Add the ability to quit all terminal instances (#11143)

Add the ability to quit all terminal instances. Doing this separately from the window layout saving ones to lessen the number of 1k+ line monsters I make y'all review.

## References
#11083 

## PR Checklist
* [x] Closes #11081
* [ ] Documentation updated. If checked, please file a pull request on [our docs repo](https://github.com/MicrosoftDocs/terminal) and link it here: #xxx
* [x] Schema updated.

## Detailed Description of the Pull Request / Additional comments
- Warn the user before they do so to give a chance to cancel
- Percolate a QuitAll event up to the monarch who then directs each peasant to clsoe.
- Leave a window-layout-saving-sized hole to add that feature on top

## Validation Steps Performed
- quit with one window (from the monarch)
- quit from the monarch with multiple windows
- quit from a peasant
- cancel the quit dialog

![image](https://user-images.githubusercontent.com/6185249/132105775-3310f614-ce55-4454-9718-ef5c0d39fbd2.png)

doc/cascadia/profiles.schema.json

@@ -304,6 +304,7 @@
         "toggleReadOnlyMode",
         "toggleShaderEffects",
         "wt",
+        "quit",
         "unbound"
       ],
       "type": "string"

src/cascadia/Remoting/Monarch.cpp

@@ -82,6 +82,7 @@ namespace winrt::Microsoft::Terminal::Remoting::implementation
 
             peasant.ShowTrayIconRequested([this](auto&&, auto&&) { _ShowTrayIconRequestedHandlers(*this, nullptr); });
             peasant.HideTrayIconRequested([this](auto&&, auto&&) { _HideTrayIconRequestedHandlers(*this, nullptr); });
+            peasant.QuitAllRequested({ this, &Monarch::_handleQuitAll });
 
             _peasants[newPeasantsId] = peasant;
 
@@ -109,6 +110,35 @@ namespace winrt::Microsoft::Terminal::Remoting::implementation
         }
     }
 
+    // Method Description:
+    // - Gives the host process an opportunity to run any pre-close logic then
+    //   requests all peasants to close.
+    // Arguments:
+    // - <none> used
+    // Return Value:
+    // - <none>
+    void Monarch::_handleQuitAll(const winrt::Windows::Foundation::IInspectable& /*sender*/,
+                                 const winrt::Windows::Foundation::IInspectable& /*args*/)
+    {
+        // Let the process hosting the monarch run any needed logic before
+        // closing all windows.
+        _QuitAllRequestedHandlers(*this, nullptr);
+
+        // Tell all peasants to exit.
+        const auto callback = [&](const auto& /*id*/, const auto& p) {
+            p.Quit();
+        };
+        const auto onError = [&](const auto& id) {
+            TraceLoggingWrite(g_hRemotingProvider,
+                              "Monarch_handleQuitAll_Failed",
+                              TraceLoggingInt64(id, "peasantID", "The ID of the peasant which we could not close"),
+                              TraceLoggingLevel(WINEVENT_LEVEL_VERBOSE),
+                              TraceLoggingKeyword(TIL_KEYWORD_TRACE));
+        };
+
+        _forEachPeasant(callback, onError);
+    }
+
     // Method Description:
     // - Tells the monarch that a peasant is being closed.
     // Arguments:

src/cascadia/Remoting/Monarch.h

@@ -64,6 +64,7 @@ namespace winrt::Microsoft::Terminal::Remoting::implementation
         TYPED_EVENT(HideTrayIconRequested, winrt::Windows::Foundation::IInspectable, winrt::Windows::Foundation::IInspectable);
         TYPED_EVENT(WindowCreated, winrt::Windows::Foundation::IInspectable, winrt::Windows::Foundation::IInspectable);
         TYPED_EVENT(WindowClosed, winrt::Windows::Foundation::IInspectable, winrt::Windows::Foundation::IInspectable);
+        TYPED_EVENT(QuitAllRequested, winrt::Windows::Foundation::IInspectable, winrt::Windows::Foundation::IInspectable);
 
     private:
         uint64_t _ourPID;
@@ -95,6 +96,9 @@ namespace winrt::Microsoft::Terminal::Remoting::implementation
         void _renameRequested(const winrt::Windows::Foundation::IInspectable& sender,
                               const winrt::Microsoft::Terminal::Remoting::RenameRequestArgs& args);
 
+        void _handleQuitAll(const winrt::Windows::Foundation::IInspectable& sender,
+                            const winrt::Windows::Foundation::IInspectable& args);
+
         // Method Description:
         // - Helper for doing something on each and every peasant.
         // - We'll try calling func on every peasant.

src/cascadia/Remoting/Monarch.idl

@@ -58,5 +58,6 @@ namespace Microsoft.Terminal.Remoting
         event Windows.Foundation.TypedEventHandler<Object, Object> HideTrayIconRequested;
         event Windows.Foundation.TypedEventHandler<Object, Object> WindowCreated;
         event Windows.Foundation.TypedEventHandler<Object, Object> WindowClosed;
+        event Windows.Foundation.TypedEventHandler<Object, Object> QuitAllRequested;
     };
 }

src/cascadia/Remoting/Peasant.cpp

@@ -257,4 +257,36 @@ namespace winrt::Microsoft::Terminal::Remoting::implementation
                           TraceLoggingLevel(WINEVENT_LEVEL_VERBOSE),
                           TraceLoggingKeyword(TIL_KEYWORD_TRACE));
     }
+
+    void Peasant::RequestQuitAll()
+    {
+        try
+        {
+            _QuitAllRequestedHandlers(*this, nullptr);
+        }
+        catch (...)
+        {
+            LOG_CAUGHT_EXCEPTION();
+        }
+        TraceLoggingWrite(g_hRemotingProvider,
+                          "Peasant_RequestQuit",
+                          TraceLoggingLevel(WINEVENT_LEVEL_VERBOSE),
+                          TraceLoggingKeyword(TIL_KEYWORD_TRACE));
+    }
+
+    void Peasant::Quit()
+    {
+        try
+        {
+            _QuitRequestedHandlers(*this, nullptr);
+        }
+        catch (...)
+        {
+            LOG_CAUGHT_EXCEPTION();
+        }
+        TraceLoggingWrite(g_hRemotingProvider,
+                          "Peasant_Quit",
+                          TraceLoggingLevel(WINEVENT_LEVEL_VERBOSE),
+                          TraceLoggingKeyword(TIL_KEYWORD_TRACE));
+    }
 }

src/cascadia/Remoting/Peasant.h

@@ -30,6 +30,8 @@ namespace winrt::Microsoft::Terminal::Remoting::implementation
         void RequestRename(const winrt::Microsoft::Terminal::Remoting::RenameRequestArgs& args);
         void RequestShowTrayIcon();
         void RequestHideTrayIcon();
+        void RequestQuitAll();
+        void Quit();
 
         winrt::Microsoft::Terminal::Remoting::WindowActivatedArgs GetLastActivatedArgs();
 
@@ -45,6 +47,8 @@ namespace winrt::Microsoft::Terminal::Remoting::implementation
         TYPED_EVENT(SummonRequested, winrt::Windows::Foundation::IInspectable, winrt::Microsoft::Terminal::Remoting::SummonWindowBehavior);
         TYPED_EVENT(ShowTrayIconRequested, winrt::Windows::Foundation::IInspectable, winrt::Windows::Foundation::IInspectable);
         TYPED_EVENT(HideTrayIconRequested, winrt::Windows::Foundation::IInspectable, winrt::Windows::Foundation::IInspectable);
+        TYPED_EVENT(QuitAllRequested, winrt::Windows::Foundation::IInspectable, winrt::Windows::Foundation::IInspectable);
+        TYPED_EVENT(QuitRequested, winrt::Windows::Foundation::IInspectable, winrt::Windows::Foundation::IInspectable);
 
     private:
         Peasant(const uint64_t testPID);

src/cascadia/Remoting/Peasant.idl

@@ -67,6 +67,8 @@ namespace Microsoft.Terminal.Remoting
         void Summon(SummonWindowBehavior behavior);
         void RequestShowTrayIcon();
         void RequestHideTrayIcon();
+        void RequestQuitAll();
+        void Quit();
 
         event Windows.Foundation.TypedEventHandler<Object, WindowActivatedArgs> WindowActivated;
         event Windows.Foundation.TypedEventHandler<Object, CommandlineArgs> ExecuteCommandlineRequested;
@@ -76,6 +78,8 @@ namespace Microsoft.Terminal.Remoting
         event Windows.Foundation.TypedEventHandler<Object, SummonWindowBehavior> SummonRequested;
         event Windows.Foundation.TypedEventHandler<Object, Object> ShowTrayIconRequested;
         event Windows.Foundation.TypedEventHandler<Object, Object> HideTrayIconRequested;
+        event Windows.Foundation.TypedEventHandler<Object, Object> QuitAllRequested;
+        event Windows.Foundation.TypedEventHandler<Object, Object> QuitRequested;
     };
 
     [default_interface] runtimeclass Peasant : IPeasant

src/cascadia/Remoting/WindowManager.cpp

@@ -271,6 +271,7 @@ namespace winrt::Microsoft::Terminal::Remoting::implementation
         _monarch.FindTargetWindowRequested({ this, &WindowManager::_raiseFindTargetWindowRequested });
         _monarch.ShowTrayIconRequested([this](auto&&, auto&&) { _ShowTrayIconRequestedHandlers(*this, nullptr); });
         _monarch.HideTrayIconRequested([this](auto&&, auto&&) { _HideTrayIconRequestedHandlers(*this, nullptr); });
+        _monarch.QuitAllRequested([this](auto&&, auto&&) { _QuitAllRequestedHandlers(*this, nullptr); });
 
         _BecameMonarchHandlers(*this, nullptr);
     }
@@ -579,6 +580,19 @@ namespace winrt::Microsoft::Terminal::Remoting::implementation
         _peasant.RequestHideTrayIcon();
     }
 
+    // Method Description:
+    // - Ask the monarch to quit all windows.
+    // Arguments:
+    // - <none>
+    // Return Value:
+    // - <none>
+    winrt::fire_and_forget WindowManager::RequestQuitAll()
+    {
+        auto strongThis{ get_strong() };
+        co_await winrt::resume_background();
+        _peasant.RequestQuitAll();
+    }
+
     bool WindowManager::DoesQuakeWindowExist()
     {
         return _monarch.DoesQuakeWindowExist();

src/cascadia/Remoting/WindowManager.h

@@ -47,6 +47,7 @@ namespace winrt::Microsoft::Terminal::Remoting::implementation
 
         winrt::fire_and_forget RequestShowTrayIcon();
         winrt::fire_and_forget RequestHideTrayIcon();
+        winrt::fire_and_forget RequestQuitAll();
         bool DoesQuakeWindowExist();
         void UpdateActiveTabTitle(winrt::hstring title);
 
@@ -56,6 +57,7 @@ namespace winrt::Microsoft::Terminal::Remoting::implementation
         TYPED_EVENT(WindowClosed, winrt::Windows::Foundation::IInspectable, winrt::Windows::Foundation::IInspectable);
         TYPED_EVENT(ShowTrayIconRequested, winrt::Windows::Foundation::IInspectable, winrt::Windows::Foundation::IInspectable);
         TYPED_EVENT(HideTrayIconRequested, winrt::Windows::Foundation::IInspectable, winrt::Windows::Foundation::IInspectable);
+        TYPED_EVENT(QuitAllRequested, winrt::Windows::Foundation::IInspectable, winrt::Windows::Foundation::IInspectable);
 
     private:
         bool _shouldCreateWindow{ false };

src/cascadia/Remoting/WindowManager.idl

@@ -17,6 +17,7 @@ namespace Microsoft.Terminal.Remoting
         void RequestShowTrayIcon();
         void RequestHideTrayIcon();
         UInt64 GetNumberOfPeasants();
+        void RequestQuitAll();
         void UpdateActiveTabTitle(String title);
         Boolean DoesQuakeWindowExist();
         Windows.Foundation.Collections.IVectorView<PeasantInfo> GetPeasantInfos();
@@ -26,5 +27,6 @@ namespace Microsoft.Terminal.Remoting
         event Windows.Foundation.TypedEventHandler<Object, Object> WindowClosed;
         event Windows.Foundation.TypedEventHandler<Object, Object> ShowTrayIconRequested;
         event Windows.Foundation.TypedEventHandler<Object, Object> HideTrayIconRequested;
+        event Windows.Foundation.TypedEventHandler<Object, Object> QuitAllRequested;
     };
 }

src/cascadia/TerminalApp/AppActionHandlers.cpp

@@ -78,7 +78,14 @@ namespace winrt::TerminalApp::implementation
     void TerminalPage::_HandleCloseWindow(const IInspectable& /*sender*/,
                                           const ActionEventArgs& args)
     {
-        CloseWindow();
+        CloseWindow(false);
+        args.Handled(true);
+    }
+
+    void TerminalPage::_HandleQuit(const IInspectable& /*sender*/,
+                                   const ActionEventArgs& args)
+    {
+        RequestQuit();
         args.Handled(true);
     }
 

src/cascadia/TerminalApp/AppLogic.cpp

@@ -329,6 +329,14 @@ namespace winrt::TerminalApp::implementation
             TelemetryPrivacyDataTag(PDT_ProductAndServicePerformance));
     }
 
+    void AppLogic::Quit()
+    {
+        if (_root)
+        {
+            _root->CloseWindow(true);
+        }
+    }
+
     // Method Description:
     // - Show a ContentDialog with buttons to take further action. Uses the
     //   FrameworkElements provided as the title and content of this dialog, and
@@ -1154,7 +1162,7 @@ namespace winrt::TerminalApp::implementation
     {
         if (_root)
         {
-            _root->CloseWindow();
+            _root->CloseWindow(false);
         }
     }
 

src/cascadia/TerminalApp/AppLogic.h

@@ -53,6 +53,8 @@ namespace winrt::TerminalApp::implementation
         void LoadSettings();
         [[nodiscard]] Microsoft::Terminal::Settings::Model::CascadiaSettings GetSettings() const noexcept;
 
+        void Quit();
+
         int32_t SetStartupCommandline(array_view<const winrt::hstring> actions);
         int32_t ExecuteCommandline(array_view<const winrt::hstring> actions, const winrt::hstring& cwd);
         TerminalApp::FindTargetWindowResult FindTargetWindow(array_view<const winrt::hstring> actions);
@@ -173,6 +175,7 @@ namespace winrt::TerminalApp::implementation
         FORWARDED_TYPED_EVENT(RenameWindowRequested, Windows::Foundation::IInspectable, winrt::TerminalApp::RenameWindowRequestedArgs, _root, RenameWindowRequested);
         FORWARDED_TYPED_EVENT(IsQuakeWindowChanged, Windows::Foundation::IInspectable, Windows::Foundation::IInspectable, _root, IsQuakeWindowChanged);
         FORWARDED_TYPED_EVENT(SummonWindowRequested, Windows::Foundation::IInspectable, Windows::Foundation::IInspectable, _root, SummonWindowRequested);
+        FORWARDED_TYPED_EVENT(QuitRequested, Windows::Foundation::IInspectable, Windows::Foundation::IInspectable, _root, QuitRequested);
 
 #ifdef UNIT_TESTING
         friend class TerminalAppLocalTests::CommandlineTest;

src/cascadia/TerminalApp/AppLogic.idl

@@ -39,6 +39,8 @@ namespace TerminalApp
         String ParseCommandlineMessage { get; };
         Boolean ShouldExitEarly { get; };
 
+        void Quit();
+
         void LoadSettings();
         Windows.UI.Xaml.UIElement GetRoot();
 
@@ -97,5 +99,6 @@ namespace TerminalApp
         event Windows.Foundation.TypedEventHandler<Object, Object> SettingsChanged;
         event Windows.Foundation.TypedEventHandler<Object, Object> IsQuakeWindowChanged;
         event Windows.Foundation.TypedEventHandler<Object, Object> SummonWindowRequested;
+        event Windows.Foundation.TypedEventHandler<Object, Object> QuitRequested;
     }
 }

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

@@ -184,6 +184,9 @@
   <data name="CloseAll" xml:space="preserve">
     <value>Close all</value>
   </data>
+  <data name="Quit" xml:space="preserve">
+    <value>Quit</value>
+  </data>
   <data name="CloseWindowWarningTitle" xml:space="preserve">
     <value>Do you want to close all tabs?</value>
   </data>
@@ -441,6 +444,15 @@
     <value>Third-Party Notices</value>
     <comment>A hyperlink name for the Terminal's third-party notices</comment>
   </data>
+  <data name="QuitDialog.CloseButtonText" xml:space="preserve">
+    <value>Cancel</value>
+  </data>
+  <data name="QuitDialog.PrimaryButtonText" xml:space="preserve">
+    <value>Close all</value>
+  </data>
+  <data name="QuitDialog.Title" xml:space="preserve">
+    <value>Do you want to close all windows?</value>
+  </data>
   <data name="CloseAllDialog.CloseButtonText" xml:space="preserve">
     <value>Cancel</value>
   </data>

src/cascadia/TerminalApp/TerminalPage.cpp

@@ -558,6 +558,21 @@ namespace winrt::TerminalApp::implementation
         ShellExecute(nullptr, nullptr, currentPath.c_str(), nullptr, nullptr, SW_SHOW);
     }
 
+    // Method Description:
+    // - Displays a dialog to warn the user that they are about to close all open windows.
+    //   Once the user clicks the OK button, shut down the application.
+    //   If cancel is clicked, the dialog will close.
+    // - Only one dialog can be visible at a time. If another dialog is visible
+    //   when this is called, nothing happens. See _ShowDialog for details
+    winrt::Windows::Foundation::IAsyncOperation<ContentDialogResult> TerminalPage::_ShowQuitDialog()
+    {
+        if (auto presenter{ _dialogPresenter.get() })
+        {
+            co_return co_await presenter.ShowDialog(FindName(L"QuitDialog").try_as<WUX::Controls::ContentDialog>());
+        }
+        co_return ContentDialogResult::None;
+    }
+
     // Method Description:
     // - Displays a dialog for warnings found while closing the terminal app using
     //   key binding with multiple tabs opened. Display messages to warn user
@@ -1237,6 +1252,25 @@ namespace winrt::TerminalApp::implementation
         }
         return nullptr;
     }
+    // Method Description:
+    // - Warn the user that they are about to close all open windows, then
+    //   signal that we want to close everything.
+    fire_and_forget TerminalPage::RequestQuit()
+    {
+        if (!_displayingCloseDialog)
+        {
+            _displayingCloseDialog = true;
+            ContentDialogResult warningResult = co_await _ShowQuitDialog();
+            _displayingCloseDialog = false;
+
+            if (warningResult != ContentDialogResult::Primary)
+            {
+                co_return;
+            }
+
+            _QuitRequestedHandlers(nullptr, nullptr);
+        }
+    }
 
     // Method Description:
     // - Saves the window position and tab layout to the application state
@@ -1320,9 +1354,14 @@ namespace winrt::TerminalApp::implementation
     // Method Description:
     // - Close the terminal app. If there is more
     //   than one tab opened, show a warning dialog.
-    fire_and_forget TerminalPage::CloseWindow()
+    // Arguments:
+    // - bypassDialog: if true a dialog won't be shown even if the user would
+    //   normally get confirmation. This is used in the case where the user
+    //   has already been prompted by the Quit action.
+    fire_and_forget TerminalPage::CloseWindow(bool bypassDialog)
     {
-        if (_HasMultipleTabs() &&
+        if (!bypassDialog &&
+            _HasMultipleTabs() &&
             _settings.GlobalSettings().ConfirmCloseAllTabs() &&
             !_displayingCloseDialog)
         {

src/cascadia/TerminalApp/TerminalPage.h

@@ -71,7 +71,8 @@ namespace winrt::TerminalApp::implementation
         winrt::hstring ApplicationDisplayName();
         winrt::hstring ApplicationVersion();
 
-        winrt::fire_and_forget CloseWindow();
+        winrt::fire_and_forget RequestQuit();
+        winrt::fire_and_forget CloseWindow(bool bypassDialog);
 
         void ToggleFocusMode();
         void ToggleFullscreen();
@@ -131,6 +132,7 @@ namespace winrt::TerminalApp::implementation
         TYPED_EVENT(RenameWindowRequested, Windows::Foundation::IInspectable, winrt::TerminalApp::RenameWindowRequestedArgs);
         TYPED_EVENT(IsQuakeWindowChanged, IInspectable, IInspectable);
         TYPED_EVENT(SummonWindowRequested, IInspectable, IInspectable);
+        TYPED_EVENT(QuitRequested, IInspectable, IInspectable);
 
     private:
         friend struct TerminalPageT<TerminalPage>; // for Xaml to bind events
@@ -189,6 +191,7 @@ namespace winrt::TerminalApp::implementation
         std::shared_ptr<Toast> _windowRenameFailedToast{ nullptr };
 
         void _ShowAboutDialog();
+        winrt::Windows::Foundation::IAsyncOperation<winrt::Windows::UI::Xaml::Controls::ContentDialogResult> _ShowQuitDialog();
         winrt::Windows::Foundation::IAsyncOperation<winrt::Windows::UI::Xaml::Controls::ContentDialogResult> _ShowCloseWarningDialog();
         winrt::Windows::Foundation::IAsyncOperation<winrt::Windows::UI::Xaml::Controls::ContentDialogResult> _ShowCloseReadOnlyDialog();
         winrt::Windows::Foundation::IAsyncOperation<winrt::Windows::UI::Xaml::Controls::ContentDialogResult> _ShowMultiLinePasteWarningDialog();

src/cascadia/TerminalApp/TerminalPage.xaml

@@ -47,6 +47,11 @@
             </StackPanel>
         </ContentDialog>
 
+        <ContentDialog x:Name="QuitDialog"
+                       x:Uid="QuitDialog"
+                       x:Load="False"
+                       DefaultButton="Primary" />
+
         <ContentDialog x:Name="CloseAllDialog"
                        x:Uid="CloseAllDialog"
                        x:Load="False"

src/cascadia/TerminalSettingsModel/ActionAndArgs.cpp

@@ -67,6 +67,7 @@ static constexpr std::string_view QuakeModeKey{ "quakeMode" };
 static constexpr std::string_view FocusPaneKey{ "focusPane" };
 static constexpr std::string_view ClearBufferKey{ "clearBuffer" };
 static constexpr std::string_view MultipleActionsKey{ "multipleActions" };
+static constexpr std::string_view QuitKey{ "quit" };
 
 static constexpr std::string_view ActionKey{ "action" };
 
@@ -370,6 +371,7 @@ namespace winrt::Microsoft::Terminal::Settings::Model::implementation
                 { ShortcutAction::FocusPane, L"" }, // Intentionally omitted, must be generated by GenerateName
                 { ShortcutAction::ClearBuffer, L"" }, // Intentionally omitted, must be generated by GenerateName
                 { ShortcutAction::MultipleActions, L"" }, // Intentionally omitted, must be generated by GenerateName
+                { ShortcutAction::Quit, RS_(L"QuitCommandKey") },
             };
         }();
 

src/cascadia/TerminalSettingsModel/AllShortcutActions.h

@@ -80,7 +80,8 @@
     ON_ALL_ACTIONS(QuakeMode)              \
     ON_ALL_ACTIONS(FocusPane)              \
     ON_ALL_ACTIONS(ClearBuffer)            \
-    ON_ALL_ACTIONS(MultipleActions)
+    ON_ALL_ACTIONS(MultipleActions)        \
+    ON_ALL_ACTIONS(Quit)
 
 #define ALL_SHORTCUT_ACTIONS_WITH_ARGS             \
     ON_ALL_ACTIONS_WITH_ARGS(AdjustFontSize)       \

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

@@ -469,4 +469,7 @@
   <data name="MinimizeToTrayCommandKey" xml:space="preserve">
     <value>Minimize current window to tray</value>
   </data>
+  <data name="QuitCommandKey" xml:space="preserve">
+    <value>Quit the Terminal</value>
+  </data>
 </root>

src/cascadia/TerminalSettingsModel/defaults.json

@@ -301,6 +301,7 @@
         { "command": "identifyWindow" },
         { "command": "openWindowRenamer" },
         { "command": "quakeMode", "keys":"win+sc(41)" },
+        { "command": "quit" },
 
         // Tab Management
         // "command": "closeTab" is unbound by default.

src/cascadia/UnitTests_Remoting/RemotingTests.cpp

@@ -75,6 +75,8 @@ namespace RemotingUnitTests
         void Summon(const Remoting::SummonWindowBehavior& /*args*/) { throw winrt::hresult_error{}; };
         void RequestShowTrayIcon() { throw winrt::hresult_error{}; };
         void RequestHideTrayIcon() { throw winrt::hresult_error{}; };
+        void RequestQuitAll() { throw winrt::hresult_error{}; };
+        void Quit() { throw winrt::hresult_error{}; };
         TYPED_EVENT(WindowActivated, winrt::Windows::Foundation::IInspectable, Remoting::WindowActivatedArgs);
         TYPED_EVENT(ExecuteCommandlineRequested, winrt::Windows::Foundation::IInspectable, Remoting::CommandlineArgs);
         TYPED_EVENT(IdentifyWindowsRequested, winrt::Windows::Foundation::IInspectable, winrt::Windows::Foundation::IInspectable);
@@ -83,6 +85,8 @@ namespace RemotingUnitTests
         TYPED_EVENT(SummonRequested, winrt::Windows::Foundation::IInspectable, Remoting::SummonWindowBehavior);
         TYPED_EVENT(ShowTrayIconRequested, winrt::Windows::Foundation::IInspectable, winrt::Windows::Foundation::IInspectable);
         TYPED_EVENT(HideTrayIconRequested, winrt::Windows::Foundation::IInspectable, winrt::Windows::Foundation::IInspectable);
+        TYPED_EVENT(QuitAllRequested, winrt::Windows::Foundation::IInspectable, winrt::Windows::Foundation::IInspectable);
+        TYPED_EVENT(QuitRequested, winrt::Windows::Foundation::IInspectable, winrt::Windows::Foundation::IInspectable);
     };
 
     class RemotingTests

src/cascadia/WindowsTerminal/AppHost.cpp

@@ -213,6 +213,7 @@ void AppHost::_HandleCommandlineArgs()
         peasant.SummonRequested({ this, &AppHost::_HandleSummon });
 
         peasant.DisplayWindowIdRequested({ this, &AppHost::_DisplayWindowId });
+        peasant.QuitRequested({ this, &AppHost::_QuitRequested });
 
         // We need this property to be set before we get the InitialSize/Position
         // and BecameMonarch which normally sets it is only run after the window
@@ -278,6 +279,7 @@ void AppHost::Initialize()
     _logic.SettingsChanged({ this, &AppHost::_HandleSettingsChanged });
     _logic.IsQuakeWindowChanged({ this, &AppHost::_IsQuakeWindowChanged });
     _logic.SummonWindowRequested({ this, &AppHost::_SummonWindowRequested });
+    _logic.QuitRequested({ this, &AppHost::_RequestQuitAll });
 
     _window->UpdateTitle(_logic.Title());
 
@@ -690,6 +692,9 @@ void AppHost::_BecomeMonarch(const winrt::Windows::Foundation::IInspectable& /*s
     // These events are coming from peasants that become or un-become quake windows.
     _windowManager.ShowTrayIconRequested([this](auto&&, auto&&) { _ShowTrayIconRequested(); });
     _windowManager.HideTrayIconRequested([this](auto&&, auto&&) { _HideTrayIconRequested(); });
+    // If the monarch receives a QuitAll event it will signal this event to be
+    // ran before each peasant is closed.
+    _windowManager.QuitAllRequested({ this, &AppHost::_QuitAllRequested });
 }
 
 void AppHost::_listenForInboundConnections()
@@ -1024,6 +1029,28 @@ void AppHost::_IsQuakeWindowChanged(const winrt::Windows::Foundation::IInspectab
     _window->IsQuakeWindow(_logic.IsQuakeWindow());
 }
 
+winrt::fire_and_forget AppHost::_QuitRequested(const winrt::Windows::Foundation::IInspectable&,
+                                               const winrt::Windows::Foundation::IInspectable&)
+{
+    // Need to be on the main thread to close out all of the tabs.
+    co_await winrt::resume_foreground(_logic.GetRoot().Dispatcher());
+
+    _logic.Quit();
+}
+
+void AppHost::_RequestQuitAll(const winrt::Windows::Foundation::IInspectable&,
+                              const winrt::Windows::Foundation::IInspectable&)
+{
+    _windowManager.RequestQuitAll();
+}
+
+void AppHost::_QuitAllRequested(const winrt::Windows::Foundation::IInspectable&,
+                                const winrt::Windows::Foundation::IInspectable&)
+{
+    // TODO: GH#9800: For now, nothing needs to be done before the monarch closes all windows.
+    // Later when we have state saving that should go here.
+}
+
 void AppHost::_SummonWindowRequested(const winrt::Windows::Foundation::IInspectable& sender,
                                      const winrt::Windows::Foundation::IInspectable&)
 {

src/cascadia/WindowsTerminal/AppHost.h

@@ -85,6 +85,15 @@ private:
     void _SummonWindowRequested(const winrt::Windows::Foundation::IInspectable& sender,
                                 const winrt::Windows::Foundation::IInspectable& args);
 
+    winrt::fire_and_forget _QuitRequested(const winrt::Windows::Foundation::IInspectable& sender,
+                                          const winrt::Windows::Foundation::IInspectable& args);
+
+    void _RequestQuitAll(const winrt::Windows::Foundation::IInspectable& sender,
+                         const winrt::Windows::Foundation::IInspectable& args);
+
+    void _QuitAllRequested(const winrt::Windows::Foundation::IInspectable& sender,
+                           const winrt::Windows::Foundation::IInspectable& args);
+
     void _CreateTrayIcon();
     void _DestroyTrayIcon();
     void _ShowTrayIconRequested();