Send events when platform surfaces are created/about to be destroyed

These synchronously delivered events allow applications to correctly
and conveniently handle native platform surfaces being destroyed. This
is particularly useful when doing rendering on a non-gui thread as it
allows to shutdown rendering before the native surface gets destroyed
from under us.

Task-number: QTBUG-42476
Task-number: QTBUG-42483
Change-Id: I63f41bbdb32f281d0f3b8ec2537eb2b0361f3bb3
Reviewed-by: Laszlo Agocs <laszlo.agocs@digia.com>

1 files changed, 7 insertions, 0 deletions

diff --git a/src/gui/kernel/qoffscreensurface.cpp b/src/gui/kernel/qoffscreensurface.cpp
index 5cf77de5d8..fb1dfd8df5 100644
--- a/src/gui/kernel/qoffscreensurface.cpp
+++ b/src/gui/kernel/qoffscreensurface.cpp
@@ -180,6 +180,9 @@ void QOffscreenSurface::create()
             d->offscreenWindow->setGeometry(0, 0, d->size.width(), d->size.height());
             d->offscreenWindow->create();
         }
+
+        QPlatformSurfaceEvent e(QPlatformSurfaceEvent::SurfaceCreated);
+        QGuiApplication::sendEvent(this, &e);
     }
 }
 
@@ -191,6 +194,10 @@ void QOffscreenSurface::create()
 void QOffscreenSurface::destroy()
 {
     Q_D(QOffscreenSurface);
+
+    QPlatformSurfaceEvent e(QPlatformSurfaceEvent::SurfaceAboutToBeDestroyed);
+    QGuiApplication::sendEvent(this, &e);
+
     delete d->platformOffscreenSurface;
     d->platformOffscreenSurface = 0;
     if (d->offscreenWindow) {