Ignore right-click copy when copy on select is enabled (microsoft#4819)

<!-- Enter a brief description/summary of your PR here. What does it fix/what does it change/how was it tested (even manually, if necessary)? -->
## Summary of the Pull Request
Right clicking on a focused tab while Copy On Select is active currently copies any active selection. This is because `PointerReleasedHandler` doesn't check for the mouse button that was released. 
During a mouse button release, only the left mouse button release should be doing anything.

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## PR Checklist
* [x] Closes microsoft#4740
* [x] CLA signed.
* [x] Tests added/passed

<!-- Describe how you validated the behavior. Add automated tests wherever possible, but list manual validation steps taken as well -->
## Validation Steps Performed
These are the scenarios I've tested. They're a combination of in focus/out of focus, Copy On Select on/off, left/right click pressed and their move and release variants.

From Out of Focus:
- Left Click = Focus
- Left Click Move = Focus + Selection
- Left Click Release
  - CoS on = Copy
  - CoS off = Nothing
- Shift Left Click = Focus
- Right Click 
  - Focus 
  - CoS on = Paste
  - CoS off = Copy if Active Selection, Paste if not.
- Right Click Move = Nothing
- Right Click Release = Nothing

From In Focus
- Left Click = Selection if CoS off
- Left Click Move = Selection
- Left Click Release
  - CoS on = Copy
  - CoS off = Nothing
- Shift Left Click = Set Selection Anchor
- Right Click 
  - CoS on = Paste
  - CoS off = Copy if Active Selection, Paste if not.
- Right Click Move = Nothing
- Right Click Release = Nothing

src/cascadia/TerminalControl/TermControl.cpp

@@ -65,11 +65,11 @@ namespace winrt::Microsoft::Terminal::TerminalControl::implementation
         _actualFont{ DEFAULT_FONT_FACE, 0, 10, { 0, DEFAULT_FONT_SIZE }, CP_UTF8, false },
         _touchAnchor{ std::nullopt },
         _cursorTimer{},
-        _lastMouseClick{},
+        _lastMouseClickTimestamp{},
         _lastMouseClickPos{},
         _searchBox{ nullptr },
-        _unfocusedClickPos{ std::nullopt },
-        _isClickDragSelection{ false }
+        _focusRaisedClickPos{ std::nullopt },
+        _clickDrag{ false }
     {
         _EnsureStaticInitialization();
         InitializeComponent();
@@ -827,13 +827,9 @@ namespace winrt::Microsoft::Terminal::TerminalControl::implementation
         if (!_focused)
         {
             Focus(FocusState::Pointer);
-
-            // Save the click position here when the terminal does not have focus
-            // because they might be performing a click-drag selection. Since we
-            // only want to start the selection when the user moves the pointer with
-            // the left mouse button held down, the PointerMovedHandler will use
-            // this saved position to set the SelectionAnchor.
-            _unfocusedClickPos = point.Position();
+            // Save the click position that brought this control into focus
+            // in case the user wants to perform a click-drag selection.
+            _focusRaisedClickPos = point.Position();
         }
 
         if (ptr.PointerDeviceType() == Windows::Devices::Input::PointerDeviceType::Mouse || ptr.PointerDeviceType() == Windows::Devices::Input::PointerDeviceType::Pen)
@@ -846,11 +842,8 @@ namespace winrt::Microsoft::Terminal::TerminalControl::implementation
 
             if (point.Properties().IsLeftButtonPressed())
             {
-                // _unfocusedClickPos having a value signifies to us that
-                // the user clicked on an unfocused terminal. We don't want
-                // a single left click from out of focus to start a selection,
-                // so we return fast here.
-                if (_unfocusedClickPos)
+                // A single left click from out of focus should only focus.
+                if (_focusRaisedClickPos)
                 {
                     args.Handled(true);
                     return;
@@ -885,18 +878,17 @@ namespace winrt::Microsoft::Terminal::TerminalControl::implementation
                     }
                     else
                     {
-                        // save location before rendering
                         _terminal->SetSelectionAnchor(terminalPosition);
                     }
 
-                    _lastMouseClick = point.Timestamp();
+                    _lastMouseClickTimestamp = point.Timestamp();
                     _lastMouseClickPos = cursorPosition;
                 }
                 _renderer->TriggerSelection();
             }
             else if (point.Properties().IsRightButtonPressed())
             {
-                // copyOnSelect causes right-click to always paste
+                // CopyOnSelect right click always pastes
                 if (_terminal->IsCopyOnSelectActive() || !_terminal->IsSelectionActive())
                 {
                     PasteTextFromClipboard();
@@ -932,15 +924,13 @@ namespace winrt::Microsoft::Terminal::TerminalControl::implementation
         {
             if (point.Properties().IsLeftButtonPressed())
             {
-                _isClickDragSelection = true;
+                _clickDrag = true;
 
-                // If this does not have a value, it means that PointerPressedHandler already
-                // set the SelectionAnchor. If it does have a value, that means the user is
-                // performing a click-drag selection on an unfocused terminal, so
-                // a SelectionAnchor isn't set yet. We'll have to set it here.
-                if (_unfocusedClickPos)
+                // PointerPressedHandler doesn't set the SelectionAnchor when the click was
+                // from out of focus, so PointerMoved has to set it.
+                if (_focusRaisedClickPos)
                 {
-                    _terminal->SetSelectionAnchor(_GetTerminalPosition(*_unfocusedClickPos));
+                    _terminal->SetSelectionAnchor(_GetTerminalPosition(*_focusRaisedClickPos));
                 }
 
                 const auto cursorPosition = point.Position();
@@ -1011,22 +1001,26 @@ namespace winrt::Microsoft::Terminal::TerminalControl::implementation
     void TermControl::_PointerReleasedHandler(Windows::Foundation::IInspectable const& sender,
                                               Input::PointerRoutedEventArgs const& args)
     {
-        _ReleasePointerCapture(sender, args);
-
         const auto ptr = args.Pointer();
+        const auto point = args.GetCurrentPoint(*this);
+
+        _ReleasePointerCapture(sender, args);
 
         if (ptr.PointerDeviceType() == Windows::Devices::Input::PointerDeviceType::Mouse || ptr.PointerDeviceType() == Windows::Devices::Input::PointerDeviceType::Pen)
         {
-            const auto modifiers = static_cast<uint32_t>(args.KeyModifiers());
-            // static_cast to a uint32_t because we can't use the WI_IsFlagSet
-            // macro directly with a VirtualKeyModifiers
-            const auto shiftEnabled = WI_IsFlagSet(modifiers, static_cast<uint32_t>(VirtualKeyModifiers::Shift));
-
-            if (_terminal->IsCopyOnSelectActive())
+            // Only a left click release when copy on select is active should perform a copy.
+            // Right clicks and middle clicks should not need to do anything when released.
+            if (_terminal->IsCopyOnSelectActive() && point.Properties().PointerUpdateKind() == Windows::UI::Input::PointerUpdateKind::LeftButtonReleased)
             {
-                // If the terminal was in focus, copy to clipboard.
-                // If the terminal was unfocused AND a click-drag selection happened, copy to clipboard.
-                if (!_unfocusedClickPos || (_unfocusedClickPos && _isClickDragSelection))
+                const auto modifiers = static_cast<uint32_t>(args.KeyModifiers());
+                // static_cast to a uint32_t because we can't use the WI_IsFlagSet
+                // macro directly with a VirtualKeyModifiers
+                const auto shiftEnabled = WI_IsFlagSet(modifiers, static_cast<uint32_t>(VirtualKeyModifiers::Shift));
+
+                // In a Copy on Select scenario,
+                // All left click drags should copy,
+                // All left clicks on a focused control should copy if a selection is active.
+                if (_clickDrag || !_focusRaisedClickPos)
                 {
                     CopySelectionToClipboard(shiftEnabled);
                 }
@@ -1037,8 +1031,8 @@ namespace winrt::Microsoft::Terminal::TerminalControl::implementation
             _touchAnchor = std::nullopt;
         }
 
-        _unfocusedClickPos = std::nullopt;
-        _isClickDragSelection = false;
+        _focusRaisedClickPos = std::nullopt;
+        _clickDrag = false;
 
         _TryStopAutoScroll(ptr.PointerId());
 
@@ -2110,7 +2104,7 @@ namespace winrt::Microsoft::Terminal::TerminalControl::implementation
     {
         // if click occurred at a different location or past the multiClickTimer...
         Timestamp delta;
-        THROW_IF_FAILED(UInt64Sub(clickTime, _lastMouseClick, &delta));
+        THROW_IF_FAILED(UInt64Sub(clickTime, _lastMouseClickTimestamp, &delta));
         if (clickPos != _lastMouseClickPos || delta > _multiClickTimer)
         {
             // exit early. This is a single click.

src/cascadia/TerminalControl/TermControl.h

@@ -155,11 +155,12 @@ namespace winrt::Microsoft::Terminal::TerminalControl::implementation
         // imported from WinUser
         // Used for PointerPoint.Timestamp Property (https://docs.microsoft.com/en-us/uwp/api/windows.ui.input.pointerpoint.timestamp#Windows_UI_Input_PointerPoint_Timestamp)
         Timestamp _multiClickTimer;
-        Timestamp _lastMouseClick;
+        Timestamp _lastMouseClickTimestamp;
         unsigned int _multiClickCounter;
         std::optional<winrt::Windows::Foundation::Point> _lastMouseClickPos;
-        std::optional<winrt::Windows::Foundation::Point> _unfocusedClickPos;
-        bool _isClickDragSelection;
+
+        std::optional<winrt::Windows::Foundation::Point> _focusRaisedClickPos;
+        bool _clickDrag;
 
         winrt::Windows::UI::Xaml::Controls::SwapChainPanel::LayoutUpdated_revoker _layoutUpdatedRevoker;