Android: fix rendering glitch after window size changes

Issam-b · Issam-b · commit b99304cb39b2 · 2025-09-09T02:03:34.000Z
Currently, apps might end up with half of the window size not rendered or not reflecting size changes. When the root layout size changes, the available size is reported but the screen size is not always sent from Android callbacks, this is the case after an orientation change. So make sure here to update the the screen geometry also when receiving the available geometry. This part amends 7dcf58e. However, the issue was still present in 6.9 and 6.8 before that above commit, to fix that, it's needed to call sendExpose() to send expose event for the window in the new region, and this after propagating the surface change from QtSurface to the platform window. Pick-to: 6.8 6.9 6.10 6.10.0 Fixes: QTBUG-132718 Fixes: QTBUG-134082 Task-number: QTBUG-124140 Change-Id: I390aaba45f324693dc47d7d0110fdb22dc9aca61 Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>
diff --git a/src/android/jar/src/org/qtproject/qt/android/QtSurface.java b/src/android/jar/src/org/qtproject/qt/android/QtSurface.java
@@ -36,7 +36,11 @@ public void surfaceCreated(SurfaceHolder holder)
 
     @Override
     public void surfaceChanged(SurfaceHolder holder, int format, int width, int height)
-    { }
+    {
+        // FIXME: this can sometimes cause flicker on orientation change
+        if (m_surfaceCallback != null)
+            m_surfaceCallback.onSurfaceChanged(holder.getSurface());
+    }
 
     @Override
     public void surfaceDestroyed(SurfaceHolder holder)
diff --git a/src/plugins/platforms/android/qandroidplatformscreen.cpp b/src/plugins/platforms/android/qandroidplatformscreen.cpp
@@ -260,6 +260,7 @@ void QAndroidPlatformScreen::setAvailableGeometry(const QRect &rect)
     QRect oldGeometry = m_availableGeometry;
 
     m_availableGeometry = rect;
+    m_size = sizeForDisplayId(m_displayId);
     QWindowSystemInterface::handleScreenGeometryChange(QPlatformScreen::screen(), geometry(), availableGeometry());
     resizeMaximizedWindows();
 
diff --git a/src/plugins/platforms/android/qandroidplatformwindow.cpp b/src/plugins/platforms/android/qandroidplatformwindow.cpp
@@ -325,6 +325,8 @@ void QAndroidPlatformWindow::onSurfaceChanged(QtJniTypes::Surface surface)
         clearSurface();
     }
 
+    sendExpose();
+
     unlockSurface();
 }
 

Original file line number	Diff line number	Diff line change
`@@ -325,6 +325,8 @@ void QAndroidPlatformWindow::onSurfaceChanged(QtJniTypes::Surface surface)`
`325`	`325`	`clearSurface();`
`326`	`326`	`}`
`327`	`327`
	`328`	`+ sendExpose();`
	`329`	`+`
`328`	`330`	`unlockSurface();`
`329`	`331`	`}`
`330`	`332`