Settings().ActionMap().AvailableActions())
+        {
+            availableActionAndArgs.push_back(name);
+            _AvailableActionMap.Insert(name, actionAndArgs);
+        }
+        std::sort(begin(availableActionAndArgs), end(availableActionAndArgs));
+        _AvailableActionAndArgs = single_threaded_observable_vector(std::move(availableActionAndArgs));
+
         // Convert the key bindings from our settings into a view model representation
         const auto& keyBindingMap{ _State.Settings().ActionMap().KeyBindings() };
         std::vector<Editor::KeyBindingViewModel> keyBindingList;
         keyBindingList.reserve(keyBindingMap.Size());
         for (const auto& [keys, cmd] : keyBindingMap)
         {
-            auto container{ make_self<KeyBindingViewModel>(keys, cmd) };
+            // convert the cmd into a KeyBindingViewModel
+            auto container{ make_self<KeyBindingViewModel>(keys, cmd.Name(), _AvailableActionAndArgs) };
             container->PropertyChanged({ this, &Actions::_ViewModelPropertyChangedHandler });
             container->DeleteKeyBindingRequested({ this, &Actions::_ViewModelDeleteKeyBindingHandler });
-            container->RebindKeysRequested({ this, &Actions::_ViewModelRebindKeysHandler });
+            container->ModifyKeyBindingRequested({ this, &Actions::_ViewModelModifyKeyBindingHandler });
             container->IsAutomationPeerAttached(_AutomationPeerAttached);
             keyBindingList.push_back(*container);
         }
@@ -228,12 +252,42 @@ namespace winrt::Microsoft::Terminal::Settings::Editor::implementation
         }
     }
 
-    void Actions::_ViewModelRebindKeysHandler(const Editor::KeyBindingViewModel& senderVM, const Editor::RebindKeysEventArgs& args)
+    void Actions::_ViewModelModifyKeyBindingHandler(const Editor::KeyBindingViewModel& senderVM, const Editor::ModifyKeyBindingEventArgs& args)
     {
+        auto applyChangesToSettingsModel = [=]() {
+            // If the key chord was changed,
+            // update the settings model and view model appropriately
+            if (args.OldKeys().Modifiers() != args.NewKeys().Modifiers() || args.OldKeys().Vkey() != args.NewKeys().Vkey())
+            {
+                // update settings model
+                _State.Settings().ActionMap().RebindKeys(args.OldKeys(), args.NewKeys());
+
+                // update view model
+                auto senderVMImpl{ get_self<KeyBindingViewModel>(senderVM) };
+                senderVMImpl->Keys(args.NewKeys());
+            }
+
+            // If the action was changed,
+            // update the settings model and view model appropriately
+            if (args.OldActionName() != args.NewActionName())
+            {
+                // convert the action's name into a view model.
+                const auto& newAction{ _AvailableActionMap.Lookup(args.NewActionName()) };
+
+                // update settings model
+                _State.Settings().ActionMap().RegisterKeyBinding(args.NewKeys(), newAction);
+
+                // update view model
+                auto senderVMImpl{ get_self<KeyBindingViewModel>(senderVM) };
+                senderVMImpl->CurrentAction(args.NewActionName());
+            }
+        };
+
+        // Check for this special case:
+        //  we're changing the key chord,
+        //  but the new key chord is already in use
         if (args.OldKeys().Modifiers() != args.NewKeys().Modifiers() || args.OldKeys().Vkey() != args.NewKeys().Vkey())
         {
-            // We're actually changing the key chord
-            const auto senderVMImpl{ get_self<KeyBindingViewModel>(senderVM) };
             const auto& conflictingCmd{ _State.Settings().ActionMap().GetActionByKeyChord(args.NewKeys()) };
             if (conflictingCmd)
             {
@@ -262,8 +316,7 @@ namespace winrt::Microsoft::Terminal::Settings::Editor::implementation
                     senderVM.AcceptChangesFlyout(nullptr);
 
                     // update settings model and view model
-                    _State.Settings().ActionMap().RebindKeys(args.OldKeys(), args.NewKeys());
-                    senderVMImpl->Keys(args.NewKeys());
+                    applyChangesToSettingsModel();
                     senderVM.ToggleEditMode();
                 });
 
@@ -278,17 +331,14 @@ namespace winrt::Microsoft::Terminal::Settings::Editor::implementation
                 senderVM.AcceptChangesFlyout(acceptChangesFlyout);
                 return;
             }
-            else
-            {
-                // update settings model
-                _State.Settings().ActionMap().RebindKeys(args.OldKeys(), args.NewKeys());
-
-                // update view model (keys)
-                senderVMImpl->Keys(args.NewKeys());
-            }
         }
 
-        // update view model (exit edit mode)
+        // update settings model and view model
+        applyChangesToSettingsModel();
+
+        // We NEED to toggle the edit mode here,
+        // so that if nothing changed, we still exit
+        // edit mode.
         senderVM.ToggleEditMode();
     }
 

src/cascadia/TerminalSettingsEditor/Actions.h

@@ -6,7 +6,7 @@
 #include "Actions.g.h"
 #include "KeyBindingViewModel.g.h"
 #include "ActionsPageNavigationState.g.h"
-#include "RebindKeysEventArgs.g.h"
+#include "ModifyKeyBindingEventArgs.g.h"
 #include "Utils.h"
 #include "ViewModelHelpers.h"
 
@@ -20,25 +20,28 @@ namespace winrt::Microsoft::Terminal::Settings::Editor::implementation
         }
     };
 
-    struct RebindKeysEventArgs : RebindKeysEventArgsT<RebindKeysEventArgs>
+    struct ModifyKeyBindingEventArgs : ModifyKeyBindingEventArgsT<ModifyKeyBindingEventArgs>
     {
     public:
-        RebindKeysEventArgs(const Control::KeyChord& oldKeys, const Control::KeyChord& newKeys) :
+        ModifyKeyBindingEventArgs(const Control::KeyChord& oldKeys, const Control::KeyChord& newKeys, const hstring oldActionName, const hstring newActionName) :
             _OldKeys{ oldKeys },
-            _NewKeys{ newKeys } {}
+            _NewKeys{ newKeys },
+            _OldActionName{ std::move(oldActionName) },
+            _NewActionName{ std::move(newActionName) } {}
 
         WINRT_PROPERTY(Control::KeyChord, OldKeys, nullptr);
         WINRT_PROPERTY(Control::KeyChord, NewKeys, nullptr);
+        WINRT_PROPERTY(hstring, OldActionName);
+        WINRT_PROPERTY(hstring, NewActionName);
     };
 
     struct KeyBindingViewModel : KeyBindingViewModelT<KeyBindingViewModel>, ViewModelHelper<KeyBindingViewModel>
     {
     public:
-        KeyBindingViewModel(const Control::KeyChord& keys, const Settings::Model::Command& cmd);
+        KeyBindingViewModel(const Control::KeyChord& keys, const hstring& name, const Windows::Foundation::Collections::IObservableVector<hstring>& availableActions);
 
-        hstring Name() const { return _Command.Name(); }
+        hstring Name() const { return _CurrentAction; }
         hstring KeyChordText() const { return _KeyChordText; }
-        Settings::Model::Command Command() const { return _Command; };
 
         // UIA Text
         hstring EditButtonName() const noexcept;
@@ -59,20 +62,35 @@ namespace winrt::Microsoft::Terminal::Settings::Editor::implementation
         void AttemptAcceptChanges(hstring newKeyChordText);
         void DeleteKeyBinding() { _DeleteKeyBindingRequestedHandlers(*this, _Keys); }
 
-        VIEW_MODEL_OBSERVABLE_PROPERTY(bool, IsInEditMode, false);
+        // ProposedAction:   the entry selected by the combo box; may disagree with the settings model.
+        // CurrentAction:    the combo box item that maps to the settings model value.
+        // AvailableActions: the list of options in the combo box; both actions above must be in this list.
+        // NOTE: ProposedAction and CurrentAction may disagree mainly due to the "edit mode" system in place.
+        //       Current Action serves as...
+        //       1 - a record of what to set ProposedAction to on a cancellation
+        //       2 - a form of translation between ProposedAction and the settings model
+        //       We would also need an ActionMap reference to remove this, but this is a better separation
+        //       of responsibilities.
+        VIEW_MODEL_OBSERVABLE_PROPERTY(IInspectable, ProposedAction);
+        VIEW_MODEL_OBSERVABLE_PROPERTY(hstring, CurrentAction);
+        WINRT_PROPERTY(Windows::Foundation::Collections::IObservableVector<hstring>, AvailableActions, nullptr);
+
+        // ProposedKeys: the text shown in the text box; may disagree with the settings model.
+        // Keys:         the key chord bound in the settings model.
         VIEW_MODEL_OBSERVABLE_PROPERTY(hstring, ProposedKeys);
         VIEW_MODEL_OBSERVABLE_PROPERTY(Control::KeyChord, Keys, nullptr);
+
+        VIEW_MODEL_OBSERVABLE_PROPERTY(bool, IsInEditMode, false);
         VIEW_MODEL_OBSERVABLE_PROPERTY(Windows::UI::Xaml::Controls::Flyout, AcceptChangesFlyout, nullptr);
         VIEW_MODEL_OBSERVABLE_PROPERTY(bool, IsAutomationPeerAttached, false);
         VIEW_MODEL_OBSERVABLE_PROPERTY(bool, IsHovered, false);
         VIEW_MODEL_OBSERVABLE_PROPERTY(bool, IsContainerFocused, false);
         VIEW_MODEL_OBSERVABLE_PROPERTY(bool, IsEditButtonFocused, false);
         VIEW_MODEL_OBSERVABLE_PROPERTY(Windows::UI::Xaml::Media::Brush, ContainerBackground, nullptr);
-        TYPED_EVENT(RebindKeysRequested, Editor::KeyBindingViewModel, Editor::RebindKeysEventArgs);
+        TYPED_EVENT(ModifyKeyBindingRequested, Editor::KeyBindingViewModel, Editor::ModifyKeyBindingEventArgs);
         TYPED_EVENT(DeleteKeyBindingRequested, Editor::KeyBindingViewModel, Terminal::Control::KeyChord);
 
     private:
-        Settings::Model::Command _Command{ nullptr };
         hstring _KeyChordText{};
     };
 
@@ -101,11 +119,13 @@ namespace winrt::Microsoft::Terminal::Settings::Editor::implementation
     private:
         void _ViewModelPropertyChangedHandler(const Windows::Foundation::IInspectable& senderVM, const Windows::UI::Xaml::Data::PropertyChangedEventArgs& args);
         void _ViewModelDeleteKeyBindingHandler(const Editor::KeyBindingViewModel& senderVM, const Control::KeyChord& args);
-        void _ViewModelRebindKeysHandler(const Editor::KeyBindingViewModel& senderVM, const Editor::RebindKeysEventArgs& args);
+        void _ViewModelModifyKeyBindingHandler(const Editor::KeyBindingViewModel& senderVM, const Editor::ModifyKeyBindingEventArgs& args);
 
         std::optional<uint32_t> _GetContainerIndexByKeyChord(const Control::KeyChord& keys);
 
         bool _AutomationPeerAttached{ false };
+        Windows::Foundation::Collections::IObservableVector<hstring> _AvailableActionAndArgs;
+        Windows::Foundation::Collections::IMap<hstring, Model::ActionAndArgs> _AvailableActionMap;
     };
 }
 

src/cascadia/TerminalSettingsEditor/Actions.idl

@@ -5,10 +5,12 @@ import "EnumEntry.idl";
 
 namespace Microsoft.Terminal.Settings.Editor
 {
-    runtimeclass RebindKeysEventArgs
+    runtimeclass ModifyKeyBindingEventArgs
     {
         Microsoft.Terminal.Control.KeyChord OldKeys { get; };
         Microsoft.Terminal.Control.KeyChord NewKeys { get; };
+        String OldActionName { get; };
+        String NewActionName { get; };
     }
 
     runtimeclass KeyBindingViewModel : Windows.UI.Xaml.Data.INotifyPropertyChanged
@@ -21,6 +23,7 @@ namespace Microsoft.Terminal.Settings.Editor
         Boolean ShowEditButton { get; };
         Boolean IsInEditMode { get; };
         String ProposedKeys;
+        Object ProposedAction;
         Windows.UI.Xaml.Controls.Flyout AcceptChangesFlyout;
         String EditButtonName { get; };
         String CancelButtonName { get; };
@@ -34,11 +37,12 @@ namespace Microsoft.Terminal.Settings.Editor
         void ActionLostFocus();
         void EditButtonGettingFocus();
         void EditButtonLosingFocus();
+        IObservableVector<String> AvailableActions { get; };
         void ToggleEditMode();
         void AttemptAcceptChanges();
         void DeleteKeyBinding();
 
-        event Windows.Foundation.TypedEventHandler<KeyBindingViewModel, RebindKeysEventArgs> RebindKeysRequested;
+        event Windows.Foundation.TypedEventHandler<KeyBindingViewModel, ModifyKeyBindingEventArgs> ModifyKeyBindingRequested;
         event Windows.Foundation.TypedEventHandler<KeyBindingViewModel, Microsoft.Terminal.Control.KeyChord> DeleteKeyBindingRequested;
     }
 

src/cascadia/TerminalSettingsEditor/Actions.xaml

@@ -198,7 +198,15 @@
                         <!--  Command Name  -->
                         <TextBlock Grid.Column="0"
                                    Style="{StaticResource KeyBindingNameTextBlockStyle}"
-                                   Text="{x:Bind Name, Mode=OneWay}" />
+                                   Text="{x:Bind Name, Mode=OneWay}"
+                                   Visibility="{x:Bind IsInEditMode, Mode=OneWay, Converter={StaticResource InvertedBooleanToVisibilityConverter}}" />
+
+                        <!--  Edit Mode: Action Combo-box  -->
+                        <ComboBox Grid.Column="0"
+                                  VerticalAlignment="Center"
+                                  ItemsSource="{x:Bind AvailableActions, Mode=OneWay}"
+                                  SelectedItem="{x:Bind ProposedAction, Mode=TwoWay}"
+                                  Visibility="{x:Bind IsInEditMode, Mode=OneWay}" />
 
                         <!--  Key Chord Text  -->
                         <Border Grid.Column="1"

src/cascadia/TerminalSettingsEditor/Profiles.h

@@ -77,9 +77,9 @@ namespace winrt::Microsoft::Terminal::Settings::Editor::implementation
         OBSERVABLE_PROJECTED_SETTING(_profile, UseAcrylic);
         OBSERVABLE_PROJECTED_SETTING(_profile, AcrylicOpacity);
         OBSERVABLE_PROJECTED_SETTING(_profile, ScrollState);
-        OBSERVABLE_PROJECTED_SETTING(_profile, FontFace);
-        OBSERVABLE_PROJECTED_SETTING(_profile, FontSize);
-        OBSERVABLE_PROJECTED_SETTING(_profile, FontWeight);
+        OBSERVABLE_PROJECTED_SETTING(_profile.FontInfo(), FontFace);
+        OBSERVABLE_PROJECTED_SETTING(_profile.FontInfo(), FontSize);
+        OBSERVABLE_PROJECTED_SETTING(_profile.FontInfo(), FontWeight);
         OBSERVABLE_PROJECTED_SETTING(_profile, Padding);
         OBSERVABLE_PROJECTED_SETTING(_profile, Commandline);
         OBSERVABLE_PROJECTED_SETTING(_profile, StartingDirectory);

src/cascadia/TerminalSettingsEditor/Resources/en-US/Resources.resw

@@ -216,7 +216,7 @@
     <comment>This is the header for a control that lets the user select the yellow color for text displayed on the screen.</comment>
   </data>
   <data name="Globals_Language.Header" xml:space="preserve">
-    <value>Language</value>
+    <value>Language (requires relaunch)</value>
     <comment>The header for a control allowing users to choose the app's language.</comment>
   </data>
   <data name="Globals_Language.HelpText" xml:space="preserve">

src/cascadia/TerminalSettingsModel/ActionAndArgs.cpp

@@ -5,6 +5,7 @@
 #include "ActionAndArgs.g.cpp"
 
 #include "JsonUtils.h"
+#include "HashUtils.h"
 
 #include <LibraryResources.h>
 
@@ -117,6 +118,35 @@ namespace winrt::Microsoft::Terminal::Settings::Model::implementation
 #undef ON_ALL_ACTIONS_WITH_ARGS
     };
 
+    ActionAndArgs::ActionAndArgs(ShortcutAction action)
+    {
+        // Find the deserializer
+        const auto deserializersIter = argSerializerMap.find(action);
+        if (deserializersIter != argSerializerMap.end())
+        {
+            auto pfn = deserializersIter->second.first;
+            if (pfn)
+            {
+                // Call the deserializer on an empty JSON object.
+                // This ensures that we have a valid ActionArgs
+                std::vector<Microsoft::Terminal::Settings::Model::SettingsLoadWarnings> parseWarnings;
+                std::tie(_Args, parseWarnings) = pfn({});
+            }
+
+            // if an arg parser was registered, but failed,
+            // return the invalid ActionAndArgs we started with.
+            if (pfn && _Args == nullptr)
+            {
+                return;
+            }
+        }
+
+        // Either...
+        // (1) we don't have a deserializer, so it's ok for _Args to be null, or
+        // (2) we had one AND it worked, so _Args is set up properly
+        _Action = action;
+    }
+
     // Function Description:
     // - Attempts to match a string to a ShortcutAction. If there's no match, then
     //   returns ShortcutAction::Invalid
@@ -280,7 +310,7 @@ namespace winrt::Microsoft::Terminal::Settings::Model::implementation
                 { ShortcutAction::AdjustFontSize, RS_(L"AdjustFontSizeCommandKey") },
                 { ShortcutAction::CloseOtherTabs, L"" }, // Intentionally omitted, must be generated by GenerateName
                 { ShortcutAction::ClosePane, RS_(L"ClosePaneCommandKey") },
-                { ShortcutAction::CloseTab, RS_(L"CloseTabCommandKey") },
+                { ShortcutAction::CloseTab, L"" }, // Intentionally omitted, must be generated by GenerateName
                 { ShortcutAction::CloseTabsAfter, L"" }, // Intentionally omitted, must be generated by GenerateName
                 { ShortcutAction::CloseWindow, RS_(L"CloseWindowCommandKey") },
                 { ShortcutAction::CopyText, RS_(L"CopyTextCommandKey") },

src/cascadia/TerminalSettingsModel/ActionAndArgs.h

@@ -18,6 +18,7 @@ namespace winrt::Microsoft::Terminal::Settings::Model::implementation
         static Json::Value ToJson(const Model::ActionAndArgs& val);
 
         ActionAndArgs() = default;
+        ActionAndArgs(ShortcutAction action);
         ActionAndArgs(ShortcutAction action, IActionArgs args) :
             _Action{ action },
             _Args{ args } {};

src/cascadia/TerminalSettingsModel/ActionArgs.cpp

@@ -22,6 +22,7 @@
 #include "ExecuteCommandlineArgs.g.cpp"
 #include "CloseOtherTabsArgs.g.cpp"
 #include "CloseTabsAfterArgs.g.cpp"
+#include "CloseTabArgs.g.cpp"
 #include "MoveTabArgs.g.cpp"
 #include "FindMatchArgs.g.cpp"
 #include "ToggleCommandPaletteArgs.g.cpp"
@@ -469,6 +470,19 @@ namespace winrt::Microsoft::Terminal::Settings::Model::implementation
         return RS_(L"CloseTabsAfterDefaultCommandKey");
     }
 
+    winrt::hstring CloseTabArgs::GenerateName() const
+    {
+        if (Index())
+        {
+            // "Close tab at index {0}"
+            return winrt::hstring{
+                fmt::format(std::wstring_view(RS_(L"CloseTabAtIndexCommandKey")),
+                            Index().Value())
+            };
+        }
+        return RS_(L"CloseTabCommandKey");
+    }
+
     winrt::hstring ScrollUpArgs::GenerateName() const
     {
         if (RowsToScroll())

src/cascadia/TerminalSettingsModel/ActionArgs.h

@@ -22,6 +22,7 @@
 #include "ExecuteCommandlineArgs.g.h"
 #include "CloseOtherTabsArgs.g.h"
 #include "CloseTabsAfterArgs.g.h"
+#include "CloseTabArgs.g.h"
 #include "ScrollUpArgs.g.h"
 #include "ScrollDownArgs.g.h"
 #include "MoveTabArgs.g.h"
@@ -996,6 +997,57 @@ namespace winrt::Microsoft::Terminal::Settings::Model::implementation
         }
     };
 
+    struct CloseTabArgs : public CloseTabArgsT<CloseTabArgs>
+    {
+        CloseTabArgs() = default;
+        CloseTabArgs(uint32_t tabIndex) :
+            _Index{ tabIndex } {};
+        ACTION_ARG(Windows::Foundation::IReference<uint32_t>, Index, nullptr);
+
+        static constexpr std::string_view IndexKey{ "index" };
+
+    public:
+        hstring GenerateName() const;
+
+        bool Equals(const IActionArgs& other)
+        {
+            auto otherAsUs = other.try_as<CloseTabArgs>();
+            if (otherAsUs)
+            {
+                return otherAsUs->_Index == _Index;
+            }
+            return false;
+        };
+        static FromJsonResult FromJson(const Json::Value& json)
+        {
+            // LOAD BEARING: Not using make_self here _will_ break you in the future!
+            auto args = winrt::make_self<CloseTabArgs>();
+            JsonUtils::GetValueForKey(json, IndexKey, args->_Index);
+            return { *args, {} };
+        }
+        static Json::Value ToJson(const IActionArgs& val)
+        {
+            if (!val)
+            {
+                return {};
+            }
+            Json::Value json{ Json::ValueType::objectValue };
+            const auto args{ get_self<CloseTabArgs>(val) };
+            JsonUtils::SetValueForKey(json, IndexKey, args->_Index);
+            return json;
+        }
+        IActionArgs Copy() const
+        {
+            auto copy{ winrt::make_self<CloseTabArgs>() };
+            copy->_Index = _Index;
+            return *copy;
+        }
+        size_t Hash() const
+        {
+            return ::Microsoft::Terminal::Settings::Model::HashUtils::HashProperty(Index());
+        }
+    };
+
     struct MoveTabArgs : public MoveTabArgsT<MoveTabArgs>
     {
         MoveTabArgs() = default;
@@ -1600,6 +1652,7 @@ namespace winrt::Microsoft::Terminal::Settings::Model::factory_implementation
     BASIC_FACTORY(ExecuteCommandlineArgs);
     BASIC_FACTORY(CloseOtherTabsArgs);
     BASIC_FACTORY(CloseTabsAfterArgs);
+    BASIC_FACTORY(CloseTabArgs);
     BASIC_FACTORY(MoveTabArgs);
     BASIC_FACTORY(OpenSettingsArgs);
     BASIC_FACTORY(FindMatchArgs);

src/cascadia/TerminalSettingsModel/ActionArgs.idl

@@ -221,6 +221,12 @@ namespace Microsoft.Terminal.Settings.Model
         Windows.Foundation.IReference<UInt32> Index { get; };
     };
 
+    [default_interface] runtimeclass CloseTabArgs : IActionArgs
+    {
+        CloseTabArgs(UInt32 tabIndex);
+        Windows.Foundation.IReference<UInt32> Index { get; };
+    };
+
     [default_interface] runtimeclass MoveTabArgs : IActionArgs
     {
         MoveTabArgs(MoveTabDirection direction);

src/cascadia/TerminalSettingsModel/ActionMap.cpp

@@ -4,6 +4,7 @@
 #include "pch.h"
 #include "AllShortcutActions.h"
 #include "ActionMap.h"
+#include "AllShortcutActions.h"
 
 #include "ActionMap.g.cpp"
 
@@ -96,6 +97,75 @@ namespace winrt::Microsoft::Terminal::Settings::Model::implementation
         return std::nullopt;
     }
 
+    static void RegisterShortcutAction(ShortcutAction shortcutAction, std::unordered_map<hstring, Model::ActionAndArgs>& list, std::unordered_set<InternalActionID>& visited)
+    {
+        const auto actionAndArgs{ make_self<ActionAndArgs>(shortcutAction) };
+        if (actionAndArgs->Action() != ShortcutAction::Invalid)
+        {
+            /*We have a valid action.*/
+            /*Check if the action was already added.*/
+            if (visited.find(Hash(*actionAndArgs)) == visited.end())
+            {
+                /*This is an action that wasn't added!*/
+                /*Let's add it.*/
+                const auto name{ actionAndArgs->GenerateName() };
+                list.insert({ name, *actionAndArgs });
+            }
+        }
+    }
+
+    // Method Description:
+    // - Retrieves a map of actions that can be bound to a key
+    Windows::Foundation::Collections::IMapView<hstring, Model::ActionAndArgs> ActionMap::AvailableActions()
+    {
+        if (!_AvailableActionsCache)
+        {
+            // populate _AvailableActionsCache
+            std::unordered_map<hstring, Model::ActionAndArgs> availableActions;
+            std::unordered_set<InternalActionID> visitedActionIDs;
+            _PopulateAvailableActionsWithStandardCommands(availableActions, visitedActionIDs);
+
+// now add any ShortcutActions that we might have missed
+#define ON_ALL_ACTIONS(action) RegisterShortcutAction(ShortcutAction::action, availableActions, visitedActionIDs);
+            ALL_SHORTCUT_ACTIONS
+#undef ON_ALL_ACTIONS
+
+            _AvailableActionsCache = single_threaded_map<hstring, Model::ActionAndArgs>(std::move(availableActions));
+        }
+        return _AvailableActionsCache.GetView();
+    }
+
+    void ActionMap::_PopulateAvailableActionsWithStandardCommands(std::unordered_map<hstring, Model::ActionAndArgs>& availableActions, std::unordered_set<InternalActionID>& visitedActionIDs) const
+    {
+        // Update AvailableActions and visitedActionIDs with our current layer
+        for (const auto& [actionID, cmd] : _ActionMap)
+        {
+            if (cmd.ActionAndArgs().Action() != ShortcutAction::Invalid)
+            {
+                // Only populate AvailableActions with actions that haven't been visited already.
+                if (visitedActionIDs.find(actionID) == visitedActionIDs.end())
+                {
+                    const auto& name{ cmd.Name() };
+                    if (!name.empty())
+                    {
+                        // Update AvailableActions.
+                        const auto actionAndArgsImpl{ get_self<ActionAndArgs>(cmd.ActionAndArgs()) };
+                        availableActions.insert_or_assign(name, *actionAndArgsImpl->Copy());
+                    }
+
+                    // Record that we already handled adding this action to the NameMap.
+                    visitedActionIDs.insert(actionID);
+                }
+            }
+        }
+
+        // Update NameMap and visitedActionIDs with our parents
+        for (const auto& parent : _parents)
+        {
+            parent->_PopulateAvailableActionsWithStandardCommands(availableActions, visitedActionIDs);
+        }
+    }
+
     // Method Description:
     // - Retrieves a map of command names to the commands themselves
     // - These commands should not be modified directly because they may result in
@@ -164,25 +234,23 @@ namespace winrt::Microsoft::Terminal::Settings::Model::implementation
         std::unordered_set<InternalActionID> visitedActionIDs;
         for (const auto& cmd : _GetCumulativeActions())
         {
-            // skip over all invalid actions
-            if (cmd.ActionAndArgs().Action() == ShortcutAction::Invalid)
+            // only populate with valid commands
+            if (cmd.ActionAndArgs().Action() != ShortcutAction::Invalid)
             {
-                continue;
-            }
-
-            // Only populate NameMap with actions that haven't been visited already.
-            const auto actionID{ Hash(cmd.ActionAndArgs()) };
-            if (visitedActionIDs.find(actionID) == visitedActionIDs.end())
-            {
-                const auto& name{ cmd.Name() };
-                if (!name.empty())
+                // Only populate NameMap with actions that haven't been visited already.
+                const auto actionID{ Hash(cmd.ActionAndArgs()) };
+                if (visitedActionIDs.find(actionID) == visitedActionIDs.end())
                 {
-                    // Update NameMap.
-                    nameMap.insert_or_assign(name, cmd);
-                }
+                    const auto& name{ cmd.Name() };
+                    if (!name.empty())
+                    {
+                        // Update NameMap.
+                        nameMap.insert_or_assign(name, cmd);
+                    }
 
-                // Record that we already handled adding this action to the NameMap.
-                visitedActionIDs.emplace(actionID);
+                    // Record that we already handled adding this action to the NameMap.
+                    visitedActionIDs.emplace(actionID);
+                }
             }
         }
     }
@@ -759,4 +827,20 @@ namespace winrt::Microsoft::Terminal::Settings::Model::implementation
         cmd->RegisterKey(keys);
         AddAction(*cmd);
     }
+
+    // Method Description:
+    // - Add a new key binding
+    // - If the key chord is already in use, the conflicting command is overwritten.
+    // Arguments:
+    // - keys: the key chord that is being bound
+    // - action: the action that the keys are being bound to
+    // Return Value:
+    // - <none>
+    void ActionMap::RegisterKeyBinding(Control::KeyChord keys, Model::ActionAndArgs action)
+    {
+        auto cmd{ make_self<Command>() };
+        cmd->RegisterKey(keys);
+        cmd->ActionAndArgs(action);
+        AddAction(*cmd);
+    }
 }

src/cascadia/TerminalSettingsModel/ActionMap.h

@@ -53,6 +53,7 @@ namespace winrt::Microsoft::Terminal::Settings::Model::implementation
         ActionMap();
 
         // views
+        Windows::Foundation::Collections::IMapView<hstring, Model::ActionAndArgs> AvailableActions();
         Windows::Foundation::Collections::IMapView<hstring, Model::Command> NameMap();
         Windows::Foundation::Collections::IMapView<Control::KeyChord, Model::Command> GlobalHotkeys();
         Windows::Foundation::Collections::IMapView<Control::KeyChord, Model::Command> KeyBindings();
@@ -74,6 +75,7 @@ namespace winrt::Microsoft::Terminal::Settings::Model::implementation
         // modification
         bool RebindKeys(Control::KeyChord const& oldKeys, Control::KeyChord const& newKeys);
         void DeleteKeyBinding(Control::KeyChord const& keys);
+        void RegisterKeyBinding(Control::KeyChord keys, Model::ActionAndArgs action);
 
         static Windows::System::VirtualKeyModifiers ConvertVKModifiers(Control::KeyModifiers modifiers);
 
@@ -81,6 +83,7 @@ namespace winrt::Microsoft::Terminal::Settings::Model::implementation
         std::optional<Model::Command> _GetActionByID(const InternalActionID actionID) const;
         std::optional<Model::Command> _GetActionByKeyChordInternal(Control::KeyChord const& keys) const;
 
+        void _PopulateAvailableActionsWithStandardCommands(std::unordered_map<hstring, Model::ActionAndArgs>& availableActions, std::unordered_set<InternalActionID>& visitedActionIDs) const;
         void _PopulateNameMapWithSpecialCommands(std::unordered_map<hstring, Model::Command>& nameMap) const;
         void _PopulateNameMapWithStandardCommands(std::unordered_map<hstring, Model::Command>& nameMap) const;
         void _PopulateKeyBindingMapWithStandardCommands(std::unordered_map<Control::KeyChord, Model::Command, KeyChordHash, KeyChordEquality>& keyBindingsMap, std::unordered_set<Control::KeyChord, KeyChordHash, KeyChordEquality>& unboundKeys) const;
@@ -90,6 +93,7 @@ namespace winrt::Microsoft::Terminal::Settings::Model::implementation
         void _TryUpdateName(const Model::Command& cmd, const Model::Command& oldCmd, const Model::Command& consolidatedCmd);
         void _TryUpdateKeyChord(const Model::Command& cmd, const Model::Command& oldCmd, const Model::Command& consolidatedCmd);
 
+        Windows::Foundation::Collections::IMap<hstring, Model::ActionAndArgs> _AvailableActionsCache{ nullptr };
         Windows::Foundation::Collections::IMap<hstring, Model::Command> _NameMapCache{ nullptr };
         Windows::Foundation::Collections::IMap<Control::KeyChord, Model::Command> _GlobalHotkeysCache{ nullptr };
         Windows::Foundation::Collections::IMap<Control::KeyChord, Model::Command> _KeyBindingMapCache{ nullptr };

src/cascadia/TerminalSettingsModel/ActionMap.idl

@@ -13,6 +13,8 @@ namespace Microsoft.Terminal.Settings.Model
         Microsoft.Terminal.Control.KeyChord GetKeyBindingForAction(ShortcutAction action);
         [method_name("GetKeyBindingForActionWithArgs")] Microsoft.Terminal.Control.KeyChord GetKeyBindingForAction(ShortcutAction action, IActionArgs actionArgs);
 
+        Windows.Foundation.Collections.IMapView<String, ActionAndArgs> AvailableActions { get; };
+
         Windows.Foundation.Collections.IMapView<String, Command> NameMap { get; };
         Windows.Foundation.Collections.IMapView<Microsoft.Terminal.Control.KeyChord, Command> KeyBindings { get; };
         Windows.Foundation.Collections.IMapView<Microsoft.Terminal.Control.KeyChord, Command> GlobalHotkeys { get; };
@@ -20,7 +22,9 @@ namespace Microsoft.Terminal.Settings.Model
 
     [default_interface] runtimeclass ActionMap : IActionMapView
     {
-        Boolean RebindKeys(Microsoft.Terminal.Control.KeyChord oldKeys, Microsoft.Terminal.Control.KeyChord newKeys);
+        void RebindKeys(Microsoft.Terminal.Control.KeyChord oldKeys, Microsoft.Terminal.Control.KeyChord newKeys);
         void DeleteKeyBinding(Microsoft.Terminal.Control.KeyChord keys);
+
+        void RegisterKeyBinding(Microsoft.Terminal.Control.KeyChord keys, ActionAndArgs action);
     }
 }

src/cascadia/TerminalSettingsModel/AllShortcutActions.h

@@ -81,6 +81,7 @@
     ON_ALL_ACTIONS_WITH_ARGS(AdjustFontSize)       \
     ON_ALL_ACTIONS_WITH_ARGS(CloseOtherTabs)       \
     ON_ALL_ACTIONS_WITH_ARGS(CloseTabsAfter)       \
+    ON_ALL_ACTIONS_WITH_ARGS(CloseTab)             \
     ON_ALL_ACTIONS_WITH_ARGS(CopyText)             \
     ON_ALL_ACTIONS_WITH_ARGS(ExecuteCommandline)   \
     ON_ALL_ACTIONS_WITH_ARGS(FindMatch)            \

src/cascadia/TerminalSettingsModel/ApplicationState.cpp

@@ -0,0 +1,173 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT license.
+
+#include "pch.h"
+#include "ApplicationState.h"
+#include "CascadiaSettings.h"
+#include "ApplicationState.g.cpp"
+
+#include "JsonUtils.h"
+#include "FileUtils.h"
+
+constexpr std::wstring_view stateFileName{ L"state.json" };
+
+namespace Microsoft::Terminal::Settings::Model::JsonUtils
+{
+    // This trait exists in order to serialize the std::unordered_set for GeneratedProfiles.
+    template<typename T>
+    struct ConversionTrait<std::unordered_set<T>>
+    {
+        std::unordered_set<T> FromJson(const Json::Value& json) const
+        {
+            ConversionTrait<T> trait;
+            std::unordered_set<T> val;
+            val.reserve(json.size());
+
+            for (const auto& element : json)
+            {
+                val.emplace(trait.FromJson(element));
+            }
+
+            return val;
+        }
+
+        bool CanConvert(const Json::Value& json) const
+        {
+            ConversionTrait<T> trait;
+            return json.isArray() && std::all_of(json.begin(), json.end(), [trait](const auto& json) -> bool { return trait.CanConvert(json); });
+        }
+
+        Json::Value ToJson(const std::unordered_set<T>& val)
+        {
+            ConversionTrait<T> trait;
+            Json::Value json{ Json::arrayValue };
+
+            for (const auto& key : val)
+            {
+                json.append(trait.ToJson(key));
+            }
+
+            return json;
+        }
+
+        std::string TypeDescription() const
+        {
+            return fmt::format("{}[]", ConversionTrait<GUID>{}.TypeDescription());
+        }
+    };
+}
+
+using namespace ::Microsoft::Terminal::Settings::Model;
+
+namespace winrt::Microsoft::Terminal::Settings::Model::implementation
+{
+    // Returns the application-global ApplicationState object.
+    Microsoft::Terminal::Settings::Model::ApplicationState ApplicationState::SharedInstance()
+    {
+        static auto state = winrt::make_self<ApplicationState>(GetBaseSettingsPath() / stateFileName);
+        return *state;
+    }
+
+    ApplicationState::ApplicationState(std::filesystem::path path) noexcept :
+        _path{ std::move(path) },
+        _throttler{ std::chrono::seconds(1), [this]() { _write(); } }
+    {
+        _read();
+    }
+
+    // The destructor ensures that the last write is flushed to disk before returning.
+    ApplicationState::~ApplicationState()
+    {
+        // This will ensure that we not just cancel the last outstanding timer,
+        // but instead force it to run as soon as possible and wait for it to complete.
+        _throttler.flush();
+    }
+
+    // Re-read the state.json from disk.
+    void ApplicationState::Reload() const noexcept
+    {
+        _read();
+    }
+
+    // Returns the state.json path on the disk.
+    winrt::hstring ApplicationState::FilePath() const noexcept
+    {
+        return winrt::hstring{ _path.wstring() };
+    }
+
+    // Generate all getter/setters
+#define MTSM_APPLICATION_STATE_GEN(type, name, key, ...)    \
+    type ApplicationState::name() const noexcept            \
+    {                                                       \
+        const auto state = _state.lock_shared();            \
+        const auto& value = state->name;                    \
+        return value ? *value : type{ __VA_ARGS__ };        \
+    }                                                       \
+                                                            \
+    void ApplicationState::name(const type& value) noexcept \
+    {                                                       \
+        {                                                   \
+            auto state = _state.lock();                     \
+            state->name.emplace(value);                     \
+        }                                                   \
+                                                            \
+        _throttler();                                       \
+    }
+    MTSM_APPLICATION_STATE_FIELDS(MTSM_APPLICATION_STATE_GEN)
+#undef MTSM_APPLICATION_STATE_GEN
+
+    // Deserializes the state.json at _path into this ApplicationState.
+    // * ANY errors during app state will result in the creation of a new empty state.
+    // * ANY errors during runtime will result in changes being partially ignored.
+    void ApplicationState::_read() const noexcept
+    try
+    {
+        const auto data = ReadUTF8FileIfExists(_path).value_or(std::string{});
+        if (data.empty())
+        {
+            return;
+        }
+
+        std::string errs;
+        std::unique_ptr<Json::CharReader> reader{ Json::CharReaderBuilder::CharReaderBuilder().newCharReader() };
+
+        Json::Value root;
+        if (!reader->parse(data.data(), data.data() + data.size(), &root, &errs))
+        {
+            throw winrt::hresult_error(WEB_E_INVALID_JSON_STRING, winrt::to_hstring(errs));
+        }
+
+        auto state = _state.lock();
+        // GetValueForKey() comes in two variants:
+        // * take a std::optional<T> reference
+        // * return std::optional<T> by value
+        // At the time of writing the former version skips missing fields in the json,
+        // but we want to explicitly clear state fields that were removed from state.json.
+#define MTSM_APPLICATION_STATE_GEN(type, name, key, ...) state->name = JsonUtils::GetValueForKey<std::optional<type>>(root, key);
+        MTSM_APPLICATION_STATE_FIELDS(MTSM_APPLICATION_STATE_GEN)
+#undef MTSM_APPLICATION_STATE_GEN
+    }
+    CATCH_LOG()
+
+    // Serialized this ApplicationState (in `context`) into the state.json at _path.
+    // * Errors are only logged.
+    // * _state->_writeScheduled is set to false, signaling our
+    //   setters that _synchronize() needs to be called again.
+    void ApplicationState::_write() const noexcept
+    try
+    {
+        Json::Value root{ Json::objectValue };
+
+        {
+            auto state = _state.lock_shared();
+#define MTSM_APPLICATION_STATE_GEN(type, name, key, ...) JsonUtils::SetValueForKey(root, key, state->name);
+            MTSM_APPLICATION_STATE_FIELDS(MTSM_APPLICATION_STATE_GEN)
+#undef MTSM_APPLICATION_STATE_GEN
+        }
+
+        Json::StreamWriterBuilder wbuilder;
+        const auto content = Json::writeString(wbuilder, root);
+        WriteUTF8FileAtomic(_path, content);
+    }
+    CATCH_LOG()
+}

src/cascadia/TerminalSettingsModel/ApplicationState.h

@@ -0,0 +1,69 @@
+/*++
+Copyright (c) Microsoft Corporation
+Licensed under the MIT license.
+
+Module Name:
+- ApplicationState.h
+
+Abstract:
+- If the CascadiaSettings class were AppData, then this class would be LocalAppData.
+  Put anything in here that you wouldn't want to be stored next to user-editable settings.
+- Modify ApplicationState.idl and MTSM_APPLICATION_STATE_FIELDS to add new fields.
+--*/
+#pragma once
+
+#include "ApplicationState.g.h"
+
+#include <inc/cppwinrt_utils.h>
+#include <til/mutex.h>
+#include <til/throttled_func.h>
+
+// This macro generates all getters and setters for ApplicationState.
+// It provides X with the following arguments:
+//   (type, function name, JSON key, ...variadic construction arguments)
+#define MTSM_APPLICATION_STATE_FIELDS(X) \
+    X(std::unordered_set<winrt::guid>, GeneratedProfiles, "generatedProfiles")
+
+namespace winrt::Microsoft::Terminal::Settings::Model::implementation
+{
+    struct ApplicationState : ApplicationStateT<ApplicationState>
+    {
+        static Microsoft::Terminal::Settings::Model::ApplicationState SharedInstance();
+
+        ApplicationState(std::filesystem::path path) noexcept;
+        ~ApplicationState();
+
+        // Methods
+        void Reload() const noexcept;
+
+        // General getters/setters
+        winrt::hstring FilePath() const noexcept;
+
+        // State getters/setters
+#define MTSM_APPLICATION_STATE_GEN(type, name, key, ...) \
+    type name() const noexcept;                          \
+    void name(const type& value) noexcept;
+        MTSM_APPLICATION_STATE_FIELDS(MTSM_APPLICATION_STATE_GEN)
+#undef MTSM_APPLICATION_STATE_GEN
+
+    private:
+        struct state_t
+        {
+#define MTSM_APPLICATION_STATE_GEN(type, name, key, ...) std::optional<type> name{ __VA_ARGS__ };
+            MTSM_APPLICATION_STATE_FIELDS(MTSM_APPLICATION_STATE_GEN)
+#undef MTSM_APPLICATION_STATE_GEN
+        };
+
+        void _write() const noexcept;
+        void _read() const noexcept;
+
+        std::filesystem::path _path;
+        til::shared_mutex<state_t> _state;
+        til::throttled_func_trailing<> _throttler;
+    };
+}
+
+namespace winrt::Microsoft::Terminal::Settings::Model::factory_implementation
+{
+    BASIC_FACTORY(ApplicationState);
+}

src/cascadia/TerminalSettingsModel/ApplicationState.idl

@@ -0,0 +1,13 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT license.
+
+namespace Microsoft.Terminal.Settings.Model
+{
+    [default_interface] runtimeclass ApplicationState {
+        static ApplicationState SharedInstance();
+
+        void Reload();
+
+        String FilePath { get; };
+    }
+}

src/cascadia/TerminalSettingsModel/CascadiaSettings.cpp

@@ -296,6 +296,13 @@ winrt::Microsoft::Terminal::Settings::Model::Profile CascadiaSettings::Duplicate
         duplicated->##settingName(source.##settingName());                                                                                     \
     }
 
+#define DUPLICATE_FONT_SETTING_MACRO(settingName)                                                                                                                                    \
+    if (source.FontInfo().Has##settingName() ||                                                                                                                                      \
+        (source.FontInfo().##settingName##OverrideSource() != nullptr && source.FontInfo().##settingName##OverrideSource().SourceProfile().Origin() != OriginTag::ProfilesDefaults)) \
+    {                                                                                                                                                                                \
+        duplicated->FontInfo().##settingName(source.FontInfo().##settingName());                                                                                                     \
+    }
+
 #define DUPLICATE_APPEARANCE_SETTING_MACRO(settingName)                                                                                                                                                \
     if (source.DefaultAppearance().Has##settingName() ||                                                                                                                                               \
         (source.DefaultAppearance().##settingName##OverrideSource() != nullptr && source.DefaultAppearance().##settingName##OverrideSource().SourceProfile().Origin() != OriginTag::ProfilesDefaults)) \
@@ -312,9 +319,6 @@ winrt::Microsoft::Terminal::Settings::Model::Profile CascadiaSettings::Duplicate
     DUPLICATE_SETTING_MACRO(UseAcrylic);
     DUPLICATE_SETTING_MACRO(AcrylicOpacity);
     DUPLICATE_SETTING_MACRO(ScrollState);
-    DUPLICATE_SETTING_MACRO(FontFace);
-    DUPLICATE_SETTING_MACRO(FontSize);
-    DUPLICATE_SETTING_MACRO(FontWeight);
     DUPLICATE_SETTING_MACRO(Padding);
     DUPLICATE_SETTING_MACRO(Commandline);
     DUPLICATE_SETTING_MACRO(StartingDirectory);
@@ -326,6 +330,10 @@ winrt::Microsoft::Terminal::Settings::Model::Profile CascadiaSettings::Duplicate
     DUPLICATE_SETTING_MACRO(AltGrAliasing);
     DUPLICATE_SETTING_MACRO(BellStyle);
 
+    DUPLICATE_FONT_SETTING_MACRO(FontFace);
+    DUPLICATE_FONT_SETTING_MACRO(FontSize);
+    DUPLICATE_FONT_SETTING_MACRO(FontWeight);
+
     DUPLICATE_APPEARANCE_SETTING_MACRO(ColorSchemeName);
     DUPLICATE_APPEARANCE_SETTING_MACRO(Foreground);
     DUPLICATE_APPEARANCE_SETTING_MACRO(Background);

src/cascadia/TerminalSettingsModel/CascadiaSettings.h

@@ -147,9 +147,8 @@ namespace winrt::Microsoft::Terminal::Settings::Model::implementation
         std::unordered_set<std::string> _AccumulateJsonFilesInDirectory(const std::wstring_view directory);
         void _ParseAndLayerFragmentFiles(const std::unordered_set<std::string> files, const winrt::hstring source);
 
-        static void _WriteSettings(std::string_view content, const hstring filepath);
+        static const std::filesystem::path& _SettingsPath();
         static std::optional<std::string> _ReadUserSettings();
-        static std::optional<std::string> _ReadFile(HANDLE hFile);
 
         std::optional<guid> _GetProfileGuidByName(const hstring) const;
         std::optional<guid> _GetProfileGuidByIndex(std::optional<int> index) const;

src/cascadia/TerminalSettingsModel/CascadiaSettingsSerialization.cpp

@@ -7,8 +7,6 @@
 #include <fmt/chrono.h>
 #include <shlobj.h>
 
-#include <WtExeUtils.h>
-
 // defaults.h is a file containing the default json settings in a std::string_view
 #include "defaults.h"
 #include "defaults-universal.h"
@@ -17,12 +15,15 @@
 // Both defaults.h and userDefaults.h are generated at build time into the
 // "Generated Files" directory.
 
+#include "ApplicationState.h"
+#include "FileUtils.h"
+
 using namespace winrt::Microsoft::Terminal::Settings::Model::implementation;
 using namespace ::Microsoft::Console;
+using namespace ::Microsoft::Terminal::Settings::Model;
 
 static constexpr std::wstring_view SettingsFilename{ L"settings.json" };
 static constexpr std::wstring_view LegacySettingsFilename{ L"profiles.json" };
-static constexpr std::wstring_view UnpackagedSettingsFolderName{ L"Microsoft\\Windows Terminal\\" };
 
 static constexpr std::wstring_view DefaultsFilename{ L"defaults.json" };
 
@@ -40,7 +41,6 @@ static constexpr std::string_view GuidKey{ "guid" };
 
 static constexpr std::string_view DisabledProfileSourcesKey{ "disabledProfileSources" };
 
-static constexpr std::string_view Utf8Bom{ u8"\uFEFF" };
 static constexpr std::string_view SettingsSchemaFragment{ "\n"
                                                           R"(    "$schema": "https://aka.ms/terminal-profiles-schema")" };
 
@@ -234,7 +234,7 @@ winrt::Microsoft::Terminal::Settings::Model::CascadiaSettings CascadiaSettings::
 
             try
             {
-                _WriteSettings(resultPtr->_userSettingsString, CascadiaSettings::SettingsPath());
+                WriteUTF8FileAtomic(_SettingsPath(), resultPtr->_userSettingsString);
             }
             catch (...)
             {
@@ -491,23 +491,11 @@ std::unordered_set<std::string> CascadiaSettings::_AccumulateJsonFilesInDirector
     {
         if (fragmentExt.path().extension() == jsonExtension)
         {
-            wil::unique_hfile hFile{ CreateFileW(fragmentExt.path().c_str(),
-                                                 GENERIC_READ,
-                                                 FILE_SHARE_READ | FILE_SHARE_WRITE,
-                                                 nullptr,
-                                                 OPEN_EXISTING,
-                                                 FILE_ATTRIBUTE_NORMAL,
-                                                 nullptr) };
-
-            if (!hFile)
+            try
             {
-                LOG_LAST_ERROR();
-            }
-            else
-            {
-                const auto fileData = _ReadFile(hFile.get()).value();
-                jsonFiles.emplace(fileData);
+                jsonFiles.emplace(ReadUTF8File(fragmentExt.path()));
             }
+            CATCH_LOG();
         }
     }
     return jsonFiles;
@@ -637,13 +625,8 @@ void CascadiaSettings::_ParseJsonString(std::string_view fileData, const bool is
 Json::Value CascadiaSettings::_ParseUtf8JsonString(std::string_view fileData)
 {
     Json::Value result;
-    // Ignore UTF-8 BOM
-    auto actualDataStart = fileData.data();
+    const auto actualDataStart = fileData.data();
     const auto actualDataEnd = fileData.data() + fileData.size();
-    if (fileData.compare(0, Utf8Bom.size(), Utf8Bom) == 0)
-    {
-        actualDataStart += Utf8Bom.size();
-    }
 
     std::string errs; // This string will receive any error text from failing to parse.
     std::unique_ptr<Json::CharReader> reader{ Json::CharReaderBuilder::CharReaderBuilder().newCharReader() };
@@ -693,8 +676,7 @@ bool CascadiaSettings::_PrependSchemaDirective()
 //   them into the user's settings at the end of the list of profiles.
 // - Does not reformat the user's settings file.
 // - Does not write the file! Only modifies in-place the _userSettingsString
-//   member. Callers should make sure to call
-//   _WriteSettings(_userSettingsString) to make sure to persist these changes!
+//   member. Callers should make sure to persist these changes (see WriteSettingsToDisk).
 // - Assumes that the `profiles` object is at an indentation of 4 spaces, and
 //   therefore each profile should be indented 8 spaces. If the user's settings
 //   have a different indentation, we'll still insert valid json, it'll just be
@@ -1056,28 +1038,15 @@ winrt::com_ptr<ColorScheme> CascadiaSettings::_FindMatchingColorScheme(const Jso
 }
 
 // Method Description:
-// - Writes the given content in UTF-8 to a settings file using the Win32 APIS's.
-//   Will overwrite any existing content in the file.
+// - Returns the path of the settings.json file.
 // Arguments:
-// - content: the given string of content to write to the file.
-// Return Value:
 // - <none>
-//   This can throw an exception if we fail to open the file for writing, or we
-//      fail to write the file
-void CascadiaSettings::_WriteSettings(const std::string_view content, const hstring filepath)
+// Return Value:
+// - Returns a path in 80% of cases. I measured!
+const std::filesystem::path& CascadiaSettings::_SettingsPath()
 {
-    wil::unique_hfile hOut{ CreateFileW(filepath.c_str(),
-                                        GENERIC_WRITE,
-                                        FILE_SHARE_READ | FILE_SHARE_WRITE,
-                                        nullptr,
-                                        CREATE_ALWAYS,
-                                        FILE_ATTRIBUTE_NORMAL,
-                                        nullptr) };
-    if (!hOut)
-    {
-        THROW_LAST_ERROR();
-    }
-    THROW_LAST_ERROR_IF(!WriteFile(hOut.get(), content.data(), gsl::narrow<DWORD>(content.size()), nullptr, nullptr));
+    static const auto path = GetBaseSettingsPath() / SettingsFilename;
+    return path;
 }
 
 // Method Description:
@@ -1091,92 +1060,7 @@ void CascadiaSettings::_WriteSettings(const std::string_view content, const hstr
 //      from reading the file
 std::optional<std::string> CascadiaSettings::_ReadUserSettings()
 {
-    const auto pathToSettingsFile{ CascadiaSettings::SettingsPath() };
-    wil::unique_hfile hFile{ CreateFileW(pathToSettingsFile.c_str(),
-                                         GENERIC_READ,
-                                         FILE_SHARE_READ | FILE_SHARE_WRITE,
-                                         nullptr,
-                                         OPEN_EXISTING,
-                                         FILE_ATTRIBUTE_NORMAL,
-                                         nullptr) };
-
-    if (!hFile)
-    {
-        // GH#5186 - We moved from profiles.json to settings.json; we want to
-        // migrate any file we find. We're using MoveFile in case their settings.json
-        // is a symbolic link.
-        std::filesystem::path pathToLegacySettingsFile{ std::wstring_view{ pathToSettingsFile } };
-        pathToLegacySettingsFile.replace_filename(LegacySettingsFilename);
-
-        wil::unique_hfile hLegacyFile{ CreateFileW(pathToLegacySettingsFile.c_str(),
-                                                   GENERIC_READ,
-                                                   FILE_SHARE_READ | FILE_SHARE_WRITE,
-                                                   nullptr,
-                                                   OPEN_EXISTING,
-                                                   FILE_ATTRIBUTE_NORMAL,
-                                                   nullptr) };
-
-        if (hLegacyFile)
-        {
-            // Close the file handle, move it, and re-open the file in its new location.
-            hLegacyFile.reset();
-
-            // Note: We're unsure if this is unsafe. Theoretically it's possible
-            // that two instances of the app will try and move the settings file
-            // simultaneously. We don't know what might happen in that scenario,
-            // but we're also not sure how to safely lock the file to prevent
-            // that from occurring.
-            THROW_LAST_ERROR_IF(!MoveFile(pathToLegacySettingsFile.c_str(),
-                                          pathToSettingsFile.c_str()));
-
-            hFile.reset(CreateFileW(pathToSettingsFile.c_str(),
-                                    GENERIC_READ,
-                                    FILE_SHARE_READ | FILE_SHARE_WRITE,
-                                    nullptr,
-                                    OPEN_EXISTING,
-                                    FILE_ATTRIBUTE_NORMAL,
-                                    nullptr));
-
-            // hFile shouldn't be INVALID. That's unexpected - We just moved the
-            // file, we should be able to open it. Throw the error so we can get
-            // some information here.
-            THROW_LAST_ERROR_IF(!hFile);
-        }
-        else
-        {
-            // If the roaming file didn't exist, and the local file doesn't exist,
-            //      that's fine. Just log the error and return nullopt - we'll
-            //      create the defaults.
-            LOG_LAST_ERROR();
-            return std::nullopt;
-        }
-    }
-
-    return _ReadFile(hFile.get());
-}
-
-// Method Description:
-// - Reads the content in UTF-8 encoding of the given file using the Win32 APIs
-// Arguments:
-// - <none>
-// Return Value:
-// - an optional with the content of the file if we were able to read it. If we
-//   fail to read it, this can throw an exception from reading the file
-std::optional<std::string> CascadiaSettings::_ReadFile(HANDLE hFile)
-{
-    // fileSize is in bytes
-    const auto fileSize = GetFileSize(hFile, nullptr);
-    THROW_LAST_ERROR_IF(fileSize == INVALID_FILE_SIZE);
-
-    auto utf8buffer = std::make_unique<char[]>(fileSize);
-
-    DWORD bytesRead = 0;
-    THROW_LAST_ERROR_IF(!ReadFile(hFile, utf8buffer.get(), fileSize, &bytesRead, nullptr));
-
-    // convert buffer to UTF-8 string
-    std::string utf8string(utf8buffer.get(), fileSize);
-
-    return { utf8string };
+    return ReadUTF8FileIfExists(_SettingsPath());
 }
 
 // function Description:
@@ -1191,23 +1075,7 @@ std::optional<std::string> CascadiaSettings::_ReadFile(HANDLE hFile)
 // - the full path to the settings file
 winrt::hstring CascadiaSettings::SettingsPath()
 {
-    wil::unique_cotaskmem_string localAppDataFolder;
-    // KF_FLAG_FORCE_APP_DATA_REDIRECTION, when engaged, causes SHGet... to return
-    // the new AppModel paths (Packages/xxx/RoamingState, etc.) for standard path requests.
-    // Using this flag allows us to avoid Windows.Storage.ApplicationData completely.
-    THROW_IF_FAILED(SHGetKnownFolderPath(FOLDERID_LocalAppData, KF_FLAG_FORCE_APP_DATA_REDIRECTION, nullptr, &localAppDataFolder));
-
-    std::filesystem::path parentDirectoryForSettingsFile{ localAppDataFolder.get() };
-
-    if (!IsPackaged())
-    {
-        parentDirectoryForSettingsFile /= UnpackagedSettingsFolderName;
-    }
-
-    // Create the directory if it doesn't exist
-    std::filesystem::create_directories(parentDirectoryForSettingsFile);
-
-    return winrt::hstring{ (parentDirectoryForSettingsFile / SettingsFilename).wstring() };
+    return winrt::hstring{ _SettingsPath().wstring() };
 }
 
 winrt::hstring CascadiaSettings::DefaultSettingsPath()
@@ -1222,15 +1090,12 @@ winrt::hstring CascadiaSettings::DefaultSettingsPath()
     // directory as the exe, that will work for unpackaged scenarios as well. So
     // let's try that.
 
-    HMODULE hModule = GetModuleHandle(nullptr);
-    THROW_LAST_ERROR_IF(hModule == nullptr);
-
     std::wstring exePathString;
-    THROW_IF_FAILED(wil::GetModuleFileNameW(hModule, exePathString));
+    THROW_IF_FAILED(wil::GetModuleFileNameW(nullptr, exePathString));
 
-    const std::filesystem::path exePath{ exePathString };
-    const std::filesystem::path rootDir = exePath.parent_path();
-    return winrt::hstring{ (rootDir / DefaultsFilename).wstring() };
+    std::filesystem::path path{ exePathString };
+    path.replace_filename(DefaultsFilename);
+    return winrt::hstring{ path.wstring() };
 }
 
 // Function Description:
@@ -1275,15 +1140,13 @@ const Json::Value& CascadiaSettings::_GetDisabledProfileSourcesJsonObject(const
 // - <none>
 void CascadiaSettings::WriteSettingsToDisk() const
 {
-    const auto settingsPath{ CascadiaSettings::SettingsPath() };
+    const auto settingsPath = _SettingsPath();
 
     try
     {
         // create a timestamped backup file
-        const auto clock{ std::chrono::system_clock() };
-        const auto timeStamp{ clock.to_time_t(clock.now()) };
-        const winrt::hstring backupSettingsPath{ fmt::format(L"{}.{:%Y-%m-%dT%H-%M-%S}.backup", settingsPath, fmt::localtime(timeStamp)) };
-        _WriteSettings(_userSettingsString, backupSettingsPath);
+        const auto backupSettingsPath = fmt::format(L"{}.{:%Y-%m-%dT%H-%M-%S}.backup", settingsPath.wstring(), fmt::localtime(std::time(nullptr)));
+        WriteUTF8File(backupSettingsPath, _userSettingsString);
     }
     CATCH_LOG();
 
@@ -1293,7 +1156,7 @@ void CascadiaSettings::WriteSettingsToDisk() const
     wbuilder.settings_["enableYAMLCompatibility"] = true; // suppress spaces around colons
 
     const auto styledString{ Json::writeString(wbuilder, ToJson()) };
-    _WriteSettings(styledString, settingsPath);
+    WriteUTF8FileAtomic(settingsPath, styledString);
 
     // Persists the default terminal choice
     //

src/cascadia/TerminalSettingsModel/FileUtils.cpp

@@ -0,0 +1,137 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT license.
+
+#include "pch.h"
+#include "FileUtils.h"
+
+#include <appmodel.h>
+#include <shlobj.h>
+#include <WtExeUtils.h>
+
+static constexpr std::string_view Utf8Bom{ u8"\uFEFF" };
+static constexpr std::wstring_view UnpackagedSettingsFolderName{ L"Microsoft\\Windows Terminal\\" };
+
+namespace Microsoft::Terminal::Settings::Model
+{
+    // Returns a path like C:\Users\<username>\AppData\Local\Packages\<packagename>\LocalState
+    // You can put your settings.json or state.json in this directory.
+    std::filesystem::path GetBaseSettingsPath()
+    {
+        static std::filesystem::path baseSettingsPath = []() {
+            wil::unique_cotaskmem_string localAppDataFolder;
+            // KF_FLAG_FORCE_APP_DATA_REDIRECTION, when engaged, causes SHGet... to return
+            // the new AppModel paths (Packages/xxx/RoamingState, etc.) for standard path requests.
+            // Using this flag allows us to avoid Windows.Storage.ApplicationData completely.
+            THROW_IF_FAILED(SHGetKnownFolderPath(FOLDERID_LocalAppData, KF_FLAG_FORCE_APP_DATA_REDIRECTION, nullptr, &localAppDataFolder));
+
+            std::filesystem::path parentDirectoryForSettingsFile{ localAppDataFolder.get() };
+
+            if (!IsPackaged())
+            {
+                parentDirectoryForSettingsFile /= UnpackagedSettingsFolderName;
+            }
+
+            // Create the directory if it doesn't exist
+            std::filesystem::create_directories(parentDirectoryForSettingsFile);
+
+            return parentDirectoryForSettingsFile;
+        }();
+        return baseSettingsPath;
+    }
+
+    // Tries to read a file somewhat atomically without locking it.
+    // Strips the UTF8 BOM if it exists.
+    std::string ReadUTF8File(const std::filesystem::path& path)
+    {
+        // From some casual observations we can determine that:
+        // * ReadFile() always returns the requested amount of data (unless the file is smaller)
+        // * It's unlikely that the file was changed between GetFileSize() and ReadFile()
+        // -> Lets add a retry-loop just in case, to not fail if the file size changed while reading.
+        for (int i = 0; i < 3; ++i)
+        {
+            wil::unique_hfile file{ CreateFileW(path.c_str(), GENERIC_READ, FILE_SHARE_READ | FILE_SHARE_WRITE, nullptr, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, nullptr) };
+            THROW_LAST_ERROR_IF(!file);
+
+            const auto fileSize = GetFileSize(file.get(), nullptr);
+            THROW_LAST_ERROR_IF(fileSize == INVALID_FILE_SIZE);
+
+            // By making our buffer just slightly larger we can detect if
+            // the file size changed and we've failed to read the full file.
+            std::string buffer(static_cast<size_t>(fileSize) + 1, '\0');
+            DWORD bytesRead = 0;
+            THROW_IF_WIN32_BOOL_FALSE(ReadFile(file.get(), buffer.data(), gsl::narrow<DWORD>(buffer.size()), &bytesRead, nullptr));
+
+            // This implementation isn't atomic as we'd need to use an exclusive file lock.
+            // But this would be annoying for users as it forces them to close the file in their editor.
+            // The next best alternative is to at least try to detect file changes and retry the read.
+            if (bytesRead != fileSize)
+            {
+                // This continue is unlikely to be hit (see the prior for loop comment).
+                std::this_thread::sleep_for(std::chrono::milliseconds(100));
+                continue;
+            }
+
+            // As mentioned before our buffer was allocated oversized.
+            buffer.resize(bytesRead);
+
+            if (til::starts_with(buffer, Utf8Bom))
+            {
+                // Yeah this memmove()s the entire content.
+                // But I don't really want to deal with UTF8 BOMs any more than necessary,
+                // as basically not a single editor writes a BOM for UTF8.
+                buffer.erase(0, Utf8Bom.size());
+            }
+
+            return buffer;
+        }
+
+        THROW_WIN32_MSG(ERROR_READ_FAULT, "file size changed while reading");
+    }
+
+    // Same as ReadUTF8File, but returns an empty optional, if the file couldn't be opened.
+    std::optional<std::string> ReadUTF8FileIfExists(const std::filesystem::path& path)
+    {
+        try
+        {
+            return { ReadUTF8File(path) };
+        }
+        catch (const wil::ResultException& exception)
+        {
+            if (exception.GetErrorCode() == HRESULT_FROM_WIN32(ERROR_FILE_NOT_FOUND))
+            {
+                return {};
+            }
+
+            throw;
+        }
+    }
+
+    void WriteUTF8File(const std::filesystem::path& path, const std::string_view content)
+    {
+        wil::unique_hfile file{ CreateFileW(path.c_str(), GENERIC_WRITE, FILE_SHARE_READ | FILE_SHARE_WRITE, nullptr, CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, nullptr) };
+        THROW_LAST_ERROR_IF(!file);
+
+        const auto fileSize = gsl::narrow<DWORD>(content.size());
+        DWORD bytesWritten = 0;
+        THROW_IF_WIN32_BOOL_FALSE(WriteFile(file.get(), content.data(), fileSize, &bytesWritten, nullptr));
+
+        if (bytesWritten != fileSize)
+        {
+            THROW_WIN32_MSG(ERROR_WRITE_FAULT, "failed to write whole file");
+        }
+    }
+
+    void WriteUTF8FileAtomic(const std::filesystem::path& path, const std::string_view content)
+    {
+        auto tmpPath = path;
+        tmpPath += L".tmp";
+
+        // Writing to a file isn't atomic, but...
+        WriteUTF8File(tmpPath, content);
+
+        // renaming one is (supposed to be) atomic.
+        // Wait... "supposed to be"!? Well it's technically not always atomic,
+        // but it's pretty darn close to it, so... better than nothing.
+        std::filesystem::rename(tmpPath, path);
+    }
+}

src/cascadia/TerminalSettingsModel/FileUtils.h

@@ -0,0 +1,11 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT license.
+
+namespace Microsoft::Terminal::Settings::Model
+{
+    std::filesystem::path GetBaseSettingsPath();
+    std::string ReadUTF8File(const std::filesystem::path& path);
+    std::optional<std::string> ReadUTF8FileIfExists(const std::filesystem::path& path);
+    void WriteUTF8File(const std::filesystem::path& path, const std::string_view content);
+    void WriteUTF8FileAtomic(const std::filesystem::path& path, const std::string_view content);
+}

src/cascadia/TerminalSettingsModel/FontConfig.cpp

@@ -0,0 +1,86 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT license.
+
+#include "pch.h"
+#include "FontConfig.h"
+#include "FontConfig.g.cpp"
+#include "TerminalSettingsSerializationHelpers.h"
+#include "JsonUtils.h"
+
+using namespace Microsoft::Terminal::Settings::Model;
+using namespace winrt::Microsoft::Terminal::Settings::Model::implementation;
+
+static constexpr std::string_view FontInfoKey{ "font" };
+static constexpr std::string_view FontFaceKey{ "face" };
+static constexpr std::string_view FontSizeKey{ "size" };
+static constexpr std::string_view FontWeightKey{ "weight" };
+static constexpr std::string_view LegacyFontFaceKey{ "fontFace" };
+static constexpr std::string_view LegacyFontSizeKey{ "fontSize" };
+static constexpr std::string_view LegacyFontWeightKey{ "fontWeight" };
+
+winrt::Microsoft::Terminal::Settings::Model::implementation::FontConfig::FontConfig(winrt::weak_ref<Profile> sourceProfile) :
+    _sourceProfile(std::move(sourceProfile))
+{
+}
+
+winrt::com_ptr<FontConfig> FontConfig::CopyFontInfo(const winrt::com_ptr<FontConfig> source, winrt::weak_ref<Profile> sourceProfile)
+{
+    auto fontInfo{ winrt::make_self<FontConfig>(std::move(sourceProfile)) };
+    fontInfo->_FontFace = source->_FontFace;
+    fontInfo->_FontSize = source->_FontSize;
+    fontInfo->_FontWeight = source->_FontWeight;
+    return fontInfo;
+}
+
+Json::Value FontConfig::ToJson() const
+{
+    Json::Value json{ Json::ValueType::objectValue };
+
+    JsonUtils::SetValueForKey(json, FontFaceKey, _FontFace);
+    JsonUtils::SetValueForKey(json, FontSizeKey, _FontSize);
+    JsonUtils::SetValueForKey(json, FontWeightKey, _FontWeight);
+
+    return json;
+}
+
+// Method Description:
+// - Layer values from the given json object on top of the existing properties
+//   of this object. For any keys we're expecting to be able to parse in the
+//   given object, we'll parse them and replace our settings with values from
+//   the new json object. Properties that _aren't_ in the json object will _not_
+//   be replaced.
+// - Optional values that are set to `null` in the json object
+//   will be set to nullopt.
+// - This is similar to Profile::LayerJson but for FontConfig
+// Arguments:
+// - json: an object which should be a partial serialization of a FontConfig object.
+void FontConfig::LayerJson(const Json::Value& json)
+{
+    // Legacy users may not have a font object defined in their profile,
+    // so check for that before we decide how to parse this
+    if (json.isMember(JsonKey(FontInfoKey)))
+    {
+        // A font object is defined, use that
+        const auto fontInfoJson = json[JsonKey(FontInfoKey)];
+        JsonUtils::GetValueForKey(fontInfoJson, FontFaceKey, _FontFace);
+        JsonUtils::GetValueForKey(fontInfoJson, FontSizeKey, _FontSize);
+        JsonUtils::GetValueForKey(fontInfoJson, FontWeightKey, _FontWeight);
+    }
+    else
+    {
+        // No font object is defined
+        JsonUtils::GetValueForKey(json, LegacyFontFaceKey, _FontFace);
+        JsonUtils::GetValueForKey(json, LegacyFontSizeKey, _FontSize);
+        JsonUtils::GetValueForKey(json, LegacyFontWeightKey, _FontWeight);
+    }
+}
+
+bool FontConfig::HasAnyOptionSet() const
+{
+    return HasFontFace() || HasFontSize() || HasFontWeight();
+}
+
+winrt::Microsoft::Terminal::Settings::Model::Profile FontConfig::SourceProfile()
+{
+    return _sourceProfile.get();
+}

src/cascadia/TerminalSettingsModel/FontConfig.h

@@ -0,0 +1,46 @@
+/*++
+Copyright (c) Microsoft Corporation
+Licensed under the MIT license.
+
+Module Name:
+- FontConfig
+
+Abstract:
+- The implementation of the FontConfig winrt class. Provides settings related
+  to the font settings of the terminal, for the terminal control.
+
+Author(s):
+- Pankaj Bhojwani - June 2021
+
+--*/
+
+#pragma once
+
+#include "pch.h"
+#include "FontConfig.g.h"
+#include "JsonUtils.h"
+#include "../inc/cppwinrt_utils.h"
+#include "IInheritable.h"
+#include <DefaultSettings.h>
+
+namespace winrt::Microsoft::Terminal::Settings::Model::implementation
+{
+    struct FontConfig : FontConfigT<FontConfig>, IInheritable<FontConfig>
+    {
+    public:
+        FontConfig(winrt::weak_ref<Profile> sourceProfile);
+        static winrt::com_ptr<FontConfig> CopyFontInfo(const winrt::com_ptr<FontConfig> source, winrt::weak_ref<Profile> sourceProfile);
+        Json::Value ToJson() const;
+        void LayerJson(const Json::Value& json);
+        bool HasAnyOptionSet() const;
+
+        Model::Profile SourceProfile();
+
+        INHERITABLE_SETTING(Model::FontConfig, hstring, FontFace, DEFAULT_FONT_FACE);
+        INHERITABLE_SETTING(Model::FontConfig, int32_t, FontSize, DEFAULT_FONT_SIZE);
+        INHERITABLE_SETTING(Model::FontConfig, Windows::UI::Text::FontWeight, FontWeight, DEFAULT_FONT_WEIGHT);
+
+    private:
+        winrt::weak_ref<Profile> _sourceProfile;
+    };
+}

src/cascadia/TerminalSettingsModel/FontConfig.idl

@@ -0,0 +1,20 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT license.
+
+import "Profile.idl";
+#include "IInheritable.idl.h"
+
+#define INHERITABLE_FONT_SETTING(Type, Name) \
+    _BASE_INHERITABLE_SETTING(Type, Name);      \
+    Microsoft.Terminal.Settings.Model.FontConfig Name##OverrideSource { get; }
+
+namespace Microsoft.Terminal.Settings.Model
+{
+    [default_interface] runtimeclass FontConfig {
+        Microsoft.Terminal.Settings.Model.Profile SourceProfile { get; };
+
+        INHERITABLE_FONT_SETTING(String, FontFace);
+        INHERITABLE_FONT_SETTING(Int32, FontSize);
+        INHERITABLE_FONT_SETTING(Windows.UI.Text.FontWeight, FontWeight);
+    }
+}

src/cascadia/TerminalSettingsModel/Microsoft.Terminal.Settings.ModelLib.vcxproj

@@ -32,6 +32,9 @@
       <DependentUpon>ActionMap.idl</DependentUpon>
     </ClInclude>
     <ClInclude Include="AzureCloudShellGenerator.h" />
+    <ClInclude Include="ApplicationState.h">
+      <DependentUpon>ApplicationState.idl</DependentUpon>
+    </ClInclude>
     <ClInclude Include="CascadiaSettings.h">
       <DependentUpon>CascadiaSettings.idl</DependentUpon>
     </ClInclude>
@@ -42,6 +45,7 @@
       <DependentUpon>Command.idl</DependentUpon>
     </ClInclude>
     <ClInclude Include="DefaultProfileUtils.h" />
+    <ClInclude Include="FileUtils.h" />
     <ClInclude Include="GlobalAppSettings.h">
       <DependentUpon>GlobalAppSettings.idl</DependentUpon>
     </ClInclude>
@@ -59,6 +63,9 @@
     <ClInclude Include="AppearanceConfig.h">
       <DependentUpon>AppearanceConfig.idl</DependentUpon>
     </ClInclude>
+    <ClInclude Include="FontConfig.h">
+      <DependentUpon>FontConfig.idl</DependentUpon>
+    </ClInclude>
     <ClInclude Include="EnumMappings.h">
       <DependentUpon>EnumMappings.idl</DependentUpon>
     </ClInclude>
@@ -97,6 +104,9 @@
       <DependentUpon>ActionMap.idl</DependentUpon>
     </ClCompile>
     <ClCompile Include="AzureCloudShellGenerator.cpp" />
+    <ClCompile Include="ApplicationState.cpp">
+      <DependentUpon>ApplicationState.idl</DependentUpon>
+    </ClCompile>
     <ClCompile Include="CascadiaSettings.cpp">
       <DependentUpon>CascadiaSettings.idl</DependentUpon>
     </ClCompile>
@@ -110,6 +120,7 @@
       <DependentUpon>Command.idl</DependentUpon>
     </ClCompile>
     <ClCompile Include="DefaultProfileUtils.cpp" />
+    <ClCompile Include="FileUtils.cpp" />
     <ClCompile Include="GlobalAppSettings.cpp">
       <DependentUpon>GlobalAppSettings.idl</DependentUpon>
     </ClCompile>
@@ -123,6 +134,9 @@
     <ClCompile Include="AppearanceConfig.cpp">
       <DependentUpon>AppearanceConfig.idl</DependentUpon>
     </ClCompile>
+    <ClCompile Include="FontConfig.cpp">
+      <DependentUpon>FontConfig.idl</DependentUpon>
+    </ClCompile>
     <ClCompile Include="TerminalSettings.cpp">
       <DependentUpon>TerminalSettings.idl</DependentUpon>
     </ClCompile>
@@ -141,6 +155,7 @@
   <ItemGroup>
     <Midl Include="ActionArgs.idl" />
     <Midl Include="ActionMap.idl" />
+    <Midl Include="ApplicationState.idl" />
     <Midl Include="CascadiaSettings.idl" />
     <Midl Include="ColorScheme.idl" />
     <Midl Include="Command.idl" />
@@ -154,6 +169,7 @@
     <Midl Include="KeyChordSerialization.idl" />
     <Midl Include="AppearanceConfig.idl" />
     <Midl Include="IAppearanceConfig.idl" />
+    <Midl Include="FontConfig.idl" />
   </ItemGroup>
   <!-- ========================= Misc Files ======================== -->
   <ItemGroup>

src/cascadia/TerminalSettingsModel/Microsoft.Terminal.Settings.ModelLib.vcxproj.filters

@@ -82,6 +82,7 @@
     <Midl Include="TerminalSettings.idl" />
     <Midl Include="AppearanceConfig.idl" />
     <Midl Include="IAppearanceConfig.idl" />
+    <Midl Include="FontConfig.idl" />
     <Midl Include="DefaultTerminal.idl" />
   </ItemGroup>
   <ItemGroup>

src/cascadia/TerminalSettingsModel/Profile.cpp

@@ -10,6 +10,7 @@
 #include "LegacyProfileGeneratorNamespaces.h"
 #include "TerminalSettingsSerializationHelpers.h"
 #include "AppearanceConfig.h"
+#include "FontConfig.h"
 
 #include "Profile.g.cpp"
 
@@ -34,9 +35,7 @@ static constexpr std::string_view AltGrAliasingKey{ "altGrAliasing" };
 
 static constexpr std::string_view ConnectionTypeKey{ "connectionType" };
 static constexpr std::string_view CommandlineKey{ "commandline" };
-static constexpr std::string_view FontFaceKey{ "fontFace" };
-static constexpr std::string_view FontSizeKey{ "fontSize" };
-static constexpr std::string_view FontWeightKey{ "fontWeight" };
+static constexpr std::string_view FontInfoKey{ "font" };
 static constexpr std::string_view AcrylicTransparencyKey{ "acrylicOpacity" };
 static constexpr std::string_view UseAcrylicKey{ "useAcrylic" };
 static constexpr std::string_view ScrollbarStateKey{ "scrollbarState" };
@@ -76,9 +75,6 @@ winrt::com_ptr<Profile> Profile::CopySettings(winrt::com_ptr<Profile> source)
     profile->_UseAcrylic = source->_UseAcrylic;
     profile->_AcrylicOpacity = source->_AcrylicOpacity;
     profile->_ScrollState = source->_ScrollState;
-    profile->_FontFace = source->_FontFace;
-    profile->_FontSize = source->_FontSize;
-    profile->_FontWeight = source->_FontWeight;
     profile->_Padding = source->_Padding;
     profile->_Commandline = source->_Commandline;
     profile->_StartingDirectory = source->_StartingDirectory;
@@ -92,8 +88,14 @@ winrt::com_ptr<Profile> Profile::CopySettings(winrt::com_ptr<Profile> source)
     profile->_ConnectionType = source->_ConnectionType;
     profile->_Origin = source->_Origin;
 
-    // Copy over the appearance
+    // Copy over the font info
     const auto weakRefToProfile = weak_ref<Model::Profile>(*profile);
+    winrt::com_ptr<FontConfig> sourceFontInfoImpl;
+    sourceFontInfoImpl.copy_from(winrt::get_self<FontConfig>(source->_FontInfo));
+    auto copiedFontInfo = FontConfig::CopyFontInfo(sourceFontInfoImpl, weakRefToProfile);
+    profile->_FontInfo = *copiedFontInfo;
+
+    // Copy over the appearance
     winrt::com_ptr<AppearanceConfig> sourceDefaultAppearanceImpl;
     sourceDefaultAppearanceImpl.copy_from(winrt::get_self<AppearanceConfig>(source->_DefaultAppearance));
     auto copiedDefaultAppearance = AppearanceConfig::CopyAppearance(sourceDefaultAppearanceImpl, weakRefToProfile);
@@ -315,6 +317,10 @@ void Profile::LayerJson(const Json::Value& json)
     auto defaultAppearanceImpl = winrt::get_self<implementation::AppearanceConfig>(_DefaultAppearance);
     defaultAppearanceImpl->LayerJson(json);
 
+    // Font Settings
+    auto fontInfoImpl = winrt::get_self<implementation::FontConfig>(_FontInfo);
+    fontInfoImpl->LayerJson(json);
+
     // Profile-specific Settings
     JsonUtils::GetValueForKey(json, NameKey, _Name);
     JsonUtils::GetValueForKey(json, GuidKey, _Guid);
@@ -328,11 +334,8 @@ void Profile::LayerJson(const Json::Value& json)
     JsonUtils::GetValueForKey(json, TabTitleKey, _TabTitle);
 
     // Control Settings
-    JsonUtils::GetValueForKey(json, FontWeightKey, _FontWeight);
     JsonUtils::GetValueForKey(json, ConnectionTypeKey, _ConnectionType);
     JsonUtils::GetValueForKey(json, CommandlineKey, _Commandline);
-    JsonUtils::GetValueForKey(json, FontFaceKey, _FontFace);
-    JsonUtils::GetValueForKey(json, FontSizeKey, _FontSize);
     JsonUtils::GetValueForKey(json, AcrylicTransparencyKey, _AcrylicOpacity);
     JsonUtils::GetValueForKey(json, UseAcrylicKey, _UseAcrylic);
     JsonUtils::GetValueForKey(json, SuppressApplicationTitleKey, _SuppressApplicationTitle);
@@ -392,6 +395,19 @@ void Profile::_FinalizeInheritance()
             }
         }
     }
+    if (auto fontInfoImpl = get_self<FontConfig>(_FontInfo))
+    {
+        // Clear any existing parents first, we don't want duplicates from any previous
+        // calls to this function
+        fontInfoImpl->ClearParents();
+        for (auto& parent : _parents)
+        {
+            if (auto parentFontInfoImpl = parent->_FontInfo.try_as<FontConfig>())
+            {
+                fontInfoImpl->InsertParent(parentFontInfoImpl);
+            }
+        }
+    }
 }
 
 winrt::Microsoft::Terminal::Settings::Model::IAppearanceConfig Profile::DefaultAppearance()
@@ -399,6 +415,11 @@ winrt::Microsoft::Terminal::Settings::Model::IAppearanceConfig Profile::DefaultA
     return _DefaultAppearance;
 }
 
+winrt::Microsoft::Terminal::Settings::Model::FontConfig Profile::FontInfo()
+{
+    return _FontInfo;
+}
+
 // Method Description:
 // - Helper function for expanding any environment variables in a user-supplied starting directory and validating the resulting path
 // Arguments:
@@ -510,11 +531,8 @@ Json::Value Profile::ToJson() const
     JsonUtils::SetValueForKey(json, TabTitleKey, _TabTitle);
 
     // Control Settings
-    JsonUtils::SetValueForKey(json, FontWeightKey, _FontWeight);
     JsonUtils::SetValueForKey(json, ConnectionTypeKey, _ConnectionType);
     JsonUtils::SetValueForKey(json, CommandlineKey, _Commandline);
-    JsonUtils::SetValueForKey(json, FontFaceKey, _FontFace);
-    JsonUtils::SetValueForKey(json, FontSizeKey, _FontSize);
     JsonUtils::SetValueForKey(json, AcrylicTransparencyKey, _AcrylicOpacity);
     JsonUtils::SetValueForKey(json, UseAcrylicKey, _UseAcrylic);
     JsonUtils::SetValueForKey(json, SuppressApplicationTitleKey, _SuppressApplicationTitle);
@@ -530,6 +548,13 @@ Json::Value Profile::ToJson() const
     JsonUtils::SetValueForKey(json, TabColorKey, _TabColor);
     JsonUtils::SetValueForKey(json, BellStyleKey, _BellStyle);
 
+    // Font settings
+    const auto fontInfoImpl = winrt::get_self<FontConfig>(_FontInfo);
+    if (fontInfoImpl->HasAnyOptionSet())
+    {
+        json[JsonKey(FontInfoKey)] = winrt::get_self<FontConfig>(_FontInfo)->ToJson();
+    }
+
     if (_UnfocusedAppearance)
     {
         json[JsonKey(UnfocusedAppearanceKey)] = winrt::get_self<AppearanceConfig>(_UnfocusedAppearance.value())->ToJson();

src/cascadia/TerminalSettingsModel/Profile.h

@@ -51,6 +51,7 @@ Author(s):
 #include "JsonUtils.h"
 #include <DefaultSettings.h>
 #include "AppearanceConfig.h"
+#include "FontConfig.h"
 
 // fwdecl unittest classes
 namespace SettingsModelLocalTests
@@ -98,6 +99,7 @@ namespace winrt::Microsoft::Terminal::Settings::Model::implementation
         static guid GetGuidOrGenerateForJson(const Json::Value& json) noexcept;
 
         Model::IAppearanceConfig DefaultAppearance();
+        Model::FontConfig FontInfo();
 
         void _FinalizeInheritance() override;
 
@@ -121,9 +123,6 @@ namespace winrt::Microsoft::Terminal::Settings::Model::implementation
         INHERITABLE_SETTING(Model::Profile, double, AcrylicOpacity, 0.5);
         INHERITABLE_SETTING(Model::Profile, Microsoft::Terminal::Control::ScrollbarState, ScrollState, Microsoft::Terminal::Control::ScrollbarState::Visible);
 
-        INHERITABLE_SETTING(Model::Profile, hstring, FontFace, DEFAULT_FONT_FACE);
-        INHERITABLE_SETTING(Model::Profile, int32_t, FontSize, DEFAULT_FONT_SIZE);
-        INHERITABLE_SETTING(Model::Profile, Windows::UI::Text::FontWeight, FontWeight, DEFAULT_FONT_WEIGHT);
         INHERITABLE_SETTING(Model::Profile, hstring, Padding, DEFAULT_PADDING);
 
         INHERITABLE_SETTING(Model::Profile, hstring, Commandline, L"cmd.exe");
@@ -143,6 +142,7 @@ namespace winrt::Microsoft::Terminal::Settings::Model::implementation
 
     private:
         Model::IAppearanceConfig _DefaultAppearance{ winrt::make<AppearanceConfig>(weak_ref<Model::Profile>(*this)) };
+        Model::FontConfig _FontInfo{ winrt::make<FontConfig>(weak_ref<Model::Profile>(*this)) };
         static std::wstring EvaluateStartingDirectory(const std::wstring& directory);
 
         static guid _GenerateGuidForProfile(const hstring& name, const hstring& source) noexcept;

src/cascadia/TerminalSettingsModel/Profile.idl

@@ -2,6 +2,7 @@
 // Licensed under the MIT license.
 
 import "IAppearanceConfig.idl";
+import "FontConfig.idl";
 #include "IInheritable.idl.h"
 
 #define INHERITABLE_PROFILE_SETTING(Type, Name) \
@@ -62,15 +63,14 @@ namespace Microsoft.Terminal.Settings.Model
         INHERITABLE_PROFILE_SETTING(Boolean, UseAcrylic);
         INHERITABLE_PROFILE_SETTING(Double, AcrylicOpacity);
         INHERITABLE_PROFILE_SETTING(Microsoft.Terminal.Control.ScrollbarState, ScrollState);
-        INHERITABLE_PROFILE_SETTING(String, FontFace);
-        INHERITABLE_PROFILE_SETTING(Int32, FontSize);
-        INHERITABLE_PROFILE_SETTING(Windows.UI.Text.FontWeight, FontWeight);
         INHERITABLE_PROFILE_SETTING(String, Padding);
         INHERITABLE_PROFILE_SETTING(String, Commandline);
 
         INHERITABLE_PROFILE_SETTING(String, StartingDirectory);
         String EvaluatedStartingDirectory { get; };
 
+        FontConfig FontInfo { get; };
+
         IAppearanceConfig DefaultAppearance { get; };
         INHERITABLE_PROFILE_SETTING(IAppearanceConfig, UnfocusedAppearance);
 

src/cascadia/TerminalSettingsModel/Resources/en-US/Resources.resw

@@ -1,17 +1,17 @@
 <?xml version="1.0" encoding="utf-8"?>
 <root>
-  <!--
-    Microsoft ResX Schema
-
+  <!-- 
+    Microsoft ResX Schema 
+    
     Version 2.0
-
-    The primary goals of this format is to allow a simple XML format
-    that is mostly human readable. The generation and parsing of the
-    various data types are done through the TypeConverter classes
+    
+    The primary goals of this format is to allow a simple XML format 
+    that is mostly human readable. The generation and parsing of the 
+    various data types are done through the TypeConverter classes 
     associated with the data types.
-
+    
     Example:
-
+    
     ... ado.net/XML headers & schema ...
     <resheader name="resmimetype">text/microsoft-resx</resheader>
     <resheader name="version">2.0</resheader>
@@ -26,36 +26,36 @@
         <value>[base64 mime encoded string representing a byte array form of the .NET Framework object]</value>
         <comment>This is a comment</comment>
     </data>
-
-    There are any number of "resheader" rows that contain simple
+                
+    There are any number of "resheader" rows that contain simple 
     name/value pairs.
-
-    Each data row contains a name, and value. The row also contains a
-    type or mimetype. Type corresponds to a .NET class that support
-    text/value conversion through the TypeConverter architecture.
-    Classes that don't support this are serialized and stored with the
+    
+    Each data row contains a name, and value. The row also contains a 
+    type or mimetype. Type corresponds to a .NET class that support 
+    text/value conversion through the TypeConverter architecture. 
+    Classes that don't support this are serialized and stored with the 
     mimetype set.
-
-    The mimetype is used for serialized objects, and tells the
-    ResXResourceReader how to depersist the object. This is currently not
+    
+    The mimetype is used for serialized objects, and tells the 
+    ResXResourceReader how to depersist the object. This is currently not 
     extensible. For a given mimetype the value must be set accordingly:
-
-    Note - application/x-microsoft.net.object.binary.base64 is the format
-    that the ResXResourceWriter will generate, however the reader can
+    
+    Note - application/x-microsoft.net.object.binary.base64 is the format 
+    that the ResXResourceWriter will generate, however the reader can 
     read any of the formats listed below.
-
+    
     mimetype: application/x-microsoft.net.object.binary.base64
-    value   : The object must be serialized with
+    value   : The object must be serialized with 
             : System.Runtime.Serialization.Formatters.Binary.BinaryFormatter
             : and then encoded with base64 encoding.
-
+    
     mimetype: application/x-microsoft.net.object.soap.base64
-    value   : The object must be serialized with
+    value   : The object must be serialized with 
             : System.Runtime.Serialization.Formatters.Soap.SoapFormatter
             : and then encoded with base64 encoding.
 
     mimetype: application/x-microsoft.net.object.bytearray.base64
-    value   : The object must be serialized into a byte array
+    value   : The object must be serialized into a byte array 
             : using a System.ComponentModel.TypeConverter
             : and then encoded with base64 encoding.
     -->
@@ -147,6 +147,10 @@
   <data name="ClosePaneCommandKey" xml:space="preserve">
     <value>Close pane</value>
   </data>
+  <data name="CloseTabAtIndexCommandKey" xml:space="preserve">
+    <value>Close tab at index {0}</value>
+    <comment>{0} will be replaced with a number</comment>
+  </data>
   <data name="CloseTabCommandKey" xml:space="preserve">
     <value>Close tab</value>
   </data>
@@ -413,4 +417,4 @@
     <value>Windows Console Host</value>
     <comment>Name describing the usage of the classic windows console as the terminal UI. (`conhost.exe`)</comment>
   </data>
-</root>
+</root>

src/cascadia/TerminalSettingsModel/TerminalSettings.cpp

@@ -260,9 +260,9 @@ namespace winrt::Microsoft::Terminal::Settings::Model::implementation
         _UseAcrylic = profile.UseAcrylic();
         _TintOpacity = profile.AcrylicOpacity();
 
-        _FontFace = profile.FontFace();
-        _FontSize = profile.FontSize();
-        _FontWeight = profile.FontWeight();
+        _FontFace = profile.FontInfo().FontFace();
+        _FontSize = profile.FontInfo().FontSize();
+        _FontWeight = profile.FontInfo().FontWeight();
         _Padding = profile.Padding();
 
         _Commandline = profile.Commandline();

src/cascadia/WinRTUtils/WinRTUtils.vcxproj

@@ -17,6 +17,7 @@
     <ClInclude Include="pch.h" />
     <ClInclude Include="ScopedResourceLoader.h" />
     <ClInclude Include="inc\LibraryResources.h" />
+    <ClInclude Include="inc\ThrottledFunc.h" />
     <ClInclude Include="inc\Utils.h" />
     <ClInclude Include="inc\WtExeUtils.h" />
   </ItemGroup>

src/cascadia/WinRTUtils/WinRTUtils.vcxproj.filters

@@ -12,6 +12,7 @@
     <ClInclude Include="pch.h" />
     <ClInclude Include="ScopedResourceLoader.h" />
     <ClInclude Include="inc\LibraryResources.h" />
+    <ClInclude Include="inc\ThrottledFunc.h" />
     <ClInclude Include="inc\Utils.h" />
     <ClInclude Include="inc\WtExeUtils.h" />
   </ItemGroup>

src/cascadia/WinRTUtils/inc/ThrottledFunc.h

@@ -0,0 +1,141 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT license.
+
+#pragma once
+
+#include "til/throttled_func.h"
+
+// ThrottledFunc is a copy of til::throttled_func,
+// specialized for the use with a WinRT Dispatcher.
+template<bool leading, typename... Args>
+class ThrottledFunc : public std::enable_shared_from_this<ThrottledFunc<leading, Args...>>
+{
+public:
+    using filetime_duration = std::chrono::duration<int64_t, std::ratio<1, 10000000>>;
+    using function = std::function<void(Args...)>;
+
+    // Throttles invocations to the given `func` to not occur more often than `delay`.
+    //
+    // If this is a:
+    // * ThrottledFuncLeading: `func` will be invoked immediately and
+    //   further invocations prevented until `delay` time has passed.
+    // * ThrottledFuncTrailing: On the first invocation a timer of `delay` time will
+    //   be started. After the timer has expired `func` will be invoked just once.
+    //
+    // After `func` was invoked the state is reset and this cycle is repeated again.
+    ThrottledFunc(
+        winrt::Windows::UI::Core::CoreDispatcher dispatcher,
+        filetime_duration delay,
+        function func) :
+        _dispatcher{ std::move(dispatcher) },
+        _func{ std::move(func) },
+        _timer{ _create_timer() }
+    {
+        const auto d = -delay.count();
+        if (d >= 0)
+        {
+            throw std::invalid_argument("non-positive delay specified");
+        }
+
+        memcpy(&_delay, &d, sizeof(d));
+    }
+
+    // ThrottledFunc uses its `this` pointer when creating _timer.
+    // Since the timer cannot be recreated, instances cannot be moved either.
+    ThrottledFunc(const ThrottledFunc&) = delete;
+    ThrottledFunc& operator=(const ThrottledFunc&) = delete;
+    ThrottledFunc(ThrottledFunc&&) = delete;
+    ThrottledFunc& operator=(ThrottledFunc&&) = delete;
+
+    // Throttles the invocation of the function passed to the constructor.
+    // If this is a trailing_throttled_func:
+    //   If you call this function again before the underlying
+    //   timer has expired, the new arguments will be used.
+    template<typename... MakeArgs>
+    void Run(MakeArgs&&... args)
+    {
+        if (!_storage.emplace(std::forward<MakeArgs>(args)...))
+        {
+            _leading_edge();
+        }
+    }
+
+    // Modifies the pending arguments for the next function
+    // invocation, if there is one pending currently.
+    //
+    // `func` will be invoked as func(Args...). Make sure to bind any
+    // arguments in `func` by reference if you'd like to modify them.
+    template<typename F>
+    void ModifyPending(F func)
+    {
+        _storage.modify_pending(func);
+    }
+
+private:
+    static void __stdcall _timer_callback(PTP_CALLBACK_INSTANCE /*instance*/, PVOID context, PTP_TIMER /*timer*/) noexcept
+    {
+        static_cast<ThrottledFunc*>(context)->_trailing_edge();
+    }
+
+    void _leading_edge()
+    {
+        if constexpr (leading)
+        {
+            _dispatcher.RunAsync(winrt::Windows::UI::Core::CoreDispatcherPriority::Normal, [weakSelf = this->weak_from_this()]() {
+                if (auto self{ weakSelf.lock() })
+                {
+                    try
+                    {
+                        self->_func();
+                    }
+                    CATCH_LOG();
+
+                    SetThreadpoolTimerEx(self->_timer.get(), &self->_delay, 0, 0);
+                }
+            });
+        }
+        else
+        {
+            SetThreadpoolTimerEx(_timer.get(), &_delay, 0, 0);
+        }
+    }
+
+    void _trailing_edge()
+    {
+        if constexpr (leading)
+        {
+            _storage.reset();
+        }
+        else
+        {
+            _dispatcher.RunAsync(winrt::Windows::UI::Core::CoreDispatcherPriority::Normal, [weakSelf = this->weak_from_this()]() {
+                if (auto self{ weakSelf.lock() })
+                {
+                    try
+                    {
+                        std::apply(self->_func, self->_storage.take());
+                    }
+                    CATCH_LOG();
+                }
+            });
+        }
+    }
+
+    inline wil::unique_threadpool_timer _create_timer()
+    {
+        wil::unique_threadpool_timer timer{ CreateThreadpoolTimer(&_timer_callback, this, nullptr) };
+        THROW_LAST_ERROR_IF(!timer);
+        return timer;
+    }
+
+    FILETIME _delay;
+    winrt::Windows::UI::Core::CoreDispatcher _dispatcher;
+    function _func;
+
+    wil::unique_threadpool_timer _timer;
+    til::details::throttled_func_storage<Args...> _storage;
+};
+
+template<typename... Args>
+using ThrottledFuncTrailing = ThrottledFunc<false, Args...>;
+using ThrottledFuncLeading = ThrottledFunc<true>;

src/host/ConsoleArguments.cpp

@@ -103,10 +103,7 @@ ConsoleArguments::ConsoleArguments(const std::wstring& commandline,
                                    const HANDLE hStdOut) :
     _commandline(commandline),
     _vtInHandle(hStdIn),
-    _vtOutHandle(hStdOut),
-    _receivedEarlySizeChange{ false },
-    _originalWidth{ -1 },
-    _originalHeight{ -1 }
+    _vtOutHandle(hStdOut)
 {
     _clientCommandline = L"";
     _vtMode = L"";
@@ -144,7 +141,6 @@ ConsoleArguments& ConsoleArguments::operator=(const ConsoleArguments& other)
         _width = other._width;
         _height = other._height;
         _inheritCursor = other._inheritCursor;
-        _receivedEarlySizeChange = other._receivedEarlySizeChange;
         _runAsComServer = other._runAsComServer;
         _forceNoHandoff = other._forceNoHandoff;
     }
@@ -668,33 +664,6 @@ bool ConsoleArguments::IsWin32InputModeEnabled() const
     return _win32InputMode;
 }
 
-// Method Description:
-// - Tell us to use a different size than the one parsed as the size of the
-//      console. This is called by the PtySignalInputThread when it receives a
-//      resize before the first client has connected. Because there's no client,
-//      there's also no buffer yet, so it has nothing to resize.
-//      However, we shouldn't just discard that first resize message. Instead,
-//      store it in here, so we can use the value when the first client does connect.
-// Arguments:
-// - dimensions: the new size in characters of the conpty buffer & viewport.
-// Return Value:
-// - <none>
-void ConsoleArguments::SetExpectedSize(COORD dimensions) noexcept
-{
-    _width = dimensions.X;
-    _height = dimensions.Y;
-    // Stash away the original values we parsed when this is called.
-    // This is to help debugging - if the signal thread DOES change these values,
-    //      we can still recover what was given to us on the commandline.
-    if (!_receivedEarlySizeChange)
-    {
-        _originalWidth = _width;
-        _originalHeight = _height;
-        // Mark that we've changed size from what our commandline values were
-        _receivedEarlySizeChange = true;
-    }
-}
-
 #ifdef UNIT_TESTING
 // Method Description:
 // - This is a test helper method. It can be used to trick us into thinking

src/host/ConsoleArguments.hpp

@@ -56,8 +56,6 @@ public:
     bool IsResizeQuirkEnabled() const;
     bool IsWin32InputModeEnabled() const;
 
-    void SetExpectedSize(COORD dimensions) noexcept;
-
 #ifdef UNIT_TESTING
     void EnableConptyModeForTests();
 #endif
@@ -113,9 +111,6 @@ private:
         _signalHandle(signalHandle),
         _inheritCursor(inheritCursor),
         _resizeQuirk(false),
-        _receivedEarlySizeChange{ false },
-        _originalWidth{ -1 },
-        _originalHeight{ -1 },
         _runAsComServer{ runAsComServer }
     {
     }
@@ -146,10 +141,6 @@ private:
     bool _resizeQuirk{ false };
     bool _win32InputMode{ false };
 
-    bool _receivedEarlySizeChange;
-    short _originalWidth;
-    short _originalHeight;
-
     [[nodiscard]] HRESULT _GetClientCommandline(_Inout_ std::vector<std::wstring>& args,
                                                 const size_t index,
                                                 const bool skipFirst);

src/host/PtySignalInputThread.cpp

@@ -10,14 +10,6 @@
 #include "../interactivity/inc/ServiceLocator.hpp"
 #include "../terminal/adapter/DispatchCommon.hpp"
 
-#define PTY_SIGNAL_RESIZE_WINDOW 8u
-
-struct PTY_SIGNAL_RESIZE
-{
-    unsigned short sx;
-    unsigned short sy;
-};
-
 using namespace Microsoft::Console;
 using namespace Microsoft::Console::Interactivity;
 using namespace Microsoft::Console::VirtualTerminal;
@@ -63,6 +55,8 @@ DWORD WINAPI PtySignalInputThread::StaticThreadProc(_In_ LPVOID lpParameter)
 //      do something with the messages we receive now. Before this is set, there
 //      is no guarantee that a client has attached, so most parts of the console
 //      (in and screen buffers) haven't yet been initialized.
+// - NOTE: Call under LockConsole() to ensure other threads have an opportunity
+//         to set early-work state.
 // Arguments:
 // - <none>
 // Return Value:
@@ -70,6 +64,10 @@ DWORD WINAPI PtySignalInputThread::StaticThreadProc(_In_ LPVOID lpParameter)
 void PtySignalInputThread::ConnectConsole() noexcept
 {
     _consoleConnected = true;
+    if (_earlyResize)
+    {
+        _DoResizeWindow(*_earlyResize);
+    }
 }
 
 // Method Description:
@@ -79,38 +77,30 @@ void PtySignalInputThread::ConnectConsole() noexcept
 // - Otherwise it may cause an application termination and never return.
 [[nodiscard]] HRESULT PtySignalInputThread::_InputThread()
 {
-    unsigned short signalId;
+    PtySignal signalId;
     while (_GetData(&signalId, sizeof(signalId)))
     {
         switch (signalId)
         {
-        case PTY_SIGNAL_RESIZE_WINDOW:
+        case PtySignal::ResizeWindow:
         {
-            PTY_SIGNAL_RESIZE resizeMsg = { 0 };
+            ResizeWindowData resizeMsg = { 0 };
             _GetData(&resizeMsg, sizeof(resizeMsg));
 
             LockConsole();
             auto Unlock = wil::scope_exit([&] { UnlockConsole(); });
+
             // If the client app hasn't yet connected, stash the new size in the launchArgs.
             // We'll later use the value in launchArgs to set up the console buffer
+            // We must be under lock here to ensure that someone else doesn't come in
+            // and set with `ConnectConsole` while we're looking and modifying this.
             if (!_consoleConnected)
             {
-                short sColumns = 0;
-                short sRows = 0;
-                if (SUCCEEDED(UShortToShort(resizeMsg.sx, &sColumns)) &&
-                    SUCCEEDED(UShortToShort(resizeMsg.sy, &sRows)) &&
-                    (sColumns > 0 && sRows > 0))
-                {
-                    ServiceLocator::LocateGlobals().launchArgs.SetExpectedSize({ sColumns, sRows });
-                }
-                break;
+                _earlyResize = resizeMsg;
             }
             else
             {
-                if (DispatchCommon::s_ResizeWindow(*_pConApi, resizeMsg.sx, resizeMsg.sy))
-                {
-                    DispatchCommon::s_SuppressResizeRepaint(*_pConApi);
-                }
+                _DoResizeWindow(resizeMsg);
             }
 
             break;
@@ -124,6 +114,20 @@ void PtySignalInputThread::ConnectConsole() noexcept
     return S_OK;
 }
 
+// Method Description:
+// - Dispatches a resize window message to the rest of the console code
+// Arguments:
+// - data - Packet information containing width/height (size) information
+// Return Value:
+// - <none>
+void PtySignalInputThread::_DoResizeWindow(const ResizeWindowData& data)
+{
+    if (DispatchCommon::s_ResizeWindow(*_pConApi, data.sx, data.sy))
+    {
+        DispatchCommon::s_SuppressResizeRepaint(*_pConApi);
+    }
+}
+
 // Method Description:
 // - Retrieves bytes from the file stream and exits or throws errors should the pipe state
 //   be compromised.

src/host/PtySignalInputThread.hpp

@@ -33,14 +33,27 @@ namespace Microsoft::Console
         void ConnectConsole() noexcept;
 
     private:
+        enum class PtySignal : unsigned short
+        {
+            ResizeWindow = 8
+        };
+
+        struct ResizeWindowData
+        {
+            unsigned short sx;
+            unsigned short sy;
+        };
+
         [[nodiscard]] HRESULT _InputThread();
         bool _GetData(_Out_writes_bytes_(cbBuffer) void* const pBuffer, const DWORD cbBuffer);
+        void _DoResizeWindow(const ResizeWindowData& data);
         void _Shutdown();
 
         wil::unique_hfile _hFile;
         wil::unique_handle _hThread;
         DWORD _dwThreadId;
         bool _consoleConnected;
+        std::optional<ResizeWindowData> _earlyResize;
         std::unique_ptr<Microsoft::Console::VirtualTerminal::ConGetSet> _pConApi;
     };
 }

src/host/outputStream.cpp

@@ -76,8 +76,15 @@ void WriteBuffer::_DefaultStringCase(const std::wstring_view string)
 {
     size_t dwNumBytes = string.size() * sizeof(wchar_t);
 
-    _io.GetActiveOutputBuffer().GetTextBuffer().GetCursor().SetIsOn(true);
+    Cursor& cursor = _io.GetActiveOutputBuffer().GetTextBuffer().GetCursor();
+    if (!cursor.IsOn())
+    {
+        cursor.SetIsOn(true);
+    }
 
+    // Defer the cursor drawing while we are iterating the string, for a better performance.
+    // We can not waste time displaying a cursor event when we know more text is coming right behind it.
+    cursor.StartDeferDrawing();
     _ntstatus = WriteCharsLegacy(_io.GetActiveOutputBuffer(),
                                  string.data(),
                                  string.data(),
@@ -87,6 +94,7 @@ void WriteBuffer::_DefaultStringCase(const std::wstring_view string)
                                  _io.GetActiveOutputBuffer().GetTextBuffer().GetCursor().GetPosition().X,
                                  WC_LIMIT_BACKSPACE | WC_DELAY_EOL_WRAP,
                                  nullptr);
+    cursor.EndDeferDrawing();
 }
 
 ConhostInternalGetSet::ConhostInternalGetSet(_In_ IIoProvider& io) :

src/inc/til/latch.h

@@ -0,0 +1,86 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT license.
+
+#pragma once
+
+#ifdef __cpp_lib_latch
+#include <latch>
+#endif
+
+namespace til
+{
+#ifdef __cpp_lib_latch
+    using latch = std::latch;
+#else
+    class latch
+    {
+    public:
+        [[nodiscard]] static constexpr ptrdiff_t max() noexcept
+        {
+            return std::numeric_limits<ptrdiff_t>::max();
+        }
+
+        constexpr explicit latch(const ptrdiff_t expected) noexcept :
+            counter{ expected }
+        {
+            assert(expected >= 0);
+        }
+
+        latch(const latch&) = delete;
+        latch& operator=(const latch&) = delete;
+
+        void count_down(const ptrdiff_t n = 1) noexcept
+        {
+            assert(n >= 0);
+
+            const auto old = counter.fetch_sub(n, std::memory_order_release);
+            if (old == n)
+            {
+                WakeByAddressAll(&counter);
+                return;
+            }
+
+            assert(old > n);
+        }
+
+        [[nodiscard]] bool try_wait() const noexcept
+        {
+            return counter.load(std::memory_order_acquire) == 0;
+        }
+
+        void wait() const noexcept
+        {
+            while (true)
+            {
+                auto current = counter.load(std::memory_order_acquire);
+                if (current == 0)
+                {
+                    return;
+                }
+
+                assert(current > 0);
+                WaitOnAddress(const_cast<decltype(counter)*>(&counter), &current, sizeof(counter), INFINITE);
+            }
+        }
+
+        void arrive_and_wait(const ptrdiff_t n = 1) noexcept
+        {
+            assert(n >= 0);
+
+            auto old = counter.fetch_sub(n, std::memory_order_acq_rel);
+            if (old == n)
+            {
+                WakeByAddressAll(&counter);
+                return;
+            }
+
+            assert(old > n);
+            WaitOnAddress(&counter, &old, sizeof(counter), INFINITE);
+            wait();
+        }
+
+    private:
+        std::atomic<ptrdiff_t> counter;
+    };
+#endif
+}

src/inc/til/mutex.h

@@ -0,0 +1,108 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT license.
+
+namespace til
+{
+    namespace details
+    {
+        template<typename T, typename Lock>
+        class shared_mutex_guard
+        {
+        public:
+            shared_mutex_guard(T& data, std::shared_mutex& mutex) :
+                _data{ data },
+                _lock{ mutex }
+            {
+            }
+
+            shared_mutex_guard(const shared_mutex_guard&) = delete;
+            shared_mutex_guard& operator=(const shared_mutex_guard&) = delete;
+
+            shared_mutex_guard(shared_mutex_guard&&) = default;
+            shared_mutex_guard& operator=(shared_mutex_guard&&) = default;
+
+            [[nodiscard]] constexpr T* operator->() const
+            {
+                return &_data;
+            }
+
+            [[nodiscard]] constexpr T& operator*() const&
+            {
+                return _data;
+            }
+
+            [[nodiscard]] constexpr T&& operator*() const&&
+            {
+                return std::move(_data);
+            }
+
+        private:
+            // We could reduce this to a single pointer member,
+            // by storing a reference to the til::shared_mutex& class
+            // and accessing its private members as a friend class.
+            // But MSVC doesn't support strict aliasing. Nice!
+            //
+            // For instance if we had:
+            //   struct foo { int a, b; };
+            //   struct bar { foo& f; };
+            //
+            //   void test(bar& b) {
+            //       b.f.a = 123;
+            //       b.f.b = 456;
+            //   }
+            //
+            // This would generate the following suboptimal assembly despite /O2:
+            //   mov rax, QWORD PTR [rcx]
+            //   mov DWORD PTR [rax], 123
+            //
+            //   mov rax, QWORD PTR [rcx]
+            //   mov DWORD PTR [rax+4], 456
+            T& _data;
+            Lock _lock;
+        };
+    } // namespace details
+
+    // shared_mutex is a std::shared_mutex which also contains the data it's protecting.
+    // It only allows access to the underlying data by locking the mutex and thus
+    // ensures you don't forget to do so, unlike with std::mutex/std::shared_mutex.
+    template<typename T>
+    class shared_mutex
+    {
+    public:
+        // An exclusive, read/write reference to a til::shared_mutex's underlying data.
+        // If you drop the guard the mutex is unlocked.
+        using guard = details::shared_mutex_guard<T, std::unique_lock<std::shared_mutex>>;
+
+        // A shared, read-only reference to a til::shared_mutex's underlying data.
+        // If you drop the shared_guard the mutex is unlocked.
+        using shared_guard = details::shared_mutex_guard<const T, std::shared_lock<std::shared_mutex>>;
+
+        shared_mutex() = default;
+
+        template<typename... Args>
+        shared_mutex(Args&&... args) :
+            _data{ std::forward<Args>(args)... }
+        {
+        }
+
+        // Acquire an exclusive, read/write reference to T.
+        // For instance:
+        //   .lock()->foo = bar;
+        [[nodiscard]] guard lock() const noexcept
+        {
+            return { _data, _mutex };
+        }
+
+        // Acquire a shared, read-only reference to T.
+        // For instance:
+        //   bar = .lock_shared()->foo;
+        [[nodiscard]] shared_guard lock_shared() const noexcept
+        {
+            return { _data, _mutex };
+        }
+
+    private:
+        mutable T _data{};
+        mutable std::shared_mutex _mutex;
+    };
+} // namespace til

src/inc/til/string.h

@@ -48,4 +48,26 @@ namespace til // Terminal Implementation Library. Also: "Today I Learned"
     {
         return starts_with<>(str, prefix);
     };
+
+    template<typename T, typename Traits>
+    constexpr bool ends_with(const std::basic_string_view<T, Traits> str, const std::basic_string_view<T, Traits> prefix) noexcept
+    {
+#ifdef __cpp_lib_ends_ends_with
+#error This code can be replaced in C++20, which natively supports .ends_with().
+#endif
+#pragma warning(push)
+#pragma warning(disable : 26481) // Don't use pointer arithmetic. Use span instead (bounds.1).
+        return str.size() >= prefix.size() && Traits::compare(str.data() + (str.size() - prefix.size()), prefix.data(), prefix.size()) == 0;
+#pragma warning(pop)
+    };
+
+    constexpr bool ends_with(const std::string_view str, const std::string_view prefix) noexcept
+    {
+        return ends_with<>(str, prefix);
+    };
+
+    constexpr bool ends_with(const std::wstring_view str, const std::wstring_view prefix) noexcept
+    {
+        return ends_with<>(str, prefix);
+    };
 }

src/inc/til/throttled_func.h

@@ -0,0 +1,206 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT license.
+
+#pragma once
+
+namespace til
+{
+    namespace details
+    {
+        template<typename... Args>
+        class throttled_func_storage
+        {
+        public:
+            template<typename... MakeArgs>
+            bool emplace(MakeArgs&&... args)
+            {
+                std::unique_lock guard{ _lock };
+                const bool hadValue = _pendingRunArgs.has_value();
+                _pendingRunArgs.emplace(std::forward<MakeArgs>(args)...);
+                return hadValue;
+            }
+
+            template<typename F>
+            void modify_pending(F f)
+            {
+                std::unique_lock guard{ _lock };
+                if (_pendingRunArgs)
+                {
+                    std::apply(f, *_pendingRunArgs);
+                }
+            }
+
+            std::tuple<Args...> take()
+            {
+                std::unique_lock guard{ _lock };
+                auto pendingRunArgs = std::move(*_pendingRunArgs);
+                _pendingRunArgs.reset();
+                return pendingRunArgs;
+            }
+
+            explicit operator bool() const
+            {
+                std::shared_lock guard{ _lock };
+                return _pendingRunArgs.has_value();
+            }
+
+        private:
+            // std::mutex uses imperfect Critical Sections on Windows.
+            // --> std::shared_mutex uses SRW locks that are small and fast.
+            mutable std::shared_mutex _lock;
+            std::optional<std::tuple<Args...>> _pendingRunArgs;
+        };
+
+        template<>
+        class throttled_func_storage<>
+        {
+        public:
+            bool emplace()
+            {
+                return _isPending.exchange(true, std::memory_order_relaxed);
+            }
+
+            std::tuple<> take()
+            {
+                reset();
+                return {};
+            }
+
+            void reset()
+            {
+                _isPending.store(false, std::memory_order_relaxed);
+            }
+
+            explicit operator bool() const
+            {
+                return _isPending.load(std::memory_order_relaxed);
+            }
+
+        private:
+            std::atomic<bool> _isPending;
+        };
+    } // namespace details
+
+    template<bool leading, typename... Args>
+    class throttled_func
+    {
+    public:
+        using filetime_duration = std::chrono::duration<int64_t, std::ratio<1, 10000000>>;
+        using function = std::function<void(Args...)>;
+
+        // Throttles invocations to the given `func` to not occur more often than `delay`.
+        //
+        // If this is a:
+        // * throttled_func_leading: `func` will be invoked immediately and
+        //   further invocations prevented until `delay` time has passed.
+        // * throttled_func_trailing: On the first invocation a timer of `delay` time will
+        //   be started. After the timer has expired `func` will be invoked just once.
+        //
+        // After `func` was invoked the state is reset and this cycle is repeated again.
+        throttled_func(filetime_duration delay, function func) :
+            _func{ std::move(func) },
+            _timer{ _createTimer() }
+        {
+            const auto d = -delay.count();
+            if (d >= 0)
+            {
+                throw std::invalid_argument("non-positive delay specified");
+            }
+
+            memcpy(&_delay, &d, sizeof(d));
+        }
+
+        // throttled_func uses its `this` pointer when creating _timer.
+        // Since the timer cannot be recreated, instances cannot be moved either.
+        throttled_func(const throttled_func&) = delete;
+        throttled_func& operator=(const throttled_func&) = delete;
+        throttled_func(throttled_func&&) = delete;
+        throttled_func& operator=(throttled_func&&) = delete;
+
+        // Throttles the invocation of the function passed to the constructor.
+        // If this is a trailing_throttled_func:
+        //   If you call this function again before the underlying
+        //   timer has expired, the new arguments will be used.
+        template<typename... MakeArgs>
+        void operator()(MakeArgs&&... args)
+        {
+            if (!_storage.emplace(std::forward<MakeArgs>(args)...))
+            {
+                _leading_edge();
+            }
+        }
+
+        // Modifies the pending arguments for the next function
+        // invocation, if there is one pending currently.
+        //
+        // `func` will be invoked as func(Args...). Make sure to bind any
+        // arguments in `func` by reference if you'd like to modify them.
+        template<typename F>
+        void modify_pending(F func)
+        {
+            _storage.modify_pending(func);
+        }
+
+        // Makes sure that the currently pending timer is executed
+        // as soon as possible and in that case waits for its completion.
+        // You can use this function in your destructor to ensure that any
+        // pending callback invocation is completed as soon as possible.
+        //
+        // NOTE: Don't call this function if the operator()
+        //       could still be called concurrently.
+        void flush()
+        {
+            WaitForThreadpoolTimerCallbacks(_timer.get(), true);
+            if (_storage)
+            {
+                _trailing_edge();
+            }
+        }
+
+    private:
+        static void __stdcall _timer_callback(PTP_CALLBACK_INSTANCE /*instance*/, PVOID context, PTP_TIMER /*timer*/) noexcept
+        try
+        {
+            static_cast<throttled_func*>(context)->_trailing_edge();
+        }
+        CATCH_LOG()
+
+        void _leading_edge()
+        {
+            if constexpr (leading)
+            {
+                _func();
+            }
+
+            SetThreadpoolTimerEx(_timer.get(), &_delay, 0, 0);
+        }
+
+        void _trailing_edge()
+        {
+            if constexpr (leading)
+            {
+                _storage.reset();
+            }
+            else
+            {
+                std::apply(_func, _storage.take());
+            }
+        }
+
+        inline wil::unique_threadpool_timer _createTimer()
+        {
+            wil::unique_threadpool_timer timer{ CreateThreadpoolTimer(&_timer_callback, this, nullptr) };
+            THROW_LAST_ERROR_IF(!timer);
+            return timer;
+        }
+
+        FILETIME _delay;
+        function _func;
+        wil::unique_threadpool_timer _timer;
+        details::throttled_func_storage<Args...> _storage;
+    };
+
+    template<typename... Args>
+    using throttled_func_trailing = throttled_func<false, Args...>;
+    using throttled_func_leading = throttled_func<true>;
+} // namespace til

src/renderer/dx/CustomTextLayout.cpp

@@ -133,10 +133,21 @@ CATCH_RETURN()
                                                                _In_ IDWriteTextRenderer* renderer,
                                                                FLOAT originX,
                                                                FLOAT originY) noexcept
+try
 {
     const auto drawingContext = static_cast<const DrawingContext*>(clientDrawingContext);
-    _formatInUse = drawingContext->useItalicFont ? _fontRenderData->ItalicTextFormat().Get() : _fontRenderData->DefaultTextFormat().Get();
-    _fontInUse = drawingContext->useItalicFont ? _fontRenderData->ItalicFontFace().Get() : _fontRenderData->DefaultFontFace().Get();
+
+    const DWRITE_FONT_WEIGHT weight = _fontRenderData->DefaultFontWeight();
+    DWRITE_FONT_STYLE style = _fontRenderData->DefaultFontStyle();
+    const DWRITE_FONT_STRETCH stretch = _fontRenderData->DefaultFontStretch();
+
+    if (drawingContext->useItalicFont)
+    {
+        style = DWRITE_FONT_STYLE_ITALIC;
+    }
+
+    _formatInUse = _fontRenderData->TextFormatWithAttribute(weight, style, stretch).Get();
+    _fontInUse = _fontRenderData->FontFaceWithAttribute(weight, style, stretch).Get();
 
     RETURN_IF_FAILED(_AnalyzeTextComplexity());
     RETURN_IF_FAILED(_AnalyzeRuns());
@@ -151,6 +162,7 @@ CATCH_RETURN()
 
     return S_OK;
 }
+CATCH_RETURN()
 
 // Routine Description:
 // - Uses the internal text information and the analyzers/font information from construction

src/renderer/dx/DxFontInfo.cpp

@@ -0,0 +1,405 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT license.
+
+#include "precomp.h"
+
+#include "DxFontInfo.h"
+
+#include "unicode.hpp"
+
+#include <VersionHelpers.h>
+
+static constexpr std::wstring_view FALLBACK_FONT_FACES[] = { L"Consolas", L"Lucida Console", L"Courier New" };
+
+using namespace Microsoft::Console::Render;
+
+DxFontInfo::DxFontInfo() noexcept :
+    _familyName(),
+    _weight(DWRITE_FONT_WEIGHT_NORMAL),
+    _style(DWRITE_FONT_STYLE_NORMAL),
+    _stretch(DWRITE_FONT_STRETCH_NORMAL),
+    _didFallback(false)
+{
+}
+
+DxFontInfo::DxFontInfo(std::wstring_view familyName,
+                       unsigned int weight,
+                       DWRITE_FONT_STYLE style,
+                       DWRITE_FONT_STRETCH stretch) :
+    DxFontInfo(familyName, static_cast<DWRITE_FONT_WEIGHT>(weight), style, stretch)
+{
+}
+
+DxFontInfo::DxFontInfo(std::wstring_view familyName,
+                       DWRITE_FONT_WEIGHT weight,
+                       DWRITE_FONT_STYLE style,
+                       DWRITE_FONT_STRETCH stretch) :
+    _familyName(familyName),
+    _weight(weight),
+    _style(style),
+    _stretch(stretch),
+    _didFallback(false)
+{
+}
+
+bool DxFontInfo::operator==(const DxFontInfo& other) const noexcept
+{
+    return (_familyName == other._familyName &&
+            _weight == other._weight &&
+            _style == other._style &&
+            _stretch == other._stretch &&
+            _didFallback == other._didFallback);
+}
+
+std::wstring_view DxFontInfo::GetFamilyName() const noexcept
+{
+    return _familyName;
+}
+
+void DxFontInfo::SetFamilyName(const std::wstring_view familyName)
+{
+    _familyName = familyName;
+}
+
+DWRITE_FONT_WEIGHT DxFontInfo::GetWeight() const noexcept
+{
+    return _weight;
+}
+
+void DxFontInfo::SetWeight(const DWRITE_FONT_WEIGHT weight) noexcept
+{
+    _weight = weight;
+}
+
+DWRITE_FONT_STYLE DxFontInfo::GetStyle() const noexcept
+{
+    return _style;
+}
+
+void DxFontInfo::SetStyle(const DWRITE_FONT_STYLE style) noexcept
+{
+    _style = style;
+}
+
+DWRITE_FONT_STRETCH DxFontInfo::GetStretch() const noexcept
+{
+    return _stretch;
+}
+
+void DxFontInfo::SetStretch(const DWRITE_FONT_STRETCH stretch) noexcept
+{
+    _stretch = stretch;
+}
+
+bool DxFontInfo::GetFallback() const noexcept
+{
+    return _didFallback;
+}
+
+void DxFontInfo::SetFromEngine(const std::wstring_view familyName,
+                               const DWRITE_FONT_WEIGHT weight,
+                               const DWRITE_FONT_STYLE style,
+                               const DWRITE_FONT_STRETCH stretch)
+{
+    _familyName = familyName;
+    _weight = weight;
+    _style = style;
+    _stretch = stretch;
+}
+
+// Routine Description:
+// - Attempts to locate the font given, but then begins falling back if we cannot find it.
+// - We'll try to fall back to Consolas with the given weight/stretch/style first,
+//   then try Consolas again with normal weight/stretch/style,
+//   and if nothing works, then we'll throw an error.
+// Arguments:
+// - dwriteFactory - The DWrite factory to use
+// - localeName - Locale to search for appropriate fonts
+// Return Value:
+// - Smart pointer holding interface reference for queryable font data.
+[[nodiscard]] Microsoft::WRL::ComPtr<IDWriteFontFace1> DxFontInfo::ResolveFontFaceWithFallback(gsl::not_null<IDWriteFactory1*> dwriteFactory,
+                                                                                               std::wstring& localeName)
+{
+    // First attempt to find exactly what the user asked for.
+    _didFallback = false;
+    Microsoft::WRL::ComPtr<IDWriteFontFace1> face{ nullptr };
+
+    // GH#10211 - wrap this all up in a try/catch. If the nearby fonts are
+    // corrupted, then we don't want to throw out of this top half of this
+    // method. We still want to fall back to a font that's reasonable, below.
+    try
+    {
+        face = _FindFontFace(dwriteFactory, localeName, true);
+
+        if (!face)
+        {
+            // If we missed, try looking a little more by trimming the last word off the requested family name a few times.
+            // Quite often, folks are specifying weights or something in the familyName and it causes failed resolution and
+            // an unexpected error dialog. We theoretically could detect the weight words and convert them, but this
+            // is the quick fix for the majority scenario.
+            // The long/full fix is backlogged to GH#9744
+            // Also this doesn't count as a fallback because we don't want to annoy folks with the warning dialog over
+            // this resolution.
+            while (!face && !_familyName.empty())
+            {
+                const auto lastSpace = _familyName.find_last_of(UNICODE_SPACE);
+
+                // value is unsigned and npos will be greater than size.
+                // if we didn't find anything to trim, leave.
+                if (lastSpace >= _familyName.size())
+                {
+                    break;
+                }
+
+                // trim string down to just before the found space
+                // (space found at 6... trim from 0 for 6 length will give us 0-5 as the new string)
+                _familyName = _familyName.substr(0, lastSpace);
+
+                // Try to find it with the shortened family name
+                face = _FindFontFace(dwriteFactory, localeName, true);
+            }
+        }
+    }
+    CATCH_LOG();
+
+    // Alright, if our quick shot at trimming didn't work either...
+    // move onto looking up a font from our hardcoded list of fonts
+    // that should really always be available.
+    if (!face)
+    {
+        for (const auto fallbackFace : FALLBACK_FONT_FACES)
+        {
+            _familyName = fallbackFace;
+            // With these fonts, don't attempt the nearby lookup. We're looking
+            // for system fonts only. If one of the nearby fonts is causing us
+            // problems (like in GH#10211), then we don't want to go anywhere
+
+            // near it in this part.
+            face = _FindFontFace(dwriteFactory, localeName, false);
+
+            if (face)
+            {
+                _didFallback = true;
+                break;
+            }
+
+            _familyName = fallbackFace;
+            _weight = DWRITE_FONT_WEIGHT_NORMAL;
+            _stretch = DWRITE_FONT_STRETCH_NORMAL;
+            _style = DWRITE_FONT_STYLE_NORMAL;
+            face = _FindFontFace(dwriteFactory, localeName, false);
+
+            if (face)
+            {
+                _didFallback = true;
+                break;
+            }
+        }
+    }
+
+    THROW_HR_IF_NULL(E_FAIL, face);
+
+    return face;
+}
+
+// Routine Description:
+// - Locates a suitable font face from the given information
+// Arguments:
+// - dwriteFactory - The DWrite factory to use
+// - localeName - Locale to search for appropriate fonts
+// Return Value:
+// - Smart pointer holding interface reference for queryable font data.
+[[nodiscard]] Microsoft::WRL::ComPtr<IDWriteFontFace1> DxFontInfo::_FindFontFace(gsl::not_null<IDWriteFactory1*> dwriteFactory, std::wstring& localeName, const bool withNearbyLookup)
+{
+    Microsoft::WRL::ComPtr<IDWriteFontFace1> fontFace;
+
+    Microsoft::WRL::ComPtr<IDWriteFontCollection> fontCollection;
+    THROW_IF_FAILED(dwriteFactory->GetSystemFontCollection(&fontCollection, false));
+
+    UINT32 familyIndex;
+    BOOL familyExists;
+    THROW_IF_FAILED(fontCollection->FindFamilyName(_familyName.data(), &familyIndex, &familyExists));
+
+    // If the system collection missed, try the files sitting next to our binary.
+    if (withNearbyLookup && !familyExists)
+    {
+        auto&& nearbyCollection = _NearbyCollection(dwriteFactory);
+
+        // May be null on OS below Windows 10. If null, just skip the attempt.
+        if (nearbyCollection)
+        {
+            nearbyCollection.As(&fontCollection);
+            THROW_IF_FAILED(fontCollection->FindFamilyName(_familyName.data(), &familyIndex, &familyExists));
+        }
+    }
+
+    if (familyExists)
+    {
+        Microsoft::WRL::ComPtr<IDWriteFontFamily> fontFamily;
+        THROW_IF_FAILED(fontCollection->GetFontFamily(familyIndex, &fontFamily));
+
+        Microsoft::WRL::ComPtr<IDWriteFont> font;
+        THROW_IF_FAILED(fontFamily->GetFirstMatchingFont(GetWeight(), GetStretch(), GetStyle(), &font));
+
+        Microsoft::WRL::ComPtr<IDWriteFontFace> fontFace0;
+        THROW_IF_FAILED(font->CreateFontFace(&fontFace0));
+
+        THROW_IF_FAILED(fontFace0.As(&fontFace));
+
+        // Retrieve metrics in case the font we created was different than what was requested.
+        _weight = font->GetWeight();
+        _stretch = font->GetStretch();
+        _style = font->GetStyle();
+
+        // Dig the family name out at the end to return it.
+        _familyName = _GetFontFamilyName(fontFamily.Get(), localeName);
+    }
+
+    return fontFace;
+}
+
+// Routine Description:
+// - Retrieves the font family name out of the given object in the given locale.
+// - If we can't find a valid name for the given locale, we'll fallback and report it back.
+// Arguments:
+// - fontFamily - DirectWrite font family object
+// - localeName - The locale in which the name should be retrieved.
+//              - If fallback occurred, this is updated to what we retrieved instead.
+// Return Value:
+// - Localized string name of the font family
+[[nodiscard]] std::wstring DxFontInfo::_GetFontFamilyName(gsl::not_null<IDWriteFontFamily*> const fontFamily,
+                                                          std::wstring& localeName)
+{
+    // See: https://docs.microsoft.com/en-us/windows/win32/api/dwrite/nn-dwrite-idwritefontcollection
+    Microsoft::WRL::ComPtr<IDWriteLocalizedStrings> familyNames;
+    THROW_IF_FAILED(fontFamily->GetFamilyNames(&familyNames));
+
+    // First we have to find the right family name for the locale. We're going to bias toward what the caller
+    // requested, but fallback if we need to and reply with the locale we ended up choosing.
+    UINT32 index = 0;
+    BOOL exists = false;
+
+    // This returns S_OK whether or not it finds a locale name. Check exists field instead.
+    // If it returns an error, it's a real problem, not an absence of this locale name.
+    // https://docs.microsoft.com/en-us/windows/win32/api/dwrite/nf-dwrite-idwritelocalizedstrings-findlocalename
+    THROW_IF_FAILED(familyNames->FindLocaleName(localeName.data(), &index, &exists));
+
+    // If we tried and it still doesn't exist, try with the fallback locale.
+    if (!exists)
+    {
+        localeName = L"en-us";
+        THROW_IF_FAILED(familyNames->FindLocaleName(localeName.data(), &index, &exists));
+    }
+
+    // If it still doesn't exist, we're going to try index 0.
+    if (!exists)
+    {
+        index = 0;
+
+        // Get the locale name out so at least the caller knows what locale this name goes with.
+        UINT32 length = 0;
+        THROW_IF_FAILED(familyNames->GetLocaleNameLength(index, &length));
+        localeName.resize(length);
+
+        // https://docs.microsoft.com/en-us/windows/win32/api/dwrite/nf-dwrite-idwritelocalizedstrings-getlocalenamelength
+        // https://docs.microsoft.com/en-us/windows/win32/api/dwrite/nf-dwrite-idwritelocalizedstrings-getlocalename
+        // GetLocaleNameLength does not include space for null terminator, but GetLocaleName needs it so add one.
+        THROW_IF_FAILED(familyNames->GetLocaleName(index, localeName.data(), length + 1));
+    }
+
+    // OK, now that we've decided which family name and the locale that it's in... let's go get it.
+    UINT32 length = 0;
+    THROW_IF_FAILED(familyNames->GetStringLength(index, &length));
+
+    // Make our output buffer and resize it so it is allocated.
+    std::wstring retVal;
+    retVal.resize(length);
+
+    // FINALLY, go fetch the string name.
+    // https://docs.microsoft.com/en-us/windows/win32/api/dwrite/nf-dwrite-idwritelocalizedstrings-getstringlength
+    // https://docs.microsoft.com/en-us/windows/win32/api/dwrite/nf-dwrite-idwritelocalizedstrings-getstring
+    // Once again, GetStringLength is without the null, but GetString needs the null. So add one.
+    THROW_IF_FAILED(familyNames->GetString(index, retVal.data(), length + 1));
+
+    // and return it.
+    return retVal;
+}
+
+// Routine Description:
+// - Creates a DirectWrite font collection of font files that are sitting next to the running
+//   binary (in the same directory as the EXE).
+// Arguments:
+// - dwriteFactory - The DWrite factory to use
+// Return Value:
+// - DirectWrite font collection. May be null if one cannot be created.
+[[nodiscard]] const Microsoft::WRL::ComPtr<IDWriteFontCollection1>& DxFontInfo::_NearbyCollection(gsl::not_null<IDWriteFactory1*> dwriteFactory) const
+{
+    // Magic static so we only attempt to grovel the hard disk once no matter how many instances
+    // of the font collection itself we require.
+    static const auto knownPaths = s_GetNearbyFonts();
+
+    // The convenience interfaces for loading fonts from files
+    // are only available on Windows 10+.
+    // Don't try to look up if below that OS version.
+    static const bool s_isWindows10OrGreater = IsWindows10OrGreater();
+
+    if (s_isWindows10OrGreater && !_nearbyCollection)
+    {
+        // Factory3 has a convenience to get us a font set builder.
+        ::Microsoft::WRL::ComPtr<IDWriteFactory3> factory3;
+        THROW_IF_FAILED(dwriteFactory->QueryInterface<IDWriteFactory3>(&factory3));
+
+        ::Microsoft::WRL::ComPtr<IDWriteFontSetBuilder> fontSetBuilder;
+        THROW_IF_FAILED(factory3->CreateFontSetBuilder(&fontSetBuilder));
+
+        // Builder2 has a convenience to just feed in paths to font files.
+        ::Microsoft::WRL::ComPtr<IDWriteFontSetBuilder2> fontSetBuilder2;
+        THROW_IF_FAILED(fontSetBuilder.As(&fontSetBuilder2));
+
+        for (auto& p : knownPaths)
+        {
+            fontSetBuilder2->AddFontFile(p.c_str());
+        }
+
+        ::Microsoft::WRL::ComPtr<IDWriteFontSet> fontSet;
+        THROW_IF_FAILED(fontSetBuilder2->CreateFontSet(&fontSet));
+
+        THROW_IF_FAILED(factory3->CreateFontCollectionFromFontSet(fontSet.Get(), &_nearbyCollection));
+    }
+
+    return _nearbyCollection;
+}
+
+// Routine Description:
+// - Digs through the directory that the current executable is running within to find
+//   any TTF files sitting next to it.
+// Arguments:
+// - <none>
+// Return Value:
+// - Iterable collection of filesystem paths, one per font file that was found
+[[nodiscard]] std::vector<std::filesystem::path> DxFontInfo::s_GetNearbyFonts()
+{
+    std::vector<std::filesystem::path> paths;
+
+    // Find the directory we're running from then enumerate all the TTF files
+    // sitting next to us.
+    const std::filesystem::path module{ wil::GetModuleFileNameW<std::wstring>(nullptr) };
+    const auto folder{ module.parent_path() };
+
+    for (auto& p : std::filesystem::directory_iterator(folder))
+    {
+        if (p.is_regular_file())
+        {
+            auto extension = p.path().extension().wstring();
+            std::transform(extension.begin(), extension.end(), extension.begin(), std::towlower);
+
+            static constexpr std::wstring_view ttfExtension{ L".ttf" };
+            if (ttfExtension == extension)
+            {
+                paths.push_back(p);
+            }
+        }
+    }
+
+    return paths;
+}

src/renderer/dx/DxFontInfo.h

@@ -0,0 +1,108 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT license.
+
+#pragma once
+
+#include <dwrite.h>
+#include <dwrite_1.h>
+#include <dwrite_2.h>
+#include <dwrite_3.h>
+
+namespace Microsoft::Console::Render
+{
+    class DxFontInfo
+    {
+    public:
+        DxFontInfo() noexcept;
+
+        DxFontInfo(std::wstring_view familyName,
+                   unsigned int weight,
+                   DWRITE_FONT_STYLE style,
+                   DWRITE_FONT_STRETCH stretch);
+
+        DxFontInfo(std::wstring_view familyName,
+                   DWRITE_FONT_WEIGHT weight,
+                   DWRITE_FONT_STYLE style,
+                   DWRITE_FONT_STRETCH stretch);
+
+        bool operator==(const DxFontInfo& other) const noexcept;
+
+        std::wstring_view GetFamilyName() const noexcept;
+        void SetFamilyName(const std::wstring_view familyName);
+
+        DWRITE_FONT_WEIGHT GetWeight() const noexcept;
+        void SetWeight(const DWRITE_FONT_WEIGHT weight) noexcept;
+
+        DWRITE_FONT_STYLE GetStyle() const noexcept;
+        void SetStyle(const DWRITE_FONT_STYLE style) noexcept;
+
+        DWRITE_FONT_STRETCH GetStretch() const noexcept;
+        void SetStretch(const DWRITE_FONT_STRETCH stretch) noexcept;
+
+        bool GetFallback() const noexcept;
+
+        void SetFromEngine(const std::wstring_view familyName,
+                           const DWRITE_FONT_WEIGHT weight,
+                           const DWRITE_FONT_STYLE style,
+                           const DWRITE_FONT_STRETCH stretch);
+
+        [[nodiscard]] ::Microsoft::WRL::ComPtr<IDWriteFontFace1> ResolveFontFaceWithFallback(gsl::not_null<IDWriteFactory1*> dwriteFactory,
+                                                                                             std::wstring& localeName);
+
+    private:
+        [[nodiscard]] ::Microsoft::WRL::ComPtr<IDWriteFontFace1> _FindFontFace(gsl::not_null<IDWriteFactory1*> dwriteFactory,
+                                                                               std::wstring& localeName,
+                                                                               const bool withNearbyLookup);
+
+        [[nodiscard]] std::wstring _GetFontFamilyName(gsl::not_null<IDWriteFontFamily*> const fontFamily,
+                                                      std::wstring& localeName);
+
+        [[nodiscard]] const Microsoft::WRL::ComPtr<IDWriteFontCollection1>& _NearbyCollection(gsl::not_null<IDWriteFactory1*> dwriteFactory) const;
+
+        [[nodiscard]] static std::vector<std::filesystem::path> s_GetNearbyFonts();
+
+        mutable ::Microsoft::WRL::ComPtr<IDWriteFontCollection1> _nearbyCollection;
+
+        // The font name we should be looking for
+        std::wstring _familyName;
+
+        // The weight (bold, light, etc.)
+        DWRITE_FONT_WEIGHT _weight;
+
+        // Normal, italic, etc.
+        DWRITE_FONT_STYLE _style;
+
+        // The stretch of the font is the spacing between each letter
+        DWRITE_FONT_STRETCH _stretch;
+
+        // Indicates whether we couldn't match the user request and had to choose from a hardcoded default list.
+        bool _didFallback;
+    };
+}
+
+namespace std
+{
+    template<>
+    struct hash<Microsoft::Console::Render::DxFontInfo>
+    {
+        size_t operator()(const Microsoft::Console::Render::DxFontInfo& fontInfo) const noexcept
+        {
+            const size_t h1 = std::hash<std::wstring_view>{}(fontInfo.GetFamilyName());
+            const size_t h2 = std::hash<DWRITE_FONT_WEIGHT>{}(fontInfo.GetWeight());
+            const size_t h3 = std::hash<DWRITE_FONT_STYLE>{}(fontInfo.GetStyle());
+            const size_t h4 = std::hash<DWRITE_FONT_STRETCH>{}(fontInfo.GetStretch());
+            const size_t h5 = std::hash<bool>{}(fontInfo.GetFallback());
+
+            static const auto combine = [](std::initializer_list<size_t> list) {
+                size_t seed = 0;
+                for (auto hash : list)
+                {
+                    seed ^= hash + 0x9e3779b9 + (seed << 6) + (seed >> 2);
+                }
+                return seed;
+            };
+
+            return combine({ h1, h2, h3, h4, h5 });
+        }
+    };
+}

src/renderer/dx/DxFontRenderData.cpp

@@ -17,14 +17,22 @@ using namespace Microsoft::Console::Render;
 
 DxFontRenderData::DxFontRenderData(::Microsoft::WRL::ComPtr<IDWriteFactory1> dwriteFactory) noexcept :
     _dwriteFactory(dwriteFactory),
+    _fontSize{},
     _glyphCell{},
-    _lineMetrics({}),
-    _boxDrawingEffect{}
+    _lineMetrics{},
+    _lineSpacing{}
 {
 }
 
-[[nodiscard]] Microsoft::WRL::ComPtr<IDWriteTextAnalyzer1> DxFontRenderData::Analyzer() noexcept
+[[nodiscard]] Microsoft::WRL::ComPtr<IDWriteTextAnalyzer1> DxFontRenderData::Analyzer()
 {
+    if (!_dwriteTextAnalyzer)
+    {
+        Microsoft::WRL::ComPtr<IDWriteTextAnalyzer> analyzer;
+        THROW_IF_FAILED(_dwriteFactory->CreateTextAnalyzer(&analyzer));
+        THROW_IF_FAILED(analyzer.As(&_dwriteTextAnalyzer));
+    }
+
     return _dwriteTextAnalyzer;
 }
 
@@ -40,49 +48,24 @@ DxFontRenderData::DxFontRenderData(::Microsoft::WRL::ComPtr<IDWriteFactory1> dwr
     return _systemFontFallback;
 }
 
-// Routine Description:
-// - Creates a DirectWrite font collection of font files that are sitting next to the running
-//   binary (in the same directory as the EXE).
-// Arguments:
-// - <none>
-// Return Value:
-// - DirectWrite font collection. May be null if one cannot be created.
-[[nodiscard]] const Microsoft::WRL::ComPtr<IDWriteFontCollection1>& DxFontRenderData::NearbyCollection() const
+[[nodiscard]] std::wstring DxFontRenderData::UserLocaleName()
 {
-    // Magic static so we only attempt to grovel the hard disk once no matter how many instances
-    // of the font collection itself we require.
-    static const auto knownPaths = s_GetNearbyFonts();
-
-    // The convenience interfaces for loading fonts from files
-    // are only available on Windows 10+.
-    // Don't try to look up if below that OS version.
-    static const bool s_isWindows10OrGreater = IsWindows10OrGreater();
-
-    if (s_isWindows10OrGreater && !_nearbyCollection)
+    if (_userLocaleName.empty())
     {
-        // Factory3 has a convenience to get us a font set builder.
-        ::Microsoft::WRL::ComPtr<IDWriteFactory3> factory3;
-        THROW_IF_FAILED(_dwriteFactory.As(&factory3));
+        std::array<wchar_t, LOCALE_NAME_MAX_LENGTH> localeName;
 
-        ::Microsoft::WRL::ComPtr<IDWriteFontSetBuilder> fontSetBuilder;
-        THROW_IF_FAILED(factory3->CreateFontSetBuilder(&fontSetBuilder));
-
-        // Builder2 has a convenience to just feed in paths to font files.
-        ::Microsoft::WRL::ComPtr<IDWriteFontSetBuilder2> fontSetBuilder2;
-        THROW_IF_FAILED(fontSetBuilder.As(&fontSetBuilder2));
-
-        for (auto& p : knownPaths)
+        const auto returnCode = GetUserDefaultLocaleName(localeName.data(), gsl::narrow<int>(localeName.size()));
+        if (returnCode)
         {
-            fontSetBuilder2->AddFontFile(p.c_str());
+            _userLocaleName = { localeName.data() };
+        }
+        else
+        {
+            _userLocaleName = { FALLBACK_LOCALE.data(), FALLBACK_LOCALE.size() };
         }
-
-        ::Microsoft::WRL::ComPtr<IDWriteFontSet> fontSet;
-        THROW_IF_FAILED(fontSetBuilder2->CreateFontSet(&fontSet));
-
-        THROW_IF_FAILED(factory3->CreateFontCollectionFromFontSet(fontSet.Get(), &_nearbyCollection));
     }
 
-    return _nearbyCollection;
+    return _userLocaleName;
 }
 
 [[nodiscard]] til::size DxFontRenderData::GlyphCell() noexcept
@@ -95,29 +78,96 @@ DxFontRenderData::DxFontRenderData(::Microsoft::WRL::ComPtr<IDWriteFactory1> dwr
     return _lineMetrics;
 }
 
-[[nodiscard]] Microsoft::WRL::ComPtr<IDWriteTextFormat> DxFontRenderData::DefaultTextFormat() noexcept
+[[nodiscard]] DWRITE_FONT_WEIGHT DxFontRenderData::DefaultFontWeight() noexcept
 {
-    return _dwriteTextFormat;
+    return _defaultFontInfo.GetWeight();
 }
 
-[[nodiscard]] Microsoft::WRL::ComPtr<IDWriteFontFace1> DxFontRenderData::DefaultFontFace() noexcept
+[[nodiscard]] DWRITE_FONT_STYLE DxFontRenderData::DefaultFontStyle() noexcept
 {
-    return _dwriteFontFace;
+    return _defaultFontInfo.GetStyle();
 }
 
-[[nodiscard]] Microsoft::WRL::ComPtr<IBoxDrawingEffect> DxFontRenderData::DefaultBoxDrawingEffect() noexcept
+[[nodiscard]] DWRITE_FONT_STRETCH DxFontRenderData::DefaultFontStretch() noexcept
 {
+    return _defaultFontInfo.GetStretch();
+}
+
+[[nodiscard]] Microsoft::WRL::ComPtr<IDWriteTextFormat> DxFontRenderData::DefaultTextFormat()
+{
+    return TextFormatWithAttribute(_defaultFontInfo.GetWeight(), _defaultFontInfo.GetStyle(), _defaultFontInfo.GetStretch());
+}
+
+[[nodiscard]] Microsoft::WRL::ComPtr<IDWriteFontFace1> DxFontRenderData::DefaultFontFace()
+{
+    return FontFaceWithAttribute(_defaultFontInfo.GetWeight(), _defaultFontInfo.GetStyle(), _defaultFontInfo.GetStretch());
+}
+
+[[nodiscard]] Microsoft::WRL::ComPtr<IBoxDrawingEffect> DxFontRenderData::DefaultBoxDrawingEffect()
+{
+    if (!_boxDrawingEffect)
+    {
+        // Calculate and cache the box effect for the base font. Scale is 1.0f because the base font is exactly the scale we want already.
+        THROW_IF_FAILED(s_CalculateBoxEffect(DefaultTextFormat().Get(), _glyphCell.width(), DefaultFontFace().Get(), 1.0f, &_boxDrawingEffect));
+    }
+
     return _boxDrawingEffect;
 }
 
-[[nodiscard]] Microsoft::WRL::ComPtr<IDWriteTextFormat> DxFontRenderData::ItalicTextFormat() noexcept
+[[nodiscard]] Microsoft::WRL::ComPtr<IDWriteTextFormat> DxFontRenderData::TextFormatWithAttribute(DWRITE_FONT_WEIGHT weight,
+                                                                                                  DWRITE_FONT_STYLE style,
+                                                                                                  DWRITE_FONT_STRETCH stretch)
 {
-    return _dwriteTextFormatItalic;
+    DxFontInfo fontInfo = _defaultFontInfo;
+    fontInfo.SetWeight(weight);
+    fontInfo.SetStyle(style);
+    fontInfo.SetStretch(stretch);
+
+    const auto textFormatIt = _textFormatMap.find(fontInfo);
+    if (textFormatIt == _textFormatMap.end())
+    {
+        // Create the font with the fractional pixel height size.
+        // It should have an integer pixel width by our math.
+        // Then below, apply the line spacing to the format to position the floating point pixel height characters
+        // into a cell that has an integer pixel height leaving some padding above/below as necessary to round them out.
+        std::wstring localeName = UserLocaleName();
+        Microsoft::WRL::ComPtr<IDWriteTextFormat> textFormat;
+        THROW_IF_FAILED(_BuildTextFormat(fontInfo, localeName).As(&textFormat));
+        THROW_IF_FAILED(textFormat->SetLineSpacing(_lineSpacing.method, _lineSpacing.height, _lineSpacing.baseline));
+        THROW_IF_FAILED(textFormat->SetParagraphAlignment(DWRITE_PARAGRAPH_ALIGNMENT_NEAR));
+        THROW_IF_FAILED(textFormat->SetWordWrapping(DWRITE_WORD_WRAPPING_NO_WRAP));
+
+        _textFormatMap.insert({ fontInfo, textFormat });
+        return textFormat;
+    }
+    else
+    {
+        return (*textFormatIt).second;
+    }
 }
 
-[[nodiscard]] Microsoft::WRL::ComPtr<IDWriteFontFace1> DxFontRenderData::ItalicFontFace() noexcept
+[[nodiscard]] Microsoft::WRL::ComPtr<IDWriteFontFace1> DxFontRenderData::FontFaceWithAttribute(DWRITE_FONT_WEIGHT weight,
+                                                                                               DWRITE_FONT_STYLE style,
+                                                                                               DWRITE_FONT_STRETCH stretch)
 {
-    return _dwriteFontFaceItalic;
+    DxFontInfo fontInfo = _defaultFontInfo;
+    fontInfo.SetWeight(weight);
+    fontInfo.SetStyle(style);
+    fontInfo.SetStretch(stretch);
+
+    const auto fontFaceIt = _fontFaceMap.find(fontInfo);
+    if (fontFaceIt == _fontFaceMap.end())
+    {
+        std::wstring fontLocaleName = UserLocaleName();
+        Microsoft::WRL::ComPtr<IDWriteFontFace1> fontFace = fontInfo.ResolveFontFaceWithFallback(_dwriteFactory.Get(), fontLocaleName);
+
+        _fontFaceMap.insert({ fontInfo, fontFace });
+        return fontFace;
+    }
+    else
+    {
+        return (*fontFaceIt).second;
+    }
 }
 
 // Routine Description:
@@ -133,247 +183,17 @@ DxFontRenderData::DxFontRenderData(::Microsoft::WRL::ComPtr<IDWriteFactory1> dwr
     try
     {
         _userLocaleName.clear();
+        _textFormatMap.clear();
+        _fontFaceMap.clear();
+        _boxDrawingEffect.Reset();
 
-        std::wstring fontName(desired.GetFaceName());
-        DWRITE_FONT_WEIGHT weight = static_cast<DWRITE_FONT_WEIGHT>(desired.GetWeight());
-        DWRITE_FONT_STYLE style = DWRITE_FONT_STYLE_NORMAL;
-        DWRITE_FONT_STRETCH stretch = DWRITE_FONT_STRETCH_NORMAL;
-        std::wstring localeName = _GetUserLocaleName();
+        // Initialize the default font info and build everything from here.
+        _defaultFontInfo = DxFontInfo(desired.GetFaceName(),
+                                      desired.GetWeight(),
+                                      DWRITE_FONT_STYLE_NORMAL,
+                                      DWRITE_FONT_STRETCH_NORMAL);
 
-        // _ResolveFontFaceWithFallback overrides the last argument with the locale name of the font,
-        // but we should use the system's locale to render the text.
-        std::wstring fontLocaleName = localeName;
-
-        bool didFallback = false;
-        const auto face = _ResolveFontFaceWithFallback(fontName, weight, stretch, style, fontLocaleName, didFallback);
-
-        DWRITE_FONT_METRICS1 fontMetrics;
-        face->GetMetrics(&fontMetrics);
-
-        const UINT32 spaceCodePoint = L'M';
-        UINT16 spaceGlyphIndex;
-        THROW_IF_FAILED(face->GetGlyphIndicesW(&spaceCodePoint, 1, &spaceGlyphIndex));
-
-        INT32 advanceInDesignUnits;
-        THROW_IF_FAILED(face->GetDesignGlyphAdvances(1, &spaceGlyphIndex, &advanceInDesignUnits));
-
-        DWRITE_GLYPH_METRICS spaceMetrics = { 0 };
-        THROW_IF_FAILED(face->GetDesignGlyphMetrics(&spaceGlyphIndex, 1, &spaceMetrics));
-
-        // The math here is actually:
-        // Requested Size in Points * DPI scaling factor * Points to Pixels scaling factor.
-        // - DPI = dots per inch
-        // - PPI = points per inch or "points" as usually seen when choosing a font size
-        // - The DPI scaling factor is the current monitor DPI divided by 96, the default DPI.
-        // - The Points to Pixels factor is based on the typography definition of 72 points per inch.
-        //    As such, converting requires taking the 96 pixel per inch default and dividing by the 72 points per inch
-        //    to get a factor of 1 and 1/3.
-        // This turns into something like:
-        // - 12 ppi font * (96 dpi / 96 dpi) * (96 dpi / 72 points per inch) = 16 pixels tall font for 100% display (96 dpi is 100%)
-        // - 12 ppi font * (144 dpi / 96 dpi) * (96 dpi / 72 points per inch) = 24 pixels tall font for 150% display (144 dpi is 150%)
-        // - 12 ppi font * (192 dpi / 96 dpi) * (96 dpi / 72 points per inch) = 32 pixels tall font for 200% display (192 dpi is 200%)
-        float heightDesired = static_cast<float>(desired.GetEngineSize().Y) * static_cast<float>(USER_DEFAULT_SCREEN_DPI) / POINTS_PER_INCH;
-
-        // The advance is the number of pixels left-to-right (X dimension) for the given font.
-        // We're finding a proportional factor here with the design units in "ems", not an actual pixel measurement.
-
-        // Now we play trickery with the font size. Scale by the DPI to get the height we expect.
-        heightDesired *= (static_cast<float>(dpi) / static_cast<float>(USER_DEFAULT_SCREEN_DPI));
-
-        const float widthAdvance = static_cast<float>(advanceInDesignUnits) / fontMetrics.designUnitsPerEm;
-
-        // Use the real pixel height desired by the "em" factor for the width to get the number of pixels
-        // we will need per character in width. This will almost certainly result in fractional X-dimension pixels.
-        const float widthApprox = heightDesired * widthAdvance;
-
-        // Since we can't deal with columns of the presentation grid being fractional pixels in width, round to the nearest whole pixel.
-        const float widthExact = round(widthApprox);
-
-        // Now reverse the "em" factor from above to turn the exact pixel width into a (probably) fractional
-        // height in pixels of each character. It's easier for us to pad out height and align vertically
-        // than it is horizontally.
-        const auto fontSize = widthExact / widthAdvance;
-
-        // Now figure out the basic properties of the character height which include ascent and descent
-        // for this specific font size.
-        const float ascent = (fontSize * fontMetrics.ascent) / fontMetrics.designUnitsPerEm;
-        const float descent = (fontSize * fontMetrics.descent) / fontMetrics.designUnitsPerEm;
-
-        // Get the gap.
-        const float gap = (fontSize * fontMetrics.lineGap) / fontMetrics.designUnitsPerEm;
-        const float halfGap = gap / 2;
-
-        // We're going to build a line spacing object here to track all of this data in our format.
-        DWRITE_LINE_SPACING lineSpacing = {};
-        lineSpacing.method = DWRITE_LINE_SPACING_METHOD_UNIFORM;
-
-        // We need to make sure the baseline falls on a round pixel (not a fractional pixel).
-        // If the baseline is fractional, the text appears blurry, especially at small scales.
-        // Since we also need to make sure the bounding box as a whole is round pixels
-        // (because the entire console system maths in full cell units),
-        // we're just going to ceiling up the ascent and descent to make a full pixel amount
-        // and set the baseline to the full round pixel ascent value.
-        //
-        // For reference, for the letters "ag":
-        // ...
-        //          gggggg      bottom of previous line
-        //
-        // -----------------    <===========================================|
-        //                         | topSideBearing       |  1/2 lineGap    |
-        // aaaaaa   ggggggg     <-------------------------|-------------|   |
-        //      a   g    g                                |             |   |
-        //  aaaaa   ggggg                                 |<-ascent     |   |
-        // a    a   g                                     |             |   |---- lineHeight
-        // aaaaa a  gggggg      <----baseline, verticalOriginY----------|---|
-        //          g     g                               |<-descent    |   |
-        //          gggggg      <-------------------------|-------------|   |
-        //                         | bottomSideBearing    | 1/2 lineGap     |
-        // -----------------    <===========================================|
-        //
-        // aaaaaa   ggggggg     top of next line
-        // ...
-        //
-        // Also note...
-        // We're going to add half the line gap to the ascent and half the line gap to the descent
-        // to ensure that the spacing is balanced vertically.
-        // Generally speaking, the line gap is added to the ascent by DirectWrite itself for
-        // horizontally drawn text which can place the baseline and glyphs "lower" in the drawing
-        // box than would be desired for proper alignment of things like line and box characters
-        // which will try to sit centered in the area and touch perfectly with their neighbors.
-
-        const auto fullPixelAscent = ceil(ascent + halfGap);
-        const auto fullPixelDescent = ceil(descent + halfGap);
-        lineSpacing.height = fullPixelAscent + fullPixelDescent;
-        lineSpacing.baseline = fullPixelAscent;
-
-        // According to MSDN (https://docs.microsoft.com/en-us/windows/win32/api/dwrite_3/ne-dwrite_3-dwrite_font_line_gap_usage)
-        // Setting "ENABLED" means we've included the line gapping in the spacing numbers given.
-        lineSpacing.fontLineGapUsage = DWRITE_FONT_LINE_GAP_USAGE_ENABLED;
-
-        // Create the font with the fractional pixel height size.
-        // It should have an integer pixel width by our math above.
-        // Then below, apply the line spacing to the format to position the floating point pixel height characters
-        // into a cell that has an integer pixel height leaving some padding above/below as necessary to round them out.
-        Microsoft::WRL::ComPtr<IDWriteTextFormat> format;
-        THROW_IF_FAILED(_dwriteFactory->CreateTextFormat(fontName.data(),
-                                                         nullptr,
-                                                         weight,
-                                                         style,
-                                                         stretch,
-                                                         fontSize,
-                                                         localeName.data(),
-                                                         &format));
-
-        THROW_IF_FAILED(format.As(&_dwriteTextFormat));
-
-        // We also need to create an italic variant of the font face and text
-        // format, based on the same parameters, but using an italic style.
-        std::wstring fontNameItalic = fontName;
-        DWRITE_FONT_WEIGHT weightItalic = weight;
-        DWRITE_FONT_STYLE styleItalic = DWRITE_FONT_STYLE_ITALIC;
-        DWRITE_FONT_STRETCH stretchItalic = stretch;
-        bool didItalicFallback = false;
-
-        const auto faceItalic = _ResolveFontFaceWithFallback(fontNameItalic, weightItalic, stretchItalic, styleItalic, fontLocaleName, didItalicFallback);
-
-        Microsoft::WRL::ComPtr<IDWriteTextFormat> formatItalic;
-        THROW_IF_FAILED(_dwriteFactory->CreateTextFormat(fontNameItalic.data(),
-                                                         nullptr,
-                                                         weightItalic,
-                                                         styleItalic,
-                                                         stretchItalic,
-                                                         fontSize,
-                                                         localeName.data(),
-                                                         &formatItalic));
-
-        THROW_IF_FAILED(formatItalic.As(&_dwriteTextFormatItalic));
-
-        Microsoft::WRL::ComPtr<IDWriteTextAnalyzer> analyzer;
-        THROW_IF_FAILED(_dwriteFactory->CreateTextAnalyzer(&analyzer));
-        THROW_IF_FAILED(analyzer.As(&_dwriteTextAnalyzer));
-
-        _dwriteFontFace = face;
-        _dwriteFontFaceItalic = faceItalic;
-
-        THROW_IF_FAILED(_dwriteTextFormat->SetLineSpacing(lineSpacing.method, lineSpacing.height, lineSpacing.baseline));
-        THROW_IF_FAILED(_dwriteTextFormat->SetParagraphAlignment(DWRITE_PARAGRAPH_ALIGNMENT_NEAR));
-        THROW_IF_FAILED(_dwriteTextFormat->SetWordWrapping(DWRITE_WORD_WRAPPING_NO_WRAP));
-
-        // The scaled size needs to represent the pixel box that each character will fit within for the purposes
-        // of hit testing math and other such multiplication/division.
-        COORD coordSize = { 0 };
-        coordSize.X = gsl::narrow<SHORT>(widthExact);
-        coordSize.Y = gsl::narrow_cast<SHORT>(lineSpacing.height);
-
-        // Unscaled is for the purposes of re-communicating this font back to the renderer again later.
-        // As such, we need to give the same original size parameter back here without padding
-        // or rounding or scaling manipulation.
-        const COORD unscaled = desired.GetEngineSize();
-
-        const COORD scaled = coordSize;
-
-        actual.SetFromEngine(fontName,
-                             desired.GetFamily(),
-                             _dwriteTextFormat->GetFontWeight(),
-                             false,
-                             scaled,
-                             unscaled);
-        actual.SetFallback(didFallback);
-
-        LineMetrics lineMetrics;
-        // There is no font metric for the grid line width, so we use a small
-        // multiple of the font size, which typically rounds to a pixel.
-        lineMetrics.gridlineWidth = std::round(fontSize * 0.025f);
-
-        // All other line metrics are in design units, so to get a pixel value,
-        // we scale by the font size divided by the design-units-per-em.
-        const auto scale = fontSize / fontMetrics.designUnitsPerEm;
-        lineMetrics.underlineOffset = std::round(fontMetrics.underlinePosition * scale);
-        lineMetrics.underlineWidth = std::round(fontMetrics.underlineThickness * scale);
-        lineMetrics.strikethroughOffset = std::round(fontMetrics.strikethroughPosition * scale);
-        lineMetrics.strikethroughWidth = std::round(fontMetrics.strikethroughThickness * scale);
-
-        // We always want the lines to be visible, so if a stroke width ends up
-        // at zero after rounding, we need to make it at least 1 pixel.
-        lineMetrics.gridlineWidth = std::max(lineMetrics.gridlineWidth, 1.0f);
-        lineMetrics.underlineWidth = std::max(lineMetrics.underlineWidth, 1.0f);
-        lineMetrics.strikethroughWidth = std::max(lineMetrics.strikethroughWidth, 1.0f);
-
-        // Offsets are relative to the base line of the font, so we subtract
-        // from the ascent to get an offset relative to the top of the cell.
-        lineMetrics.underlineOffset = fullPixelAscent - lineMetrics.underlineOffset;
-        lineMetrics.strikethroughOffset = fullPixelAscent - lineMetrics.strikethroughOffset;
-
-        // For double underlines we need a second offset, just below the first,
-        // but with a bit of a gap (about double the grid line width).
-        lineMetrics.underlineOffset2 = lineMetrics.underlineOffset +
-                                       lineMetrics.underlineWidth +
-                                       std::round(fontSize * 0.05f);
-
-        // However, we don't want the underline to extend past the bottom of the
-        // cell, so we clamp the offset to fit just inside.
-        const auto maxUnderlineOffset = lineSpacing.height - lineMetrics.underlineWidth;
-        lineMetrics.underlineOffset2 = std::min(lineMetrics.underlineOffset2, maxUnderlineOffset);
-
-        // But if the resulting gap isn't big enough even to register as a thicker
-        // line, it's better to place the second line slightly above the first.
-        if (lineMetrics.underlineOffset2 < lineMetrics.underlineOffset + lineMetrics.gridlineWidth)
-        {
-            lineMetrics.underlineOffset2 = lineMetrics.underlineOffset - lineMetrics.gridlineWidth;
-        }
-
-        // We also add half the stroke width to the offsets, since the line
-        // coordinates designate the center of the line.
-        lineMetrics.underlineOffset += lineMetrics.underlineWidth / 2.0f;
-        lineMetrics.underlineOffset2 += lineMetrics.underlineWidth / 2.0f;
-        lineMetrics.strikethroughOffset += lineMetrics.strikethroughWidth / 2.0f;
-
-        _lineMetrics = lineMetrics;
-
-        _glyphCell = actual.GetSize();
-
-        // Calculate and cache the box effect for the base font. Scale is 1.0f because the base font is exactly the scale we want already.
-        RETURN_IF_FAILED(s_CalculateBoxEffect(DefaultTextFormat().Get(), _glyphCell.width(), DefaultFontFace().Get(), 1.0f, &_boxDrawingEffect));
+        _BuildFontRenderData(desired, actual, dpi);
     }
     CATCH_RETURN();
 
@@ -622,288 +442,212 @@ try
 CATCH_RETURN()
 
 // Routine Description:
-// - Attempts to locate the font given, but then begins falling back if we cannot find it.
-// - We'll try to fall back to Consolas with the given weight/stretch/style first,
-//   then try Consolas again with normal weight/stretch/style,
-//   and if nothing works, then we'll throw an error.
+// - Build the needed data for rendering according to the font used
 // Arguments:
-// - familyName - The font name we should be looking for
-// - weight - The weight (bold, light, etc.)
-// - stretch - The stretch of the font is the spacing between each letter
-// - style - Normal, italic, etc.
-// - localeName - Locale to search for appropriate fonts
-// - didFallback - Indicates whether we couldn't match the user request and had to choose from a hardcoded default list.
+// - desired - Information specifying the font that is requested
+// - actual - Filled with the nearest font actually chosen for drawing
+// - dpi - The DPI of the screen
 // Return Value:
-// - Smart pointer holding interface reference for queryable font data.
-[[nodiscard]] Microsoft::WRL::ComPtr<IDWriteFontFace1> DxFontRenderData::_ResolveFontFaceWithFallback(std::wstring& familyName,
-                                                                                                      DWRITE_FONT_WEIGHT& weight,
-                                                                                                      DWRITE_FONT_STRETCH& stretch,
-                                                                                                      DWRITE_FONT_STYLE& style,
-                                                                                                      std::wstring& localeName,
-                                                                                                      bool& didFallback) const
+// - None
+void DxFontRenderData::_BuildFontRenderData(const FontInfoDesired& desired, FontInfo& actual, const int dpi)
 {
-    // First attempt to find exactly what the user asked for.
-    didFallback = false;
-    Microsoft::WRL::ComPtr<IDWriteFontFace1> face{ nullptr };
+    std::wstring fontLocaleName = UserLocaleName();
+    // This is the first attempt to resolve font face after `UpdateFont`.
+    // Note that the following line may cause property changes _inside_ `_defaultFontInfo` because the desired font may not exist.
+    // See the implementation of `ResolveFontFaceWithFallback` for details.
+    const Microsoft::WRL::ComPtr<IDWriteFontFace1> face = _defaultFontInfo.ResolveFontFaceWithFallback(_dwriteFactory.Get(), fontLocaleName);
 
-    // GH#10211 - wrap this all up in a try/catch. If the nearby fonts are
-    // corrupted, then we don't want to throw out of this top half of this
-    // method. We still want to fall back to a font that's reasonable, below.
-    try
+    DWRITE_FONT_METRICS1 fontMetrics;
+    face->GetMetrics(&fontMetrics);
+
+    const UINT32 spaceCodePoint = L'M';
+    UINT16 spaceGlyphIndex;
+    THROW_IF_FAILED(face->GetGlyphIndicesW(&spaceCodePoint, 1, &spaceGlyphIndex));
+
+    INT32 advanceInDesignUnits;
+    THROW_IF_FAILED(face->GetDesignGlyphAdvances(1, &spaceGlyphIndex, &advanceInDesignUnits));
+
+    DWRITE_GLYPH_METRICS spaceMetrics = { 0 };
+    THROW_IF_FAILED(face->GetDesignGlyphMetrics(&spaceGlyphIndex, 1, &spaceMetrics));
+
+    // The math here is actually:
+    // Requested Size in Points * DPI scaling factor * Points to Pixels scaling factor.
+    // - DPI = dots per inch
+    // - PPI = points per inch or "points" as usually seen when choosing a font size
+    // - The DPI scaling factor is the current monitor DPI divided by 96, the default DPI.
+    // - The Points to Pixels factor is based on the typography definition of 72 points per inch.
+    //    As such, converting requires taking the 96 pixel per inch default and dividing by the 72 points per inch
+    //    to get a factor of 1 and 1/3.
+    // This turns into something like:
+    // - 12 ppi font * (96 dpi / 96 dpi) * (96 dpi / 72 points per inch) = 16 pixels tall font for 100% display (96 dpi is 100%)
+    // - 12 ppi font * (144 dpi / 96 dpi) * (96 dpi / 72 points per inch) = 24 pixels tall font for 150% display (144 dpi is 150%)
+    // - 12 ppi font * (192 dpi / 96 dpi) * (96 dpi / 72 points per inch) = 32 pixels tall font for 200% display (192 dpi is 200%)
+    float heightDesired = static_cast<float>(desired.GetEngineSize().Y) * static_cast<float>(USER_DEFAULT_SCREEN_DPI) / POINTS_PER_INCH;
+
+    // The advance is the number of pixels left-to-right (X dimension) for the given font.
+    // We're finding a proportional factor here with the design units in "ems", not an actual pixel measurement.
+
+    // Now we play trickery with the font size. Scale by the DPI to get the height we expect.
+    heightDesired *= (static_cast<float>(dpi) / static_cast<float>(USER_DEFAULT_SCREEN_DPI));
+
+    const float widthAdvance = static_cast<float>(advanceInDesignUnits) / fontMetrics.designUnitsPerEm;
+
+    // Use the real pixel height desired by the "em" factor for the width to get the number of pixels
+    // we will need per character in width. This will almost certainly result in fractional X-dimension pixels.
+    const float widthApprox = heightDesired * widthAdvance;
+
+    // Since we can't deal with columns of the presentation grid being fractional pixels in width, round to the nearest whole pixel.
+    const float widthExact = round(widthApprox);
+
+    // Now reverse the "em" factor from above to turn the exact pixel width into a (probably) fractional
+    // height in pixels of each character. It's easier for us to pad out height and align vertically
+    // than it is horizontally.
+    const auto fontSize = widthExact / widthAdvance;
+    _fontSize = fontSize;
+
+    // Now figure out the basic properties of the character height which include ascent and descent
+    // for this specific font size.
+    const float ascent = (fontSize * fontMetrics.ascent) / fontMetrics.designUnitsPerEm;
+    const float descent = (fontSize * fontMetrics.descent) / fontMetrics.designUnitsPerEm;
+
+    // Get the gap.
+    const float gap = (fontSize * fontMetrics.lineGap) / fontMetrics.designUnitsPerEm;
+    const float halfGap = gap / 2;
+
+    // We're going to build a line spacing object here to track all of this data in our format.
+    DWRITE_LINE_SPACING lineSpacing = {};
+    lineSpacing.method = DWRITE_LINE_SPACING_METHOD_UNIFORM;
+
+    // We need to make sure the baseline falls on a round pixel (not a fractional pixel).
+    // If the baseline is fractional, the text appears blurry, especially at small scales.
+    // Since we also need to make sure the bounding box as a whole is round pixels
+    // (because the entire console system maths in full cell units),
+    // we're just going to ceiling up the ascent and descent to make a full pixel amount
+    // and set the baseline to the full round pixel ascent value.
+    //
+    // For reference, for the letters "ag":
+    // ...
+    //          gggggg      bottom of previous line
+    //
+    // -----------------    <===========================================|
+    //                         | topSideBearing       |  1/2 lineGap    |
+    // aaaaaa   ggggggg     <-------------------------|-------------|   |
+    //      a   g    g                                |             |   |
+    //  aaaaa   ggggg                                 |<-ascent     |   |
+    // a    a   g                                     |             |   |---- lineHeight
+    // aaaaa a  gggggg      <----baseline, verticalOriginY----------|---|
+    //          g     g                               |<-descent    |   |
+    //          gggggg      <-------------------------|-------------|   |
+    //                         | bottomSideBearing    | 1/2 lineGap     |
+    // -----------------    <===========================================|
+    //
+    // aaaaaa   ggggggg     top of next line
+    // ...
+    //
+    // Also note...
+    // We're going to add half the line gap to the ascent and half the line gap to the descent
+    // to ensure that the spacing is balanced vertically.
+    // Generally speaking, the line gap is added to the ascent by DirectWrite itself for
+    // horizontally drawn text which can place the baseline and glyphs "lower" in the drawing
+    // box than would be desired for proper alignment of things like line and box characters
+    // which will try to sit centered in the area and touch perfectly with their neighbors.
+
+    const auto fullPixelAscent = ceil(ascent + halfGap);
+    const auto fullPixelDescent = ceil(descent + halfGap);
+    lineSpacing.height = fullPixelAscent + fullPixelDescent;
+    lineSpacing.baseline = fullPixelAscent;
+
+    // According to MSDN (https://docs.microsoft.com/en-us/windows/win32/api/dwrite_3/ne-dwrite_3-dwrite_font_line_gap_usage)
+    // Setting "ENABLED" means we've included the line gapping in the spacing numbers given.
+    lineSpacing.fontLineGapUsage = DWRITE_FONT_LINE_GAP_USAGE_ENABLED;
+
+    _lineSpacing = lineSpacing;
+
+    // The scaled size needs to represent the pixel box that each character will fit within for the purposes
+    // of hit testing math and other such multiplication/division.
+    COORD coordSize = { 0 };
+    coordSize.X = gsl::narrow<SHORT>(widthExact);
+    coordSize.Y = gsl::narrow_cast<SHORT>(lineSpacing.height);
+
+    // Unscaled is for the purposes of re-communicating this font back to the renderer again later.
+    // As such, we need to give the same original size parameter back here without padding
+    // or rounding or scaling manipulation.
+    const COORD unscaled = desired.GetEngineSize();
+
+    const COORD scaled = coordSize;
+
+    actual.SetFromEngine(_defaultFontInfo.GetFamilyName(),
+                         desired.GetFamily(),
+                         DefaultTextFormat()->GetFontWeight(),
+                         false,
+                         scaled,
+                         unscaled);
+
+    actual.SetFallback(_defaultFontInfo.GetFallback());
+
+    LineMetrics lineMetrics;
+    // There is no font metric for the grid line width, so we use a small
+    // multiple of the font size, which typically rounds to a pixel.
+    lineMetrics.gridlineWidth = std::round(fontSize * 0.025f);
+
+    // All other line metrics are in design units, so to get a pixel value,
+    // we scale by the font size divided by the design-units-per-em.
+    const auto scale = fontSize / fontMetrics.designUnitsPerEm;
+    lineMetrics.underlineOffset = std::round(fontMetrics.underlinePosition * scale);
+    lineMetrics.underlineWidth = std::round(fontMetrics.underlineThickness * scale);
+    lineMetrics.strikethroughOffset = std::round(fontMetrics.strikethroughPosition * scale);
+    lineMetrics.strikethroughWidth = std::round(fontMetrics.strikethroughThickness * scale);
+
+    // We always want the lines to be visible, so if a stroke width ends up
+    // at zero after rounding, we need to make it at least 1 pixel.
+    lineMetrics.gridlineWidth = std::max(lineMetrics.gridlineWidth, 1.0f);
+    lineMetrics.underlineWidth = std::max(lineMetrics.underlineWidth, 1.0f);
+    lineMetrics.strikethroughWidth = std::max(lineMetrics.strikethroughWidth, 1.0f);
+
+    // Offsets are relative to the base line of the font, so we subtract
+    // from the ascent to get an offset relative to the top of the cell.
+    lineMetrics.underlineOffset = fullPixelAscent - lineMetrics.underlineOffset;
+    lineMetrics.strikethroughOffset = fullPixelAscent - lineMetrics.strikethroughOffset;
+
+    // For double underlines we need a second offset, just below the first,
+    // but with a bit of a gap (about double the grid line width).
+    lineMetrics.underlineOffset2 = lineMetrics.underlineOffset +
+                                   lineMetrics.underlineWidth +
+                                   std::round(fontSize * 0.05f);
+
+    // However, we don't want the underline to extend past the bottom of the
+    // cell, so we clamp the offset to fit just inside.
+    const auto maxUnderlineOffset = lineSpacing.height - lineMetrics.underlineWidth;
+    lineMetrics.underlineOffset2 = std::min(lineMetrics.underlineOffset2, maxUnderlineOffset);
+
+    // But if the resulting gap isn't big enough even to register as a thicker
+    // line, it's better to place the second line slightly above the first.
+    if (lineMetrics.underlineOffset2 < lineMetrics.underlineOffset + lineMetrics.gridlineWidth)
     {
-        face = _FindFontFace(familyName, weight, stretch, style, localeName, true);
-
-        if (!face)
-        {
-            // If we missed, try looking a little more by trimming the last word off the requested family name a few times.
-            // Quite often, folks are specifying weights or something in the familyName and it causes failed resolution and
-            // an unexpected error dialog. We theoretically could detect the weight words and convert them, but this
-            // is the quick fix for the majority scenario.
-            // The long/full fix is backlogged to GH#9744
-            // Also this doesn't count as a fallback because we don't want to annoy folks with the warning dialog over
-            // this resolution.
-            while (!face && !familyName.empty())
-            {
-                const auto lastSpace = familyName.find_last_of(UNICODE_SPACE);
-
-                // value is unsigned and npos will be greater than size.
-                // if we didn't find anything to trim, leave.
-                if (lastSpace >= familyName.size())
-                {
-                    break;
-                }
-
-                // trim string down to just before the found space
-                // (space found at 6... trim from 0 for 6 length will give us 0-5 as the new string)
-                familyName = familyName.substr(0, lastSpace);
-
-                // Try to find it with the shortened family name
-                face = _FindFontFace(familyName, weight, stretch, style, localeName, true);
-            }
-        }
-    }
-    CATCH_LOG();
-
-    // Alright, if our quick shot at trimming didn't work either...
-    // move onto looking up a font from our hardcoded list of fonts
-    // that should really always be available.
-    if (!face)
-    {
-        for (const auto fallbackFace : FALLBACK_FONT_FACES)
-        {
-            familyName = fallbackFace;
-            // With these fonts, don't attempt the nearby lookup. We're looking
-            // for system fonts only. If one of the nearby fonts is causing us
-            // problems (like in GH#10211), then we don't want to go anywhere
-
-            // near it in this part.
-            face = _FindFontFace(familyName, weight, stretch, style, localeName, false);
-
-            if (face)
-            {
-                didFallback = true;
-                break;
-            }
-
-            familyName = fallbackFace;
-            weight = DWRITE_FONT_WEIGHT_NORMAL;
-            stretch = DWRITE_FONT_STRETCH_NORMAL;
-            style = DWRITE_FONT_STYLE_NORMAL;
-            face = _FindFontFace(familyName, weight, stretch, style, localeName, false);
-
-            if (face)
-            {
-                didFallback = true;
-                break;
-            }
-        }
+        lineMetrics.underlineOffset2 = lineMetrics.underlineOffset - lineMetrics.gridlineWidth;
     }
 
-    THROW_HR_IF_NULL(E_FAIL, face);
+    // We also add half the stroke width to the offsets, since the line
+    // coordinates designate the center of the line.
+    lineMetrics.underlineOffset += lineMetrics.underlineWidth / 2.0f;
+    lineMetrics.underlineOffset2 += lineMetrics.underlineWidth / 2.0f;
+    lineMetrics.strikethroughOffset += lineMetrics.strikethroughWidth / 2.0f;
 
-    return face;
+    _lineMetrics = lineMetrics;
+
+    _glyphCell = actual.GetSize();
 }
 
-// Routine Description:
-// - Locates a suitable font face from the given information
-// Arguments:
-// - familyName - The font name we should be looking for
-// - weight - The weight (bold, light, etc.)
-// - stretch - The stretch of the font is the spacing between each letter
-// - style - Normal, italic, etc.
-// Return Value:
-// - Smart pointer holding interface reference for queryable font data.
-[[nodiscard]] Microsoft::WRL::ComPtr<IDWriteFontFace1> DxFontRenderData::_FindFontFace(std::wstring& familyName,
-                                                                                       DWRITE_FONT_WEIGHT& weight,
-                                                                                       DWRITE_FONT_STRETCH& stretch,
-                                                                                       DWRITE_FONT_STYLE& style,
-                                                                                       std::wstring& localeName,
-                                                                                       const bool withNearbyLookup) const
+Microsoft::WRL::ComPtr<IDWriteTextFormat> DxFontRenderData::_BuildTextFormat(const DxFontInfo fontInfo, const std::wstring_view localeName)
 {
-    Microsoft::WRL::ComPtr<IDWriteFontFace1> fontFace;
-
-    Microsoft::WRL::ComPtr<IDWriteFontCollection> fontCollection;
-    THROW_IF_FAILED(_dwriteFactory->GetSystemFontCollection(&fontCollection, false));
-
-    UINT32 familyIndex;
-    BOOL familyExists;
-    THROW_IF_FAILED(fontCollection->FindFamilyName(familyName.data(), &familyIndex, &familyExists));
-
-    // If the system collection missed, try the files sitting next to our binary.
-    if (withNearbyLookup && !familyExists)
-    {
-        auto&& nearbyCollection = NearbyCollection();
-
-        // May be null on OS below Windows 10. If null, just skip the attempt.
-        if (nearbyCollection)
-        {
-            nearbyCollection.As(&fontCollection);
-            THROW_IF_FAILED(fontCollection->FindFamilyName(familyName.data(), &familyIndex, &familyExists));
-        }
-    }
-
-    if (familyExists)
-    {
-        Microsoft::WRL::ComPtr<IDWriteFontFamily> fontFamily;
-        THROW_IF_FAILED(fontCollection->GetFontFamily(familyIndex, &fontFamily));
-
-        Microsoft::WRL::ComPtr<IDWriteFont> font;
-        THROW_IF_FAILED(fontFamily->GetFirstMatchingFont(weight, stretch, style, &font));
-
-        Microsoft::WRL::ComPtr<IDWriteFontFace> fontFace0;
-        THROW_IF_FAILED(font->CreateFontFace(&fontFace0));
-
-        THROW_IF_FAILED(fontFace0.As(&fontFace));
-
-        // Retrieve metrics in case the font we created was different than what was requested.
-        weight = font->GetWeight();
-        stretch = font->GetStretch();
-        style = font->GetStyle();
-
-        // Dig the family name out at the end to return it.
-        familyName = _GetFontFamilyName(fontFamily.Get(), localeName);
-    }
-
-    return fontFace;
-}
-
-// Routine Description:
-// - Retrieves the font family name out of the given object in the given locale.
-// - If we can't find a valid name for the given locale, we'll fallback and report it back.
-// Arguments:
-// - fontFamily - DirectWrite font family object
-// - localeName - The locale in which the name should be retrieved.
-//              - If fallback occurred, this is updated to what we retrieved instead.
-// Return Value:
-// - Localized string name of the font family
-[[nodiscard]] std::wstring DxFontRenderData::_GetFontFamilyName(gsl::not_null<IDWriteFontFamily*> const fontFamily,
-                                                                std::wstring& localeName) const
-{
-    // See: https://docs.microsoft.com/en-us/windows/win32/api/dwrite/nn-dwrite-idwritefontcollection
-    Microsoft::WRL::ComPtr<IDWriteLocalizedStrings> familyNames;
-    THROW_IF_FAILED(fontFamily->GetFamilyNames(&familyNames));
-
-    // First we have to find the right family name for the locale. We're going to bias toward what the caller
-    // requested, but fallback if we need to and reply with the locale we ended up choosing.
-    UINT32 index = 0;
-    BOOL exists = false;
-
-    // This returns S_OK whether or not it finds a locale name. Check exists field instead.
-    // If it returns an error, it's a real problem, not an absence of this locale name.
-    // https://docs.microsoft.com/en-us/windows/win32/api/dwrite/nf-dwrite-idwritelocalizedstrings-findlocalename
-    THROW_IF_FAILED(familyNames->FindLocaleName(localeName.data(), &index, &exists));
-
-    // If we tried and it still doesn't exist, try with the fallback locale.
-    if (!exists)
-    {
-        localeName = FALLBACK_LOCALE;
-        THROW_IF_FAILED(familyNames->FindLocaleName(localeName.data(), &index, &exists));
-    }
-
-    // If it still doesn't exist, we're going to try index 0.
-    if (!exists)
-    {
-        index = 0;
-
-        // Get the locale name out so at least the caller knows what locale this name goes with.
-        UINT32 length = 0;
-        THROW_IF_FAILED(familyNames->GetLocaleNameLength(index, &length));
-        localeName.resize(length);
-
-        // https://docs.microsoft.com/en-us/windows/win32/api/dwrite/nf-dwrite-idwritelocalizedstrings-getlocalenamelength
-        // https://docs.microsoft.com/en-us/windows/win32/api/dwrite/nf-dwrite-idwritelocalizedstrings-getlocalename
-        // GetLocaleNameLength does not include space for null terminator, but GetLocaleName needs it so add one.
-        THROW_IF_FAILED(familyNames->GetLocaleName(index, localeName.data(), length + 1));
-    }
-
-    // OK, now that we've decided which family name and the locale that it's in... let's go get it.
-    UINT32 length = 0;
-    THROW_IF_FAILED(familyNames->GetStringLength(index, &length));
-
-    // Make our output buffer and resize it so it is allocated.
-    std::wstring retVal;
-    retVal.resize(length);
-
-    // FINALLY, go fetch the string name.
-    // https://docs.microsoft.com/en-us/windows/win32/api/dwrite/nf-dwrite-idwritelocalizedstrings-getstringlength
-    // https://docs.microsoft.com/en-us/windows/win32/api/dwrite/nf-dwrite-idwritelocalizedstrings-getstring
-    // Once again, GetStringLength is without the null, but GetString needs the null. So add one.
-    THROW_IF_FAILED(familyNames->GetString(index, retVal.data(), length + 1));
-
-    // and return it.
-    return retVal;
-}
-
-[[nodiscard]] std::wstring DxFontRenderData::_GetUserLocaleName()
-{
-    if (_userLocaleName.empty())
-    {
-        std::array<wchar_t, LOCALE_NAME_MAX_LENGTH> localeName;
-
-        const auto returnCode = GetUserDefaultLocaleName(localeName.data(), gsl::narrow<int>(localeName.size()));
-        if (returnCode)
-        {
-            _userLocaleName = { localeName.data() };
-        }
-        else
-        {
-            _userLocaleName = { FALLBACK_LOCALE.data(), FALLBACK_LOCALE.size() };
-        }
-    }
-
-    return _userLocaleName;
-}
-
-// Routine Description:
-// - Digs through the directory that the current executable is running within to find
-//   any TTF files sitting next to it.
-// Arguments:
-// - <none>
-// Return Value:
-// - Iterable collection of filesystem paths, one per font file that was found
-[[nodiscard]] std::vector<std::filesystem::path> DxFontRenderData::s_GetNearbyFonts()
-{
-    std::vector<std::filesystem::path> paths;
-
-    // Find the directory we're running from then enumerate all the TTF files
-    // sitting next to us.
-    const std::filesystem::path module{ wil::GetModuleFileNameW<std::wstring>(nullptr) };
-    const auto folder{ module.parent_path() };
-
-    for (auto& p : std::filesystem::directory_iterator(folder))
-    {
-        if (p.is_regular_file())
-        {
-            auto extension = p.path().extension().wstring();
-            std::transform(extension.begin(), extension.end(), extension.begin(), std::towlower);
-
-            static constexpr std::wstring_view ttfExtension{ L".ttf" };
-            if (ttfExtension == extension)
-            {
-                paths.push_back(p);
-            }
-        }
-    }
-
-    return paths;
+    Microsoft::WRL::ComPtr<IDWriteTextFormat> format;
+    THROW_IF_FAILED(_dwriteFactory->CreateTextFormat(fontInfo.GetFamilyName().data(),
+                                                     nullptr,
+                                                     fontInfo.GetWeight(),
+                                                     fontInfo.GetStyle(),
+                                                     fontInfo.GetStretch(),
+                                                     _fontSize,
+                                                     localeName.data(),
+                                                     &format));
+    return format;
 }

src/renderer/dx/DxFontRenderData.h

@@ -4,6 +4,7 @@
 #pragma once
 
 #include "../../renderer/inc/FontInfoDesired.hpp"
+#include "DxFontInfo.h"
 #include "BoxDrawingEffect.h"
 
 #include <dwrite.h>
@@ -31,73 +32,69 @@ namespace Microsoft::Console::Render
         DxFontRenderData(::Microsoft::WRL::ComPtr<IDWriteFactory1> dwriteFactory) noexcept;
 
         // DirectWrite text analyzer from the factory
-        [[nodiscard]] Microsoft::WRL::ComPtr<IDWriteTextAnalyzer1> Analyzer() noexcept;
+        [[nodiscard]] Microsoft::WRL::ComPtr<IDWriteTextAnalyzer1> Analyzer();
 
         [[nodiscard]] Microsoft::WRL::ComPtr<IDWriteFontFallback> SystemFontFallback();
 
-        [[nodiscard]] const Microsoft::WRL::ComPtr<IDWriteFontCollection1>& NearbyCollection() const;
+        // A locale that can be used on construction of assorted DX objects that want to know one.
+        [[nodiscard]] std::wstring UserLocaleName();
 
         [[nodiscard]] til::size GlyphCell() noexcept;
         [[nodiscard]] LineMetrics GetLineMetrics() noexcept;
 
+        // The weight of default font
+        [[nodiscard]] DWRITE_FONT_WEIGHT DefaultFontWeight() noexcept;
+
+        // The style of default font
+        [[nodiscard]] DWRITE_FONT_STYLE DefaultFontStyle() noexcept;
+
+        // The stretch of default font
+        [[nodiscard]] DWRITE_FONT_STRETCH DefaultFontStretch() noexcept;
+
         // The DirectWrite format object representing the size and other text properties to be applied (by default)
-        [[nodiscard]] Microsoft::WRL::ComPtr<IDWriteTextFormat> DefaultTextFormat() noexcept;
+        [[nodiscard]] Microsoft::WRL::ComPtr<IDWriteTextFormat> DefaultTextFormat();
 
         // The DirectWrite font face to use while calculating layout (by default)
-        [[nodiscard]] Microsoft::WRL::ComPtr<IDWriteFontFace1> DefaultFontFace() noexcept;
+        [[nodiscard]] Microsoft::WRL::ComPtr<IDWriteFontFace1> DefaultFontFace();
 
         // Box drawing scaling effects that are cached for the base font across layouts
-        [[nodiscard]] Microsoft::WRL::ComPtr<IBoxDrawingEffect> DefaultBoxDrawingEffect() noexcept;
+        [[nodiscard]] Microsoft::WRL::ComPtr<IBoxDrawingEffect> DefaultBoxDrawingEffect();
 
-        // The italic variant of the format object representing the size and other text properties for italic text
-        [[nodiscard]] Microsoft::WRL::ComPtr<IDWriteTextFormat> ItalicTextFormat() noexcept;
+        // The attributed variants of the format object representing the size and other text properties
+        [[nodiscard]] Microsoft::WRL::ComPtr<IDWriteTextFormat> TextFormatWithAttribute(DWRITE_FONT_WEIGHT weight,
+                                                                                        DWRITE_FONT_STYLE style,
+                                                                                        DWRITE_FONT_STRETCH stretch);
 
-        // The italic variant of the font face to use while calculating layout for italic text
-        [[nodiscard]] Microsoft::WRL::ComPtr<IDWriteFontFace1> ItalicFontFace() noexcept;
+        // The attributed variants of the font face to use while calculating layout
+        [[nodiscard]] Microsoft::WRL::ComPtr<IDWriteFontFace1> FontFaceWithAttribute(DWRITE_FONT_WEIGHT weight,
+                                                                                     DWRITE_FONT_STYLE style,
+                                                                                     DWRITE_FONT_STRETCH stretch);
 
         [[nodiscard]] HRESULT UpdateFont(const FontInfoDesired& desired, FontInfo& fiFontInfo, const int dpi) noexcept;
 
         [[nodiscard]] static HRESULT STDMETHODCALLTYPE s_CalculateBoxEffect(IDWriteTextFormat* format, size_t widthPixels, IDWriteFontFace1* face, float fontScale, IBoxDrawingEffect** effect) noexcept;
 
     private:
-        [[nodiscard]] ::Microsoft::WRL::ComPtr<IDWriteFontFace1> _ResolveFontFaceWithFallback(std::wstring& familyName,
-                                                                                              DWRITE_FONT_WEIGHT& weight,
-                                                                                              DWRITE_FONT_STRETCH& stretch,
-                                                                                              DWRITE_FONT_STYLE& style,
-                                                                                              std::wstring& localeName,
-                                                                                              bool& didFallback) const;
-
-        [[nodiscard]] ::Microsoft::WRL::ComPtr<IDWriteFontFace1> _FindFontFace(std::wstring& familyName,
-                                                                               DWRITE_FONT_WEIGHT& weight,
-                                                                               DWRITE_FONT_STRETCH& stretch,
-                                                                               DWRITE_FONT_STYLE& style,
-                                                                               std::wstring& localeName,
-                                                                               const bool withNearbyLookup) const;
-
-        [[nodiscard]] std::wstring _GetFontFamilyName(gsl::not_null<IDWriteFontFamily*> const fontFamily,
-                                                      std::wstring& localeName) const;
-
-        // A locale that can be used on construction of assorted DX objects that want to know one.
-        [[nodiscard]] std::wstring _GetUserLocaleName();
-
-        [[nodiscard]] static std::vector<std::filesystem::path> s_GetNearbyFonts();
+        void _BuildFontRenderData(const FontInfoDesired& desired, FontInfo& actual, const int dpi);
+        Microsoft::WRL::ComPtr<IDWriteTextFormat> _BuildTextFormat(const DxFontInfo fontInfo, const std::wstring_view localeName);
 
         ::Microsoft::WRL::ComPtr<IDWriteFactory1> _dwriteFactory;
 
         ::Microsoft::WRL::ComPtr<IDWriteTextAnalyzer1> _dwriteTextAnalyzer;
-        ::Microsoft::WRL::ComPtr<IDWriteTextFormat> _dwriteTextFormat;
-        ::Microsoft::WRL::ComPtr<IDWriteTextFormat> _dwriteTextFormatItalic;
-        ::Microsoft::WRL::ComPtr<IDWriteFontFace1> _dwriteFontFace;
-        ::Microsoft::WRL::ComPtr<IDWriteFontFace1> _dwriteFontFaceItalic;
+
+        std::unordered_map<DxFontInfo, ::Microsoft::WRL::ComPtr<IDWriteTextFormat>> _textFormatMap;
+        std::unordered_map<DxFontInfo, ::Microsoft::WRL::ComPtr<IDWriteFontFace1>> _fontFaceMap;
 
         ::Microsoft::WRL::ComPtr<IBoxDrawingEffect> _boxDrawingEffect;
 
         ::Microsoft::WRL::ComPtr<IDWriteFontFallback> _systemFontFallback;
         mutable ::Microsoft::WRL::ComPtr<IDWriteFontCollection1> _nearbyCollection;
         std::wstring _userLocaleName;
+        DxFontInfo _defaultFontInfo;
 
+        float _fontSize;
         til::size _glyphCell;
-
+        DWRITE_LINE_SPACING _lineSpacing;
         LineMetrics _lineMetrics;
     };
 }

src/renderer/dx/lib/dx.vcxproj

@@ -21,6 +21,7 @@
     <ClCompile Include="..\precomp.cpp">
       <PrecompiledHeader>Create</PrecompiledHeader>
     </ClCompile>
+    <ClCompile Include="..\DxFontInfo.cpp" />
     <ClCompile Include="..\DxFontRenderData.cpp" />
     <ClCompile Include="..\DxRenderer.cpp" />
   </ItemGroup>
@@ -30,6 +31,7 @@
     <ClInclude Include="..\CustomTextRenderer.h" />
     <ClInclude Include="..\precomp.h" />
     <ClInclude Include="..\DxRenderer.hpp" />
+    <ClInclude Include="..\DxFontInfo.h" />
     <ClInclude Include="..\DxFontRenderData.h" />
     <ClInclude Include="..\ScreenPixelShader.h" />
     <ClInclude Include="..\ScreenVertexShader.h" />

src/renderer/dx/sources.inc

@@ -33,6 +33,7 @@ INCLUDES = \
 SOURCES = \
     $(SOURCES) \
     ..\DxRenderer.cpp \
+    ..\DxFontInfo.cpp \
     ..\DxFontRenderData.cpp \
     ..\CustomTextRenderer.cpp \
     ..\CustomTextLayout.cpp \

src/terminal/parser/stateMachine.cpp

@@ -1818,7 +1818,7 @@ bool StateMachine::FlushToTerminal()
         //      that pwchCurr was processed.
         // However, if we're here, then the processing of pwchChar triggered the
         //      engine to request the entire sequence get passed through, including pwchCurr.
-        success = _engine->ActionPassThroughString(_run);
+        success = _engine->ActionPassThroughString(_CurrentRun());
     }
 
     return success;
@@ -1838,17 +1838,22 @@ void StateMachine::ProcessString(const std::wstring_view string)
     size_t start = 0;
     size_t current = start;
 
+    _currentString = string;
+    _runOffset = 0;
+    _runSize = 0;
+
     while (current < string.size())
     {
         // The run will be everything from the start INCLUDING the current one
         // in case we process the current character and it turns into a passthrough
         // fallback that picks up this _run inside `FlushToTerminal` above.
-        _run = string.substr(start, current - start + 1);
+        _runOffset = start;
+        _runSize = current - start + 1;
 
         if (_processingIndividually)
         {
             // If we're processing characters individually, send it to the state machine.
-            ProcessCharacter(string.at(current));
+            ProcessCharacter(til::at(string, current));
             ++current;
             if (_state == VTStates::Ground) // Then check if we're back at ground. If we are, the next character (pwchCurr)
             { //   is the start of the next run of characters that might be printable.
@@ -1858,14 +1863,15 @@ void StateMachine::ProcessString(const std::wstring_view string)
         }
         else
         {
-            if (_isActionableFromGround(string.at(current))) // If the current char is the start of an escape sequence, or should be executed in ground state...
+            if (_isActionableFromGround(til::at(string, current))) // If the current char is the start of an escape sequence, or should be executed in ground state...
             {
-                if (!_run.empty())
+                if (_runSize > 0)
                 {
-                    // Because the _run above is composed INCLUDING current, we must
+                    // Because the run above is composed INCLUDING current, we must
                     // trim it off here since we just determined it's actionable
                     // and only pass through everything before it.
-                    const auto allLeadingUpTo = _run.substr(0, _run.size() - 1);
+                    _runSize -= 1;
+                    const auto allLeadingUpTo = _CurrentRun();
 
                     _engine->ActionPrintString(allLeadingUpTo); // ... print all the chars leading up to it as part of the run...
                     _trace.DispatchPrintRunTrace(allLeadingUpTo);
@@ -1885,14 +1891,23 @@ void StateMachine::ProcessString(const std::wstring_view string)
     // When we leave the loop, current has been advanced to the length of the string itself
     // (or one past the array index to the final char) so this `substr` operation doesn't +1
     // to include the final character (unlike the one inside the top of the loop above.)
-    _run = start < string.size() ? string.substr(start) : std::wstring_view{};
+    if (start < string.size())
+    {
+        _runOffset = start;
+        _runSize = std::string::npos;
+    }
+    else
+    {
+        _runSize = 0;
+    }
 
+    const auto run = _CurrentRun();
     // If we're at the end of the string and have remaining un-printed characters,
-    if (!_processingIndividually && !_run.empty())
+    if (!_processingIndividually && !run.empty())
     {
         // print the rest of the characters in the string
-        _engine->ActionPrintString(_run);
-        _trace.DispatchPrintRunTrace(_run);
+        _engine->ActionPrintString(run);
+        _trace.DispatchPrintRunTrace(run);
     }
     else if (_processingIndividually)
     {
@@ -1920,8 +1935,8 @@ void StateMachine::ProcessString(const std::wstring_view string)
             // Reset our state, and put all but the last char in again.
             ResetState();
             // Chars to flush are [pwchSequenceStart, pwchCurr)
-            auto wchIter = _run.cbegin();
-            while (wchIter < _run.cend() - 1)
+            auto wchIter = run.cbegin();
+            while (wchIter < run.cend() - 1)
             {
                 ProcessCharacter(*wchIter);
                 wchIter++;
@@ -1961,7 +1976,13 @@ void StateMachine::ProcessString(const std::wstring_view string)
             // If the engine doesn't require flushing at the end of the string, we
             // want to cache the partial sequence in case we have to flush the whole
             // thing to the terminal later.
-            _cachedSequence = _cachedSequence.value_or(std::wstring{}) + std::wstring{ _run };
+            if (!_cachedSequence)
+            {
+                _cachedSequence.emplace(std::wstring{});
+            }
+
+            auto& cachedSequence = *_cachedSequence;
+            cachedSequence.append(run);
         }
     }
 }

src/terminal/parser/stateMachine.hpp

@@ -146,7 +146,18 @@ namespace Microsoft::Console::VirtualTerminal
 
         bool _isInAnsiMode;
 
-        std::wstring_view _run;
+        std::wstring_view _currentString;
+        size_t _runOffset;
+        size_t _runSize;
+
+        // Construct current run.
+        //
+        // Note: We intentionally use this method to create the run lazily for better performance.
+        //       You may find the usage of offset & size unsafe, but under heavy load it shows noticeable performance benefit.
+        std::wstring_view _CurrentRun() const
+        {
+            return _currentString.substr(_runOffset, _runSize);
+        }
 
         VTIDBuilder _identifier;
         std::vector<VTParameter> _parameters;

src/terminal/parser/tracing.cpp

@@ -10,25 +10,20 @@ using namespace Microsoft::Console::VirtualTerminal;
 #pragma warning(disable : 26447) // The function is declared 'noexcept' but calls function '_tlgWrapBinary<wchar_t>()' which may throw exceptions
 #pragma warning(disable : 26477) // Use 'nullptr' rather than 0 or NULL
 
-ParserTracing::ParserTracing() noexcept
-{
-    ClearSequenceTrace();
-}
-
-void ParserTracing::TraceStateChange(const std::wstring_view name) const noexcept
+void ParserTracing::TraceStateChange(_In_z_ const wchar_t* name) const noexcept
 {
     TraceLoggingWrite(g_hConsoleVirtTermParserEventTraceProvider,
                       "StateMachine_EnterState",
-                      TraceLoggingCountedWideString(name.data(), gsl::narrow_cast<ULONG>(name.size())),
+                      TraceLoggingWideString(name),
                       TraceLoggingLevel(WINEVENT_LEVEL_VERBOSE),
                       TraceLoggingKeyword(TIL_KEYWORD_TRACE));
 }
 
-void ParserTracing::TraceOnAction(const std::wstring_view name) const noexcept
+void ParserTracing::TraceOnAction(_In_z_ const wchar_t* name) const noexcept
 {
     TraceLoggingWrite(g_hConsoleVirtTermParserEventTraceProvider,
                       "StateMachine_Action",
-                      TraceLoggingCountedWideString(name.data(), gsl::narrow_cast<ULONG>(name.size())),
+                      TraceLoggingWideString(name),
                       TraceLoggingLevel(WINEVENT_LEVEL_VERBOSE),
                       TraceLoggingKeyword(TIL_KEYWORD_TRACE));
 }
@@ -55,11 +50,11 @@ void ParserTracing::TraceOnExecuteFromEscape(const wchar_t wch) const noexcept
                       TraceLoggingKeyword(TIL_KEYWORD_TRACE));
 }
 
-void ParserTracing::TraceOnEvent(const std::wstring_view name) const noexcept
+void ParserTracing::TraceOnEvent(_In_z_ const wchar_t* name) const noexcept
 {
     TraceLoggingWrite(g_hConsoleVirtTermParserEventTraceProvider,
                       "StateMachine_Event",
-                      TraceLoggingCountedWideString(name.data(), gsl::narrow_cast<ULONG>(name.size())),
+                      TraceLoggingWideString(name),
                       TraceLoggingLevel(WINEVENT_LEVEL_VERBOSE),
                       TraceLoggingKeyword(TIL_KEYWORD_TRACE));
 }
@@ -67,12 +62,11 @@ void ParserTracing::TraceOnEvent(const std::wstring_view name) const noexcept
 void ParserTracing::TraceCharInput(const wchar_t wch)
 {
     AddSequenceTrace(wch);
-    const auto sch = gsl::narrow_cast<INT16>(wch);
 
     TraceLoggingWrite(g_hConsoleVirtTermParserEventTraceProvider,
                       "StateMachine_NewChar",
                       TraceLoggingWChar(wch),
-                      TraceLoggingHexInt16(sch),
+                      TraceLoggingHexInt16(gsl::narrow_cast<INT16>(wch)),
                       TraceLoggingLevel(WINEVENT_LEVEL_VERBOSE),
                       TraceLoggingKeyword(TIL_KEYWORD_TRACE));
 }
@@ -114,7 +108,7 @@ void ParserTracing::ClearSequenceTrace() noexcept
 }
 
 // NOTE: I'm expecting this to not be null terminated
-void ParserTracing::DispatchPrintRunTrace(const std::wstring_view string) const
+void ParserTracing::DispatchPrintRunTrace(const std::wstring_view& string) const
 {
     if (string.size() == 1)
     {

src/terminal/parser/tracing.hpp

@@ -21,19 +21,30 @@ namespace Microsoft::Console::VirtualTerminal
     class ParserTracing sealed
     {
     public:
-        ParserTracing() noexcept;
+        // NOTE: This code uses
+        //   (_In_z_ const wchar_t* name)
+        // as arguments instead of the more modern std::wstring_view
+        // for performance reasons.
+        //
+        // Passing structures larger than the register size is very expensive
+        // due to Microsoft's x64 calling convention. We could reduce the
+        // overhead by passing the string-view by reference, but this forces us
+        // to allocate the parameters as static string-views on the data
+        // segment of our binary. I've found that passing them as classic
+        // C-strings is more ergonomic instead and fits the need for
+        // high performance in this particular code.
 
-        void TraceStateChange(const std::wstring_view name) const noexcept;
-        void TraceOnAction(const std::wstring_view name) const noexcept;
+        void TraceStateChange(_In_z_ const wchar_t* name) const noexcept;
+        void TraceOnAction(_In_z_ const wchar_t* name) const noexcept;
         void TraceOnExecute(const wchar_t wch) const noexcept;
         void TraceOnExecuteFromEscape(const wchar_t wch) const noexcept;
-        void TraceOnEvent(const std::wstring_view name) const noexcept;
+        void TraceOnEvent(_In_z_ const wchar_t* name) const noexcept;
         void TraceCharInput(const wchar_t wch);
 
         void AddSequenceTrace(const wchar_t wch);
         void DispatchSequenceTrace(const bool fSuccess) noexcept;
         void ClearSequenceTrace() noexcept;
-        void DispatchPrintRunTrace(const std::wstring_view string) const;
+        void DispatchPrintRunTrace(const std::wstring_view& string) const;
 
     private:
         std::wstring _sequenceTrace;

src/til/ut_til/VisualizeControlCodesTests.cpp

@@ -1,23 +0,0 @@
-// Copyright (c) Microsoft Corporation.
-// Licensed under the MIT license.
-
-#include "precomp.h"
-
-#include "til/operators.h"
-
-using namespace WEX::Common;
-using namespace WEX::Logging;
-using namespace WEX::TestExecution;
-
-class VisualizeControlCodesTests
-{
-    TEST_CLASS(VisualizeControlCodesTests);
-
-    TEST_METHOD(EscapeSequence)
-    {
-        const std::wstring_view expected{ L"\u241b[A\u2423\u241b[B" };
-
-        const std::wstring_view input{ L"\u001b[A \u001b[B" };
-        VERIFY_ARE_EQUAL(expected, til::visualize_control_codes(input));
-    }
-};

src/til/ut_til/mutex.cpp

@@ -0,0 +1,46 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT license.
+
+#include "precomp.h"
+
+#include "til/mutex.h"
+
+using namespace WEX::Common;
+using namespace WEX::Logging;
+using namespace WEX::TestExecution;
+
+class MutexTests
+{
+    BEGIN_TEST_CLASS(MutexTests)
+        TEST_CLASS_PROPERTY(L"TestTimeout", L"0:0:10") // 10s timeout
+    END_TEST_CLASS()
+
+    TEST_METHOD(Basic)
+    {
+        struct TestData
+        {
+            int foo;
+            int bar;
+        };
+
+        const til::shared_mutex<TestData> mutex{ TestData{ 1, 2 } };
+
+        {
+            auto lock = mutex.lock();
+            *lock = TestData{ 3, 4 };
+            lock->foo = 5;
+        }
+
+        {
+            auto lock1 = mutex.lock_shared();
+            auto lock2 = mutex.lock_shared();
+
+            VERIFY_ARE_EQUAL(5, lock1->foo);
+            VERIFY_ARE_EQUAL(4, lock2->bar);
+        }
+
+        // This is here just to ensure that the prior
+        // .lock_shared() properly unlocked the mutex.
+        auto lock = mutex.lock();
+    }
+};

src/til/ut_til/string.cpp

@@ -0,0 +1,55 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT license.
+
+#include "precomp.h"
+
+using namespace WEX::Common;
+using namespace WEX::Logging;
+using namespace WEX::TestExecution;
+
+class StringTests
+{
+    TEST_CLASS(StringTests);
+
+    TEST_METHOD(VisualizeControlCodes)
+    {
+        const std::wstring_view input{ L"\u001b[A \u001b[B\x7f" };
+        const std::wstring_view expected{ L"\u241b[A\u2423\u241b[B\x2421" };
+        const auto actual = til::visualize_control_codes(input);
+        VERIFY_ARE_EQUAL(expected, actual);
+    }
+
+    TEST_METHOD(StartsWith)
+    {
+        VERIFY_IS_TRUE(til::starts_with("", ""));
+
+        VERIFY_IS_TRUE(til::starts_with("abc", ""));
+        VERIFY_IS_TRUE(til::starts_with("abc", "a"));
+        VERIFY_IS_TRUE(til::starts_with("abc", "ab"));
+        VERIFY_IS_TRUE(til::starts_with("abc", "abc"));
+        VERIFY_IS_FALSE(til::starts_with("abc", "abcd"));
+
+        VERIFY_IS_FALSE(til::starts_with("", "abc"));
+        VERIFY_IS_FALSE(til::starts_with("a", "abc"));
+        VERIFY_IS_FALSE(til::starts_with("ab", "abc"));
+        VERIFY_IS_TRUE(til::starts_with("abc", "abc"));
+        VERIFY_IS_TRUE(til::starts_with("abcd", "abc"));
+    }
+
+    TEST_METHOD(EndsWith)
+    {
+        VERIFY_IS_TRUE(til::ends_with("", ""));
+
+        VERIFY_IS_TRUE(til::ends_with("abc", ""));
+        VERIFY_IS_TRUE(til::ends_with("abc", "c"));
+        VERIFY_IS_TRUE(til::ends_with("abc", "bc"));
+        VERIFY_IS_TRUE(til::ends_with("abc", "abc"));
+        VERIFY_IS_FALSE(til::ends_with("abc", "0abc"));
+
+        VERIFY_IS_FALSE(til::ends_with("", "abc"));
+        VERIFY_IS_FALSE(til::ends_with("c", "abc"));
+        VERIFY_IS_FALSE(til::ends_with("bc", "abc"));
+        VERIFY_IS_TRUE(til::ends_with("abc", "abc"));
+        VERIFY_IS_TRUE(til::ends_with("0abc", "abc"));
+    }
+};

src/til/ut_til/throttled_func.cpp

@@ -0,0 +1,42 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT license.
+
+#include "precomp.h"
+
+#include "til/latch.h"
+#include "til/throttled_func.h"
+
+using namespace WEX::Common;
+using namespace WEX::Logging;
+using namespace WEX::TestExecution;
+
+class ThrottledFuncTests
+{
+    BEGIN_TEST_CLASS(ThrottledFuncTests)
+        TEST_CLASS_PROPERTY(L"TestTimeout", L"0:0:10") // 10s timeout
+    END_TEST_CLASS()
+
+    TEST_METHOD(Basic)
+    {
+        using namespace std::chrono_literals;
+        using throttled_func = til::throttled_func_trailing<bool>;
+
+        til::latch latch{ 2 };
+
+        std::unique_ptr<throttled_func> tf;
+        tf = std::make_unique<throttled_func>(10ms, [&](bool reschedule) {
+            latch.count_down();
+
+            // This will ensure that the callback is called even if we
+            // invoke the throttled_func from inside the callback itself.
+            if (reschedule)
+            {
+                tf->operator()(false);
+            }
+        });
+        // This will ensure that the throttled_func invokes the callback in general.
+        tf->operator()(true);
+
+        latch.wait();
+    }
+};

src/til/ut_til/til.unit.tests.vcxproj

@@ -10,24 +10,26 @@
   </PropertyGroup>
   <Import Project="$(SolutionDir)src\common.build.pre.props" />
   <ItemGroup>
-    <ClCompile Include="BaseTests.cpp" />
-    <ClCompile Include="BitmapTests.cpp" />
-    <ClCompile Include="OperatorTests.cpp" />
-    <ClCompile Include="PointTests.cpp" />
-    <ClCompile Include="StaticMapTests.cpp" />
-    <ClCompile Include="MathTests.cpp" />
-    <ClCompile Include="RectangleTests.cpp" />
-    <ClCompile Include="RunLengthEncodingTests.cpp" />
-    <ClCompile Include="SizeTests.cpp" />
-    <ClCompile Include="ColorTests.cpp" />
-    <ClCompile Include="CoalesceTests.cpp" />
-    <ClCompile Include="ReplaceTests.cpp" />
-    <ClCompile Include="SomeTests.cpp" />
-    <ClCompile Include="VisualizeControlCodesTests.cpp" />
     <ClCompile Include="..\precomp.cpp">
       <PrecompiledHeader>Create</PrecompiledHeader>
     </ClCompile>
+    <ClCompile Include="BaseTests.cpp" />
+    <ClCompile Include="BitmapTests.cpp" />
+    <ClCompile Include="CoalesceTests.cpp" />
+    <ClCompile Include="ColorTests.cpp" />
+    <ClCompile Include="MathTests.cpp" />
+    <ClCompile Include="mutex.cpp" />
+    <ClCompile Include="OperatorTests.cpp" />
+    <ClCompile Include="PointTests.cpp" />
+    <ClCompile Include="RectangleTests.cpp" />
+    <ClCompile Include="ReplaceTests.cpp" />
+    <ClCompile Include="RunLengthEncodingTests.cpp" />
+    <ClCompile Include="SizeTests.cpp" />
+    <ClCompile Include="SomeTests.cpp" />
     <ClCompile Include="SPSCTests.cpp" />
+    <ClCompile Include="StaticMapTests.cpp" />
+    <ClCompile Include="string.cpp" />
+    <ClCompile Include="throttled_func.cpp" />
     <ClCompile Include="u8u16convertTests.cpp" />
   </ItemGroup>
   <ItemGroup>

src/til/ut_til/til.unit.tests.vcxproj.filters

@@ -4,19 +4,25 @@
     <Natvis Include="$(SolutionDir)tools\ConsoleTypes.natvis" />
   </ItemGroup>
   <ItemGroup>
-    <ClCompile Include="SomeTests.cpp" />
     <ClCompile Include="..\precomp.cpp" />
-    <ClCompile Include="u8u16convertTests.cpp" />
-    <ClCompile Include="SizeTests.cpp" />
-    <ClCompile Include="ColorTests.cpp" />
-    <ClCompile Include="PointTests.cpp" />
-    <ClCompile Include="StaticMapTests.cpp" />
-    <ClCompile Include="RectangleTests.cpp" />
-    <ClCompile Include="BitmapTests.cpp" />
-    <ClCompile Include="OperatorTests.cpp" />
-    <ClCompile Include="MathTests.cpp" />
     <ClCompile Include="BaseTests.cpp" />
+    <ClCompile Include="BitmapTests.cpp" />
+    <ClCompile Include="CoalesceTests.cpp" />
+    <ClCompile Include="ColorTests.cpp" />
+    <ClCompile Include="MathTests.cpp" />
+    <ClCompile Include="mutex.cpp" />
+    <ClCompile Include="OperatorTests.cpp" />
+    <ClCompile Include="PointTests.cpp" />
+    <ClCompile Include="RectangleTests.cpp" />
+    <ClCompile Include="ReplaceTests.cpp" />
+    <ClCompile Include="RunLengthEncodingTests.cpp" />
+    <ClCompile Include="SizeTests.cpp" />
+    <ClCompile Include="SomeTests.cpp" />
     <ClCompile Include="SPSCTests.cpp" />
+    <ClCompile Include="StaticMapTests.cpp" />
+    <ClCompile Include="string.cpp" />
+    <ClCompile Include="throttled_func.cpp" />
+    <ClCompile Include="u8u16convertTests.cpp" />
   </ItemGroup>
   <ItemGroup>
     <ClInclude Include="..\precomp.h" />