XtAllocateGC(3Xt) XT FUNCTIONS XtAllocateGC(3Xt)NAMEXtAllocateGC - 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 speci-
fied.
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 mod-
ified 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 speci-
fied widget or of the nearest widget ancestor of the spec-
ified 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 may assume that at all times all
fields not specified in either dynamic_mask or unused_mask
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XtAllocateGC(3Xt) XT FUNCTIONS XtAllocateGC(3Xt)
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 con-
flicts. 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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