[FancyZones] Responsive drawing (#7125)

* Made drawing zones not clog message processing

* Fixed synchronization bugs

* call BufferedPaintInit

* Some refactoring, the animation is back

* Rename a function

* Align parameters

src/common/on_thread_executor.cpp

@@ -16,6 +16,14 @@ std::future<void> OnThreadExecutor::submit(task_t task)
     return future;
 }
 
+void OnThreadExecutor::cancel()
+{
+    std::lock_guard lock{ _task_mutex };
+    _task_queue = {};
+    _task_cv.notify_one();
+}
+
+
 void OnThreadExecutor::worker_thread()
 {
     while (!_shutdown_request)

src/common/on_thread_executor.h

@@ -18,6 +18,7 @@ public:
     OnThreadExecutor();
     ~OnThreadExecutor();
     std::future<void> submit(task_t task);
+    void cancel();
 
 private:
     void worker_thread();

src/modules/fancyzones/lib/ZoneWindow.cpp

@@ -1,6 +1,7 @@
 #include "pch.h"
 
 #include <common/common.h>
+#include <common/on_thread_executor.h>
 
 #include "FancyZonesData.h"
 #include "FancyZonesDataTypes.h"
@@ -58,6 +59,56 @@ namespace ZoneWindowUtils
 
         return result;
     }
+
+    void PaintZoneWindow(HDC hdc,
+                         HWND window,
+                         bool hasActiveZoneSet,
+                         COLORREF hostZoneColor,
+                         COLORREF hostZoneBorderColor,
+                         COLORREF hostZoneHighlightColor,
+                         int hostZoneHighlightOpacity,
+                         std::vector<winrt::com_ptr<IZone>> zones,
+                         std::vector<size_t> highlightZone,
+                         bool flashMode,
+                         bool drawHints)
+    {
+        PAINTSTRUCT ps;
+        HDC oldHdc = hdc;
+        if (!hdc)
+        {
+            hdc = BeginPaint(window, &ps);
+        }
+
+        RECT clientRect;
+        GetClientRect(window, &clientRect);
+
+        wil::unique_hdc hdcMem;
+        HPAINTBUFFER bufferedPaint = BeginBufferedPaint(hdc, &clientRect, BPBF_TOPDOWNDIB, nullptr, &hdcMem);
+        if (bufferedPaint)
+        {
+            ZoneWindowDrawing::DrawBackdrop(hdcMem, clientRect);
+
+            if (hasActiveZoneSet)
+            {
+                ZoneWindowDrawing::DrawActiveZoneSet(hdcMem,
+                                                     hostZoneColor,
+                                                     hostZoneBorderColor,
+                                                     hostZoneHighlightColor,
+                                                     hostZoneHighlightOpacity,
+                                                     zones,
+                                                     highlightZone,
+                                                     flashMode,
+                                                     drawHints);
+            }
+
+            EndBufferedPaint(bufferedPaint, TRUE);
+        }
+
+        if (!oldHdc)
+        {
+            EndPaint(window, &ps);
+        }
+    }
 }
 
 struct ZoneWindow : public winrt::implements<ZoneWindow, IZoneWindow>
@@ -106,7 +157,7 @@ private:
     void CalculateZoneSet() noexcept;
     void UpdateActiveZoneSet(_In_opt_ IZoneSet* zoneSet) noexcept;
     LRESULT WndProc(UINT message, WPARAM wparam, LPARAM lparam) noexcept;
-    void OnPaint(wil::unique_hdc& hdc) noexcept;
+    void OnPaint(HDC hdc) noexcept;
     void OnKeyUp(WPARAM wparam) noexcept;
     std::vector<size_t> ZonesFromPoint(POINT pt) noexcept;
     void CycleActiveZoneSetInternal(DWORD wparam, Trace::ZoneWindow::InputMode mode) noexcept;
@@ -128,6 +179,8 @@ private:
     static const UINT m_showAnimationDuration = 200; // ms
     static const UINT m_flashDuration = 700; // ms
     
+    std::atomic<bool> m_animating;
+    OnThreadExecutor m_paintExecutor;
     ULONG_PTR gdiplusToken;
 };
 
@@ -143,11 +196,13 @@ ZoneWindow::ZoneWindow(HINSTANCE hinstance)
 
     Gdiplus::GdiplusStartupInput gdiplusStartupInput;
     Gdiplus::GdiplusStartup(&gdiplusToken, &gdiplusStartupInput, NULL);
+    m_paintExecutor.submit(OnThreadExecutor::task_t{ []() { BufferedPaintInit(); } });
 }
 
 ZoneWindow::~ZoneWindow()
 {
     Gdiplus::GdiplusShutdown(gdiplusToken);
+    m_paintExecutor.submit(OnThreadExecutor::task_t{ []() { BufferedPaintUnInit(); } });
 }
 
 bool ZoneWindow::Init(IZoneWindowHost* host, HINSTANCE hinstance, HMONITOR monitor, const std::wstring& uniqueId, const std::wstring& parentUniqueId, bool flashZones)
@@ -400,6 +455,7 @@ ZoneWindow::ShowZoneWindow() noexcept
     SetWindowPos(window, windowInsertAfter, 0, 0, 0, 0, flags);
 
     std::thread{ [this, strong_this{ get_strong() }]() {
+        m_animating = true;
         auto window = m_window.get();
         AnimateWindow(window, m_showAnimationDuration, AW_BLEND);
         InvalidateRect(window, nullptr, true);
@@ -407,6 +463,7 @@ ZoneWindow::ShowZoneWindow() noexcept
         {
             HideZoneWindow();
         }
+        m_animating = false;
     } }.detach();
 }
 
@@ -541,23 +598,13 @@ LRESULT ZoneWindow::WndProc(UINT message, WPARAM wparam, LPARAM lparam) noexcept
         return 1;
 
     case WM_PRINTCLIENT:
+    {
+        OnPaint(reinterpret_cast<HDC>(wparam));
+    }
+    break;
     case WM_PAINT:
     {
-        PAINTSTRUCT ps;
-        wil::unique_hdc hdc{ reinterpret_cast<HDC>(wparam) };
-        if (!hdc)
-        {
-            hdc.reset(BeginPaint(m_window.get(), &ps));
-        }
-
-        OnPaint(hdc);
-
-        if (wparam == 0)
-        {
-            EndPaint(m_window.get(), &ps);
-        }
-
-        hdc.release();
+        OnPaint(NULL);
     }
     break;
 
@@ -569,31 +616,51 @@ LRESULT ZoneWindow::WndProc(UINT message, WPARAM wparam, LPARAM lparam) noexcept
     return 0;
 }
 
-void ZoneWindow::OnPaint(wil::unique_hdc& hdc) noexcept
+void ZoneWindow::OnPaint(HDC hdc) noexcept
 {
-    RECT clientRect;
-    GetClientRect(m_window.get(), &clientRect);
+    HWND window = m_window.get();
+    bool hasActiveZoneSet = m_activeZoneSet && m_host;
+    COLORREF hostZoneColor{};
+    COLORREF hostZoneBorderColor{};
+    COLORREF hostZoneHighlightColor{};
+    int hostZoneHighlightOpacity{};
+    std::vector<winrt::com_ptr<IZone>> zones{};
+    std::vector<size_t> highlightZone = m_highlightZone;
+    bool flashMode = m_flashMode;
+    bool drawHints = m_drawHints;
 
-    wil::unique_hdc hdcMem;
-    HPAINTBUFFER bufferedPaint = BeginBufferedPaint(hdc.get(), &clientRect, BPBF_TOPDOWNDIB, nullptr, &hdcMem);
-    if (bufferedPaint)
+    if (hasActiveZoneSet)
     {
-        ZoneWindowDrawing::DrawBackdrop(hdcMem, clientRect);
+        hostZoneColor = m_host->GetZoneColor();
+        hostZoneBorderColor = m_host->GetZoneBorderColor();
+        hostZoneHighlightColor = m_host->GetZoneHighlightColor();
+        hostZoneHighlightOpacity = m_host->GetZoneHighlightOpacity();
+        zones = m_activeZoneSet->GetZones();
+    }
 
-        if (m_activeZoneSet && m_host)
-        {
-            ZoneWindowDrawing::DrawActiveZoneSet(hdcMem,
-                                                   m_host->GetZoneColor(),
-                                                   m_host->GetZoneBorderColor(),
-                                                   m_host->GetZoneHighlightColor(),
-                                                   m_host->GetZoneHighlightOpacity(),
-                                                   m_activeZoneSet->GetZones(),
-                                                   m_highlightZone,
-                                                   m_flashMode,
-                                                   m_drawHints);
-        }
+    OnThreadExecutor::task_t task{
+        [=]() {
+        ZoneWindowUtils::PaintZoneWindow(hdc,
+                                         window,
+                                         hasActiveZoneSet,
+                                         hostZoneColor,
+                                         hostZoneBorderColor,
+                                         hostZoneHighlightColor,
+                                         hostZoneHighlightOpacity,
+                                         zones,
+                                         highlightZone,
+                                         flashMode,
+                                         drawHints);
+        } };
 
-        EndBufferedPaint(bufferedPaint, TRUE);
+    if (m_animating)
+    {
+        task();
+    }
+    else
+    {
+        m_paintExecutor.cancel();
+        m_paintExecutor.submit(std::move(task));
     }
 }