1. Make all demo applications be able to record and restore the previous window geometry.
2. Improve the robustness of the widgets and quick implementation.
Signed-off-by: Yuhang Zhao <2546789017@qq.com>
It's pure implementation detail, so should not be publicly visible
Also fixed the crash of the QOpenGLWidget demo application.
Signed-off-by: Yuhang Zhao <2546789017@qq.com>
1. Finish the simple title bar of the QOpenGLWidget demo
2. Minor improvements of the Quick implementation
Signed-off-by: Yuhang Zhao <2546789017@qq.com>