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 #include <vlc/vlc.h>
  28
  29 #include "history.h"
  30
  31 #include "xarray.h"
  32
  33 #ifdef HAVE_STDLIB_H
  34 #   include <stdlib.h>                                          /* realloc() */
  35 #endif
  36
  37 #undef HISTORY_DEBUG
  38
  39 /*****************************************************************************
  40  * Local prototypes
  41  *****************************************************************************/
  42 static void history_Dump( history_t *p_history );
  43
  44 /*****************************************************************************
  45  * Local structure lock
  46  *****************************************************************************/
  47
  48 /*****************************************************************************
  49  * Actual history code
  50  *****************************************************************************/
  51
  52 history_t *history_New( void )
  53 {
  54    history_t *p_new_history;
  55
  56    p_new_history = calloc( 1, sizeof( struct history_t ) );
  57    if( p_new_history == NULL ) return NULL;
  58
  59    p_new_history->p_xarray = xarray_New( 0 );
  60    if( p_new_history->p_xarray == NULL )
  61    {
  62        free( p_new_history );
  63        return NULL;
  64    }
  65
  66 #ifndef HISTORY_DEBUG
  67    /* make dummy reference to history_Dump to avoid compiler warnings */
  68    while (0)
  69    {
  70        void *p_tmp;
  71
  72        p_tmp = history_Dump;
  73    }
  74 #endif
  75
  76    return p_new_history;
  77 }
  78
  79 vlc_bool_t history_GoBackSavingCurrentItem ( history_t *p_history,
  80                                              history_item_t *p_item )
  81 {
  82     history_PruneAndInsert( p_history, p_item );
  83
  84     /* PruneAndInsert will increment the index, so we need to go
  85      * back one position to reset the index to the place we were at
  86      * before saving the current state, and then go back one more to
  87      * actually go back */
  88     p_history->i_index -= 2;
  89
  90 #ifdef HISTORY_DEBUG
  91     history_Dump( p_history );
  92 #endif
  93     return VLC_TRUE;
  94 }
  95
  96 static void history_Dump( history_t *p_history )
  97 {
  98     unsigned int i_count;
  99     int i;
 100
 101     if( xarray_Count( p_history->p_xarray, &i_count ) != XARRAY_SUCCESS )
 102         return;
 103
 104     for (i = 0; i < (int) i_count; i++)
 105     {
 106         history_item_t *p_item;
 107         void *pv_item;
 108
 109         xarray_ObjectAtIndex( p_history->p_xarray, i, &pv_item );
 110
 111         p_item = (history_item_t *) pv_item;
 112
 113         if( p_item == NULL )
 114             fprintf( stderr, "HISTORY: [%d] NULL\n", i );
 115         else
 116             fprintf( stderr, "HISTORY: [%d] %p (%p->%s)\n", i, p_item,
 117                      p_item->psz_uri, p_item->psz_uri );
 118     }
 119 }
 120
 121 vlc_bool_t history_GoForwardSavingCurrentItem ( history_t *p_history,
 122                                                 history_item_t *p_item )
 123 {
 124 #ifdef HISTORY_DEBUG
 125     history_Dump( p_history );
 126 #endif
 127
 128     if( xarray_ReplaceObject( p_history->p_xarray, p_history->i_index, p_item )
 129         == XARRAY_SUCCESS )
 130     {
 131         p_history->i_index++;
 132         return VLC_TRUE;
 133     }
 134     else
 135     {
 136         return VLC_FALSE;
 137     }
 138 }
 139
 140 vlc_bool_t history_CanGoBack( history_t *p_history )
 141 {
 142     if( p_history->i_index > 0 )
 143         return VLC_TRUE;
 144     else
 145         return VLC_FALSE;
 146 }
 147
 148 vlc_bool_t history_CanGoForward( history_t *p_history )
 149 {
 150     unsigned int i_count;
 151
 152     if( xarray_Count( p_history->p_xarray, &i_count ) != XARRAY_SUCCESS )
 153         return VLC_FALSE;
 154
 155     if( p_history->i_index < i_count )
 156         return VLC_TRUE;
 157     else
 158         return VLC_FALSE;
 159 }
 160
 161 history_item_t *history_Item( history_t *p_history )
 162 {
 163     history_item_t *p_item;
 164     void *pv_item;
 165
 166     if( xarray_ObjectAtIndex( p_history->p_xarray, p_history->i_index,
 167                               &pv_item )
 168         == XARRAY_SUCCESS )
 169     {
 170         p_item = (history_item_t *) pv_item;
 171         return p_item;
 172     }
 173     else
 174     {
 175         return NULL;
 176     }
 177 }
 178
 179 void history_Prune( history_t *p_history )
 180 {
 181     xarray_RemoveObjectsAfter( p_history->p_xarray, p_history->i_index );
 182     xarray_RemoveObject( p_history->p_xarray, p_history->i_index );
 183 }
 184
 185 void history_PruneAndInsert( history_t *p_history, history_item_t *p_item )
 186 {
 187     unsigned int i_count;
 188
 189     xarray_Count( p_history->p_xarray, &i_count );
 190
 191     if( i_count == 0 )
 192     {
 193         xarray_InsertObject( p_history->p_xarray, p_item, 0 );
 194         p_history->i_index = 1;
 195     }
 196     else
 197     {
 198         history_Prune( p_history );
 199         xarray_InsertObject( p_history->p_xarray, p_item, p_history->i_index );
 200         p_history->i_index++;
 201     }
 202 }
 203
 204 unsigned int history_Count( history_t *p_history )
 205 {
 206     unsigned int i_count;
 207     xarray_Count( p_history->p_xarray, &i_count );
 208     return i_count;
 209 }
 210
 211 unsigned int history_Index( history_t *p_history )
 212 {
 213     return p_history->i_index;
 214 }
 215
 216 history_item_t * historyItem_New( char *psz_name, char *psz_uri )
 217 {
 218     history_item_t *p_history_item = NULL;
 219
 220     p_history_item = (history_item_t *) malloc( sizeof(history_item_t) );
 221     if( !p_history_item ) return NULL;
 222
 223     p_history_item->psz_uri = strdup( psz_uri );
 224     p_history_item->psz_name = strdup( psz_name );
 225
 226     return p_history_item;
 227 }
 228