364 lines
9.9 KiB
C
364 lines
9.9 KiB
C
/*
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* tkGC.c --
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*
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* This file maintains a database of read-only graphics contexts
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* for the Tk toolkit, in order to allow GC's to be shared.
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*
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* Copyright (c) 1990-1994 The Regents of the University of California.
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* Copyright (c) 1994 Sun Microsystems, Inc.
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*
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* See the file "license.terms" for information on usage and redistribution
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* of this file, and for a DISCLAIMER OF ALL WARRANTIES.
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*
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* SCCS: @(#) tkGC.c 1.18 96/02/15 18:53:32
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*/
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#include "tkPort.h"
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#include "tk.h"
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/*
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* One of the following data structures exists for each GC that is
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* currently active. The structure is indexed with two hash tables,
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* one based on the values in the graphics context and the other
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* based on the display and GC identifier.
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*/
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typedef struct {
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GC gc; /* Graphics context. */
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Display *display; /* Display to which gc belongs. */
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int refCount; /* Number of active uses of gc. */
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Tcl_HashEntry *valueHashPtr;/* Entry in valueTable (needed when deleting
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* this structure). */
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} TkGC;
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/*
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* Hash table to map from a GC's values to a TkGC structure describing
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* a GC with those values (used by Tk_GetGC).
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*/
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static Tcl_HashTable valueTable;
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typedef struct {
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XGCValues values; /* Desired values for GC. */
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Display *display; /* Display for which GC is valid. */
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int screenNum; /* screen number of display */
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int depth; /* and depth for which GC is valid. */
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} ValueKey;
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/*
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* Hash table for <display + GC> -> TkGC mapping. This table is used by
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* Tk_FreeGC.
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*/
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static Tcl_HashTable idTable;
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typedef struct {
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Display *display; /* Display for which GC was allocated. */
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GC gc; /* X's identifier for GC. */
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} IdKey;
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static int initialized = 0; /* 0 means static structures haven't been
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* initialized yet. */
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/*
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* Forward declarations for procedures defined in this file:
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*/
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static void GCInit _ANSI_ARGS_((void));
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/*
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*----------------------------------------------------------------------
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*
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* Tk_GetGC --
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*
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* Given a desired set of values for a graphics context, find
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* a read-only graphics context with the desired values.
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*
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* Results:
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* The return value is the X identifer for the desired graphics
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* context. The caller should never modify this GC, and should
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* call Tk_FreeGC when the GC is no longer needed.
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*
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* Side effects:
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* The GC is added to an internal database with a reference count.
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* For each call to this procedure, there should eventually be a call
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* to Tk_FreeGC, so that the database can be cleaned up when GC's
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* aren't needed anymore.
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*
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*----------------------------------------------------------------------
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*/
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GC
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Tk_GetGC(tkwin, valueMask, valuePtr)
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Tk_Window tkwin; /* Window in which GC will be used. */
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register unsigned long valueMask;
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/* 1 bits correspond to values specified
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* in *valuesPtr; other values are set
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* from defaults. */
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register XGCValues *valuePtr;
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/* Values are specified here for bits set
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* in valueMask. */
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{
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ValueKey valueKey;
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IdKey idKey;
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Tcl_HashEntry *valueHashPtr, *idHashPtr;
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register TkGC *gcPtr;
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int new;
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Drawable d, freeDrawable;
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if (!initialized) {
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GCInit();
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}
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/*
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* Must zero valueKey at start to clear out pad bytes that may be
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* part of structure on some systems.
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*/
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memset((VOID *) &valueKey, 0, sizeof(valueKey));
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/*
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* First, check to see if there's already a GC that will work
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* for this request (exact matches only, sorry).
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*/
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if (valueMask & GCFunction) {
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valueKey.values.function = valuePtr->function;
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} else {
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valueKey.values.function = GXcopy;
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}
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if (valueMask & GCPlaneMask) {
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valueKey.values.plane_mask = valuePtr->plane_mask;
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} else {
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valueKey.values.plane_mask = (unsigned) ~0;
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}
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if (valueMask & GCForeground) {
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valueKey.values.foreground = valuePtr->foreground;
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} else {
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valueKey.values.foreground = 0;
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}
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if (valueMask & GCBackground) {
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valueKey.values.background = valuePtr->background;
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} else {
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valueKey.values.background = 1;
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}
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if (valueMask & GCLineWidth) {
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valueKey.values.line_width = valuePtr->line_width;
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} else {
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valueKey.values.line_width = 0;
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}
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if (valueMask & GCLineStyle) {
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valueKey.values.line_style = valuePtr->line_style;
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} else {
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valueKey.values.line_style = LineSolid;
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}
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if (valueMask & GCCapStyle) {
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valueKey.values.cap_style = valuePtr->cap_style;
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} else {
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valueKey.values.cap_style = CapButt;
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}
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if (valueMask & GCJoinStyle) {
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valueKey.values.join_style = valuePtr->join_style;
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} else {
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valueKey.values.join_style = JoinMiter;
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}
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if (valueMask & GCFillStyle) {
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valueKey.values.fill_style = valuePtr->fill_style;
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} else {
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valueKey.values.fill_style = FillSolid;
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}
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if (valueMask & GCFillRule) {
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valueKey.values.fill_rule = valuePtr->fill_rule;
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} else {
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valueKey.values.fill_rule = EvenOddRule;
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}
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if (valueMask & GCArcMode) {
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valueKey.values.arc_mode = valuePtr->arc_mode;
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} else {
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valueKey.values.arc_mode = ArcPieSlice;
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}
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if (valueMask & GCTile) {
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valueKey.values.tile = valuePtr->tile;
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} else {
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valueKey.values.tile = None;
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}
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if (valueMask & GCStipple) {
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valueKey.values.stipple = valuePtr->stipple;
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} else {
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valueKey.values.stipple = None;
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}
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if (valueMask & GCTileStipXOrigin) {
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valueKey.values.ts_x_origin = valuePtr->ts_x_origin;
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} else {
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valueKey.values.ts_x_origin = 0;
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}
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if (valueMask & GCTileStipYOrigin) {
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valueKey.values.ts_y_origin = valuePtr->ts_y_origin;
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} else {
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valueKey.values.ts_y_origin = 0;
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}
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if (valueMask & GCFont) {
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valueKey.values.font = valuePtr->font;
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} else {
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valueKey.values.font = None;
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}
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if (valueMask & GCSubwindowMode) {
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valueKey.values.subwindow_mode = valuePtr->subwindow_mode;
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} else {
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valueKey.values.subwindow_mode = ClipByChildren;
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}
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if (valueMask & GCGraphicsExposures) {
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valueKey.values.graphics_exposures = valuePtr->graphics_exposures;
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} else {
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valueKey.values.graphics_exposures = True;
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}
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if (valueMask & GCClipXOrigin) {
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valueKey.values.clip_x_origin = valuePtr->clip_x_origin;
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} else {
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valueKey.values.clip_x_origin = 0;
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}
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if (valueMask & GCClipYOrigin) {
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valueKey.values.clip_y_origin = valuePtr->clip_y_origin;
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} else {
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valueKey.values.clip_y_origin = 0;
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}
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if (valueMask & GCClipMask) {
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valueKey.values.clip_mask = valuePtr->clip_mask;
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} else {
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valueKey.values.clip_mask = None;
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}
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if (valueMask & GCDashOffset) {
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valueKey.values.dash_offset = valuePtr->dash_offset;
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} else {
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valueKey.values.dash_offset = 0;
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}
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if (valueMask & GCDashList) {
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valueKey.values.dashes = valuePtr->dashes;
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} else {
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valueKey.values.dashes = 4;
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}
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valueKey.display = Tk_Display(tkwin);
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valueKey.screenNum = Tk_ScreenNumber(tkwin);
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valueKey.depth = Tk_Depth(tkwin);
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valueHashPtr = Tcl_CreateHashEntry(&valueTable, (char *) &valueKey, &new);
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if (!new) {
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gcPtr = (TkGC *) Tcl_GetHashValue(valueHashPtr);
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gcPtr->refCount++;
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return gcPtr->gc;
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}
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/*
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* No GC is currently available for this set of values. Allocate a
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* new GC and add a new structure to the database.
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*/
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gcPtr = (TkGC *) ckalloc(sizeof(TkGC));
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/*
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* Find or make a drawable to use to specify the screen and depth
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* of the GC. We may have to make a small pixmap, to avoid doing
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* Tk_MakeWindowExist on the window.
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*/
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freeDrawable = None;
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if (Tk_WindowId(tkwin) != None) {
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d = Tk_WindowId(tkwin);
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} else if (valueKey.depth ==
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DefaultDepth(valueKey.display, valueKey.screenNum)) {
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d = RootWindow(valueKey.display, valueKey.screenNum);
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} else {
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d = Tk_GetPixmap(valueKey.display,
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RootWindow(valueKey.display, valueKey.screenNum),
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1, 1, valueKey.depth);
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freeDrawable = d;
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}
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gcPtr->gc = XCreateGC(valueKey.display, d, valueMask, &valueKey.values);
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gcPtr->display = valueKey.display;
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gcPtr->refCount = 1;
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gcPtr->valueHashPtr = valueHashPtr;
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idKey.display = valueKey.display;
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idKey.gc = gcPtr->gc;
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idHashPtr = Tcl_CreateHashEntry(&idTable, (char *) &idKey, &new);
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if (!new) {
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panic("GC already registered in Tk_GetGC");
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}
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Tcl_SetHashValue(valueHashPtr, gcPtr);
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Tcl_SetHashValue(idHashPtr, gcPtr);
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if (freeDrawable != None) {
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Tk_FreePixmap(valueKey.display, freeDrawable);
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}
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return gcPtr->gc;
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}
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/*
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*----------------------------------------------------------------------
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*
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* Tk_FreeGC --
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*
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* This procedure is called to release a graphics context allocated by
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* Tk_GetGC.
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*
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* Results:
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* None.
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*
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* Side effects:
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* The reference count associated with gc is decremented, and
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* gc is officially deallocated if no-one is using it anymore.
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*
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*----------------------------------------------------------------------
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*/
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void
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Tk_FreeGC(display, gc)
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Display *display; /* Display for which gc was allocated. */
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GC gc; /* Graphics context to be released. */
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{
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IdKey idKey;
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Tcl_HashEntry *idHashPtr;
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register TkGC *gcPtr;
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if (!initialized) {
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panic("Tk_FreeGC called before Tk_GetGC");
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}
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idKey.display = display;
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idKey.gc = gc;
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idHashPtr = Tcl_FindHashEntry(&idTable, (char *) &idKey);
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if (idHashPtr == NULL) {
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panic("Tk_FreeGC received unknown gc argument");
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}
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gcPtr = (TkGC *) Tcl_GetHashValue(idHashPtr);
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gcPtr->refCount--;
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if (gcPtr->refCount == 0) {
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Tk_FreeXId(gcPtr->display, (XID) XGContextFromGC(gcPtr->gc));
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XFreeGC(gcPtr->display, gcPtr->gc);
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Tcl_DeleteHashEntry(gcPtr->valueHashPtr);
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Tcl_DeleteHashEntry(idHashPtr);
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ckfree((char *) gcPtr);
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}
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}
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/*
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*----------------------------------------------------------------------
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*
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* GCInit --
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*
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* Initialize the structures used for GC management.
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*
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* Results:
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* None.
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*
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* Side effects:
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* Read the code.
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*
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*----------------------------------------------------------------------
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*/
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static void
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GCInit()
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{
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initialized = 1;
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Tcl_InitHashTable(&valueTable, sizeof(ValueKey)/sizeof(int));
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Tcl_InitHashTable(&idTable, sizeof(IdKey)/sizeof(int));
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}
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