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IsValidWindowPtr
Reports whether a pointer is a valid window pointer.
pascal Boolean IsValidWindowPtr (GrafPtr grafPort);
-
grafPort
-
A pointer to a graphics port. You pass the pointer to be examined.
-
function result
-
A value of type
Boolean
. The function returns
true
if the specified pointer is a valid window pointer; otherwise,
false
.
DISCUSSION
A custom control definition may use the
IsValidWindowPtr
function to determine whether it is being asked to draw onscreen or offscreen.
This function is primarily intended for use with debugging your application.
SPECIAL CONSIDERATIONS
The
IsValidWindowPtr
function is a processor-intensive call.
VERSION NOTES
Available with Mac OS 8.5 and later.
© 1999 Apple Computer, Inc. – (Last Updated 18 March 99)