mdw@git.distorted.org.uk Git - disorder/blob - lib/selection.c

   1 /*
   2  * This file is part of DisOrder
   3  * Copyright (C) 2006, 2007 Richard Kettlewell
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
  18  * USA
  19  */
  20 /** @file lib/selection.c
  21  * @brief Select management for Disobedience
  22  */
  23
  24 #include <config.h>
  25 #include "types.h"
  26
  27 #include "mem.h"
  28 #include "hash.h"
  29 #include "selection.h"
  30
  31 /** @brief Create a new selection manager
  32  * @return Pointer to @ref hash used to manage the selection
  33  */
  34 hash *selection_new(void) {
  35   return hash_new(sizeof (int));
  36 }
  37
  38 /** @brief Add or remove a key in a selection
  39  * @param h Hash representing selection
  40  * @param key Key to insert
  41  * @param selected non-0 if key is selected, 0 if it is not
  42  *
  43  * @p key is copied so the pointer need not remain valid.  Newly selected keys
  44  * are not marked as live.
  45  */
  46 void selection_set(hash *h, const char *key, int selected) {
  47   if(selected) {
  48     int *const liveness = xmalloc_noptr(sizeof (int));
  49     *liveness = 0;
  50     hash_add(h, key, liveness, HASH_INSERT_OR_REPLACE);
  51   } else
  52     hash_remove(h, key);
  53 }
  54
  55 /** @brief Test whether a key is set in a selection
  56  * @param h Hash representing selection
  57  * @param key Key to check
  58  * @return non-0 if key is present, 0 if it is not
  59  */
  60 int selection_selected(hash *h, const char *key) {
  61   return hash_find(h, key) != 0;
  62 }
  63
  64 /** @brief Invert a key's selection status
  65  * @param h Hash representing selection
  66  * @param key Key to flip
  67  *
  68  * If the key is selected as a result it is not marked as live.
  69  */
  70 void selection_flip(hash *h, const char *key) {
  71   selection_set(h, key, !selection_selected(h, key));
  72 }
  73
  74 /** @brief Mark a selection key as live
  75  * @param h Hash representing selection
  76  * @param key Key to mark as live
  77  *
  78  * Live keys will survive a call to selection_cleanup().  @p need not be in the
  79  * selection (if it is not then the call will be ignored).
  80  */
  81 void selection_live(hash *h, const char *key) {
  82   int *ptr = hash_find(h, key);
  83
  84   if(ptr)
  85     *ptr = 1;
  86 }
  87
  88 static int selection_cleanup_callback(const char *key,
  89                                       void *value,
  90                                       void *v) {
  91   if(*(int *)value)
  92     *(int *)value = 0;
  93   else
  94     hash_remove((hash *)v, key);
  95   return 0;
  96 }
  97
  98 /** @brief Delete all non-live keys from a selection
  99  * @param h Hash representing selection
 100  *
 101  * After cleanup, no keys are marked as live.
 102  */
 103 void selection_cleanup(hash *h) {
 104   hash_foreach(h, selection_cleanup_callback, h);
 105 }
 106
 107 static int selection_empty_callback(const char *key,
 108                                     void attribute((unused)) *value,
 109                                     void *v) {
 110   hash_remove((hash *)v, key);
 111   return 0;
 112 }
 113
 114 /** @brief Remove all keys from a selection
 115  * @param h Hash representing selection
 116  */
 117 void selection_empty(hash *h) {
 118   hash_foreach(h, selection_empty_callback, h);
 119 }
 120
 121 /*
 122 Local Variables:
 123 c-basic-offset:2
 124 comment-column:40
 125 fill-column:79
 126 indent-tabs-mode:nil
 127 End:
 128 */