src/calf/lv2_data_access.h

   1 /* lv2_data_access.h - C header file for the LV2 Data Access extension.
   2  * Copyright (C) 2008 Dave Robillard <dave@drobilla.net>
   3  *
   4  * This header is free software; you can redistribute it and/or modify it
   5  * under the terms of the GNU Lesser General Public License as published
   6  * by the Free Software Foundation; either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This header is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
  12  * License for more details.
  13  *
  14  * You should have received a copy of the GNU Lesser General Public License
  15  * along with this header; if not, write to the Free Software Foundation,
  16  * Inc., 59 Temple Place, Suite 330, Boston, MA 01222-1307 USA
  17  */
  18
  19 #ifndef LV2_DATA_ACCESS_H
  20 #define LV2_DATA_ACCESS_H
  21
  22 #define LV2_DATA_ACCESS_URI "http://lv2plug.in/ns/ext/data-access"
  23
  24
  25 /** @file
  26  * This header defines the LV2 Extension Data extension with the URI
  27  * <http://lv2plug.in/ns/ext/data-access>.
  28  *
  29  * This extension defines a method for (e.g.) plugin UIs to have (possibly
  30  * marshalled) access to the extension_data function on a plugin instance.
  31  */
  32
  33
  34 /** The data field of the LV2_Feature for this extension.
  35  *
  36  * To support this feature the host must pass an LV2_Feature struct to the
  37  * instantiate method with URI "http://lv2plug.in/ns/ext/data-access"
  38  * and data pointed to an instance of this struct.
  39  */
  40 typedef struct {
  41
  42         /** A pointer to a method the UI can call to get data (of a type specified
  43          * by some other extension) from the plugin.
  44          *
  45          * This call never is never guaranteed to return anything, UIs should
  46          * degrade gracefully if direct access to the plugin data is not possible
  47          * (in which case this function will return NULL).
  48          *
  49          * This is for access to large data that can only possibly work if the UI
  50          * and plugin are running in the same process.  For all other things, use
  51          * the normal LV2 UI communication system.
  52          */
  53         const void* (*data_access)(const char* uri);
  54
  55 } LV2_Extension_Data_Feature;
  56
  57
  58 #endif // LV2_DATA_ACCESS_H
  59