[Interest] Flicker in QMainWindowL::centralWidget on resize

[Patrick Stinson]

Hello there,

Just curious if anyone has seen this before I post a bug since at least 5.13.0 on Mac.

QMainWindow::centralWidget resizing is erratic when resizing QMainWindow. See two referenced + attached videos.

https://www.youtube.com/watch?v=0Qjy2wm6m9M&feature=youtu.be <https://www.youtube.com/watch?v=0Qjy2wm6m9M&feature=youtu.be>

Here is the minimal code for the above referenced youtube video:

def test_QMainWindow_resize():

    class Widget(QOpenGLWidget):
        def paintEvent(self, e):
            p = QPainter(self)
            p.setBrush(Qt.red)
            p.drawRect(self.rect())

    app = QApplication(sys.argv)
    mw = QMainWindow()
    w = Widget()
    mw.setCentralWidget(w)
    mw.show()
    w.show()
    app.exec()



As you can see, this becomes quite jarring with increased painting load:



-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.qt-project.org/pipermail/interest/attachments/20190922/e0f0e04c/attachment-0002.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: Screen Recording 2019-09-22 at 2.44.39 PM.mov
Type: video/quicktime
Size: 4363120 bytes
Desc: not available
URL: <http://lists.qt-project.org/pipermail/interest/attachments/20190922/e0f0e04c/attachment-0001.mov>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.qt-project.org/pipermail/interest/attachments/20190922/e0f0e04c/attachment-0003.html>