oldXMenu/XLookAssoc.c

   1 /* Copyright    Massachusetts Institute of Technology    1985   */
   2
   3 #include "copyright.h"
   4
   5
   6 #include <X11/Xlib.h>
   7 #include <X11/Xresource.h>
   8 #include "X10.h"
   9
  10 #ifndef NULL
  11 #define NULL 0
  12 #endif
  13
  14 /*
  15  * XLookUpAssoc - Retrieve the data stored in an XAssocTable by its XId.
  16  * If an appropriately matching XId can be found in the table the routine will
  17  * return apointer to the data associated with it. If the XId can not be found
  18  * in the table the routine will return a NULL pointer.  All XId's are relative
  19  * to the currently active Display.
  20  */
  21 caddr_t XLookUpAssoc(register Display *dpy, register XAssocTable *table, register XID x_id)
  22
  23                                         /* XAssocTable to search in. */
  24                                                 /* XId to search for. */
  25 {
  26         int hash;
  27         register XAssoc *bucket;
  28         register XAssoc *Entry;
  29
  30         /* Hash the XId to get the bucket number. */
  31         hash = x_id & (table->size - 1);
  32         /* Look up the bucket to get the entries in that bucket. */
  33         bucket = &table->buckets[hash];
  34         /* Get the first entry in the bucket. */
  35         Entry = bucket->next;
  36
  37         /* Scan through the entries in the bucket for the right XId. */
  38         for (; Entry != bucket; Entry = Entry->next) {
  39                 if (Entry->x_id == x_id) {
  40                         /* We have the right XId. */
  41                         if (Entry->display == dpy) {
  42                                 /* We have the right display. */
  43                                 /* We have the right entry! */
  44                                 return(Entry->data);
  45                         }
  46                         /* Oops, identical XId's on different displays! */
  47                         continue;
  48                 }
  49                 if (Entry->x_id > x_id) {
  50                         /* We have gone past where it should be. */
  51                         /* It is apparently not in the table. */
  52                         return(NULL);
  53                 }
  54         }
  55         /* It is apparently not in the table. */
  56         return(NULL);
  57 }
  58