Backdrop windows open behind all other non-backdrop windows, but in front of other backdrop windows that might already be open. Depth arrangement of a backdrop window affects the order of the window relative to other backdrop windows, but backdrop windows always stay behind all non-backdrop windows. No amount of depth arrangement will ever move a non-backdrop window behind a backdrop window. The only system gadget that can be attached to a backdrop window is the closewindow gadget. Application gadgets are not restricted in backdrop windows. Backdrop windows may often be used in place of drawing directly into the display memory of a custom screen. Such a technique is preferred, as backdrop windows are compatible with the Intuition windowing system. Using a backdrop window eliminates the danger of writing to the screen memory at a "bad" time or at the wrong position and overwriting data in a window. To provide a full screen display area that is compatible with the windowing system, create a full sized, borderless, backdrop window with no system gadgets. Use the ShowTitle() call to hide or reveal the screen's title bar, as appropriate. See the Amiga ROM Kernel Reference Manual: Includes and Autodocs for a complete list of arguments for ShowTitle(). Backdrop windows are created by specifying the WFLG_BACKDROP flag or the WA_Backdrop tag in the OpenWindowTagList() call.
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