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authorLaszlo Agocs <laszlo.agocs@digia.com>2014-08-08 11:00:11 +0200
committerLaszlo Agocs <laszlo.agocs@digia.com>2014-08-08 17:32:23 +0200
commit9aaa61562675ddcdbf835e5acaf044db2a08f155 (patch)
tree4b9e22d2c2a871b0b51a3f56f1a9ca418430a8c6 /src/widgets
parent1e2af8078526689b12e0c2a16bb95b21e467bd1e (diff)
Fix crash in QOpenGLWidget when changing the TLW
The documentation was also somewhat incomplete when it comes to widgets that change their tlw multiple times. Change-Id: I09dd70167804c50a5283ab3709162c93a3827e9b Reviewed-by: Gunnar Sletta <gunnar.sletta@jollamobile.com>
Diffstat (limited to 'src/widgets')
-rw-r--r--src/widgets/kernel/qopenglwidget.cpp20
1 files changed, 19 insertions, 1 deletions
diff --git a/src/widgets/kernel/qopenglwidget.cpp b/src/widgets/kernel/qopenglwidget.cpp
index e59057a662..1d86d2e8d9 100644
--- a/src/widgets/kernel/qopenglwidget.cpp
+++ b/src/widgets/kernel/qopenglwidget.cpp
@@ -314,6 +314,19 @@ QT_BEGIN_NAMESPACE
\snippet code/doc_gui_widgets_qopenglwidget.cpp 5
+ \note For widgets that change their associated top-level window multiple times
+ during their lifetime, a combined approach is essential. Whenever the widget
+ or a parent of it gets reparented so that the top-level window becomes
+ different, the widget's associated context is destroyed and a new one is
+ created. This is then followed by a call to initializeGL() where all OpenGL
+ resources must get reinitialized. Due to this the only option to perform
+ proper cleanup is to connect to the context's aboutToBeDestroyed()
+ signal. Note that the context in question may not be the current one when the
+ signal gets emitted. Therefore it is good practice to call makeCurrent() in
+ the connected slot. Additionally, the same cleanup steps must be performed
+ from the derived class' destructor, since the slot connected to the signal
+ will not get invoked when the widget is being destroyed.
+
Proper cleanup is especially important due to context sharing. Even though
each QOpenGLWidget's associated context is destroyed together with the
QOpenGLWidget, the sharable resources in that context, like textures, will
@@ -459,6 +472,9 @@ void QOpenGLWidgetPrivate::reset()
fbo = 0;
delete resolvedFbo;
resolvedFbo = 0;
+ // Delete the context first, then the surface. Slots connected to
+ // the context's aboutToBeDestroyed() may still call makeCurrent()
+ // to perform some cleanup.
delete context;
context = 0;
delete surface;
@@ -705,7 +721,9 @@ void QOpenGLWidget::makeCurrent()
}
d->context->makeCurrent(d->surface);
- d->fbo->bind();
+
+ if (d->fbo) // there may not be one if we are in reset()
+ d->fbo->bind();
}
/*!