macOS: Invalidate backingstore and trigger expose on color space changes

Fixes: QTBUG-77749
Change-Id: I677a71152e4a218c08d8863d4f886d158a79e809
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>
Reviewed-by: Timur Pocheptsov <timur.pocheptsov@qt.io>

1 files changed, 11 insertions, 0 deletions

diff --git a/src/plugins/platforms/cocoa/qcocoawindow.mm b/src/plugins/platforms/cocoa/qcocoawindow.mm
index d6f88b4f23..3008a056a2 100644
--- a/src/plugins/platforms/cocoa/qcocoawindow.mm
+++ b/src/plugins/platforms/cocoa/qcocoawindow.mm
@@ -1261,6 +1261,17 @@ void QCocoaWindow::windowDidChangeScreen()
         currentScreen->requestUpdate();
     }
 }
+/*
+    The window's backing scale factor or color space has changed.
+*/
+void QCocoaWindow::windowDidChangeBackingProperties()
+{
+    // Ideally we would plumb this thought QPA in a way that lets clients
+    // invalidate their own caches, and recreate QBackingStore. For now we
+    // trigger an expose, and let QCocoaBackingStore deal with its own
+    // buffer invalidation.
+    [m_view setNeedsDisplay:YES];
+}
 
 void QCocoaWindow::windowWillClose()
 {