cvs.zerfleddert.de Git - micropolis/blob - src/tk/tkatom.c

   1 /*
   2  * tkAtom.c --
   3  *
   4  *      This file manages a cache of X Atoms in order to avoid
   5  *      interactions with the X server.  It's much like the Xmu
   6  *      routines, except it has a cleaner interface (caller
   7  *      doesn't have to provide permanent storage for atom names,
   8  *      for example).
   9  *
  10  * Copyright 1990 Regents of the University of California.
  11  * Permission to use, copy, modify, and distribute this
  12  * software and its documentation for any purpose and without
  13  * fee is hereby granted, provided that the above copyright
  14  * notice appear in all copies.  The University of California
  15  * makes no representations about the suitability of this
  16  * software for any purpose.  It is provided "as is" without
  17  * express or implied warranty.
  18  */
  19
  20 #ifndef lint
  21 static char rcsid[] = "$Header: /user6/ouster/wish/RCS/tkAtom.c,v 1.6 92/05/07 09:51:06 ouster Exp $ SPRITE (Berkeley)";
  22 #endif
  23
  24 #include "tkconfig.h"
  25 #include "tkint.h"
  26
  27 /*
  28  * Forward references to procedures defined in this file:
  29  */
  30
  31 static void     AtomInit _ANSI_ARGS_((TkDisplay *dispPtr));
  32 \f
  33 /*
  34  *--------------------------------------------------------------
  35  *
  36  * Tk_InternAtom --
  37  *
  38  *      Given a string, produce the equivalent X atom.  This
  39  *      procedure is equivalent to XInternAtom, except that it
  40  *      keeps a local cache of atoms.  Once a name is known,
  41  *      the server need not be contacted again for that name.
  42  *
  43  * Results:
  44  *      The return value is the Atom corresponding to name.
  45  *
  46  * Side effects:
  47  *      A new entry may be added to the local atom cache.
  48  *
  49  *--------------------------------------------------------------
  50  */
  51
  52 Atom
  53 Tk_InternAtom(tkwin, name)
  54     Tk_Window tkwin;            /* Window token;  map name to atom
  55                                  * for this window's display. */
  56     char *name;                 /* Name to turn into atom. */
  57 {
  58     register TkDisplay *dispPtr;
  59     register Tcl_HashEntry *hPtr;
  60     int new;
  61
  62     dispPtr = ((TkWindow *) tkwin)->dispPtr;
  63     if (!dispPtr->atomInit) {
  64         AtomInit(dispPtr);
  65     }
  66
  67     hPtr = Tcl_CreateHashEntry(&dispPtr->nameTable, name, &new);
  68     if (new) {
  69         Tcl_HashEntry *hPtr2;
  70         Atom atom;
  71
  72         atom = XInternAtom(dispPtr->display, name, False);
  73         Tcl_SetHashValue(hPtr, atom);
  74         hPtr2 = Tcl_CreateHashEntry(&dispPtr->atomTable, (char *) atom,
  75                 &new);
  76         Tcl_SetHashValue(hPtr2, Tcl_GetHashKey(&dispPtr->nameTable, hPtr));
  77     }
  78     return (Atom) Tcl_GetHashValue(hPtr);
  79 }
  80 \f
  81 /*
  82  *--------------------------------------------------------------
  83  *
  84  * Tk_GetAtomName --
  85  *
  86  *      This procedure is equivalent to XGetAtomName except that
  87  *      it uses the local atom cache to avoid contacting the
  88  *      server.
  89  *
  90  * Results:
  91  *      The return value is a character string corresponding to
  92  *      the atom given by "atom".  This string's storage space
  93  *      is static:  it need not be freed by the caller, and should
  94  *      not be modified by the caller.  If "atom" doesn't exist
  95  *      on tkwin's display, then the string "?bad atom?" is returned.
  96  *
  97  * Side effects:
  98  *      None.
  99  *
 100  *--------------------------------------------------------------
 101  */
 102
 103 char *
 104 Tk_GetAtomName(tkwin, atom)
 105     Tk_Window tkwin;            /* Window token;  map atom to name
 106                                  * relative to this window's
 107                                  * display. */
 108     Atom atom;                  /* Atom whose name is wanted. */
 109 {
 110     register TkDisplay *dispPtr;
 111     register Tcl_HashEntry *hPtr;
 112
 113     dispPtr = ((TkWindow *) tkwin)->dispPtr;
 114     if (!dispPtr->atomInit) {
 115         AtomInit(dispPtr);
 116     }
 117
 118     hPtr = Tcl_FindHashEntry(&dispPtr->atomTable, (char *) atom);
 119     if (hPtr == NULL) {
 120         char *name;
 121         Tk_ErrorHandler handler;
 122         int new;
 123
 124         handler= Tk_CreateErrorHandler(dispPtr->display, BadAtom,
 125                 -1, -1, (int (*)()) NULL, (ClientData) NULL);
 126         name = XGetAtomName(dispPtr->display, atom);
 127         if (name == NULL) {
 128             name = "?bad atom?";
 129         }
 130         Tk_DeleteErrorHandler(handler);
 131         hPtr = Tcl_CreateHashEntry(&dispPtr->nameTable, (char *) name,
 132                 &new);
 133         Tcl_SetHashValue(hPtr, atom);
 134         name = Tcl_GetHashKey(&dispPtr->nameTable, hPtr);
 135         hPtr = Tcl_CreateHashEntry(&dispPtr->atomTable, (char *) atom,
 136                 &new);
 137         Tcl_SetHashValue(hPtr, name);
 138     }
 139     return (char *) Tcl_GetHashValue(hPtr);
 140 }
 141 \f
 142 /*
 143  *--------------------------------------------------------------
 144  *
 145  * AtomInit --
 146  *
 147  *      Initialize atom-related information for a display.
 148  *
 149  * Results:
 150  *      None.
 151  *
 152  * Side effects:
 153  *      Tables get initialized, etc. etc..
 154  *
 155  *--------------------------------------------------------------
 156  */
 157
 158 static void
 159 AtomInit(dispPtr)
 160     register TkDisplay *dispPtr;        /* Display to initialize. */
 161 {
 162     dispPtr->atomInit = 1;
 163     Tcl_InitHashTable(&dispPtr->nameTable, TCL_STRING_KEYS);
 164     Tcl_InitHashTable(&dispPtr->atomTable, TCL_ONE_WORD_KEYS);
 165 }