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qtopenglrenderingqglwidget

When is QGLWidget's paintGL called?

All I can find is "whenever the widget needs to be painted."

When is that, specifically?

Solution

  • When you call updateGL() on your widget (or update()), or just Qt decides to redraw your widget. Reasons why Qt might choose to ask for a redraw include:

    • your widget gets resized
    • your widget is hidden and shown again
    • your widget is minimized and then restored
    • something else is put in front of your widget and then moved away
    • the Moon is in the third quarter
    • a distant butterfly had flapped its wings
    • ...

    In short, you have very little control about when Qt asks for a repaint. Just be sure to paint fast! :-)