source/includes/lv2/options.h

   1 /*
   2   Copyright 2012-2016 David Robillard <http://drobilla.net>
   3
   4   Permission to use, copy, modify, and/or distribute this software for any
   5   purpose with or without fee is hereby granted, provided that the above
   6   copyright notice and this permission notice appear in all copies.
   7
   8   THIS SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
   9   WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  10   MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  11   ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  12   WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  13   ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  14   OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  15 */
  16
  17 /**
  18    @defgroup options Options
  19
  20    Instantiation time options, see <http://lv2plug.in/ns/ext/options> for
  21    details.
  22
  23    @{
  24 */
  25
  26 #ifndef LV2_OPTIONS_H
  27 #define LV2_OPTIONS_H
  28
  29 #include <stdint.h>
  30
  31 #include "urid.h"
  32 #include "lv2.h"
  33
  34 #define LV2_OPTIONS_URI    "http://lv2plug.in/ns/ext/options"  ///< http://lv2plug.in/ns/ext/options
  35 #define LV2_OPTIONS_PREFIX LV2_OPTIONS_URI "#"                 ///< http://lv2plug.in/ns/ext/options#
  36
  37 #define LV2_OPTIONS__Option          LV2_OPTIONS_PREFIX "Option"           ///< http://lv2plug.in/ns/ext/options#Option
  38 #define LV2_OPTIONS__interface       LV2_OPTIONS_PREFIX "interface"        ///< http://lv2plug.in/ns/ext/options#interface
  39 #define LV2_OPTIONS__options         LV2_OPTIONS_PREFIX "options"          ///< http://lv2plug.in/ns/ext/options#options
  40 #define LV2_OPTIONS__requiredOption  LV2_OPTIONS_PREFIX "requiredOption"   ///< http://lv2plug.in/ns/ext/options#requiredOption
  41 #define LV2_OPTIONS__supportedOption LV2_OPTIONS_PREFIX "supportedOption"  ///< http://lv2plug.in/ns/ext/options#supportedOption
  42
  43 #ifdef __cplusplus
  44 extern "C" {
  45 #endif
  46
  47 /**
  48    The context of an Option, which defines the subject it applies to.
  49 */
  50 typedef enum {
  51         /**
  52            This option applies to the instance itself.  The subject must be
  53            ignored.
  54         */
  55         LV2_OPTIONS_INSTANCE,
  56
  57         /**
  58            This option applies to some named resource.  The subject is a URI mapped
  59            to an integer (a LV2_URID, like the key)
  60         */
  61         LV2_OPTIONS_RESOURCE,
  62
  63         /**
  64            This option applies to some blank node.  The subject is a blank node
  65            identifier, which is valid only within the current local scope.
  66         */
  67         LV2_OPTIONS_BLANK,
  68
  69         /**
  70            This option applies to a port on the instance.  The subject is the
  71            port's index.
  72         */
  73         LV2_OPTIONS_PORT
  74 } LV2_Options_Context;
  75
  76 /**
  77    An option.
  78
  79    This is a property with a subject, also known as a triple or statement.
  80
  81    This struct is useful anywhere a statement needs to be passed where no
  82    memory ownership issues are present (since the value is a const pointer).
  83
  84    Options can be passed to an instance via the feature LV2_OPTIONS__options
  85    with data pointed to an array of options terminated by a zeroed option, or
  86    accessed/manipulated using LV2_Options_Interface.
  87 */
  88 typedef struct _LV2_Options_Option {
  89         LV2_Options_Context context;  /**< Context (type of subject). */
  90         uint32_t            subject;  /**< Subject. */
  91         LV2_URID            key;      /**< Key (property). */
  92         uint32_t            size;     /**< Size of value in bytes. */
  93         LV2_URID            type;     /**< Type of value (datatype). */
  94         const void*         value;    /**< Pointer to value (object). */
  95 } LV2_Options_Option;
  96
  97 /** A status code for option functions. */
  98 typedef enum {
  99         LV2_OPTIONS_SUCCESS         = 0,       /**< Completed successfully. */
 100         LV2_OPTIONS_ERR_UNKNOWN     = 1,       /**< Unknown error. */
 101         LV2_OPTIONS_ERR_BAD_SUBJECT = 1 << 1,  /**< Invalid/unsupported subject. */
 102         LV2_OPTIONS_ERR_BAD_KEY     = 1 << 2,  /**< Invalid/unsupported key. */
 103         LV2_OPTIONS_ERR_BAD_VALUE   = 1 << 3   /**< Invalid/unsupported value. */
 104 } LV2_Options_Status;
 105
 106 /**
 107    Interface for dynamically setting options (LV2_OPTIONS__interface).
 108 */
 109 typedef struct _LV2_Options_Interface {
 110         /**
 111            Get the given options.
 112
 113            Each element of the passed options array MUST have type, subject, and
 114            key set.  All other fields (size, type, value) MUST be initialised to
 115            zero, and are set to the option value if such an option is found.
 116
 117            This function is in the "instantiation" LV2 threading class, so no other
 118            instance functions may be called concurrently.
 119
 120            @return Bitwise OR of LV2_Options_Status values.
 121         */
 122         uint32_t (*get)(LV2_Handle          instance,
 123                         LV2_Options_Option* options);
 124
 125         /**
 126            Set the given options.
 127
 128            This function is in the "instantiation" LV2 threading class, so no other
 129            instance functions may be called concurrently.
 130
 131            @return Bitwise OR of LV2_Options_Status values.
 132         */
 133         uint32_t (*set)(LV2_Handle                instance,
 134                         const LV2_Options_Option* options);
 135 } LV2_Options_Interface;
 136
 137 #ifdef __cplusplus
 138 }  /* extern "C" */
 139 #endif
 140
 141 #endif  /* LV2_OPTIONS_H */
 142
 143 /**
 144    @}
 145 */