QQuickWidget: handle hide and show events properly

Task-number: QTBUG-37062
Change-Id: I3763385168eaa0ccd009ada563f56ea0251029a5
Reviewed-by: Gunnar Sletta <gunnar.sletta@jollamobile.com>

2 files changed, 21 insertions, 0 deletions

diff --git a/src/quick/items/qquickrendercontrol.cpp b/src/quick/items/qquickrendercontrol.cpp
index faee1358ae..16ed6f0e10 100644
--- a/src/quick/items/qquickrendercontrol.cpp
+++ b/src/quick/items/qquickrendercontrol.cpp
@@ -162,6 +162,26 @@ bool QQuickRenderControl::sync()
 }
 
 /*!
+  Stop rendering and release resources. This function is typically
+  called when the window is hidden. Requires a current context.
+ */
+void QQuickRenderControl::stop()
+{
+    Q_D(QQuickRenderControl);
+    if (!d->window)
+        return;
+
+    QQuickWindowPrivate *cd = QQuickWindowPrivate::get(d->window);
+    cd->fireAboutToStop();
+    cd->cleanupNodesOnShutdown();
+
+    if (!cd->persistentSceneGraph) {
+        d->rc->invalidate();
+        QCoreApplication::sendPostedEvents(0, QEvent::DeferredDelete);
+    }
+}
+
+/*!
   Render the scenegraph using the current context.
  */
 void QQuickRenderControl::render()
diff --git a/src/quick/items/qquickrendercontrol_p.h b/src/quick/items/qquickrendercontrol_p.h
index 7255a9ae0b..98dc946303 100644
--- a/src/quick/items/qquickrendercontrol_p.h
+++ b/src/quick/items/qquickrendercontrol_p.h
@@ -71,6 +71,7 @@ public:
     void polishItems();
     void render();
     bool sync();
+    void stop();
 
     QImage grab();