501 lines
16 KiB
C
501 lines
16 KiB
C
/*
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* tkColor.c --
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*
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* This file maintains a database of color values for the Tk
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* toolkit, in order to avoid round-trips to the server to
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* map color names to pixel values.
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*
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* Copyright (c) 1990-1993 The Regents of the University of California.
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* All rights reserved.
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*
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* Permission is hereby granted, without written agreement and without
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* license or royalty fees, to use, copy, modify, and distribute this
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* software and its documentation for any purpose, provided that the
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* above copyright notice and the following two paragraphs appear in
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* all copies of this software.
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*
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* IN NO EVENT SHALL THE UNIVERSITY OF CALIFORNIA BE LIABLE TO ANY PARTY FOR
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* DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING OUT
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* OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF THE UNIVERSITY OF
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* CALIFORNIA HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*
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* THE UNIVERSITY OF CALIFORNIA SPECIFICALLY DISCLAIMS ANY WARRANTIES,
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* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
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* AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
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* ON AN "AS IS" BASIS, AND THE UNIVERSITY OF CALIFORNIA HAS NO OBLIGATION TO
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* PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
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*/
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#ifndef lint
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static char rcsid[] = "$Header: /user6/ouster/wish/RCS/tkColor.c,v 1.24 93/06/16 17:15:38 ouster Exp $ SPRITE (Berkeley)";
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#endif /* not lint */
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#include "tkConfig.h"
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#include "tk.h"
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#include "tkInt.h"
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/*
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* A two-level data structure is used to manage the color database.
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* The top level consists of one entry for each color name that is
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* currently active, and the bottom level contains one entry for each
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* pixel value that is still in use. The distinction between
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* levels is necessary because the same pixel may have several
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* different names. There are two hash tables, one used to index into
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* each of the data structures. The name hash table is used when
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* allocating colors, and the pixel hash table is used when freeing
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* colors.
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*/
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/*
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* One of the following data structures is used to keep track of
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* each color that this module has allocated from the X display
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* server. These entries are indexed by two hash tables defined
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* below: nameTable and valueTable.
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*/
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#define COLOR_MAGIC ((unsigned int) 0xc6140277)
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typedef struct TkColor {
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XColor color; /* Information about this color. */
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unsigned int magic; /* Used for quick integrity check on this
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* structure. Must always have the
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* value COLOR_MAGIC. */
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Screen *screen; /* Screen where this color is valid. Used
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* to delete it. */
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Colormap colormap; /* Colormap from which this entry was
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* allocated. */
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Visual *visual; /* Visual associated with colormap. */
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int refCount; /* Number of uses of this structure. */
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Tcl_HashTable *tablePtr; /* Hash table that indexes this structure
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* (needed when deleting structure). */
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Tcl_HashEntry *hashPtr; /* Pointer to hash table entry for this
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* structure. (for use in deleting entry). */
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} TkColor;
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/*
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* Hash table for name -> TkColor mapping, and key structure used to
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* index into that table:
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*/
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static Tcl_HashTable nameTable;
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typedef struct {
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Tk_Uid name; /* Name of desired color. */
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Colormap colormap; /* Colormap from which color will be
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* allocated. */
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Display *display; /* Display for colormap. */
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} NameKey;
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/*
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* Hash table for value -> TkColor mapping, and key structure used to
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* index into that table:
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*/
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static Tcl_HashTable valueTable;
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typedef struct {
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int red, green, blue; /* Values for desired color. */
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Colormap colormap; /* Colormap from which color will be
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* allocated. */
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Display *display; /* Display for colormap. */
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} ValueKey;
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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 ColorInit _ANSI_ARGS_((void));
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/*
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*----------------------------------------------------------------------
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*
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* Tk_GetColor --
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*
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* Given a string name for a color, map the name to a corresponding
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* XColor structure.
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*
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* Results:
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* The return value is a pointer to an XColor structure that
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* indicates the red, blue, and green intensities for the color
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* given by "name", and also specifies a pixel value to use to
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* draw in that color in window "tkwin". If an error occurs,
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* then NULL is returned and an error message will be left in
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* interp->result.
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*
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* Side effects:
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* The color 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_FreeColor, so that the database is cleaned up when colors
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* aren't in use anymore.
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*
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*----------------------------------------------------------------------
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*/
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XColor *
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Tk_GetColor(interp, tkwin, colormap, name)
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Tcl_Interp *interp; /* Place to leave error message if
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* color can't be found. */
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Tk_Window tkwin; /* Window in which color will be used. */
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Colormap colormap; /* Map from which to allocate color. None
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* means use current colormap for tkwin. */
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Tk_Uid name; /* Name of color to allocated (in form
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* suitable for passing to XParseColor). */
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{
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NameKey nameKey;
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Tcl_HashEntry *nameHashPtr;
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int new;
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TkColor *tkColPtr;
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XColor color;
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if (!initialized) {
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ColorInit();
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}
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/*
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* First, check to see if there's already a mapping for this color
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* name.
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*/
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nameKey.name = name;
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if (colormap == None) {
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colormap = Tk_Colormap(tkwin);
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}
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nameKey.colormap = colormap;
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nameKey.display = Tk_Display(tkwin);
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nameHashPtr = Tcl_CreateHashEntry(&nameTable, (char *) &nameKey, &new);
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if (!new) {
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tkColPtr = (TkColor *) Tcl_GetHashValue(nameHashPtr);
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tkColPtr->refCount++;
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return &tkColPtr->color;
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}
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/*
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* The name isn't currently known. Map from the name to a pixel
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* value. There are several tricks here:
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*
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* 1. Call XAllocNamedColor rather than XParseColor for non-# names:
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* this saves a server round-trip for those names.
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* 2. If the display is supposed to be treated as mono, then look
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* up the color value and translate to mono.
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* 3. If a color allocation fails, then reset the display's color model
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* to mono, generate an error message, and retry with the mono
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* approach.
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*/
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if (*name != '#') {
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XColor screen;
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if (Tk_GetColorModel(tkwin) != TK_COLOR) {
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if (XLookupColor(Tk_Display(tkwin), colormap, name, &color,
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&screen) == 0) {
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badColorName:
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Tcl_AppendResult(interp, "unknown color name \"",
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name, "\"", (char *) NULL);
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Tcl_DeleteHashEntry(nameHashPtr);
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return (XColor *) NULL;
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}
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goto useMonoApproximation;
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}
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if (XAllocNamedColor(Tk_Display(tkwin), colormap, name,
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&screen, &color) == 0) {
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char message[120];
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/*
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* Couldn't allocate the color. Try translating the name to
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* a color value, to see whether the problem is a bad color
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* name or a full colormap. If the colormap is full, then
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* put the display into mono mode and
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*/
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if (XLookupColor(Tk_Display(tkwin), colormap, name, &color,
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&screen) == 0) {
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goto badColorName;
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}
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outOfColors:
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Tk_SetColorModel(tkwin, TK_MONO);
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Tcl_AppendResult(interp, "no more colors left in colormap; ",
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"changing screen's color model to monochrome",
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(char *) NULL);
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sprintf(message, "\n (while allocating color \"%.50s\")", name);
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Tcl_AddErrorInfo(interp, message);
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Tk_BackgroundError(interp);
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goto useMonoApproximation;
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}
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} else {
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if (XParseColor(Tk_Display(tkwin), colormap, name, &color) == 0) {
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Tcl_AppendResult(interp, "invalid color name \"", name,
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"\"", (char *) NULL);
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Tcl_DeleteHashEntry(nameHashPtr);
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return (XColor *) NULL;
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}
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if (Tk_GetColorModel(tkwin) != TK_COLOR) {
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useMonoApproximation:
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if ((((int) color.red) + ((int) color.green) + ((int) color.blue))
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> (3*65535)/2) {
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color.pixel = WhitePixelOfScreen(Tk_Screen(tkwin));
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} else {
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color.pixel = BlackPixelOfScreen(Tk_Screen(tkwin));
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}
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} else if (XAllocColor(Tk_Display(tkwin), colormap, &color) == 0) {
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goto outOfColors;
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}
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}
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/*
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* Now create a new TkColor structure and add it to nameTable.
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*/
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tkColPtr = (TkColor *) ckalloc(sizeof(TkColor));
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tkColPtr->color = color;
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tkColPtr->magic = COLOR_MAGIC;
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tkColPtr->screen = Tk_Screen(tkwin);
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tkColPtr->colormap = colormap;
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tkColPtr->visual = Tk_Visual(tkwin);
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tkColPtr->refCount = 1;
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tkColPtr->tablePtr = &nameTable;
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tkColPtr->hashPtr = nameHashPtr;
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Tcl_SetHashValue(nameHashPtr, tkColPtr);
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return &tkColPtr->color;
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}
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/*
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*----------------------------------------------------------------------
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*
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* Tk_GetColorByValue --
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*
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* Given a desired set of red-green-blue intensities for a color,
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* locate a pixel value to use to draw that color in a given
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* window.
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*
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* Results:
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* The return value is a pointer to an XColor structure that
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* indicates the closest red, blue, and green intensities available
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* to those specified in colorPtr, and also specifies a pixel
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* value to use to draw in that color in window "tkwin". If an
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* error occurs, then NULL is returned and an error message will
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* be left in interp->result.
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*
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* Side effects:
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* The color 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_FreeColor, so that the database is cleaned up when colors
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* aren't in use anymore.
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*
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*----------------------------------------------------------------------
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*/
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XColor *
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Tk_GetColorByValue(interp, tkwin, colormap, colorPtr)
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Tcl_Interp *interp; /* Place to leave error message if
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* color can't be found. */
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Tk_Window tkwin; /* Window in which color will be used. */
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Colormap colormap; /* Map from which to allocate color. None
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* means use current colormap for tkwin. */
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XColor *colorPtr; /* Red, green, and blue fields indicate
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* desired color. */
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{
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ValueKey valueKey;
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Tcl_HashEntry *valueHashPtr;
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int new;
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TkColor *tkColPtr;
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if (!initialized) {
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ColorInit();
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}
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/*
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* First, check to see if there's already a mapping for this color
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* name.
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*/
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valueKey.red = colorPtr->red;
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valueKey.green = colorPtr->green;
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valueKey.blue = colorPtr->blue;
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if (colormap == None) {
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colormap = Tk_Colormap(tkwin);
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}
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valueKey.colormap = colormap;
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valueKey.display = Tk_Display(tkwin);
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valueHashPtr = Tcl_CreateHashEntry(&valueTable, (char *) &valueKey, &new);
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if (!new) {
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tkColPtr = (TkColor *) Tcl_GetHashValue(valueHashPtr);
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tkColPtr->refCount++;
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return &tkColPtr->color;
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}
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/*
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* The name isn't currently known. Find a pixel value for this
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* color and add a new structure to valueTable.
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*/
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tkColPtr = (TkColor *) ckalloc(sizeof(TkColor));
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tkColPtr->color.red = valueKey.red;
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tkColPtr->color.green = valueKey.green;
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tkColPtr->color.blue = valueKey.blue;
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if (Tk_GetColorModel(tkwin) != TK_COLOR) {
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useMonoApproximation:
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if ((((int) tkColPtr->color.red) + ((int) tkColPtr->color.green)
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+ ((int) tkColPtr->color.blue)) > (3*65535)/2) {
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tkColPtr->color.pixel = WhitePixelOfScreen(Tk_Screen(tkwin));
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} else {
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tkColPtr->color.pixel = BlackPixelOfScreen(Tk_Screen(tkwin));
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}
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} else {
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if (XAllocColor(Tk_Display(tkwin), colormap, &tkColPtr->color) == 0) {
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Tk_SetColorModel(tkwin, TK_MONO);
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Tcl_AppendResult(interp, "no more colors left in colormap; ",
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"changing screen's color model to monochrome",
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(char *) NULL);
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Tcl_AddErrorInfo(interp,
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"\n (while allocating color in Tk_GetColorByValue)");
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Tk_BackgroundError(interp);
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goto useMonoApproximation;
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}
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}
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tkColPtr->magic = COLOR_MAGIC;
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tkColPtr->screen = Tk_Screen(tkwin);
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tkColPtr->colormap = colormap;
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tkColPtr->visual = Tk_Visual(tkwin);
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tkColPtr->refCount = 1;
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tkColPtr->tablePtr = &valueTable;
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tkColPtr->hashPtr = valueHashPtr;
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Tcl_SetHashValue(valueHashPtr, tkColPtr);
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return &tkColPtr->color;
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}
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/*
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*--------------------------------------------------------------
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*
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* Tk_NameOfColor --
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*
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* Given a color, return a textual string identifying
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* the color.
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*
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* Results:
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* If colorPtr was created by Tk_GetColor, then the return
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* value is the "string" that was used to create it.
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* Otherwise the return value is a string that could have
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* been passed to Tk_GetColor to allocate that color. The
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* storage for the returned string is only guaranteed to
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* persist up until the next call to this procedure.
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*
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* Side effects:
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* None.
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*
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*--------------------------------------------------------------
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*/
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char *
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Tk_NameOfColor(colorPtr)
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XColor *colorPtr; /* Color whose name is desired. */
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{
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register TkColor *tkColPtr = (TkColor *) colorPtr;
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static char string[20];
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if ((tkColPtr->magic == COLOR_MAGIC)
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&& (tkColPtr->tablePtr == &nameTable)) {
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return ((NameKey *) tkColPtr->hashPtr->key.words)->name;
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}
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sprintf(string, "#%4x%4x%4x", colorPtr->red, colorPtr->green,
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colorPtr->blue);
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return string;
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}
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/*
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*----------------------------------------------------------------------
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*
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* Tk_FreeColor --
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*
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* This procedure is called to release a color allocated by
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* Tk_GetColor.
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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 colorPtr is deleted, and
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* the color is released to X if there are no remaining uses
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* for it.
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*
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*----------------------------------------------------------------------
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*/
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void
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Tk_FreeColor(colorPtr)
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XColor *colorPtr; /* Color to be released. Must have been
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* allocated by Tk_GetColor or
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* Tk_GetColorByValue. */
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{
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register TkColor *tkColPtr = (TkColor *) colorPtr;
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Visual *visual;
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Screen *screen = tkColPtr->screen;
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/*
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* Do a quick sanity check to make sure this color was really
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* allocated by Tk_GetColor.
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*/
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if (tkColPtr->magic != COLOR_MAGIC) {
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panic("Tk_FreeColor called with bogus color");
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}
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tkColPtr->refCount--;
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if (tkColPtr->refCount == 0) {
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/*
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* Careful! Don't free black or white, since this will
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* make some servers very unhappy. Also, there is a bug in
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* some servers (such Sun's X11/NeWS server) where reference
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* counting is performed incorrectly, so that if a color is
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* allocated twice in different places and then freed twice,
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* the second free generates an error (this bug existed as of
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* 10/1/92). To get around this problem, ignore errors that
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* occur during the free operation.
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*/
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visual = tkColPtr->visual;
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if ((visual->class != StaticGray) && (visual->class != StaticColor)
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&& (tkColPtr->color.pixel != BlackPixelOfScreen(screen))
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&& (tkColPtr->color.pixel != WhitePixelOfScreen(screen))) {
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Tk_ErrorHandler handler;
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handler = Tk_CreateErrorHandler(DisplayOfScreen(screen),
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-1, -1, -1, (Tk_ErrorProc *) NULL, (ClientData) NULL);
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XFreeColors(DisplayOfScreen(screen), tkColPtr->colormap,
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&tkColPtr->color.pixel, 1, 0L);
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Tk_DeleteErrorHandler(handler);
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}
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Tcl_DeleteHashEntry(tkColPtr->hashPtr);
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tkColPtr->magic = 0;
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ckfree((char *) tkColPtr);
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}
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}
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/*
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*----------------------------------------------------------------------
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*
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* ColorInit --
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*
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* Initialize the structure used for color 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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ColorInit()
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{
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initialized = 1;
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Tcl_InitHashTable(&nameTable, sizeof(NameKey)/sizeof(int));
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Tcl_InitHashTable(&valueTable, sizeof(ValueKey)/sizeof(int));
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}
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