bugfix: correctly show markers when one cell selected

src/cascadia/TerminalControl/ControlCore.cpp

@@ -950,8 +950,7 @@ namespace winrt::Microsoft::Terminal::Control::implementation
         const auto end{ _terminal->SelectionEndForRendering() };
         info.EndPos = { end.X, end.Y };
 
-        info.MovingEnd = _terminal->MovingEnd();
-        info.MovingCursor = _terminal->MovingCursor();
+        info.Endpoint = static_cast<SelectionEndpointTarget>(_terminal->SelectionEndpointTarget());
 
         const auto bufferSize{ _terminal->GetTextBuffer().GetSize() };
         info.StartAtLeftBoundary = _terminal->GetSelectionAnchor().x == bufferSize.Left();

src/cascadia/TerminalControl/ControlCore.idl

@@ -29,12 +29,18 @@ namespace Microsoft.Terminal.Control
         All
     };
 
+    [flags]
+    enum SelectionEndpointTarget
+    {
+        Start = 0x1,
+        End = 0x2
+    };
+
     struct SelectionData
     {
         Microsoft.Terminal.Core.Point StartPos;
         Microsoft.Terminal.Core.Point EndPos;
-        Boolean MovingEnd;
-        Boolean MovingCursor;
+        SelectionEndpointTarget Endpoint;
         Boolean StartAtLeftBoundary;
         Boolean EndAtRightBoundary;
     };

src/cascadia/TerminalControl/TermControl.cpp

@@ -2830,9 +2830,10 @@ namespace winrt::Microsoft::Terminal::Control::implementation
 
                 // show/update selection markers
                 // figure out which endpoint to move, get it and the relevant icon (hide the other icon)
-                const auto selectionAnchor{ markerData.MovingEnd ? markerData.EndPos : markerData.StartPos };
-                const auto& marker{ markerData.MovingEnd ? SelectionEndMarker() : SelectionStartMarker() };
-                const auto& otherMarker{ markerData.MovingEnd ? SelectionStartMarker() : SelectionEndMarker() };
+                const auto movingEnd{ WI_IsFlagSet(markerData.Endpoint, SelectionEndpointTarget::End) };
+                const auto selectionAnchor{ movingEnd ? markerData.EndPos : markerData.StartPos };
+                const auto& marker{ movingEnd ? SelectionEndMarker() : SelectionStartMarker() };
+                const auto& otherMarker{ movingEnd ? SelectionStartMarker() : SelectionEndMarker() };
                 if (selectionAnchor.Y < 0 || selectionAnchor.Y >= _core.ViewHeight())
                 {
                     // if the endpoint is outside of the viewport,
@@ -2841,7 +2842,7 @@ namespace winrt::Microsoft::Terminal::Control::implementation
                     otherMarker.Visibility(Visibility::Collapsed);
                     co_return;
                 }
-                else if (markerData.MovingCursor)
+                else if (WI_AreAllFlagsSet(markerData.Endpoint, SelectionEndpointTarget::Start | SelectionEndpointTarget::End))
                 {
                     // display both markers
                     displayMarker(true);
@@ -2851,7 +2852,7 @@ namespace winrt::Microsoft::Terminal::Control::implementation
                 {
                     // display one marker,
                     // but hide the other
-                    displayMarker(markerData.MovingEnd);
+                    displayMarker(movingEnd);
                     otherMarker.Visibility(Visibility::Collapsed);
                 }
             }

src/cascadia/TerminalCore/Terminal.cpp

@@ -48,6 +48,7 @@ Terminal::Terminal() :
     _markMode{ false },
     _quickEditMode{ false },
     _selection{ std::nullopt },
+    _selectionEndpoint{ static_cast<SelectionEndpoint>(0) },
     _taskbarState{ 0 },
     _taskbarProgress{ 0 },
     _trimBlockSelection{ false },

src/cascadia/TerminalCore/Terminal.hpp

@@ -249,6 +249,13 @@ class Microsoft::Terminal::Core::Terminal final :
         Viewport,
         Buffer
     };
+
+    enum class SelectionEndpoint
+    {
+        Start = 0x1,
+        End = 0x2
+    };
+
     void MultiClickSelection(const til::point viewportPos, SelectionExpansion expansionMode);
     void SetSelectionAnchor(const til::point position);
     void SetSelectionEnd(const til::point position, std::optional<SelectionExpansion> newExpansionMode = std::nullopt);
@@ -261,10 +268,9 @@ class Microsoft::Terminal::Core::Terminal final :
 
     using UpdateSelectionParams = std::optional<std::pair<SelectionDirection, SelectionExpansion>>;
     UpdateSelectionParams ConvertKeyEventToUpdateSelectionParams(const ControlKeyStates mods, const WORD vkey) const;
-    bool MovingEnd() const noexcept;
-    bool MovingCursor() const noexcept;
     til::point SelectionStartForRendering() const;
     til::point SelectionEndForRendering() const;
+    const SelectionEndpoint SelectionEndpointTarget() const noexcept;
 
     const TextBuffer::TextAndColor RetrieveSelectedTextFromBuffer(bool trimTrailingWhitespace);
 #pragma endregion
@@ -336,6 +342,7 @@ class Microsoft::Terminal::Core::Terminal final :
     SelectionExpansion _multiClickSelectionMode;
     bool _markMode;
     bool _quickEditMode;
+    SelectionEndpoint _selectionEndpoint;
 #pragma endregion
 
     std::unique_ptr<TextBuffer> _mainBuffer;

src/cascadia/TerminalCore/TerminalSelection.cpp

@@ -7,6 +7,8 @@
 
 using namespace Microsoft::Terminal::Core;
 
+DEFINE_ENUM_FLAG_OPERATORS(Terminal::SelectionEndpoint);
+
 /* Selection Pivot Description:
  *   The pivot helps properly update the selection when a user moves a selection over itself
  *   See SelectionTest::DoubleClickDrag_Left for an example of the functionality mentioned here
@@ -120,6 +122,11 @@ til::point Terminal::SelectionEndForRendering() const
     return til::point{ pos };
 }
 
+const Terminal::SelectionEndpoint Terminal::SelectionEndpointTarget() const noexcept
+{
+    return _selectionEndpoint;
+}
+
 // Method Description:
 // - Checks if selection is active
 // Return Value:
@@ -303,6 +310,7 @@ void Terminal::ToggleMarkMode()
         _markMode = true;
         _quickEditMode = false;
         _blockSelection = false;
+        WI_SetAllFlags(_selectionEndpoint, SelectionEndpoint::Start | SelectionEndpoint::End);
     }
 }
 
@@ -354,21 +362,6 @@ Terminal::UpdateSelectionParams Terminal::ConvertKeyEventToUpdateSelectionParams
     return std::nullopt;
 }
 
-bool Terminal::MovingEnd() const noexcept
-{
-    // true --> we're moving end endpoint ("lower")
-    // false --> we're moving start endpoint ("higher")
-    return _selection->start == _selection->pivot;
-}
-
-bool Terminal::MovingCursor() const noexcept
-{
-    // Relevant for keyboard selection:
-    // true --> the selection is just a "cursor"; we're moving everything together with arrow keys
-    // false --> otherwise
-    return _selection->start == _selection->pivot && _selection->pivot == _selection->end;
-}
-
 // Method Description:
 // - updates the selection endpoints based on a direction and expansion mode. Primarily used for keyboard selection.
 // Arguments:
@@ -378,9 +371,25 @@ bool Terminal::MovingCursor() const noexcept
 void Terminal::UpdateSelection(SelectionDirection direction, SelectionExpansion mode, ControlKeyStates mods)
 {
     // 1. Figure out which endpoint to update
-    // One of the endpoints is the pivot,
-    // signifying that the other endpoint is the one we want to move.
-    auto targetPos{ MovingEnd() ? _selection->end : _selection->start };
+    // [Mark Mode]
+    // - shift pressed --> only move "end" (or "start" if "pivot" == "end")
+    // - otherwise --> move both "start" and "end" (moving cursor)
+    // [Quick Edit]
+    // - just move "end" (or "start" if "pivot" == "end")
+    _selectionEndpoint = static_cast<SelectionEndpoint>(0);
+    if (_markMode && !mods.IsShiftPressed())
+    {
+        WI_SetAllFlags(_selectionEndpoint, SelectionEndpoint::Start | SelectionEndpoint::End);
+    }
+    else if (_selection->start == _selection->pivot)
+    {
+        WI_SetFlag(_selectionEndpoint, SelectionEndpoint::End);
+    }
+    else if (_selection->end == _selection->pivot)
+    {
+        WI_SetFlag(_selectionEndpoint, SelectionEndpoint::Start);
+    }
+    auto targetPos{ WI_IsFlagSet(_selectionEndpoint, SelectionEndpoint::Start) ? _selection->start : _selection->end };
 
     // 2. Perform the movement
     switch (mode)
@@ -412,9 +421,14 @@ void Terminal::UpdateSelection(SelectionDirection direction, SelectionExpansion
     {
         // [Mark Mode] + shift --> updating a standard selection
         // This is also standard quick-edit modification
-        // NOTE: targetStart doesn't matter here
-        auto targetStart = false;
+        bool targetStart;
         std::tie(_selection->start, _selection->end) = _PivotSelection(targetPos, targetStart);
+
+        // IMPORTANT! Pivoting the selection here might've changed which endpoint we're targetting.
+        // So let's set the targetted endpoint again.
+        _selectionEndpoint = static_cast<SelectionEndpoint>(0);
+        WI_SetFlagIf(_selectionEndpoint, SelectionEndpoint::Start, targetStart);
+        WI_SetFlagIf(_selectionEndpoint, SelectionEndpoint::End, !targetStart);
     }
 
     // 4. Scroll (if necessary)
@@ -586,6 +600,7 @@ void Terminal::ClearSelection()
     _selection = std::nullopt;
     _markMode = false;
     _quickEditMode = false;
+    _selectionEndpoint = static_cast<SelectionEndpoint>(0);
 }
 
 // Method Description: