SetWindowPic
PicHandle thePicture ; the contents of the window causes the Window Manager to draw that picture instead of generating an
update event. You will no longer receive update events for theWindow.
thePicture is a handle of a picture that will be drawn automatically when the
window needs to be updated.
Notes: This function causes thePicture to be stored in the windowPic field of the
WindowRecord structure of theWindow. When that field is an address (as opposed to the default value of NIL), update events will not get generated
when that window is moved, sized, uncovered, etc. Instead, thePicture is
drawn.
SetWindowPic is typically used for windows that are never changed; for instance, an introduction window or a one-screen help window.
It can also be used to force fast screen updates, at the expense of
extravagant memory usage. For instance, you could use CopyBits to generate a picture of the content region of your window and use
SetWindowPic to point to that picture. Now you will find that moving, uncovering, or sizing the window will go faster than would be possible when
an update event occurred and you needed to redraw it from scratch.
normal generation of update events.