Fix Touch Keyboard invocation issue (#11389)

This fixes an issue that Touch Keyboard is not invoked when user taps on the PowerShell. 

Before this change, it was returning small rectangle on the right of the cursor. Touch Keyboard should be invoked by tapping anywhere inside the console.

## PR Checklist
* [ ] Closes #xxx
* [x] CLA signed. If not, go over [here](https://cla.opensource.microsoft.com/microsoft/Terminal) and sign the CLA
* [ ] Tests added/passed
* [ ] Documentation updated. If checked, please file a pull request on [our docs repo](https://github.com/MicrosoftDocs/terminal) and link it here: #xxx
* [ ] Schema updated.
* [x] I've discussed this with core contributors already. If not checked, I'm ready to accept this work might be rejected in favor of a different grand plan. Issue number where discussion took place: #xxx

## Detailed Description of the Pull Request / Additional comments
ITfContextOwner::GetScreenExt is used to define rectangle that can invoke Touch Keyboard. 
https://docs.microsoft.com/en-us/windows/win32/api/msctf/nf-msctf-itfcontextowner-getscreenext

## Validation Steps Performed
* [x] Touch keyboard was invoked by tapping inside the Console while Hardware Keyboard was not attached.
* [x] Selecting text worked as expected without invoking touch keyboard.
* [x] Long tapping the console invoked Touch Keyboard. I would like to confirm if this is the expected behavior.

src/inc/contsf.h

@@ -29,8 +29,9 @@ extern "C" {
 #endif
 
 typedef RECT (*GetSuggestionWindowPos)();
+typedef RECT (*GetTextBoxAreaPos)();
 
-BOOL ActivateTextServices(HWND hwndConsole, GetSuggestionWindowPos pfnPosition);
+BOOL ActivateTextServices(HWND hwndConsole, GetSuggestionWindowPos pfnPosition, GetTextBoxAreaPos pfnTextArea);
 void DeactivateTextServices();
 BOOL NotifyTextServices(UINT uMsg, WPARAM wParam, LPARAM lParam, LRESULT* lplResult);
 

src/interactivity/win32/WindowIme.cpp

@@ -54,3 +54,15 @@ RECT GetImeSuggestionWindowPos()
 
     return rcSuggestion;
 }
+
+// Routine Description:
+// - This method gives a rectangle to where text box is currently rendered
+//   such that the touch keyboard can pop up when the rectangle is tapped.
+// Arguments:
+// - <none>
+// Return Value:
+// - Rectangle specifying current text box area.
+RECT GetTextBoxArea()
+{
+    return Microsoft::Console::Interactivity::ServiceLocator::LocateConsoleWindow()->GetWindowRect();
+}

src/interactivity/win32/windowime.hpp

@@ -6,3 +6,4 @@
 #pragma hdrstop
 
 RECT GetImeSuggestionWindowPos();
+RECT GetTextBoxArea();

src/interactivity/win32/windowproc.cpp

@@ -263,7 +263,7 @@ using namespace Microsoft::Console::Types;
         HandleFocusEvent(TRUE);
 
         // ActivateTextServices does nothing if already active so this is OK to be called every focus.
-        ActivateTextServices(ServiceLocator::LocateConsoleWindow()->GetWindowHandle(), GetImeSuggestionWindowPos);
+        ActivateTextServices(ServiceLocator::LocateConsoleWindow()->GetWindowHandle(), GetImeSuggestionWindowPos, GetTextBoxArea);
 
         // set the text area to have focus for accessibility consumers
         if (_pUiaProvider)

src/tsf/ConsoleTSF.h

@@ -33,9 +33,11 @@ class CConsoleTSF final :
 {
 public:
     CConsoleTSF(HWND hwndConsole,
-                GetSuggestionWindowPos pfnPosition) :
+                GetSuggestionWindowPos pfnPosition,
+                GetTextBoxAreaPos pfnTextArea) :
         _hwndConsole(hwndConsole),
         _pfnPosition(pfnPosition),
+        _pfnTextArea(pfnTextArea),
         _cRef(1),
         _tid()
     {
@@ -66,21 +68,27 @@ public:
         return S_OK;
     }
 
+    // This returns Rectangle of the text box of whole console.
+    // When a user taps inside the rectangle while hardware keyboard is not available,
+    // touch keyboard is invoked.
     STDMETHODIMP GetScreenExt(RECT* pRect)
     {
         if (pRect)
         {
-            *pRect = _pfnPosition();
+            *pRect = _pfnTextArea();
         }
 
         return S_OK;
     }
 
+    // This returns rectangle of current command line edit area.
+    // When a user types in East Asian language, candidate window is shown at this position.
+    // Emoji and more panel (Win+.) is shown at the position, too.
     STDMETHODIMP GetTextExt(LONG, LONG, RECT* pRect, BOOL* pbClipped)
     {
         if (pRect)
         {
-            GetScreenExt(pRect);
+            *pRect = _pfnPosition();
         }
 
         if (pbClipped)
@@ -198,6 +206,7 @@ private:
     // Console info.
     HWND _hwndConsole;
     GetSuggestionWindowPos _pfnPosition;
+    GetTextBoxAreaPos _pfnTextArea;
 
     // Miscellaneous flags
     BOOL _fModifyingDoc = FALSE; // Set TRUE, when calls ITfRange::SetText

src/tsf/contsf.cpp

@@ -5,11 +5,11 @@
 
 CConsoleTSF* g_pConsoleTSF = nullptr;
 
-extern "C" BOOL ActivateTextServices(HWND hwndConsole, GetSuggestionWindowPos pfnPosition)
+extern "C" BOOL ActivateTextServices(HWND hwndConsole, GetSuggestionWindowPos pfnPosition, GetTextBoxAreaPos pfnTextArea)
 {
     if (!g_pConsoleTSF && hwndConsole)
     {
-        g_pConsoleTSF = new (std::nothrow) CConsoleTSF(hwndConsole, pfnPosition);
+        g_pConsoleTSF = new (std::nothrow) CConsoleTSF(hwndConsole, pfnPosition, pfnTextArea);
         if (g_pConsoleTSF && SUCCEEDED(g_pConsoleTSF->Initialize()))
         {
             // Conhost calls this function only when the console window has focus.