Update window background when the color table changes.

src/cascadia/PublicTerminalCore/HwndTerminal.cpp

@@ -239,8 +239,6 @@ HRESULT HwndTerminal::Initialize()
 
     _renderEngine = std::move(dxEngine);
 
-    _terminal->SetBackgroundCallback([](auto) {});
-
     _terminal->Create(COORD{ 80, 25 }, 1000, *_renderer);
     _terminal->SetWriteInputCallback([=](std::wstring_view input) noexcept { _WriteTextToConnection(input); });
     localPointerToThread->EnablePainting();

src/cascadia/TerminalControl/ControlCore.cpp

@@ -96,9 +96,6 @@ namespace winrt::Microsoft::Terminal::Control::implementation
         auto pfnTabColorChanged = std::bind(&ControlCore::_terminalTabColorChanged, this, std::placeholders::_1);
         _terminal->SetTabColorChangedCallback(pfnTabColorChanged);
 
-        auto pfnBackgroundColorChanged = std::bind(&ControlCore::_terminalBackgroundColorChanged, this, std::placeholders::_1);
-        _terminal->SetBackgroundCallback(pfnBackgroundColorChanged);
-
         auto pfnScrollPositionChanged = std::bind(&ControlCore::_terminalScrollPositionChanged, this, std::placeholders::_1, std::placeholders::_2, std::placeholders::_3);
         _terminal->SetScrollPositionChangedCallback(pfnScrollPositionChanged);
 
@@ -128,6 +125,8 @@ namespace winrt::Microsoft::Terminal::Control::implementation
             const auto& renderSettings = _terminal->GetRenderSettings();
             _renderer = std::make_unique<::Microsoft::Console::Render::Renderer>(renderSettings, _terminal.get(), nullptr, 0, std::move(renderThread));
 
+            _renderer->SetBackgroundColorChangedCallback([this]() { _rendererBackgroundColorChanged(); });
+
             _renderer->SetRendererEnteredErrorStateCallback([weakThis = get_weak()]() {
                 if (auto strongThis{ weakThis.get() })
                 {
@@ -1153,21 +1152,6 @@ namespace winrt::Microsoft::Terminal::Control::implementation
         _TabColorChangedHandlers(*this, nullptr);
     }
 
-    // Method Description:
-    // - Called for the Terminal's BackgroundColorChanged callback. This will
-    //   re-raise a new winrt TypedEvent that can be listened to.
-    // - The listeners to this event will re-query the control for the current
-    //   value of BackgroundColor().
-    // Arguments:
-    // - <unused>
-    // Return Value:
-    // - <none>
-    void ControlCore::_terminalBackgroundColorChanged(const COLORREF /*color*/)
-    {
-        // Raise a BackgroundColorChanged event
-        _BackgroundColorChangedHandlers(*this, nullptr);
-    }
-
     // Method Description:
     // - Update the position and size of the scrollbar to match the given
     //      viewport top, viewport height, and buffer size.
@@ -1360,6 +1344,11 @@ namespace winrt::Microsoft::Terminal::Control::implementation
         _SwapChainChangedHandlers(*this, nullptr);
     }
 
+    void ControlCore::_rendererBackgroundColorChanged()
+    {
+        _BackgroundColorChangedHandlers(*this, nullptr);
+    }
+
     void ControlCore::BlinkAttributeTick()
     {
         auto lock = _terminal->LockForWriting();
@@ -1684,8 +1673,7 @@ namespace winrt::Microsoft::Terminal::Control::implementation
 
         _renderEngine->SetSelectionBackground(til::color{ _settings->SelectionBackground() });
 
-        _renderer->TriggerRedrawAll();
-        _BackgroundColorChangedHandlers(*this, nullptr);
+        _renderer->TriggerRedrawAll(true);
     }
 
     bool ControlCore::HasUnfocusedAppearance() const

src/cascadia/TerminalControl/ControlCore.h

@@ -265,7 +265,6 @@ namespace winrt::Microsoft::Terminal::Control::implementation
         void _terminalWarningBell();
         void _terminalTitleChanged(std::wstring_view wstr);
         void _terminalTabColorChanged(const std::optional<til::color> color);
-        void _terminalBackgroundColorChanged(const COLORREF color);
         void _terminalScrollPositionChanged(const int viewTop,
                                             const int viewHeight,
                                             const int bufferSize);
@@ -277,6 +276,7 @@ namespace winrt::Microsoft::Terminal::Control::implementation
 #pragma region RendererCallbacks
         void _rendererWarning(const HRESULT hr);
         void _renderEngineSwapChainChanged();
+        void _rendererBackgroundColorChanged();
 #pragma endregion
 
         void _raiseReadOnlyWarning();

src/cascadia/TerminalCore/Terminal.cpp

@@ -1301,15 +1301,6 @@ void Terminal::SetCursorPositionChangedCallback(std::function<void()> pfn) noexc
     _pfnCursorPositionChanged.swap(pfn);
 }
 
-// Method Description:
-// - Allows setting a callback for when the background color is changed
-// Arguments:
-// - pfn: a function callback that takes a color
-void Terminal::SetBackgroundCallback(std::function<void(const til::color)> pfn) noexcept
-{
-    _pfnBackgroundColorChanged.swap(pfn);
-}
-
 // Method Description:
 // - Allows settings a callback for settings the taskbar progress indicator
 // Arguments:

src/cascadia/TerminalCore/Terminal.hpp

@@ -200,7 +200,6 @@ class Microsoft::Terminal::Core::Terminal final :
     void SetCopyToClipboardCallback(std::function<void(std::wstring_view)> pfn) noexcept;
     void SetScrollPositionChangedCallback(std::function<void(const int, const int, const int)> pfn) noexcept;
     void SetCursorPositionChangedCallback(std::function<void()> pfn) noexcept;
-    void SetBackgroundCallback(std::function<void(const til::color)> pfn) noexcept;
     void TaskbarProgressChangedCallback(std::function<void()> pfn) noexcept;
     void SetShowWindowCallback(std::function<void(bool)> pfn) noexcept;
 
@@ -268,7 +267,6 @@ class Microsoft::Terminal::Core::Terminal final :
 #endif
 
     std::function<void(const int, const int, const int)> _pfnScrollPositionChanged;
-    std::function<void(const til::color)> _pfnBackgroundColorChanged;
     std::function<void()> _pfnCursorPositionChanged;
     std::function<void(const std::optional<til::color>)> _pfnTabColorChanged;
     std::function<void()> _pfnTaskbarProgressChanged;

src/renderer/base/renderer.cpp

@@ -298,17 +298,22 @@ void Renderer::TriggerRedrawCursor(const COORD* const pcoord)
 // - Called when something that changes the output state has occurred and the entire frame is now potentially invalid.
 // - NOTE: Use sparingly. Try to reduce the refresh region where possible. Only use when a global state change has occurred.
 // Arguments:
-// - <none>
+// - backgroundChanged - Set to true if the background color has changed.
 // Return Value:
 // - <none>
-void Renderer::TriggerRedrawAll()
+void Renderer::TriggerRedrawAll(const bool backgroundChanged)
 {
     FOREACH_ENGINE(pEngine)
     {
         LOG_IF_FAILED(pEngine->InvalidateAll());
     }
 
     NotifyPaintFrame();
+
+    if (backgroundChanged && _pfnBackgroundColorChanged)
+    {
+        _pfnBackgroundColorChanged();
+    }
 }
 
 // Method Description:
@@ -1331,6 +1336,17 @@ void Renderer::AddRenderEngine(_In_ IRenderEngine* const pEngine)
     THROW_HR_MSG(E_UNEXPECTED, "engines array is full");
 }
 
+// Method Description:
+// - Registers a callback for when the background color is changed
+// Arguments:
+// - pfn: the callback
+// Return Value:
+// - <none>
+void Renderer::SetBackgroundColorChangedCallback(std::function<void()> pfn)
+{
+    _pfnBackgroundColorChanged = std::move(pfn);
+}
+
 // Method Description:
 // - Registers a callback that will be called when this renderer gives up.
 //   An application consuming a renderer can use this to display auxiliary Retry UI

src/renderer/base/renderer.hpp

@@ -52,7 +52,7 @@ namespace Microsoft::Console::Render
         void TriggerRedraw(const Microsoft::Console::Types::Viewport& region);
         void TriggerRedraw(const COORD* const pcoord);
         void TriggerRedrawCursor(const COORD* const pcoord);
-        void TriggerRedrawAll();
+        void TriggerRedrawAll(const bool backgroundChanged = false);
         void TriggerTeardown() noexcept;
 
         void TriggerSelection();
@@ -84,6 +84,7 @@ namespace Microsoft::Console::Render
 
         void AddRenderEngine(_In_ IRenderEngine* const pEngine);
 
+        void SetBackgroundColorChangedCallback(std::function<void()> pfn);
         void SetRendererEnteredErrorStateCallback(std::function<void()> pfn);
         void ResetErrorStateAndResume();
 
@@ -121,6 +122,7 @@ namespace Microsoft::Console::Render
         Microsoft::Console::Types::Viewport _viewport;
         std::vector<Cluster> _clusterBuffer;
         std::vector<SMALL_RECT> _previousSelection;
+        std::function<void()> _pfnBackgroundColorChanged;
         std::function<void()> _pfnRendererEnteredErrorState;
         bool _destructing = false;
 

src/terminal/adapter/adaptDispatch.cpp

@@ -2234,12 +2234,14 @@ bool AdaptDispatch::SetColorTableEntry(const size_t tableIndex, const DWORD dwCo
         return false;
     }
 
-    // TODO: In the Terminal we also need to call the _pfnBackgroundColorChanged
-    // handler when this is going to affect the background color.
+    // If we're updating the background color, we need to let the renderer
+    // know, since it may want to repaint the window background to match.
+    const auto backgroundIndex = _renderSettings.GetColorAliasIndex(ColorAlias::DefaultBackground);
+    const auto backgroundChanged = (tableIndex == backgroundIndex);
 
     // Update the screen colors if we're not a pty
     // No need to force a redraw in pty mode.
-    _renderer.TriggerRedrawAll();
+    _renderer.TriggerRedrawAll(backgroundChanged);
     return true;
 }