diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/widgets/kernel/qopenglwidget.cpp | 20 |
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(); } /*! |