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Diffstat (limited to 'doc/GetGC.3')
-rw-r--r-- | doc/GetGC.3 | 146 |
1 files changed, 72 insertions, 74 deletions
diff --git a/doc/GetGC.3 b/doc/GetGC.3 index 471bdfc..97ac503 100644 --- a/doc/GetGC.3 +++ b/doc/GetGC.3 @@ -1,74 +1,72 @@ -'\" -'\" Copyright (c) 1990 The Regents of the University of California. -'\" Copyright (c) 1994-1996 Sun Microsystems, Inc. -'\" -'\" See the file "license.terms" for information on usage and redistribution -'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES. -'\" -'\" RCS: @(#) $Id: GetGC.3,v 1.2 1998/09/14 18:22:49 stanton Exp $ -'\" -.so man.macros -.TH Tk_GetGC 3 "" Tk "Tk Library Procedures" -.BS -.SH NAME -Tk_GetGC, Tk_FreeGC \- maintain database of read-only graphics contexts -.SH SYNOPSIS -.nf -\fB#include <tk.h>\fR -.sp -GC -\fBTk_GetGC\fR(\fItkwin, valueMask, valuePtr\fR) -.sp -\fBTk_FreeGC(\fIdisplay, gc\fR) -.SH ARGUMENTS -.AS "unsigned long" valueMask -.AP Tk_Window tkwin in -Token for window in which the graphics context will be used. -.AP "unsigned long" valueMask in -Mask of bits (such as \fBGCForeground\fR or \fBGCStipple\fR) -indicating which fields of \fI*valuePtr\fR are valid. -.AP XGCValues *valuePtr in -Pointer to structure describing the desired values for the -graphics context. -.AP Display *display in -Display for which \fIgc\fR was allocated. -.AP GC gc in -X identifier for graphics context that is no longer needed. -Must have been allocated by \fBTk_GetGC\fR. -.BE - -.SH DESCRIPTION -.PP -\fBTk_GetGC\fR and \fBTk_FreeGC\fR manage a collection of graphics contexts -being used by an application. The procedures allow graphics contexts to be -shared, thereby avoiding the server overhead that would be incurred -if a separate GC were created for each use. \fBTk_GetGC\fR takes arguments -describing the desired graphics context and returns an X identifier -for a GC that fits the description. The graphics context that is returned -will have default values in all of the fields not specified explicitly -by \fIvalueMask\fR and \fIvaluePtr\fR. -.PP -\fBTk_GetGC\fR maintains a -database of all the graphics contexts it has created. Whenever possible, -a call to \fBTk_GetGC\fR will -return an existing graphics context rather than creating a new one. This -approach can substantially reduce server overhead, so \fBTk_GetGC\fR -should generally be used in preference to the Xlib procedure -\fBXCreateGC\fR, which creates a new graphics context on each call. -.PP -Since the return values of \fBTk_GetGC\fR -are shared, callers should never modify the graphics contexts -returned by \fBTk_GetGC\fR. -If a graphics context must be modified dynamically, then it should be -created by calling \fBXCreateGC\fR instead of \fBTk_GetGC\fR. -.PP -When a graphics context -is no longer needed, \fBTk_FreeGC\fR should be called to release it. -There should be exactly one call to \fBTk_FreeGC\fR for -each call to \fBTk_GetGC\fR. -When a graphics context is no longer in use anywhere (i.e. it has -been freed as many times as it has been gotten) \fBTk_FreeGC\fR -will release it to the X server and delete it from the database. - -.SH KEYWORDS -graphics context +'\"
+'\" Copyright (c) 1990 The Regents of the University of California.
+'\" Copyright (c) 1994-1996 Sun Microsystems, Inc.
+'\"
+'\" See the file "license.terms" for information on usage and redistribution
+'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
+'\"
+'\" RCS: @(#) $Id: GetGC.3,v 1.3 2008/06/30 22:57:01 dkf Exp $
+'\"
+.so man.macros
+.TH Tk_GetGC 3 "" Tk "Tk Library Procedures"
+.BS
+.SH NAME
+Tk_GetGC, Tk_FreeGC \- maintain database of read-only graphics contexts
+.SH SYNOPSIS
+.nf
+\fB#include <tk.h>\fR
+.sp
+GC
+\fBTk_GetGC\fR(\fItkwin, valueMask, valuePtr\fR)
+.sp
+\fBTk_FreeGC(\fIdisplay, gc\fR)
+.SH ARGUMENTS
+.AS "unsigned long" valueMask
+.AP Tk_Window tkwin in
+Token for window in which the graphics context will be used.
+.AP "unsigned long" valueMask in
+Mask of bits (such as \fBGCForeground\fR or \fBGCStipple\fR)
+indicating which fields of \fI*valuePtr\fR are valid.
+.AP XGCValues *valuePtr in
+Pointer to structure describing the desired values for the
+graphics context.
+.AP Display *display in
+Display for which \fIgc\fR was allocated.
+.AP GC gc in
+X identifier for graphics context that is no longer needed.
+Must have been allocated by \fBTk_GetGC\fR.
+.BE
+.SH DESCRIPTION
+.PP
+\fBTk_GetGC\fR and \fBTk_FreeGC\fR manage a collection of graphics contexts
+being used by an application. The procedures allow graphics contexts to be
+shared, thereby avoiding the server overhead that would be incurred
+if a separate GC were created for each use. \fBTk_GetGC\fR takes arguments
+describing the desired graphics context and returns an X identifier
+for a GC that fits the description. The graphics context that is returned
+will have default values in all of the fields not specified explicitly
+by \fIvalueMask\fR and \fIvaluePtr\fR.
+.PP
+\fBTk_GetGC\fR maintains a
+database of all the graphics contexts it has created. Whenever possible,
+a call to \fBTk_GetGC\fR will
+return an existing graphics context rather than creating a new one. This
+approach can substantially reduce server overhead, so \fBTk_GetGC\fR
+should generally be used in preference to the Xlib procedure
+\fBXCreateGC\fR, which creates a new graphics context on each call.
+.PP
+Since the return values of \fBTk_GetGC\fR
+are shared, callers should never modify the graphics contexts
+returned by \fBTk_GetGC\fR.
+If a graphics context must be modified dynamically, then it should be
+created by calling \fBXCreateGC\fR instead of \fBTk_GetGC\fR.
+.PP
+When a graphics context
+is no longer needed, \fBTk_FreeGC\fR should be called to release it.
+There should be exactly one call to \fBTk_FreeGC\fR for
+each call to \fBTk_GetGC\fR.
+When a graphics context is no longer in use anywhere (i.e. it has
+been freed as many times as it has been gotten) \fBTk_FreeGC\fR
+will release it to the X server and delete it from the database.
+.SH KEYWORDS
+graphics context
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