webkit/plugins/ppapi/npobject_var.h

   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 #ifndef WEBKIT_PLUGINS_PPAPI_NPOBJECT_VAR_H_
   6 #define WEBKIT_PLUGINS_PPAPI_NPOBJECT_VAR_H_
   7
   8 #include <string>
   9
  10 #include "base/compiler_specific.h"
  11 #include "ppapi/c/pp_instance.h"
  12 #include "ppapi/shared_impl/var.h"
  13 #include "webkit/plugins/webkit_plugins_export.h"
  14
  15 typedef struct NPObject NPObject;
  16 typedef struct _NPVariant NPVariant;
  17 typedef void* NPIdentifier;
  18
  19 namespace ppapi {
  20
  21 // NPObjectVar -----------------------------------------------------------------
  22
  23 // Represents a JavaScript object Var. By itself, this represents random
  24 // NPObjects that a given plugin (identified by the resource's module) wants to
  25 // reference. If two different modules reference the same NPObject (like the
  26 // "window" object), then there will be different NPObjectVar's (and hence
  27 // PP_Var IDs) for each module. This allows us to track all references owned by
  28 // a given module and free them when the plugin exits independently of other
  29 // plugins that may be running at the same time.
  30 class NPObjectVar : public Var {
  31  public:
  32   // You should always use FromNPObject to create an NPObjectVar. This function
  33   // guarantees that we maintain the 1:1 mapping between NPObject and
  34   // NPObjectVar.
  35   NPObjectVar(PP_Instance instance, NPObject* np_object);
  36
  37   virtual ~NPObjectVar();
  38
  39   // Var overrides.
  40   virtual NPObjectVar* AsNPObjectVar() OVERRIDE;
  41   virtual PP_VarType GetType() const OVERRIDE;
  42
  43   // Returns the underlying NPObject corresponding to this NPObjectVar.
  44   // Guaranteed non-NULL.
  45   NPObject* np_object() const { return np_object_; }
  46
  47   // Notification that the instance was deleted, the internal reference will be
  48   // zeroed out.
  49   void InstanceDeleted();
  50
  51   // Possibly 0 if the object has outlived its instance.
  52   PP_Instance pp_instance() const { return pp_instance_; }
  53
  54   // Helper function that converts a PP_Var to an object. This will return NULL
  55   // if the PP_Var is not of object type or the object is invalid.
  56   WEBKIT_PLUGINS_EXPORT static scoped_refptr<NPObjectVar> FromPPVar(PP_Var var);
  57
  58  private:
  59   // Possibly 0 if the object has outlived its instance.
  60   PP_Instance pp_instance_;
  61
  62   // Guaranteed non-NULL, this is the underlying object used by WebKit. We
  63   // hold a reference to this object.
  64   NPObject* np_object_;
  65
  66   DISALLOW_COPY_AND_ASSIGN(NPObjectVar);
  67 };
  68
  69 }  // namespace
  70
  71 #endif  // WEBKIT_PLUGINS_PPAPI_NPOBJECT_VAR_H_