ppapi/api/ppb_var.idl

   1 /* Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2  * Use of this source code is governed by a BSD-style license that can be
   3  * found in the LICENSE file.
   4  */
   5
   6 /**
   7  * This file defines the <code>PPB_Var</code> struct.
   8  */
   9
  10 label Chrome {
  11   M14 = 1.0,
  12   M18 = 1.1,
  13   M34 = 1.2
  14 };
  15
  16 /**
  17  * PPB_Var API
  18  */
  19 interface PPB_Var {
  20   /**
  21    * AddRef() adds a reference to the given var. If this is not a refcounted
  22    * object, this function will do nothing so you can always call it no matter
  23    * what the type.
  24    *
  25    * @param[in] var A <code>PP_Var</code> that will have a reference added.
  26    */
  27   [version=1.0]
  28   void AddRef([in] PP_Var var);
  29
  30   /**
  31    * Release() removes a reference to given var, deleting it if the internal
  32    * reference count becomes 0. If the given var is not a refcounted object,
  33    * this function will do nothing so you can always call it no matter what
  34    * the type.
  35    *
  36    * @param[in] var A <code>PP_Var</code> that will have a reference removed.
  37    */
  38   [version=1.0]
  39   void Release([in] PP_Var var);
  40
  41   /**
  42    * VarFromUtf8() creates a string var from a string. The string must be
  43    * encoded in valid UTF-8 and is NOT NULL-terminated, the length must be
  44    * specified in <code>len</code>. It is an error if the string is not
  45    * valid UTF-8.
  46    *
  47    * If the length is 0, the <code>*data</code> pointer will not be dereferenced
  48    * and may be <code>NULL</code>. Note, however if length is 0, the
  49    * "NULL-ness" will not be preserved, as <code>VarToUtf8</code> will never
  50    * return <code>NULL</code> on success, even for empty strings.
  51    *
  52    * The resulting object will be a refcounted string object. It will be
  53    * AddRef'ed for the caller. When the caller is done with it, it should be
  54    * Released.
  55    *
  56    * On error (basically out of memory to allocate the string, or input that
  57    * is not valid UTF-8), this function will return a Null var.
  58    *
  59    * @param[in] module A PP_Module uniquely identifying the module or .nexe.
  60    * @param[in] data A string
  61    * @param[in] len The length of the string.
  62    *
  63    * @return A <code>PP_Var</code> structure containing a reference counted
  64    * string object.
  65    */
  66   [version=1.0]
  67   PP_Var VarFromUtf8([in] PP_Module module, [in] str_t data, [in] uint32_t len);
  68
  69   /**
  70    * VarFromUtf8() creates a string var from a string. The string must be
  71    * encoded in valid UTF-8 and is NOT NULL-terminated, the length must be
  72    * specified in <code>len</code>. It is an error if the string is not
  73    * valid UTF-8.
  74    *
  75    * If the length is 0, the <code>*data</code> pointer will not be dereferenced
  76    * and may be <code>NULL</code>. Note, however if length is 0, the
  77    * "NULL-ness" will not be preserved, as <code>VarToUtf8</code> will never
  78    * return <code>NULL</code> on success, even for empty strings.
  79    *
  80    * The resulting object will be a refcounted string object. It will be
  81    * AddRef'ed for the caller. When the caller is done with it, it should be
  82    * Released.
  83    *
  84    * On error (basically out of memory to allocate the string, or input that
  85    * is not valid UTF-8), this function will return a Null var.
  86    *
  87    * @param[in] data A string
  88    * @param[in] len The length of the string.
  89    *
  90    * @return A <code>PP_Var</code> structure containing a reference counted
  91    * string object.
  92    */
  93   [version=1.1]
  94   PP_Var VarFromUtf8([in] str_t data, [in] uint32_t len);
  95
  96   /**
  97    * VarToUtf8() converts a string-type var to a char* encoded in UTF-8. This
  98    * string is NOT NULL-terminated. The length will be placed in
  99    * <code>*len</code>. If the string is valid but empty the return value will
 100    * be non-NULL, but <code>*len</code> will still be 0.
 101    *
 102    * If the var is not a string, this function will return NULL and
 103    * <code>*len</code> will be 0.
 104    *
 105    * The returned buffer will be valid as long as the underlying var is alive.
 106    * If the instance frees its reference, the string will be freed and the
 107    * pointer will be to arbitrary memory.
 108    *
 109    * @param[in] var A PP_Var struct containing a string-type var.
 110    * @param[in,out] len A pointer to the length of the string-type var.
 111    *
 112    * @return A char* encoded in UTF-8.
 113    */
 114   [version=1.0]
 115   str_t VarToUtf8([in] PP_Var var, [out] uint32_t len);
 116
 117   /**
 118    * Converts a resource-type var to a <code>PP_Resource</code>.
 119    *
 120    * @param[in] var A <code>PP_Var</code> struct containing a resource-type var.
 121    *
 122    * @return A <code>PP_Resource</code> retrieved from the var, or 0 if the var
 123    * is not a resource. The reference count of the resource is incremented on
 124    * behalf of the caller.
 125    */
 126   [version=1.2]
 127   PP_Resource VarToResource([in] PP_Var var);
 128
 129   /**
 130    * Creates a new <code>PP_Var</code> from a given resource.
 131    *
 132    * @param[in] resource A <code>PP_Resource</code> to be wrapped in a var.
 133    *
 134    * @return A <code>PP_Var</code> created for this resource, with type
 135    * <code>PP_VARTYPE_RESOURCE</code>. The reference count of the var is set to
 136    * 1 on behalf of the caller.
 137    */
 138   [version=1.2]
 139   PP_Var VarFromResource([in] PP_Resource resource);
 140 };
 141