Address PR feedback: mark setting as experimental and simplify enum defaults

Author: ghnew

src/cascadia/TerminalControl/IControlSettings.idl

@@ -29,6 +29,13 @@ namespace Microsoft.Terminal.Control
         MinGW,
     };
 
+    enum MiddleClickAction
+    {
+        Pan = 0,
+        Paste,
+        None,
+    };
+
     // Class Description:
     // TerminalSettings encapsulates all settings that control the
     //      TermControl's behavior. In these settings there is both the entirety
@@ -77,6 +84,7 @@ namespace Microsoft.Terminal.Control
 
         PathTranslationStyle PathTranslationStyle { get; };
         String DragDropDelimiter { get; };
+        Microsoft.Terminal.Control.MiddleClickAction MiddleClickAction { get; };
 
         // NOTE! When adding something here, make sure to update ControlProperties.h too!
     };

src/cascadia/TerminalControl/TermControl.cpp

@@ -1995,6 +1995,15 @@ namespace winrt::Microsoft::Terminal::Control::implementation
         else
         {
             const auto cursorPosition = point.Position();
+            if (point.Properties().IsMiddleButtonPressed() && !_core.IsVtMouseModeEnabled())
+            {
+                const auto action = _core.Settings().MiddleClickAction();
+                if (action == Control::MiddleClickAction::Pan)
+                {
+                    _isPanning = true;
+                    _panningAnchorPos = cursorPosition;
+                }
+            }
             _interactivity.PointerPressed(point.PointerId(),
                                           TermControl::GetPressedMouseButtons(point),
                                           TermControl::GetPointerUpdateKind(point),
@@ -2019,7 +2028,10 @@ namespace winrt::Microsoft::Terminal::Control::implementation
             return;
         }
 
-        RestorePointerCursor.raise(*this, nullptr);
+        if (!_isPanning)
+        {
+            RestorePointerCursor.raise(*this, nullptr);
+        }
 
         const auto ptr = args.Pointer();
         const auto point = args.GetCurrentPoint(*this);
@@ -2041,11 +2053,39 @@ namespace winrt::Microsoft::Terminal::Control::implementation
                                                                        ControlKeyStates(args.KeyModifiers()),
                                                                        pixelPosition);
 
+            if (_isPanning && _panningAnchorPos)
+            {
+                const auto dy = cursorPosition.Y - _panningAnchorPos->Y;
+                constexpr auto MinPanDist = 5.0;
+
+                if (const auto window = CoreWindow::GetForCurrentThread())
+                {
+                    if (std::abs(dy) > MinPanDist)
+                    {
+                        window.PointerCursor(CoreCursor(CoreCursorType::SizeNorthSouth, 1));
+                    }
+                    else
+                    {
+                        window.PointerCursor(CoreCursor(CoreCursorType::SizeAll, 1));
+                    }
+                }
+
+                if (std::abs(dy) > MinPanDist)
+                {
+                    const auto scrollDist = dy > 0 ? (dy - MinPanDist) : (dy + MinPanDist);
+                    const auto newVelocity = _GetAutoScrollSpeed(std::abs(scrollDist)) * (dy > 0 ? 1.0 : -1.0);
+                    _TryStartAutoScroll(point, newVelocity);
+                }
+                else
+                {
+                    _TryStopAutoScroll(ptr.PointerId());
+                }
+            }
             // GH#9109 - Only start an auto-scroll when the drag actually
             // started within our bounds. Otherwise, someone could start a drag
             // outside the terminal control, drag into the padding, and trick us
             // into starting to scroll.
-            if (!suppressFurtherHandling && _focused && _pointerPressedInBounds && point.Properties().IsLeftButtonPressed())
+            else if (!suppressFurtherHandling && _focused && _pointerPressedInBounds && point.Properties().IsLeftButtonPressed())
             {
                 // We want to find the distance relative to the bounds of the
                 // SwapChainPanel, not the entire control. If they drag out of
@@ -2124,6 +2164,16 @@ namespace winrt::Microsoft::Terminal::Control::implementation
             _interactivity.TouchReleased();
         }
 
+        if (_isPanning)
+        {
+            _isPanning = false;
+            _panningAnchorPos = std::nullopt;
+            if (const auto window = CoreWindow::GetForCurrentThread())
+            {
+                window.PointerCursor(CoreCursor(CoreCursorType::IBeam, 1));
+            }
+        }
+
         _TryStopAutoScroll(ptr.PointerId());
 
         args.Handled(true);

src/cascadia/TerminalSettingsModel/MTSMSettings.h

@@ -111,7 +111,8 @@ Author(s):
     X(bool, AllowOscNotifications, "compatibility.allowOSC777", false)                                                                                         \
     X(bool, AllowKeypadMode, "compatibility.allowDECNKM", false)                                                                                               \
     X(hstring, DragDropDelimiter, "dragDropDelimiter", L" ")                                                                                                   \
-    X(Microsoft::Terminal::Control::PathTranslationStyle, PathTranslationStyle, "pathTranslationStyle", Microsoft::Terminal::Control::PathTranslationStyle::None)
+    X(Microsoft::Terminal::Control::PathTranslationStyle, PathTranslationStyle, "pathTranslationStyle", Microsoft::Terminal::Control::PathTranslationStyle::None) \
+    X(Microsoft::Terminal::Control::MiddleClickAction, MiddleClickAction, "experimental.middleClickAction", Microsoft::Terminal::Control::MiddleClickAction::Pan)
 
 // Intentionally omitted Profile settings:
 // * Name

src/cascadia/TerminalSettingsModel/TerminalSettingsSerializationHelpers.h

@@ -874,6 +874,15 @@ JSON_ENUM_MAPPER(::winrt::Microsoft::Terminal::Control::PathTranslationStyle)
     };
 };
 
+JSON_ENUM_MAPPER(::winrt::Microsoft::Terminal::Control::MiddleClickAction)
+{
+    static constexpr std::array<pair_type, 3> mappings = {
+        pair_type{ "pan", ValueType::Pan },
+        pair_type{ "paste", ValueType::Paste },
+        pair_type{ "none", ValueType::None },
+    };
+};
+
 JSON_ENUM_MAPPER(::winrt::Microsoft::Terminal::Control::WarnAboutMultiLinePaste)
 {
     JSON_MAPPINGS(3) = {

src/cascadia/inc/ControlProperties.h

@@ -89,4 +89,5 @@
     X(winrt::Microsoft::Terminal::Control::CopyFormat, CopyFormatting, 0)                                                                                \
     X(bool, RightClickContextMenu, false)                                                                                                                \
     X(winrt::Microsoft::Terminal::Control::PathTranslationStyle, PathTranslationStyle, winrt::Microsoft::Terminal::Control::PathTranslationStyle::None)  \
-    X(winrt::hstring, DragDropDelimiter, L" ")
+    X(winrt::hstring, DragDropDelimiter, L" ")                                                                                                           \
+    X(winrt::Microsoft::Terminal::Control::MiddleClickAction, MiddleClickAction, winrt::Microsoft::Terminal::Control::MiddleClickAction::Pan)