ppapi/shared_impl/resource_var.h

   1 // Copyright 2013 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 #ifndef PPAPI_SHARED_IMPL_RESOURCE_VAR_H_
   6 #define PPAPI_SHARED_IMPL_RESOURCE_VAR_H_
   7
   8 #include "ipc/ipc_message.h"
   9 #include "ppapi/c/pp_resource.h"
  10 #include "ppapi/c/pp_var.h"
  11 #include "ppapi/shared_impl/ppapi_shared_export.h"
  12 #include "ppapi/shared_impl/var.h"
  13
  14 namespace ppapi {
  15
  16 // Represents a resource Var.
  17 class PPAPI_SHARED_EXPORT ResourceVar : public Var {
  18  public:
  19   // Makes a null resource var.
  20   ResourceVar();
  21
  22   // Makes a resource var with an existing plugin-side resource.
  23   explicit ResourceVar(PP_Resource pp_resource);
  24
  25   // Makes a resource var with a pending resource host.
  26   // The |creation_message| contains instructions on how to create the
  27   // plugin-side resource. Its type depends on the type of resource.
  28   explicit ResourceVar(const IPC::Message& creation_message);
  29
  30   virtual ~ResourceVar();
  31
  32   // Gets the resource ID associated with this var.
  33   // This is 0 if a resource is still pending.
  34   PP_Resource pp_resource() const { return pp_resource_; }
  35
  36   // Gets the message for creating a plugin-side resource.
  37   // May be an empty message.
  38   const IPC::Message& creation_message() const { return creation_message_; }
  39
  40   // Determines whether this is a pending resource.
  41   // This is true if the pp_resource is 0 and there is a non-empty
  42   // creation_message.
  43   bool IsPending() const;
  44
  45   // Var override.
  46   virtual ResourceVar* AsResourceVar() OVERRIDE;
  47   virtual PP_VarType GetType() const OVERRIDE;
  48
  49   // Helper function that converts a PP_Var to a ResourceVar. This will
  50   // return NULL if the PP_Var is not of Resource type.
  51   static ResourceVar* FromPPVar(PP_Var var);
  52
  53  private:
  54   // Real resource ID in the plugin. 0 if one has not yet been created
  55   // (indicating that there is a pending host resource).
  56   PP_Resource pp_resource_;
  57
  58   // If the plugin-side resource has not yet been created, carries a message to
  59   // create a resource of the specific type on the plugin side.
  60   // Otherwise, carries an empty message.
  61   IPC::Message creation_message_;
  62
  63   DISALLOW_COPY_AND_ASSIGN(ResourceVar);
  64 };
  65
  66 }  // namespace ppapi
  67
  68 #endif  // PPAPI_SHARED_IMPL_RESOURCE_VAR_H_