XtAllocateGC(3Xt) X Version 11 (Release 6.6) XtAllocateGC(3Xt)
NAME
XtAllocateGC - obtain a sharable GC with modifiable fields
SYNTAX
GC XtAllocateGC(w, depth, value_mask, values, dynamic_mask,
unused_mask)
Widget w;
Cardinal depth;
XtGCMask value_mask;
XGCValues *values;
XtGCMask dynamic_mask;
XtGCMask unused_mask;
ARGUMENTS
values Specifies the actual values for this GC.
value_mask
Specifies which fields of the values are
specified.
w Specifies the widget.
depth Specifies the depth for which the returned GC is
valid, or 0.
dynamic_mask
Specifies the fields of the GC that will be
modified by the caller.
unused_mask
Specifies the fields of the GC that will not be
needed by the caller.
DESCRIPTION
The XtAllocateGC function returns a sharable GC that may be
modified by the client. The screen field of the specified
widget or of the nearest widget ancestor of the specified
object and the specified depth argument supply the root and
drawable depths for which the GC is to be valid. If depth is
zero the depth is taken from the depth field of the
specified widget or of the nearest widget ancestor of the
specified object.
The value_mask argument specifies the fields of the GC that
will be initialized with the respective members of the
values structure. The dynamic_mask argument specifies
fields that the caller intends to modify during program
execution. The caller must ensure that the corresponding GC
field is sdet prior to each use of the GC. The unused_mask
argument specifies fields of the GC that are of no interest
to the caller. The caller may make no assumptions about the
contents of any fields specified in unused_mask. The caller
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XtAllocateGC(3Xt) X Version 11 (Release 6.6) XtAllocateGC(3Xt)
may assume that at all times all fields not specified in
either dynamic_mask or unused_mask have their default value
if not specified in value_mask or the value specified by
values. If a field is specified in both value_mask and
dynamic_mask, the effect is as if it were specified only in
dynamic_mask and then immediately set to the value in
values. If a field is set in unused_mask and also in either
value_mask or dynamic_mask, the specification in unused_mask
is ignored.
XtAllocateGC tries to minimize the number of unique GCs
created by comparing the arguments with those of previous
calls and returning an existing GC when there are no
conflicts. XtAllocateGC may modify and return an existing
GC if it was allocated with a nonzero unused_mask.
SEE ALSO
XtGetGC
X Toolkit Intrinsics - C Language Interface
Xlib - C Language X Interface
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