-- Optimize wxWindow OnPaint to avoid flicker, collapsing Expose events
- as per flicker fix in 1.68. It will be tricky to avoid
- interfering with non-wxScrolledWindow widgets except by
- explicitly testing for wxScrolledWindow.
-
-- Implementation of OnEraseBackground. How? Call OnEraseBackground
- just before OnPaint? Will duplicate Xlib's own erase of the background.
- However, this is usually OK, because the default wxWindow::OnEraseBackground
- can do nothing (SetBackgroundColour will make the background look OK).
- And if a custom OnEraseBackground uses the same colour as the window
- background, no flicker will be seen. If it does something else, such as
- painting a tiled bitmap, then a slight flicker might be seen unless
- X can be persuaded not to repaint the window background by default.
-
-- wxSpinButton