Windows: Improved support for DPI-aware embedded windows in HWNDComponent

modules/juce_gui_basics/native/juce_win32_Windowing.cpp

@@ -547,44 +547,46 @@ JUCE_API double getScaleFactorForWindow (HWND h)
     return 1.0;
  }
 
-#if JUCE_WIN_PER_MONITOR_DPI_AWARE
- JUCE_API void setThreadDPIAwarenessForWindow (HWND nativeWindow)
- {
-     // NB. Using local functions here because we need to call this method from the plug-in wrappers
-     // which don't load the DPI-awareness functions on startup
-     static SetThreadDPIAwarenessContextFunc        localSetThreadDPIAwarenessContext        = nullptr;
-     static GetWindowDPIAwarenessContextFunc        localGetWindowDPIAwarenessContext        = nullptr;
-     static GetThreadDPIAwarenessContextFunc        localGetThreadDPIAwarenessContext        = nullptr;
-     static GetAwarenessFromDpiAwarenessContextFunc localGetAwarenessFromDPIAwarenessContext = nullptr;
-
-     static bool hasChecked = false;
-     static bool loadedOK = false;
-
-     if (! hasChecked)
-     {
-         hasChecked = true;
-
-         localSetThreadDPIAwarenessContext        = (SetThreadDPIAwarenessContextFunc) getUser32Function ("SetThreadDpiAwarenessContext");
-         localGetWindowDPIAwarenessContext        = (GetWindowDPIAwarenessContextFunc) getUser32Function ("GetWindowDpiAwarenessContext");
-         localGetThreadDPIAwarenessContext        = (GetThreadDPIAwarenessContextFunc) getUser32Function ("GetThreadDpiAwarenessContext");
-         localGetAwarenessFromDPIAwarenessContext = (GetAwarenessFromDpiAwarenessContextFunc) getUser32Function ("GetAwarenessFromDpiAwarenessContext");
-
-         loadedOK = (localSetThreadDPIAwarenessContext != nullptr && localGetWindowDPIAwarenessContext != nullptr
-                    && localGetThreadDPIAwarenessContext != nullptr && localGetAwarenessFromDPIAwarenessContext != nullptr);
-     }
-
-     if (loadedOK)
-     {
-         auto dpiAwareWindow = localGetAwarenessFromDPIAwarenessContext (localGetWindowDPIAwarenessContext (nativeWindow)) == DPI_Awareness::DPI_Awareness_Per_Monitor_Aware;
-         auto dpiAwareThread = localGetAwarenessFromDPIAwarenessContext (localGetThreadDPIAwarenessContext()) == DPI_Awareness::DPI_Awareness_Per_Monitor_Aware;
-
-         if (dpiAwareWindow && ! dpiAwareThread)
-             localSetThreadDPIAwarenessContext (DPI_AWARENESS_CONTEXT_PER_MONITOR_AWARE);
-         else if (! dpiAwareWindow && dpiAwareThread)
-             localSetThreadDPIAwarenessContext (DPI_AWARENESS_CONTEXT_UNAWARE);
-     }
- }
-#endif
+JUCE_API void setThreadDPIAwarenessForWindow (HWND nativeWindow)
+{
+   #if JUCE_WIN_PER_MONITOR_DPI_AWARE
+    // NB. Using local functions here because we need to call this method from the plug-in wrappers
+    // which don't load the DPI-awareness functions on startup
+    static SetThreadDPIAwarenessContextFunc        localSetThreadDPIAwarenessContext        = nullptr;
+    static GetWindowDPIAwarenessContextFunc        localGetWindowDPIAwarenessContext        = nullptr;
+    static GetThreadDPIAwarenessContextFunc        localGetThreadDPIAwarenessContext        = nullptr;
+    static GetAwarenessFromDpiAwarenessContextFunc localGetAwarenessFromDPIAwarenessContext = nullptr;
+
+    static bool hasChecked = false;
+    static bool loadedOK = false;
+
+    if (! hasChecked)
+    {
+        hasChecked = true;
+
+        localSetThreadDPIAwarenessContext        = (SetThreadDPIAwarenessContextFunc) getUser32Function ("SetThreadDpiAwarenessContext");
+        localGetWindowDPIAwarenessContext        = (GetWindowDPIAwarenessContextFunc) getUser32Function ("GetWindowDpiAwarenessContext");
+        localGetThreadDPIAwarenessContext        = (GetThreadDPIAwarenessContextFunc) getUser32Function ("GetThreadDpiAwarenessContext");
+        localGetAwarenessFromDPIAwarenessContext = (GetAwarenessFromDpiAwarenessContextFunc) getUser32Function ("GetAwarenessFromDpiAwarenessContext");
+
+        loadedOK = (localSetThreadDPIAwarenessContext != nullptr && localGetWindowDPIAwarenessContext != nullptr
+                   && localGetThreadDPIAwarenessContext != nullptr && localGetAwarenessFromDPIAwarenessContext != nullptr);
+    }
+
+    if (loadedOK)
+    {
+        auto dpiAwareWindow = localGetAwarenessFromDPIAwarenessContext (localGetWindowDPIAwarenessContext (nativeWindow)) == DPI_Awareness::DPI_Awareness_Per_Monitor_Aware;
+        auto dpiAwareThread = localGetAwarenessFromDPIAwarenessContext (localGetThreadDPIAwarenessContext()) == DPI_Awareness::DPI_Awareness_Per_Monitor_Aware;
+
+        if (dpiAwareWindow && ! dpiAwareThread)
+            localSetThreadDPIAwarenessContext (DPI_AWARENESS_CONTEXT_PER_MONITOR_AWARE);
+        else if (! dpiAwareWindow && dpiAwareThread)
+            localSetThreadDPIAwarenessContext (DPI_AWARENESS_CONTEXT_UNAWARE);
+    }
+   #else
+    ignoreUnused (nativeWindow);
+   #endif
+}
 
 //==============================================================================
 static void setWindowPos (HWND hwnd, Rectangle<int> bounds, UINT flags, bool adjustTopLeft = false)

modules/juce_gui_extra/embedding/juce_HWNDComponent.h

@@ -71,6 +71,9 @@ public:
     /** Resizes this component to fit the HWND that it contains. */
     void resizeToFit();
 
+    /** @internal */
+    void paint (Graphics&) override;
+
 private:
     class Pimpl;
     std::unique_ptr<Pimpl> pimpl;

modules/juce_gui_extra/native/juce_win32_HWNDComponent.cpp

@@ -26,6 +26,8 @@
 namespace juce
 {
 
+void setThreadDPIAwarenessForWindow (HWND);
+
 class HWNDComponent::Pimpl  : public ComponentMovementWatcher
 {
 public:
@@ -44,27 +46,21 @@ public:
         DestroyWindow (hwnd);
     }
 
-    using ComponentMovementWatcher::componentMovedOrResized;
-
-    void componentMovedOrResized (bool wasMoved, bool wasResized) override
+    void componentMovedOrResized (bool, bool) override
     {
-        auto* topComponent = owner.getTopLevelComponent();
-
-        if (auto* peer = owner.getPeer())
+        if (auto* peer = owner.getTopLevelComponent()->getPeer())
         {
-            auto pos = topComponent->getLocalPoint (&owner, Point<int>());
+            auto area = (peer->getAreaCoveredBy (owner).toFloat() * peer->getPlatformScaleFactor()).toNearestInt();
 
-            auto scaled = (Rectangle<int> (pos.x, pos.y, owner.getWidth(), owner.getHeight()).toDouble()
-                            * peer->getPlatformScaleFactor()).getSmallestIntegerContainer();
+            setThreadDPIAwarenessForWindow (hwnd);
 
-            DWORD windowFlags = SWP_NOACTIVATE | SWP_NOZORDER | SWP_NOOWNERZORDER;
-            if (! wasMoved)    windowFlags |= SWP_NOMOVE;
-            if (! wasResized)  windowFlags |= SWP_NOSIZE;
-
-            SetWindowPos (hwnd, nullptr, scaled.getX(), scaled.getY(), scaled.getWidth(), scaled.getHeight(), windowFlags);
+            SetWindowPos (hwnd, nullptr, area.getX(), area.getY(), area.getWidth(), area.getHeight(),
+                          SWP_NOACTIVATE | SWP_NOZORDER | SWP_NOOWNERZORDER);
         }
     }
 
+    using ComponentMovementWatcher::componentMovedOrResized;
+
     void componentPeerChanged() override
     {
         auto* peer = owner.getPeer();
@@ -85,13 +81,13 @@ public:
             InvalidateRect (hwnd, nullptr, 0);
      }
 
-    using ComponentMovementWatcher::componentVisibilityChanged;
-
     void componentVisibilityChanged() override
     {
         componentPeerChanged();
     }
 
+    using ComponentMovementWatcher::componentVisibilityChanged;
+
     void componentBroughtToFront (Component& comp) override
     {
         ComponentMovementWatcher::componentBroughtToFront (comp);
@@ -101,11 +97,13 @@ public:
     {
         if (auto* peer = owner.getPeer())
         {
+            setThreadDPIAwarenessForWindow (hwnd);
+
             RECT r;
             GetWindowRect (hwnd, &r);
+            Rectangle<int> windowRectangle (r.right - r.left, r.bottom - r.top);
 
-            return (Rectangle<int>::leftTopRightBottom (r.left, r.top, r.right, r.bottom).toDouble()
-                     / peer->getPlatformScaleFactor()).getSmallestIntegerContainer();
+            return (windowRectangle.toFloat() / peer->getPlatformScaleFactor()).toNearestInt();
         }
 
         return {};
@@ -120,7 +118,8 @@ private:
         {
             auto windowFlags = GetWindowLongPtr (hwnd, -16);
 
-            windowFlags &= ~(WS_POPUP | WS_CHILD);
+            windowFlags &= ~WS_POPUP;
+            windowFlags |= WS_CHILD;
 
             SetWindowLongPtr (hwnd, -16, windowFlags);
             SetParent (hwnd, (HWND) currentPeer->getNativeHandle());
@@ -131,6 +130,7 @@ private:
 
     void removeFromParent()
     {
+        ShowWindow (hwnd, SW_HIDE);
         SetParent (hwnd, NULL);
     }
 
@@ -141,12 +141,11 @@ private:
 };
 
 //==============================================================================
-HWNDComponent::HWNDComponent()
-{
-}
-
+HWNDComponent::HWNDComponent()  {}
 HWNDComponent::~HWNDComponent() {}
 
+void HWNDComponent::paint (Graphics&) {}
+
 void HWNDComponent::setHWND (void* hwnd)
 {
     if (hwnd != getHWND())