NAME

       XtAllocateGC - obtain a sharable GC with modifiable fields

SYNTAX

       #include <X11/Intrinsic.h>

       GC XtAllocateGC(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 set 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 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