Create and destroy the shell surface when showing and hiding

This changes the shell surface handling for windows, and instead of
creating the shell surface at initialization time, and then attaching
a null buffer to hide it, it creates the shell surface on setVisible(true),
and destroys it on setVisible(false).
This fixes hiding when using xdg_shell, as that interface defines that
attaching a null buffer to an xdg_surface is an error.
Also this should help with bugged EGL drivers which attach a buffer
after eglSwapBuffers() returns, which used to cause a newly hidden
window to get a new valid buffer after we attached a null one, showing
it again.

Task-number: QTBUG-47902
Change-Id: I8e0a0442319a98cc1361803ea7be1d079b36fc8c
Reviewed-by: Johan Helsing <johan.helsing@qt.io>
Reviewed-by: Paul Olav Tvete <paul.tvete@qt.io>

1 files changed, 2 insertions, 0 deletions

diff --git a/src/client/qwaylandwindow_p.h b/src/client/qwaylandwindow_p.h
index 442fe9ad9..7e7078fcf 100644
--- a/src/client/qwaylandwindow_p.h
+++ b/src/client/qwaylandwindow_p.h
@@ -132,6 +132,8 @@ public:
     using QtWayland::wl_surface::damage;
     void damage(const QRect &rect);
 
+    void commit(QWaylandBuffer *buffer, const QRegion &damage);
+
     void waitForFrameSync();
 
     QMargins frameMargins() const Q_DECL_OVERRIDE;