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.ds tk X Toolkit
.ds xT X Toolkit Intrinsics \- C Language Interface
.ds xI Intrinsics
.ds xW X Toolkit Athena Widgets \- C Language Interface
.ds xL Xlib \- C Language X Interface
.ds xC Inter-Client Communication Conventions Manual
.ds Rn 3
.ds Vn 2.2
.hw XtAllocate-GC wid-get
.na
.TH XtAllocateGC 3 "libXt 1.3.0" "X Version 11" "XT FUNCTIONS"
.SH NAME
XtAllocateGC \- obtain a shareable GC with modifiable fields
.SH SYNTAX
#include <X11/Intrinsic.h>
.HP
GC XtAllocateGC(Widget \fIw\fP, Cardinal \fIdepth\fP, XtGCMask
\fIvalue_mask\fP, XGCValues *\fIvalues\fP, XtGCMask \fIdynamic_mask\fP,
XtGCMask \fIunused_mask\fP);
.SH ARGUMENTS
.IP \fIvalues\fP 1i
Specifies the actual values for this GC.
.IP \fIvalue_mask\fP 1i
Specifies which fields of the values are specified.
.IP \fIw\fP 1i
Specifies the widget.
.IP \fIdepth\fP 1i
Specifies the depth for which the returned GC is valid, or 0.
.IP  \fIdynamic_mask\fP 1i
Specifies the fields of the GC that will be modified by the caller.
.IP  \fIunused_mask\fP 1i
Specifies the fields of the GC that will not be needed by the caller.
.SH DESCRIPTION
The
.B XtAllocateGC
function returns a shareable GC that may be modified by the client.
The \fIscreen\fP field of the specified widget or of the nearest
widget ancestor of the specified object and the specified \fIdepth\fP
argument supply the root and drawable depths for which the GC is to
be valid.
If \fIdepth\fP is zero the depth is taken from the \fIdepth\fP
field of the specified widget or of the nearest widget ancestor of the
specified object.
.LP
The \fIvalue_mask\fP argument specifies the fields of the GC that will
be initialized with the respective members of the \fIvalues\fP structure.
The \fIdynamic_mask\fP 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
\fIunused_mask\fP 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 \fIunused_mask\fP. The caller may
assume that at all times all fields not specified in either
\fIdynamic_mask\fP or \fIunused_mask\fP have their default value if
not specified in \fIvalue_mask\fP or the value specified by \fIvalues\fP.
If a field is specified in both \fIvalue_mask\fP and \fPdynamic_mask\fP,
the effect is as if it were specified only in \fIdynamic_mask\fP and
then immediately set to the value in \fIvalues\fP. If a field is set
in \fIunused_mask\fP and also in either \fIvalue_mask\fP or
\fIdynamic_mask\fP, the specification in \fIunused_mask\fP is ignored.
.LP
.B 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.
.B XtAllocateGC
may modify and return an existing GC if it was allocated with a nonzero
\fIunused_mask\fP.
.SH "SEE ALSO"
.B XtGetGC
.br
\fI\*(xT\fP
.br
\fI\*(xL\fP