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