Add support for a HighlightCursor keybinding

src/cascadia/TerminalApp/AppActionHandlers.cpp

@@ -861,4 +861,14 @@ namespace winrt::TerminalApp::implementation
             }
         }
     }
+
+    void TerminalPage::_HandleHighlightCursor(const IInspectable& /*sender*/,
+                                              const ActionEventArgs& args)
+    {
+        if (const auto termControl{ _GetActiveControl() })
+        {
+            termControl.HighlightCursor();
+            args.Handled(true);
+        }
+    }
 }

src/cascadia/TerminalControl/ControlCore.cpp

@@ -1297,6 +1297,18 @@ namespace winrt::Microsoft::Terminal::Control::implementation
         return _terminal != nullptr && _terminal->IsTrackingMouseInput();
     }
 
+    bool ControlCore::IsCursorOffScreen() const
+    {
+        // If we haven't been initialized yet, then just return true
+        if (!_initializedTerminal)
+        {
+            return true;
+        }
+
+        auto lock = _terminal->LockForReading();
+        return _terminal->IsCursorOffScreen();
+    }
+
     til::point ControlCore::CursorPosition() const
     {
         // If we haven't been initialized yet, then fake it.

src/cascadia/TerminalControl/ControlCore.h

@@ -120,6 +120,7 @@ namespace winrt::Microsoft::Terminal::Control::implementation
         void CursorOn(const bool isCursorOn);
 
         bool IsVtMouseModeEnabled() const;
+        bool IsCursorOffScreen() const;
         til::point CursorPosition() const;
 
         bool HasSelection() const;

src/cascadia/TerminalControl/ControlCore.idl

@@ -80,6 +80,7 @@ namespace Microsoft.Terminal.Control
         Boolean IsInReadOnlyMode { get; };
         Boolean CursorOn;
         void EnablePainting();
+        Boolean IsCursorOffScreen();
 
         event FontSizeChangedEventArgs FontSizeChanged;
 

src/cascadia/TerminalControl/TermControl.cpp

@@ -2381,6 +2381,34 @@ namespace winrt::Microsoft::Terminal::Control::implementation
         return _core.TaskbarProgress();
     }
 
+    // Method Description:
+    // - Toggles the spotlight on the cursor
+    // - If the cursor is currently off the screen, does nothing
+    void TermControl::HighlightCursor()
+    {
+        if (CursorLight::GetIsTarget(RootGrid()))
+        {
+            CursorLight::SetIsTarget(RootGrid(), false);
+        }
+        else if (!_core.IsCursorOffScreen())
+        {
+            // Compute the location of where to place the light
+            const auto charSizeInPixels = CharacterDimensions();
+            const auto htInDips = charSizeInPixels.Height / SwapChainPanel().CompositionScaleY();
+            const auto wtInDips = charSizeInPixels.Width / SwapChainPanel().CompositionScaleX();
+            const til::size marginsInDips{ til::math::rounding, GetPadding().Left, GetPadding().Top };
+            const til::size fontSize{ til::math::rounding, _core.FontSize() };
+            const til::point cursorPos = _core.CursorPosition();
+            const til::point cursorPosInPixels{ cursorPos * fontSize };
+            const til::point cursorPosInDIPs{ cursorPosInPixels / SwapChainPanel().CompositionScaleX() };
+            const til::point cursorLocationInDIPs{ cursorPosInDIPs + marginsInDips };
+
+            CursorLight().ChangeLocation(gsl::narrow_cast<float>(cursorLocationInDIPs.x()) + wtInDips / 2,
+                                         gsl::narrow_cast<float>(cursorLocationInDIPs.y()) + htInDips / 2);
+            CursorLight::SetIsTarget(RootGrid(), true);
+        }
+    }
+
     void TermControl::BellLightOn()
     {
         // Initialize the animation if it does not exist

src/cascadia/TerminalControl/TermControl.h

@@ -100,6 +100,8 @@ namespace winrt::Microsoft::Terminal::Control::implementation
 
         void BellLightOn();
 
+        void HighlightCursor();
+
         bool ReadOnly() const noexcept;
         void ToggleReadOnly();
 

src/cascadia/TerminalControl/TermControl.idl

@@ -65,6 +65,8 @@ namespace Microsoft.Terminal.Control
 
         void BellLightOn();
 
+        void HighlightCursor();
+
         Boolean ReadOnly { get; };
         void ToggleReadOnly();
     }

src/cascadia/TerminalControl/TermControl.xaml

@@ -35,6 +35,7 @@
     <Grid x:Name="RootGrid">
         <Grid.Lights>
             <local:VisualBellLight x:Name="BellLight" />
+            <local:CursorLight x:Name="CursorLight" />
         </Grid.Lights>
         <Image x:Name="BackgroundImage"
                AutomationProperties.AccessibilityView="Raw" />

src/cascadia/TerminalControl/XamlLights.cpp

@@ -5,18 +5,15 @@
 #include "TermControl.h"
 #include "XamlLights.h"
 #include "VisualBellLight.g.cpp"
+#include "CursorLight.g.cpp"
 
 using namespace winrt::Windows::UI::Xaml;
 using namespace winrt::Windows::UI::Xaml::Media;
 
 namespace winrt::Microsoft::Terminal::Control::implementation
 {
     DependencyProperty VisualBellLight::_IsTargetProperty{ nullptr };
-
-    VisualBellLight::VisualBellLight()
-    {
-        _InitializeProperties();
-    }
+    DependencyProperty CursorLight::_IsTargetProperty{ nullptr };
 
     void VisualBellLight::_InitializeProperties()
     {
@@ -49,59 +46,66 @@ namespace winrt::Microsoft::Terminal::Control::implementation
         }
     }
 
-    // Method Description:
-    // - This function is called when there are no more target UIElements on the screen
-    // - Disposes of composition resources when no longer in use
-    // Arguments:
-    // - oldElement: unused
-    void VisualBellLight::OnDisconnected(UIElement const& /* oldElement */)
+    void CursorLight::_InitializeProperties()
     {
-        if (CompositionLight())
+        // Initialize any dependency properties here.
+        // This performs a lazy load on these properties, instead of
+        // initializing them when the DLL loads.
+        if (!_IsTargetProperty)
         {
-            CompositionLight(nullptr);
+            _IsTargetProperty =
+                DependencyProperty::RegisterAttached(
+                    L"IsTarget",
+                    winrt::xaml_typename<bool>(),
+                    winrt::xaml_typename<Control::CursorLight>(),
+                    PropertyMetadata{ winrt::box_value(false), PropertyChangedCallback{ &CursorLight::OnIsTargetChanged } });
         }
     }
 
-    winrt::hstring VisualBellLight::GetId()
+    void CursorLight::ChangeLocation(float xCoord, float yCoord)
     {
-        return VisualBellLight::GetIdStatic();
+        if (const auto light = CompositionLight())
+        {
+            if (const auto cursorLight = light.try_as<Windows::UI::Composition::SpotLight>())
+            {
+                cursorLight.Offset({ xCoord, yCoord, 100 });
+            }
+        }
+        else
+        {
+            _InitializeHelper(xCoord, yCoord);
+        }
     }
 
-    void VisualBellLight::OnIsTargetChanged(DependencyObject const& d, DependencyPropertyChangedEventArgs const& e)
+    // Method Description:
+    // - This function is called when the first target UIElement is shown on the screen,
+    //   this enables delaying composition object creation until it's actually necessary.
+    // Arguments:
+    // - newElement: unused
+    void CursorLight::OnConnected(UIElement const& /* newElement */)
     {
-        const auto uielem{ d.try_as<UIElement>() };
-        const auto brush{ d.try_as<Brush>() };
-
-        if (!uielem && !brush)
+        if (!CompositionLight())
         {
-            // terminate early
-            return;
+            _InitializeHelper(0, 0);
         }
+    }
 
-        const auto isAdding = winrt::unbox_value<bool>(e.NewValue());
-        const auto id = GetIdStatic();
-
-        if (isAdding)
-        {
-            if (uielem)
-            {
-                XamlLight::AddTargetElement(id, uielem);
-            }
-            else
-            {
-                XamlLight::AddTargetBrush(id, brush);
-            }
-        }
-        else
+    // Method Description:
+    // - Helper to initialize the propoerties of the spotlight such as the location and
+    //   the angles of the inner and outer cones
+    // Arguments:
+    // - xCoord: the x-coordinate of where to put the light
+    // - yCoord: the y-coordinate of where to put the light
+    void CursorLight::_InitializeHelper(float xCoord, float yCoord)
+    {
+        if (!CompositionLight())
         {
-            if (uielem)
-            {
-                XamlLight::RemoveTargetElement(id, uielem);
-            }
-            else
-            {
-                XamlLight::RemoveTargetBrush(id, brush);
-            }
+            auto spotLight{ Window::Current().Compositor().CreateSpotLight() };
+            spotLight.InnerConeColor(Windows::UI::Colors::White());
+            spotLight.InnerConeAngleInDegrees(10);
+            spotLight.OuterConeAngleInDegrees(25);
+            spotLight.Offset({ xCoord, yCoord, 100 });
+            CompositionLight(spotLight);
         }
     }
 }