Introduced QOpenGLContext::aboutToBeDestroyed() signal.

This signal can be used to clean up OpenGL resources in a safe way
before the context is destroyed.

Task-number: QTBUG-20083
Change-Id: I45a4be01b06af4ee7196fa502116f099d50afeab
Reviewed-by: Gunnar Sletta <gunnar.sletta@nokia.com>

1 files changed, 22 insertions, 0 deletions

diff --git a/tests/auto/gui/qopengl/tst_qopengl.cpp b/tests/auto/gui/qopengl/tst_qopengl.cpp
index aa3e70a047..d6c587b65e 100644
--- a/tests/auto/gui/qopengl/tst_qopengl.cpp
+++ b/tests/auto/gui/qopengl/tst_qopengl.cpp
@@ -50,6 +50,8 @@
 
 #include <QtTest/QtTest>
 
+#include <QSignalSpy>
+
 class tst_QOpenGL : public QObject
 {
 Q_OBJECT
@@ -62,6 +64,7 @@ private slots:
     void fboRendering();
     void fboHandleNulledAfterContextDestroyed();
     void openGLPaintDevice();
+    void aboutToBeDestroyed();
 };
 
 struct SharedResourceTracker
@@ -500,5 +503,24 @@ void tst_QOpenGL::openGLPaintDevice()
     QCOMPARE(image, fbo.toImage().convertToFormat(QImage::Format_RGB32));
 }
 
+void tst_QOpenGL::aboutToBeDestroyed()
+{
+    QWindow window;
+    window.setGeometry(0, 0, 128, 128);
+    window.create();
+
+    QOpenGLContext *context = new QOpenGLContext;
+    QSignalSpy spy(context, SIGNAL(aboutToBeDestroyed()));
+
+    context->create();
+    context->makeCurrent(&window);
+
+    QCOMPARE(spy.size(), 0);
+
+    delete context;
+
+    QCOMPARE(spy.size(), 1);
+}
+
 QTEST_MAIN(tst_QOpenGL)
 #include "tst_qopengl.moc"