For example, the style NoFrame always has a frame width 0, while the style Panel has a frame width equivalent to the line width. The frame width also includes the margin. The default value is 1. The default value is 0. The default value is 0.
Handles paint events for the frame.
Paints the frame and the contents. Handles resize events for the frame. Adjusts the frame rectangle for the resized widget. The frame rectangle is elastic, the surrounding area is static. The resulting frame rectangle may be null or invalid.