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 3 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,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU 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, see <http://www.gnu.org/licenses/>.
  17  */
  18 /** @file lib/selection.c
  19  * @brief Select management for Disobedience
  20  */
  21
  22 #include "common.h"
  23
  24 #include "mem.h"
  25 #include "hash.h"
  26 #include "selection.h"
  27
  28 /** @brief Create a new selection manager
  29  * @return Pointer to @ref hash used to manage the selection
  30  */
  31 hash *selection_new(void) {
  32   return hash_new(sizeof (int));
  33 }
  34
  35 /** @brief Add or remove a key in a selection
  36  * @param h Hash representing selection
  37  * @param key Key to insert
  38  * @param selected non-0 if key is selected, 0 if it is not
  39  *
  40  * @p key is copied so the pointer need not remain valid.  Newly selected keys
  41  * are not marked as live.
  42  */
  43 void selection_set(hash *h, const char *key, int selected) {
  44   if(selected) {
  45     int *const liveness = xmalloc_noptr(sizeof (int));
  46     *liveness = 0;
  47     hash_add(h, key, liveness, HASH_INSERT_OR_REPLACE);
  48   } else
  49     hash_remove(h, key);
  50 }
  51
  52 /** @brief Test whether a key is set in a selection
  53  * @param h Hash representing selection
  54  * @param key Key to check
  55  * @return non-0 if key is present, 0 if it is not
  56  */
  57 int selection_selected(hash *h, const char *key) {
  58   return hash_find(h, key) != 0;
  59 }
  60
  61 /** @brief Invert a key's selection status
  62  * @param h Hash representing selection
  63  * @param key Key to flip
  64  *
  65  * If the key is selected as a result it is not marked as live.
  66  */
  67 void selection_flip(hash *h, const char *key) {
  68   selection_set(h, key, !selection_selected(h, key));
  69 }
  70
  71 /** @brief Mark a selection key as live
  72  * @param h Hash representing selection
  73  * @param key Key to mark as live
  74  *
  75  * Live keys will survive a call to selection_cleanup().  @p need not be in the
  76  * selection (if it is not then the call will be ignored).
  77  */
  78 void selection_live(hash *h, const char *key) {
  79   int *ptr = hash_find(h, key);
  80
  81   if(ptr)
  82     *ptr = 1;
  83 }
  84
  85 static int selection_cleanup_callback(const char *key,
  86                                       void *value,
  87                                       void *v) {
  88   if(*(int *)value)
  89     *(int *)value = 0;
  90   else
  91     hash_remove((hash *)v, key);
  92   return 0;
  93 }
  94
  95 /** @brief Delete all non-live keys from a selection
  96  * @param h Hash representing selection
  97  *
  98  * After cleanup, no keys are marked as live.
  99  */
 100 void selection_cleanup(hash *h) {
 101   hash_foreach(h, selection_cleanup_callback, h);
 102 }
 103
 104 static int selection_empty_callback(const char *key,
 105                                     void attribute((unused)) *value,
 106                                     void *v) {
 107   hash_remove((hash *)v, key);
 108   return 0;
 109 }
 110
 111 /** @brief Remove all keys from a selection
 112  * @param h Hash representing selection
 113  */
 114 void selection_empty(hash *h) {
 115   hash_foreach(h, selection_empty_callback, h);
 116 }
 117
 118 /*
 119 Local Variables:
 120 c-basic-offset:2
 121 comment-column:40
 122 fill-column:79
 123 indent-tabs-mode:nil
 124 End:
 125 */