Add ability to select all text in the buffer (#13045)

Adds the `selectAll` action which can be used to select all text in the buffer (regardless of whether a selection is present).

## References
#3663 - Mark Mode
#4993 - [Scenario] Keyboard selection

## PR Checklist
* [x] Closes #1469
* [x] Tests added/passed

## Detailed Description of the Pull Request / Additional comments
I've made it such that selecting the "entire buffer" really just selects up to the mutable viewport. This seems like a nice QOL improvement since there's generally nothing past that.

When the user selects all, the viewport does not move. This is consistent with CMD behavior and is intended to allow the user to not lose context when selecting everything.

A minor change had to be made to the DxRenderer because this uncovered an underflow issue. Basically, the selection rects were handed to the DxEngine relative to the viewport (which means that some had a negative y-value). At some point, those rects were stored into `size_t`s, resulting in an underflow issue. This caused the renderer to behave strangely when rendering the selection. Generally, these kinds of issues weren't really noticed because selection would always modify a portion of the viewport.

Funny enough, in a way, this satisfies the "mark mode" scenario because the user now has a way to initiate a selection using only the keyboard. Though this isn't ideal, just a fun thing to point out (that's why I'm not closing the mark mode issue).

## Validation Steps Performed
- Verified using DxEngine and AtlasEngine
- select all --> keyboard selection --> start moving the top-left endpoint (and scroll to there)
- select all --> do not scroll automatically

src/cascadia/TerminalApp/AppActionHandlers.cpp

@@ -1033,4 +1033,14 @@ namespace winrt::TerminalApp::implementation
             }
         }
     }
+
+    void TerminalPage::_HandleSelectAll(const IInspectable& /*sender*/,
+                                        const ActionEventArgs& args)
+    {
+        if (const auto& control{ _GetActiveControl() })
+        {
+            control.SelectAll();
+            args.Handled(true);
+        }
+    }
 }

src/cascadia/TerminalControl/ControlCore.cpp

@@ -994,6 +994,13 @@ namespace winrt::Microsoft::Terminal::Control::implementation
         return true;
     }
 
+    void ControlCore::SelectAll()
+    {
+        auto lock = _terminal->LockForWriting();
+        _terminal->SelectAll();
+        _renderer->TriggerSelection();
+    }
+
     // Method Description:
     // - Pre-process text pasted (presumably from the clipboard)
     //   before sending it over the terminal's connection.

src/cascadia/TerminalControl/ControlCore.h

@@ -80,6 +80,7 @@ namespace winrt::Microsoft::Terminal::Control::implementation
         void SendInput(const winrt::hstring& wstr);
         void PasteText(const winrt::hstring& hstr);
         bool CopySelectionToClipboard(bool singleLine, const Windows::Foundation::IReference<CopyFormat>& formats);
+        void SelectAll();
 
         void GotFocus();
         void LostFocus();

src/cascadia/TerminalControl/ControlCore.idl

@@ -65,6 +65,7 @@ namespace Microsoft.Terminal.Control
                            Microsoft.Terminal.Core.ControlKeyStates modifiers);
         void SendInput(String text);
         void PasteText(String text);
+        void SelectAll();
         void ClearBuffer(ClearBufferType clearType);
 
         void SetHoveredCell(Microsoft.Terminal.Core.Point terminalPosition);

src/cascadia/TerminalControl/TermControl.cpp

@@ -1840,6 +1840,11 @@ namespace winrt::Microsoft::Terminal::Control::implementation
         _interactivity.RequestPasteTextFromClipboard();
     }
 
+    void TermControl::SelectAll()
+    {
+        _core.SelectAll();
+    }
+
     void TermControl::Close()
     {
         if (!_IsClosing())

src/cascadia/TerminalControl/TermControl.h

@@ -37,6 +37,7 @@ namespace winrt::Microsoft::Terminal::Control::implementation
 
         bool CopySelectionToClipboard(bool singleLine, const Windows::Foundation::IReference<CopyFormat>& formats);
         void PasteTextFromClipboard();
+        void SelectAll();
         void Close();
         Windows::Foundation::Size CharacterDimensions() const;
         Windows::Foundation::Size MinimumSize();

src/cascadia/TerminalControl/TermControl.idl

@@ -50,6 +50,7 @@ namespace Microsoft.Terminal.Control
 
         Boolean CopySelectionToClipboard(Boolean singleLine, Windows.Foundation.IReference<CopyFormat> formats);
         void PasteTextFromClipboard();
+        void SelectAll();
         void ClearBuffer(ClearBufferType clearType);
         void Close();
         Windows.Foundation.Size CharacterDimensions { get; };

src/cascadia/TerminalCore/Terminal.hpp

@@ -240,6 +240,7 @@ class Microsoft::Terminal::Core::Terminal final :
     void SetSelectionEnd(const COORD position, std::optional<SelectionExpansion> newExpansionMode = std::nullopt);
     void SetBlockSelection(const bool isEnabled) noexcept;
     void UpdateSelection(SelectionDirection direction, SelectionExpansion mode);
+    void SelectAll();
 
     using UpdateSelectionParams = std::optional<std::pair<SelectionDirection, SelectionExpansion>>;
     static UpdateSelectionParams ConvertKeyEventToUpdateSelectionParams(const ControlKeyStates mods, const WORD vkey);

src/cascadia/TerminalCore/TerminalSelection.cpp

@@ -329,6 +329,15 @@ void Terminal::UpdateSelection(SelectionDirection direction, SelectionExpansion
     }
 }
 
+void Terminal::SelectAll()
+{
+    const auto bufferSize{ _activeBuffer().GetSize() };
+    _selection = SelectionAnchors{};
+    _selection->start = bufferSize.Origin();
+    _selection->end = { bufferSize.RightInclusive(), _GetMutableViewport().BottomInclusive() };
+    _selection->pivot = _selection->end;
+}
+
 void Terminal::_MoveByChar(SelectionDirection direction, COORD& pos)
 {
     switch (direction)

src/cascadia/TerminalSettingsModel/ActionAndArgs.cpp

@@ -75,6 +75,7 @@ static constexpr std::string_view MultipleActionsKey{ "multipleActions" };
 static constexpr std::string_view QuitKey{ "quit" };
 static constexpr std::string_view AdjustOpacityKey{ "adjustOpacity" };
 static constexpr std::string_view RestoreLastClosedKey{ "restoreLastClosed" };
+static constexpr std::string_view SelectAllKey{ "selectAll" };
 
 static constexpr std::string_view ActionKey{ "action" };
 
@@ -386,6 +387,7 @@ namespace winrt::Microsoft::Terminal::Settings::Model::implementation
                 { ShortcutAction::Quit, RS_(L"QuitCommandKey") },
                 { ShortcutAction::AdjustOpacity, L"" }, // Intentionally omitted, must be generated by GenerateName
                 { ShortcutAction::RestoreLastClosed, RS_(L"RestoreLastClosedCommandKey") },
+                { ShortcutAction::SelectAll, RS_(L"SelectAllCommandKey") },
             };
         }();
 

src/cascadia/TerminalSettingsModel/AllShortcutActions.h

@@ -88,7 +88,8 @@
     ON_ALL_ACTIONS(MultipleActions)        \
     ON_ALL_ACTIONS(Quit)                   \
     ON_ALL_ACTIONS(AdjustOpacity)          \
-    ON_ALL_ACTIONS(RestoreLastClosed)
+    ON_ALL_ACTIONS(RestoreLastClosed)      \
+    ON_ALL_ACTIONS(SelectAll)
 
 #define ALL_SHORTCUT_ACTIONS_WITH_ARGS             \
     ON_ALL_ACTIONS_WITH_ARGS(AdjustFontSize)       \

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

@@ -522,4 +522,7 @@
   <data name="RestoreLastClosedCommandKey" xml:space="preserve">
     <value>Restore the last closed pane or tab</value>
   </data>
-</root>
+  <data name="SelectAllCommandKey" xml:space="preserve">
+    <value>Select all text</value>
+  </data>
+</root>

src/cascadia/TerminalSettingsModel/defaults.json

@@ -384,6 +384,7 @@
         { "command": { "action": "copy", "singleLine": false }, "keys": "ctrl+insert" },
         { "command": "paste", "keys": "ctrl+shift+v" },
         { "command": "paste", "keys": "shift+insert" },
+        { "command": "selectAll", "keys": "ctrl+shift+a" },
 
         // Scrollback
         { "command": "scrollDown", "keys": "ctrl+shift+down" },

src/renderer/dx/DxRenderer.cpp

@@ -1064,8 +1064,8 @@ HANDLE DxEngine::GetSwapChainHandle() noexcept
 void DxEngine::_InvalidateRectangle(const til::rect& rc)
 {
     const auto size = _invalidMap.size();
-    const auto topLeft = til::point{ 0, std::min(size.height, rc.top) };
-    const auto bottomRight = til::point{ size.width, std::min(size.height, rc.bottom) };
+    const auto topLeft = til::point{ 0, std::clamp(rc.top, 0, size.height) };
+    const auto bottomRight = til::point{ size.width, std::clamp(rc.bottom, 0, size.height) };
     _invalidMap.set(til::rect{ topLeft, bottomRight });
 }