Hello all -- I have a question. First, some background:
My program lets the user tap and drag icons around onscreen, atop a background bitmap image. I maintain a variety of offscreen windows to assist in the task. One offscreen window contains the entire "scene" (background bitmap image plus icon images painted onto it). As the user "drags" icons around, they are first painted to the this offscreen window, then copied onscreen via WinCopyRectangle(). To implement the dragging functionality itself, I rely on additional offscreen windows, one for each icon. Each such window is used to store the background image that the associated icon is presently covering up. When the icon is moved from its current location, this background image is first restored to the scene, then the background of the new location is saved, and finally the icon is redrawn in the new location. I also use WinCopyRectangle() to perform this save/restore during dragging (I chose not to use WinSaveBits()/WinRestoreBits() because I didn't want to constantly allocate/deallocate offscreen windows, as those routines do). Now the question: When the user drags an icon up and/or to the left, a "trail" of old icon images is left behind. Dragging down or to the right never causes this problem. I cannot find errors in my drawing or saving/restore code (which of course means their aren't any ;-) ). Does this problem as I describe it set off any bells with any of you? I'd love to hear any theories as to why this is happening. Thanks for any help you can provide! -chris -- For information on using the ACCESS Developer Forums, or to unsubscribe, please see http://www.access-company.com/developers/forums/
