Fix WaylandOutput.sizeFollowsWindow when window changes screen

If a QWaylandOutput's QWindow is moved from one screen to another and that
causes the devicePixelRatio to change, it may result in a new pixel size,
but QWindow::width and height may stay unchanged (because they're not in pixel
coordinates). This is a problem because the sizeFollowsWindow functionality of
QWaylandOutput relied on the widthChanged and heightChanged signals, which are
then not fired, although the pixel size did change.

There's no QWindow::devicePixelRatioChanged signal we can attach to, so to fix
this, we attach to screenChanged instead and then compute the new pixelSize
using QWindow::devicePixelRatio() and call the handler if it changed.

This also removes some duplication between the old width and height handlers.

Change-Id: Ibcbf10489b83498b4a0fee2b520f528f94cb9ce3
Reviewed-by: Morten Johan Sørvig <morten.sorvig@qt.io>
Reviewed-by: Paul Olav Tvete <paul.tvete@qt.io>

1 files changed, 2 insertions, 10 deletions

diff --git a/src/compositor/compositor_api/qwaylandoutputmode.cpp b/src/compositor/compositor_api/qwaylandoutputmode.cpp
index 9ae285fd5..545871175 100644
--- a/src/compositor/compositor_api/qwaylandoutputmode.cpp
+++ b/src/compositor/compositor_api/qwaylandoutputmode.cpp
@@ -128,15 +128,7 @@ int QWaylandOutputMode::refreshRate() const
 /*!
  * \internal
  */
-void QWaylandOutputMode::setWidth(int width)
+void QWaylandOutputMode::setSize(const QSize &size)
 {
-    d->size.setWidth(width);
-}
-
-/*!
- * \internal
- */
-void QWaylandOutputMode::setHeight(int height)
-{
-    d->size.setHeight(height);
+    d->size = size;
 }