ComponentPeer: Add method for overriding native scale factor

modules/juce_gui_basics/native/juce_Windowing_linux.cpp

@@ -106,7 +106,7 @@ public:
         updateScaleFactorFromNewBounds (bounds, false);
 
         auto physicalBounds = parentWindow == 0 ? Desktop::getInstance().getDisplays().logicalToPhysical (bounds)
-                                                : bounds * currentScaleFactor;
+                                                : bounds * getPlatformScaleFactor();
 
         WeakReference<Component> deletionChecker (&component);
 
@@ -140,14 +140,14 @@ public:
     {
         auto physicalParentPosition = XWindowSystem::getInstance()->getPhysicalParentScreenPosition();
         auto parentPosition = parentWindow == 0 ? Desktop::getInstance().getDisplays().physicalToLogical (physicalParentPosition)
-                                                : physicalParentPosition / currentScaleFactor;
+                                                : physicalParentPosition / getPlatformScaleFactor();
 
         auto screenBounds = parentWindow == 0 ? bounds
                                               : bounds.translated (parentPosition.x, parentPosition.y);
 
         if (physical)
             return parentWindow == 0 ? Desktop::getInstance().getDisplays().logicalToPhysical (screenBounds.getTopLeft())
-                                     : screenBounds.getTopLeft() * currentScaleFactor;
+                                     : screenBounds.getTopLeft() * getPlatformScaleFactor();
 
         return screenBounds.getTopLeft();
     }
@@ -270,7 +270,7 @@ public:
         if (trueIfInAChildWindow)
             return true;
 
-        return XWindowSystem::getInstance()->contains (windowH, localPos * currentScaleFactor);
+        return XWindowSystem::getInstance()->contains (windowH, localPos * getPlatformScaleFactor());
     }
 
     void toFront (bool makeActive) override
@@ -332,7 +332,24 @@ public:
 
     double getPlatformScaleFactor() const noexcept override
     {
-        return currentScaleFactor;
+        return scaleFactorOverride.value_or (currentScaleFactor);
+    }
+
+    void setCustomPlatformScaleFactor (std::optional<double> scaleIn) override
+    {
+        const auto prev = getPlatformScaleFactor();
+        scaleFactorOverride = scaleIn;
+        const auto next = getPlatformScaleFactor();
+
+        if (approximatelyEqual (prev, next))
+            return;
+
+        scaleFactorListeners.call ([&] (ScaleFactorListener& l) { l.nativeScaleFactorChanged (next); });
+    }
+
+    std::optional<double> getCustomPlatformScaleFactor() const override
+    {
+        return scaleFactorOverride;
     }
 
     void setAlpha (float) override                                  {}
@@ -386,7 +403,7 @@ public:
         updateScaleFactorFromNewBounds (physicalBounds, true);
 
         bounds = parentWindow == 0 ? Desktop::getInstance().getDisplays().physicalToLogical (physicalBounds)
-                                   : physicalBounds / currentScaleFactor;
+                                   : physicalBounds / getPlatformScaleFactor();
 
         updateVBlankTimer();
     }
@@ -403,7 +420,7 @@ public:
             windowBorder = [&]()
             {
                 if (auto unscaledBorderSize = XWindowSystem::getInstance()->getBorderSize (windowH))
-                    return OptionalBorderSize { (*unscaledBorderSize).multipliedBy (1.0 / currentScaleFactor) };
+                    return OptionalBorderSize { (*unscaledBorderSize).multipliedBy (1.0 / getPlatformScaleFactor()) };
 
                 return OptionalBorderSize {};
             }();
@@ -460,7 +477,7 @@ private:
 
         void repaint (Rectangle<int> area)
         {
-            regionsNeedingRepaint.add (area * peer.currentScaleFactor);
+            regionsNeedingRepaint.add (area * peer.getPlatformScaleFactor());
         }
 
         void performAnyPendingRepaintsNow()
@@ -511,7 +528,7 @@ private:
                     auto context = peer.getComponent().getLookAndFeel()
                                      .createGraphicsContext (image, -totalArea.getPosition(), adjustedList);
 
-                    context->addTransform (AffineTransform::scale ((float) peer.currentScaleFactor));
+                    context->addTransform (AffineTransform::scale ((float) peer.getPlatformScaleFactor()));
                     peer.handlePaint (*context);
                 }
 
@@ -607,6 +624,7 @@ private:
     Rectangle<int> bounds;
     ComponentPeer::OptionalBorderSize windowBorder;
     bool fullScreen = false, isAlwaysOnTop = false;
+    std::optional<double> scaleFactorOverride;
     double currentScaleFactor = 1.0;
     Array<Component*> glRepaintListeners;
     ScopedWindowAssociation association;

modules/juce_gui_basics/native/juce_Windowing_windows.cpp

@@ -558,7 +558,8 @@ static Rectangle<ValueType> convertLogicalScreenRectangleToPhysical (Rectangle<V
     return r;
 }
 
-static Point<int> convertPhysicalScreenPointToLogical (Point<int> p, HWND h) noexcept
+template <typename ValueType>
+static Point<ValueType> convertPhysicalScreenPointToLogical (Point<ValueType> p, HWND h) noexcept
 {
     if (isPerMonitorDPIAwareWindow (h))
         return Desktop::getInstance().getDisplays().physicalToLogical (p, getCurrentDisplayFromScaleFactor (h));
@@ -566,7 +567,8 @@ static Point<int> convertPhysicalScreenPointToLogical (Point<int> p, HWND h) noe
     return p;
 }
 
-static Point<int> convertLogicalScreenPointToPhysical (Point<int> p, HWND h) noexcept
+template <typename ValueType>
+static Point<ValueType> convertLogicalScreenPointToPhysical (Point<ValueType> p, HWND h) noexcept
 {
     if (isPerMonitorDPIAwareWindow (h))
         return Desktop::getInstance().getDisplays().logicalToPhysical (p, getCurrentDisplayFromScaleFactor (h));
@@ -1471,8 +1473,19 @@ public:
         return convertPhysicalScreenPointToLogical (getClientRectInScreen().getPosition(), hwnd);
     }
 
-    Point<float> localToGlobal (Point<float> relativePosition) override  { return relativePosition + getScreenPosition().toFloat(); }
+    Point<float> localToGlobal (Point<float> relativePosition) override
-    Point<float> globalToLocal (Point<float> screenPosition) override    { return screenPosition   - getScreenPosition().toFloat(); }
+    {
+        const auto localPhysical = relativePosition * getPlatformScaleFactor();
+        const auto physical = localPhysical + getClientRectInScreen().getPosition().toFloat();
+        return convertPhysicalScreenPointToLogical (physical, hwnd);
+    }
+
+    Point<float> globalToLocal (Point<float> screenPosition) override
+    {
+        const auto physical = convertLogicalScreenPointToPhysical (screenPosition, hwnd);
+        const auto localPhysical = physical - getClientRectInScreen().getPosition().toFloat();
+        return localPhysical / getPlatformScaleFactor();
+    }
 
     using ComponentPeer::localToGlobal;
     using ComponentPeer::globalToLocal;
@@ -1578,12 +1591,13 @@ public:
 
     bool contains (Point<int> localPos, bool trueIfInAChildWindow) const override
     {
-        auto r = convertPhysicalScreenRectangleToLogical (D2DUtilities::toRectangle (getWindowScreenRect (hwnd)), hwnd);
+        const auto localPhysical = localPos.toFloat() / getPlatformScaleFactor();
+        auto r = D2DUtilities::toRectangle (getWindowScreenRect (hwnd)).toFloat();
 
-        if (! r.withZeroOrigin().contains (localPos))
+        if (! r.withZeroOrigin().contains (localPhysical))
             return false;
 
-        const auto screenPos = convertLogicalScreenPointToPhysical (localPos + getScreenPosition(), hwnd);
+        const auto screenPos = (localPhysical + getClientRectInScreen().getPosition().toFloat()).roundToInt();
 
         auto w = WindowFromPoint (D2DUtilities::toPOINT (screenPos));
         return w == hwnd || (trueIfInAChildWindow && (IsChild (hwnd, w) != 0));
@@ -1596,7 +1610,7 @@ public:
 
     BorderSize<int> getFrameSize() const override
     {
-        return findPhysicalBorderSize().value_or (BorderSize<int>{}).multipliedBy (1.0 / scaleFactor);
+        return findPhysicalBorderSize().value_or (BorderSize<int>{}).multipliedBy (1.0 / getPlatformScaleFactor());
     }
 
     bool setAlwaysOnTop (bool alwaysOnTop) override
@@ -1993,7 +2007,7 @@ public:
         return peer->doKeyUp (msg.wParam);
     }
 
-    double getPlatformScaleFactor() const noexcept override
+    double getPlatformScaleFactorWithoutOverride() const noexcept
     {
        #if ! JUCE_WIN_PER_MONITOR_DPI_AWARE
         return 1.0;
@@ -2013,6 +2027,31 @@ public:
        #endif
     }
 
+    double getPlatformScaleFactor() const noexcept override
+    {
+        if (scaleFactorOverride.has_value())
+            return *scaleFactorOverride;
+
+        return getPlatformScaleFactorWithoutOverride();
+    }
+
+    void setCustomPlatformScaleFactor (std::optional<double> scaleIn) override
+    {
+        const auto prev = getPlatformScaleFactor();
+        scaleFactorOverride = scaleIn;
+        const auto next = getPlatformScaleFactor();
+
+        if (approximatelyEqual (prev, next))
+            return;
+
+        scaleFactorListeners.call ([&] (ScaleFactorListener& l) { l.nativeScaleFactorChanged (next); });
+    }
+
+    std::optional<double> getCustomPlatformScaleFactor() const override
+    {
+        return scaleFactorOverride;
+    }
+
     static void getLastError()
     {
         TCHAR messageBuffer[256] = {};
@@ -2065,7 +2104,6 @@ public:
     }
 
     bool hasTitleBar() const                 { return (styleFlags & windowHasTitleBar) != 0; }
-    double getScaleFactor() const            { return scaleFactor; }
 
 private:
     HWND hwnd, parentToAddTo;
@@ -2083,6 +2121,7 @@ private:
    #endif
 
     double scaleFactor = 1.0;
+    std::optional<double> scaleFactorOverride;
     bool inDpiChange = 0, inHandlePositionChanged = 0;
     HMONITOR currentMonitor = nullptr;
 
@@ -4264,8 +4303,8 @@ private:
         {
             if (auto parentHwnd = GetParent (hwnd))
             {
-                auto parentRect = convertPhysicalScreenRectangleToLogical (D2DUtilities::toRectangle (getWindowScreenRect (parentHwnd)), hwnd);
+                const auto parentRect = convertPhysicalScreenRectangleToLogical (D2DUtilities::toRectangle (getWindowScreenRect (parentHwnd)), hwnd);
-                newBounds.translate (parentRect.getX(), parentRect.getY());
+                newBounds += parentRect.getPosition();
             }
         }
 
@@ -5787,7 +5826,7 @@ static const Displays::Display* getCurrentDisplayFromScaleFactor (HWND hwnd)
     const auto scaleToLookFor = [&]
     {
         if (auto* peer = HWNDComponentPeer::getOwnerOfWindow (hwnd))
-            return peer->getPlatformScaleFactor();
+            return peer->getPlatformScaleFactorWithoutOverride();
 
         return getScaleFactorForWindow (hwnd);
     }();

modules/juce_gui_basics/windows/juce_ComponentPeer.h

@@ -544,6 +544,25 @@ public:
     */
     virtual double getPlatformScaleFactor() const noexcept    { return 1.0; }
 
+    /** On Windows and Linux, calling this with a non-null optional will override whatever scale
+        factor the platform has specified for this window. The new scale factor will persist even
+        in the case that the platform attempts to set a new scale! Pass a null optional to revert
+        back to the platform-provided scale.
+
+        This is intended for use by plugin wrappers, where hosts may attempt to set a scale factor
+        different from the platform scale. You should never need to call this directly.
+    */
+    virtual void setCustomPlatformScaleFactor (std::optional<double>) {}
+
+    /** Returns the custom scale factor set using setCustomPlatformScaleFactor(), if any.
+
+        If a custom scale factor has been set, getPlatformScaleFactor() will always return that
+        value, effectively overriding any scale factor requested by the system.
+        Otherwise, if the custom platform scale factor is nullopt, then the system will update the
+        scale factor automatically.
+    */
+    virtual std::optional<double> getCustomPlatformScaleFactor() const { return {}; }
+
     /** On platforms that support it, this will update the window's titlebar in some
         way to indicate that the window's document needs saving.
     */