include/vlc_services_discovery.h

   1 /*****************************************************************************
   2  * vlc_services_discovery.h : Services Discover functions
   3  *****************************************************************************
   4  * Copyright (C) 1999-2004 VLC authors and VideoLAN
   5  *
   6  * Authors: Pierre d'Herbemont <pdherbemont # videolan.org>
   7  *
   8  * This program is free software; you can redistribute it and/or modify it
   9  * under the terms of the GNU Lesser General Public License as published by
  10  * the Free Software Foundation; either version 2.1 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  16  * GNU Lesser General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public License
  19  * along with this program; if not, write to the Free Software Foundation,
  20  * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  21  *****************************************************************************/
  22
  23 #ifndef VLC_SERVICES_DISCOVERY_H_
  24 #define VLC_SERVICES_DISCOVERY_H_
  25
  26 #include <vlc_input.h>
  27 #include <vlc_probe.h>
  28
  29 /**
  30  * \file
  31  * This file lists functions and structures for service discovery (SD) in vlc
  32  */
  33
  34 # ifdef __cplusplus
  35 extern "C" {
  36 # endif
  37
  38 /**
  39  * @{
  40  */
  41
  42 struct services_discovery_callbacks
  43 {
  44     void (*item_added)(struct services_discovery_t *sd, input_item_t *parent,
  45                        input_item_t *item, const char *category);
  46     void (*item_removed)(struct services_discovery_t *sd, input_item_t *item);
  47 };
  48
  49 struct services_discovery_owner_t
  50 {
  51     const struct services_discovery_callbacks *cbs;
  52     void *sys; /**< Private data for the owner callbacks */
  53 };
  54
  55 /**
  56  * Main service discovery structure to build a SD module
  57  */
  58 struct services_discovery_t
  59 {
  60     struct vlc_common_members obj;
  61     module_t *          p_module;             /**< Loaded module */
  62
  63     char *psz_name;                           /**< Main name of the SD */
  64     config_chain_t *p_cfg;                    /**< Configuration for the SD */
  65
  66     const char *description; /**< Human-readable name */
  67
  68     /** Control function
  69      * \see services_discovery_command_e
  70      */
  71     int ( *pf_control ) ( services_discovery_t *, int, va_list );
  72
  73     void *p_sys;                              /**< Custom private data */
  74
  75     struct services_discovery_owner_t owner; /**< Owner callbacks */
  76 };
  77
  78 /**
  79  * Service discovery categories
  80  * \see vlc_sd_probe_Add
  81  */
  82 enum services_discovery_category_e
  83 {
  84     SD_CAT_DEVICES = 1,           /**< Devices, like portable music players */
  85     SD_CAT_LAN,                   /**< LAN/WAN services, like Upnp or SAP */
  86     SD_CAT_INTERNET,              /**< Internet or Website channels services */
  87     SD_CAT_MYCOMPUTER             /**< Computer services, like Discs or Apps */
  88 };
  89
  90 /**
  91  * Service discovery control commands
  92  */
  93 enum services_discovery_command_e
  94 {
  95     SD_CMD_SEARCH = 1,          /**< arg1 = query */
  96     SD_CMD_DESCRIPTOR           /**< arg1 = services_discovery_descriptor_t* */
  97 };
  98
  99 /**
 100  * Service discovery capabilities
 101  */
 102 enum services_discovery_capability_e
 103 {
 104     SD_CAP_SEARCH = 1           /**< One can search in the SD */
 105 };
 106
 107 /**
 108  * Service discovery descriptor
 109  * \see services_discovery_command_e
 110  */
 111 typedef struct
 112 {
 113     char *psz_short_desc;       /**< The short description, human-readable */
 114     char *psz_icon_url;         /**< URL to the icon that represents it */
 115     char *psz_url;              /**< URL for the service */
 116     int   i_capabilities;       /**< \see services_discovery_capability_e */
 117 } services_discovery_descriptor_t;
 118
 119
 120 /***********************************************************************
 121  * Service Discovery
 122  ***********************************************************************/
 123
 124 /**
 125  * Ask for a research in the SD
 126  * @param p_sd: the Service Discovery
 127  * @param i_control: the command to issue
 128  * @param args: the argument list
 129  * @return VLC_SUCCESS in case of success, the error code overwise
 130  */
 131 static inline int vlc_sd_control( services_discovery_t *p_sd, int i_control, va_list args )
 132 {
 133     if( p_sd->pf_control )
 134         return p_sd->pf_control( p_sd, i_control, args );
 135     else
 136         return VLC_EGENERIC;
 137 }
 138
 139 /* Get the services discovery modules names to use in Create(), in a null
 140  * terminated string array. Array and string must be freed after use. */
 141 VLC_API char ** vlc_sd_GetNames( vlc_object_t *, char ***, int ** ) VLC_USED;
 142 #define vlc_sd_GetNames(obj, pln, pcat ) \
 143         vlc_sd_GetNames(VLC_OBJECT(obj), pln, pcat)
 144
 145 /**
 146  * Creates a services discoverer.
 147  */
 148 VLC_API services_discovery_t *vlc_sd_Create(vlc_object_t *parent,
 149     const char *chain, const struct services_discovery_owner_t *owner)
 150 VLC_USED;
 151 #define vlc_sd_Create( obj, a, b ) \
 152         vlc_sd_Create( VLC_OBJECT( obj ), a, b )
 153
 154 VLC_API void vlc_sd_Destroy( services_discovery_t * );
 155
 156 /**
 157  * Added top-level service callback.
 158  *
 159  * This is a convenience wrapper for services_discovery_AddSubItem().
 160  * It covers the most comomn case wherby the added item is a top-level service,
 161  * i.e. it has no parent node.
 162  */
 163 static inline void services_discovery_AddItem(services_discovery_t *sd,
 164                                               input_item_t *item)
 165 {
 166     sd->owner.cbs->item_added(sd, NULL, item, NULL);
 167 }
 168
 169 /**
 170  * Added service callback.
 171  *
 172  * A services discovery module invokes this function when it "discovers" a new
 173  * service, i.e. a new input item.
 174  *
 175  * @note This callback does not take ownership of the input item; it might
 176  * however (and most probably will) add one of more references to the item.
 177  *
 178  * The caller is responsible for releasing its own reference(s) eventually.
 179  * Keeping a reference is necessary to call services_discovery_RemoveItem() or
 180  * to alter the item later. However, if the caller will never remove nor alter
 181  * the item, it can drop its reference(s) immediately.
 182  *
 183  * @param sd services discoverer / services discovery module instance
 184  * @param item input item to add
 185  */
 186 static inline void services_discovery_AddSubItem(services_discovery_t *sd,
 187                                                  input_item_t *parent,
 188                                                  input_item_t *item)
 189 {
 190     sd->owner.cbs->item_added(sd, parent, item, NULL);
 191 }
 192
 193 /**
 194  * Added service backward compatibility callback.
 195  *
 196  * @param category Optional name of a group that the item belongs in
 197  *                 (for backward compatibility with legacy modules)
 198  */
 199 VLC_DEPRECATED
 200 static inline void services_discovery_AddItemCat(services_discovery_t *sd,
 201                                                  input_item_t *item,
 202                                                  const char *category)
 203 {
 204     sd->owner.cbs->item_added(sd, NULL, item, category);
 205 }
 206
 207 /**
 208  * Removed service callback.
 209  *
 210  * A services discovery module invokes this function when it senses that a
 211  * service is no longer available.
 212  */
 213 static inline void services_discovery_RemoveItem(services_discovery_t *sd,
 214                                                  input_item_t *item)
 215 {
 216     sd->owner.cbs->item_removed(sd, item);
 217 }
 218
 219 /* SD probing */
 220
 221 VLC_API int vlc_sd_probe_Add(vlc_probe_t *, const char *, const char *, int category);
 222
 223 #define VLC_SD_PROBE_SUBMODULE \
 224     add_submodule() \
 225         set_capability( "services probe", 100 ) \
 226         set_callbacks( vlc_sd_probe_Open, NULL )
 227
 228 #define VLC_SD_PROBE_HELPER(name, longname, cat) \
 229 static int vlc_sd_probe_Open (vlc_object_t *obj) \
 230 { \
 231     return vlc_sd_probe_Add ((struct vlc_probe_t *)obj, name, \
 232                              longname, cat); \
 233 }
 234
 235 /** @} */
 236 # ifdef __cplusplus
 237 }
 238 # endif
 239
 240 #endif