Specifications

Developer Technical Support May 1992
Apple IIGS
#71: DA Tips and Techniques 7 of 6
position, which may overlap the window’s content. In addition, when the user chooses a menu
item, the front NDA receives the mouseUp before the menu’s image is removed, and the image
may overlap the NDA’s window. In either case, drawing in the window makes a mess.
The solution is to avoid drawing in direct response to a mouseUp. Instead, invalidate part of the
window to force an update event to happen later.