5 files changed, 53 insertions, 20 deletions
diff --git a/src/plugins/platforms/cocoa/qcocoabackingstore.mm b/src/plugins/platforms/cocoa/qcocoabackingstore.mm
index 6970c44a12..b211b5d02d 100644
--- a/src/plugins/platforms/cocoa/qcocoabackingstore.mm
+++ b/src/plugins/platforms/cocoa/qcocoabackingstore.mm
@@ -23,8 +23,9 @@ QCocoaBackingStore::QCocoaBackingStore(QWindow *window)
 
 QCFType<CGColorSpaceRef> QCocoaBackingStore::colorSpace() const
 {
-    NSView *view = static_cast<QCocoaWindow *>(window()->handle())->view();
-    return QCFType<CGColorSpaceRef>::constructFromGet(view.window.colorSpace.CGColorSpace);
+    const auto *platformWindow = static_cast<QCocoaWindow *>(window()->handle());
+    const QNSView *view = qnsview_cast(platformWindow->view());
+    return QCFType<CGColorSpaceRef>::constructFromGet(view.colorSpace.CGColorSpace);
 }
 
 // ----------------------------------------------------------------------------
@@ -188,8 +189,9 @@ bool QCALayerBackingStore::recreateBackBufferIfNeeded()
         }
 #endif
 
-        qCInfo(lcQpaBackingStore) << "Creating surface of" << requestedBufferSize
-            << "based on requested" << m_requestedSize << "and dpr =" << devicePixelRatio;
+        qCInfo(lcQpaBackingStore)<< "Creating surface of" << requestedBufferSize
+            << "for" << window() << "based on requested" << m_requestedSize
+            << "dpr =" << devicePixelRatio << "and color space" << colorSpace();
 
         static auto pixelFormat = QImage::toPixelFormat(QImage::Format_ARGB32_Premultiplied);
         auto *newBackBuffer = new GraphicsBuffer(requestedBufferSize, devicePixelRatio, pixelFormat, colorSpace());
@@ -477,10 +479,11 @@ void QCALayerBackingStore::backingPropertiesChanged()
 
     qCDebug(lcQpaBackingStore) << "Backing properties for" << window() << "did change";
 
-    qCDebug(lcQpaBackingStore) << "Updating color space of existing buffers";
+    const auto newColorSpace = colorSpace();
+    qCDebug(lcQpaBackingStore) << "Updating color space of existing buffers to" << newColorSpace;
     for (auto &buffer : m_buffers) {
         if (buffer)
-            buffer->setColorSpace(colorSpace());
+            buffer->setColorSpace(newColorSpace);
     }
 }
 
diff --git a/src/plugins/platforms/cocoa/qcocoawindow.mm b/src/plugins/platforms/cocoa/qcocoawindow.mm
index 14c72fd91a..4a245a0f8a 100644
--- a/src/plugins/platforms/cocoa/qcocoawindow.mm
+++ b/src/plugins/platforms/cocoa/qcocoawindow.mm
@@ -1812,11 +1812,15 @@ QCocoaNSWindow *QCocoaWindow::createNSWindow(bool shouldBePanel)
 
     applyContentBorderThickness(nsWindow);
 
-    if (QColorSpace colorSpace = format().colorSpace(); colorSpace.isValid()) {
-        NSData *iccData = colorSpace.iccProfile().toNSData();
-        nsWindow.colorSpace = [[[NSColorSpace alloc] initWithICCProfileData:iccData] autorelease];
-        qCDebug(lcQpaDrawing) << "Set" << this << "color space to" << nsWindow.colorSpace;
-    }
+    // We propagate the view's color space granulary to both the IOSurfaces
+    // used for QSurface::RasterSurface, as well as the CAMetalLayer used for
+    // QSurface::MetalSurface, but for QSurface::OpenGLSurface we don't have
+    // that option as we use NSOpenGLContext instead of CAOpenGLLayer. As a
+    // workaround we set the NSWindow's color space, which affects GL drawing
+    // with NSOpenGLContext as well. This does not conflict with the granular
+    // modifications we do to each surface for raster or Metal.
+    if (auto *qtView = qnsview_cast(m_view))
+        nsWindow.colorSpace = qtView.colorSpace;
 
     return nsWindow;
 }
diff --git a/src/plugins/platforms/cocoa/qnsview.h b/src/plugins/platforms/cocoa/qnsview.h
index e41f5a7296..7f845a5c3b 100644
--- a/src/plugins/platforms/cocoa/qnsview.h
+++ b/src/plugins/platforms/cocoa/qnsview.h
@@ -32,6 +32,12 @@ QT_DECLARE_NAMESPACED_OBJC_INTERFACE(QNSView, NSView
 - (void)cancelComposingText;
 @end
 
+Q_FORWARD_DECLARE_OBJC_CLASS(NSColorSpace);
+
+@interface QNSView (DrawingAPI)
+@property (nonatomic, readonly) NSColorSpace *colorSpace;
+@end
+
 @interface QNSView (QtExtras)
 @property (nonatomic, readonly) QCocoaWindow *platformWindow;
 @end
diff --git a/src/plugins/platforms/cocoa/qnsview.mm b/src/plugins/platforms/cocoa/qnsview.mm
index 6cb10efa7f..1286e8e382 100644
--- a/src/plugins/platforms/cocoa/qnsview.mm
+++ b/src/plugins/platforms/cocoa/qnsview.mm
@@ -90,6 +90,7 @@ QT_NAMESPACE_ALIAS_OBJC_CLASS(QNSViewMenuHelper);
 @property (assign) NSView* previousSuperview;
 @property (assign) NSWindow* previousWindow;
 @property (retain) QNSViewMenuHelper* menuHelper;
+@property (nonatomic, retain) NSColorSpace *colorSpace;
 @end
 
 @implementation QNSView {
@@ -119,6 +120,8 @@ QT_NAMESPACE_ALIAS_OBJC_CLASS(QNSViewMenuHelper);
     NSDraggingContext m_lastSeenContext;
 }
 
+@synthesize colorSpace = m_colorSpace;
+
 - (instancetype)initWithCocoaWindow:(QCocoaWindow *)platformWindow
 {
     if ((self = [super initWithFrame:NSZeroRect])) {
diff --git a/src/plugins/platforms/cocoa/qnsview_drawing.mm b/src/plugins/platforms/cocoa/qnsview_drawing.mm
index 77fa8259ac..bf102e43f8 100644
--- a/src/plugins/platforms/cocoa/qnsview_drawing.mm
+++ b/src/plugins/platforms/cocoa/qnsview_drawing.mm
@@ -13,6 +13,14 @@
             << " QT_MAC_WANTS_LAYER/_q_mac_wantsLayer has no effect.";
     }
 
+    // Pick up and persist requested color space from surface format
+    const QSurfaceFormat surfaceFormat = m_platformWindow->format();
+    if (QColorSpace colorSpace = surfaceFormat.colorSpace(); colorSpace.isValid()) {
+        NSData *iccData = colorSpace.iccProfile().toNSData();
+        self.colorSpace = [[[NSColorSpace alloc] initWithICCProfileData:iccData] autorelease];
+    }
+
+    // Trigger creation of the layer
     self.wantsLayer = YES;
 }
 
@@ -28,6 +36,12 @@
     return YES;
 }
 
+- (NSColorSpace*)colorSpace
+{
+    // If no explicit color space was set, use the NSWindow's color space
+    return m_colorSpace ? m_colorSpace : self.window.colorSpace;
+}
+
 // ----------------------- Layer setup -----------------------
 
 - (BOOL)shouldUseMetalLayer
@@ -93,12 +107,7 @@
 
     [super setLayer:layer];
 
-    // When adding a view to a view hierarchy the backing properties will change
-    // which results in updating the contents scale, but in case of switching the
-    // layer on a view that's already in a view hierarchy we need to manually ensure
-    // the scale is up to date.
-    if (self.superview)
-        [self updateLayerContentsScale];
+    [self propagateBackingProperties];
 
     if (self.opaque && lcQpaDrawing().isDebugEnabled()) {
         // If the view claims to be opaque we expect it to fill the entire
@@ -131,8 +140,7 @@
 {
     qCDebug(lcQpaDrawing) << "Backing properties changed for" << self;
 
-    if (self.layer)
-        [self updateLayerContentsScale];
+    [self propagateBackingProperties];
 
     // Ideally we would plumb this situation through QPA in a way that lets
     // clients invalidate their own caches, recreate QBackingStore, etc.
@@ -141,8 +149,11 @@
     [self setNeedsDisplay:YES];
 }
 
-- (void)updateLayerContentsScale
+- (void)propagateBackingProperties
 {
+    if (!self.layer)
+        return;
+
     // We expect clients to fill the layer with retina aware content,
     // based on the devicePixelRatio of the QWindow, so we set the
     // layer's content scale to match that. By going via devicePixelRatio
@@ -153,6 +164,12 @@
     auto devicePixelRatio = m_platformWindow->devicePixelRatio();
     qCDebug(lcQpaDrawing) << "Updating" << self.layer << "content scale to" << devicePixelRatio;
     self.layer.contentsScale = devicePixelRatio;
+
+    if ([self.layer isKindOfClass:CAMetalLayer.class]) {
+        CAMetalLayer *metalLayer = static_cast<CAMetalLayer *>(self.layer);
+        metalLayer.colorspace = self.colorSpace.CGColorSpace;
+        qCDebug(lcQpaDrawing) << "Set" << metalLayer << "color space to" << metalLayer.colorspace;
+    }
 }
 
 /*