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 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

       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