git.sesse.net Git - vlc/blob - modules/codec/cmml/history.c

   1 /*****************************************************************************
   2  * history.c: vlc_history_t (web-browser-like back/forward history) handling
   3  *****************************************************************************
   4  * Copyright (C) 2004 Commonwealth Scientific and Industrial Research
   5  *                    Organisation (CSIRO) Australia
   6  * Copyright (C) 2004 the VideoLAN team
   7  *
   8  * $Id$
   9  *
  10  * Authors: Andre Pang <Andre.Pang@csiro.au>
  11  *
  12  * This program is free software; you can redistribute it and/or modify
  13  * it under the terms of the GNU General Public License as published by
  14  * the Free Software Foundation; either version 2 of the License, or
  15  * (at your option) any later version.
  16  *
  17  * This program is distributed in the hope that it will be useful,
  18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20  * GNU General Public License for more details.
  21  *
  22  * You should have received a copy of the GNU General Public License
  23  * along with this program; if not, write to the Free Software
  24  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  25  *****************************************************************************/
  26
  27 #ifdef HAVE_CONFIG_H
  28 # include "config.h"
  29 #endif
  30
  31 #include <vlc_common.h>
  32 #include <vlc_input.h>
  33
  34 #include "history.h"
  35
  36 #include "xarray.h"
  37
  38 #ifdef HAVE_STDLIB_H
  39 #   include <stdlib.h>                                          /* realloc() */
  40 #endif
  41
  42 #undef HISTORY_DEBUG
  43
  44 /*****************************************************************************
  45  * Local prototypes
  46  *****************************************************************************/
  47 #ifdef HISTORY_DEBUG
  48 static void history_Dump( history_t *p_history );
  49 #endif
  50
  51 /*****************************************************************************
  52  * Local structure lock
  53  *****************************************************************************/
  54
  55 /*****************************************************************************
  56  * Actual history code
  57  *****************************************************************************/
  58
  59 history_t *history_New( void )
  60 {
  61    history_t *p_new_history;
  62
  63    p_new_history = calloc( 1, sizeof( struct history_t ) );
  64    if( p_new_history == NULL ) return NULL;
  65
  66    p_new_history->p_xarray = xarray_New( 0 );
  67    if( p_new_history->p_xarray == NULL )
  68    {
  69        free( p_new_history );
  70        return NULL;
  71    }
  72
  73    return p_new_history;
  74 }
  75
  76 bool history_GoBackSavingCurrentItem ( history_t *p_history,
  77                                              history_item_t *p_item )
  78 {
  79     history_PruneAndInsert( p_history, p_item );
  80
  81     /* PruneAndInsert will increment the index, so we need to go
  82      * back one position to reset the index to the place we were at
  83      * before saving the current state, and then go back one more to
  84      * actually go back */
  85     p_history->i_index -= 2;
  86
  87 #ifdef HISTORY_DEBUG
  88     history_Dump( p_history );
  89 #endif
  90     return true;
  91 }
  92
  93 #ifdef HISTORY_DEBUG
  94 static void history_Dump( history_t *p_history )
  95 {
  96     unsigned int i_count;
  97     int i;
  98
  99     if( xarray_Count( p_history->p_xarray, &i_count ) != XARRAY_SUCCESS )
 100         return;
 101
 102     for (i = 0; i < (int) i_count; i++)
 103     {
 104         history_item_t *p_item;
 105         void *pv_item;
 106
 107         xarray_ObjectAtIndex( p_history->p_xarray, i, &pv_item );
 108
 109         p_item = (history_item_t *) pv_item;
 110
 111         if( p_item == NULL )
 112             fprintf( stderr, "HISTORY: [%d] NULL\n", i );
 113         else
 114         {
 115             fprintf( stderr, "HISTORY: [%d] %p (%p->%s)\n", i, p_item,
 116                      p_item->psz_uri, p_item->psz_uri );
 117         }
 118     }
 119 }
 120 #endif
 121
 122 bool history_GoForwardSavingCurrentItem ( history_t *p_history,
 123                                                 history_item_t *p_item )
 124 {
 125 #ifdef HISTORY_DEBUG
 126     history_Dump( p_history );
 127 #endif
 128
 129     if( xarray_ReplaceObject( p_history->p_xarray, p_history->i_index, p_item )
 130         == XARRAY_SUCCESS )
 131     {
 132         p_history->i_index++;
 133         return true;
 134     }
 135     else
 136     {
 137         return false;
 138     }
 139 }
 140
 141 bool history_CanGoBack( history_t *p_history )
 142 {
 143     if( p_history->i_index > 0 )
 144         return true;
 145     else
 146         return false;
 147 }
 148
 149 bool history_CanGoForward( history_t *p_history )
 150 {
 151     unsigned int i_count;
 152
 153     if( xarray_Count( p_history->p_xarray, &i_count ) != XARRAY_SUCCESS )
 154         return false;
 155
 156     if( p_history->i_index < i_count )
 157         return true;
 158     else
 159         return false;
 160 }
 161
 162 history_item_t *history_Item( history_t *p_history )
 163 {
 164     history_item_t *p_item;
 165     void *pv_item;
 166
 167     if( xarray_ObjectAtIndex( p_history->p_xarray, p_history->i_index,
 168                               &pv_item )
 169         == XARRAY_SUCCESS )
 170     {
 171         p_item = (history_item_t *) pv_item;
 172         return p_item;
 173     }
 174     else
 175     {
 176         return NULL;
 177     }
 178 }
 179
 180 void history_Prune( history_t *p_history )
 181 {
 182     xarray_RemoveObjectsAfter( p_history->p_xarray, p_history->i_index );
 183     xarray_RemoveObject( p_history->p_xarray, p_history->i_index );
 184 }
 185
 186 void history_PruneAndInsert( history_t *p_history, history_item_t *p_item )
 187 {
 188     unsigned int i_count;
 189
 190     xarray_Count( p_history->p_xarray, &i_count );
 191
 192     if( i_count == 0 )
 193     {
 194         xarray_InsertObject( p_history->p_xarray, p_item, 0 );
 195         p_history->i_index = 1;
 196     }
 197     else
 198     {
 199         history_Prune( p_history );
 200         xarray_InsertObject( p_history->p_xarray, p_item, p_history->i_index );
 201         p_history->i_index++;
 202     }
 203 }
 204
 205 unsigned int history_Count( history_t *p_history )
 206 {
 207     unsigned int i_count;
 208     xarray_Count( p_history->p_xarray, &i_count );
 209     return i_count;
 210 }
 211
 212 unsigned int history_Index( history_t *p_history )
 213 {
 214     return p_history->i_index;
 215 }
 216
 217 history_item_t * historyItem_New( char *psz_name, char *psz_uri )
 218 {
 219     history_item_t *p_history_item = NULL;
 220
 221     p_history_item = (history_item_t *) malloc( sizeof(history_item_t) );
 222     if( !p_history_item ) return NULL;
 223
 224     p_history_item->psz_uri = strdup( psz_uri );
 225     p_history_item->psz_name = strdup( psz_name );
 226
 227     return p_history_item;
 228 }
 229