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 "common.h"
  25
  26 #include "mem.h"
  27 #include "hash.h"
  28 #include "selection.h"
  29
  30 /** @brief Create a new selection manager
  31  * @return Pointer to @ref hash used to manage the selection
  32  */
  33 hash *selection_new(void) {
  34   return hash_new(sizeof (int));
  35 }
  36
  37 /** @brief Add or remove a key in a selection
  38  * @param h Hash representing selection
  39  * @param key Key to insert
  40  * @param selected non-0 if key is selected, 0 if it is not
  41  *
  42  * @p key is copied so the pointer need not remain valid.  Newly selected keys
  43  * are not marked as live.
  44  */
  45 void selection_set(hash *h, const char *key, int selected) {
  46   if(selected) {
  47     int *const liveness = xmalloc_noptr(sizeof (int));
  48     *liveness = 0;
  49     hash_add(h, key, liveness, HASH_INSERT_OR_REPLACE);
  50   } else
  51     hash_remove(h, key);
  52 }
  53
  54 /** @brief Test whether a key is set in a selection
  55  * @param h Hash representing selection
  56  * @param key Key to check
  57  * @return non-0 if key is present, 0 if it is not
  58  */
  59 int selection_selected(hash *h, const char *key) {
  60   return hash_find(h, key) != 0;
  61 }
  62
  63 /** @brief Invert a key's selection status
  64  * @param h Hash representing selection
  65  * @param key Key to flip
  66  *
  67  * If the key is selected as a result it is not marked as live.
  68  */
  69 void selection_flip(hash *h, const char *key) {
  70   selection_set(h, key, !selection_selected(h, key));
  71 }
  72
  73 /** @brief Mark a selection key as live
  74  * @param h Hash representing selection
  75  * @param key Key to mark as live
  76  *
  77  * Live keys will survive a call to selection_cleanup().  @p need not be in the
  78  * selection (if it is not then the call will be ignored).
  79  */
  80 void selection_live(hash *h, const char *key) {
  81   int *ptr = hash_find(h, key);
  82
  83   if(ptr)
  84     *ptr = 1;
  85 }
  86
  87 static int selection_cleanup_callback(const char *key,
  88                                       void *value,
  89                                       void *v) {
  90   if(*(int *)value)
  91     *(int *)value = 0;
  92   else
  93     hash_remove((hash *)v, key);
  94   return 0;
  95 }
  96
  97 /** @brief Delete all non-live keys from a selection
  98  * @param h Hash representing selection
  99  *
 100  * After cleanup, no keys are marked as live.
 101  */
 102 void selection_cleanup(hash *h) {
 103   hash_foreach(h, selection_cleanup_callback, h);
 104 }
 105
 106 static int selection_empty_callback(const char *key,
 107                                     void attribute((unused)) *value,
 108                                     void *v) {
 109   hash_remove((hash *)v, key);
 110   return 0;
 111 }
 112
 113 /** @brief Remove all keys from a selection
 114  * @param h Hash representing selection
 115  */
 116 void selection_empty(hash *h) {
 117   hash_foreach(h, selection_empty_callback, h);
 118 }
 119
 120 /*
 121 Local Variables:
 122 c-basic-offset:2
 123 comment-column:40
 124 fill-column:79
 125 indent-tabs-mode:nil
 126 End:
 127 */