content/renderer/pepper/plugin_object.h

   1 // Copyright (c) 2010 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 CONTENT_RENDERER_PEPPER_PLUGIN_OBJECT_H_
   6 #define CONTENT_RENDERER_PEPPER_PLUGIN_OBJECT_H_
   7
   8 #include <string>
   9
  10 #include "base/basictypes.h"
  11
  12 struct PP_Var;
  13 struct PPP_Class_Deprecated;
  14 typedef struct NPObject NPObject;
  15 typedef struct _NPVariant NPVariant;
  16
  17 namespace content {
  18
  19 class PepperPluginInstanceImpl;
  20
  21 // A PluginObject is a JS-accessible object implemented by the plugin.
  22 //
  23 // In contrast, a var of type PP_VARTYPE_OBJECT is a reference to a JS object,
  24 // which might be implemented by the plugin (here) or by the JS engine.
  25 class PluginObject {
  26  public:
  27   virtual ~PluginObject();
  28
  29   // Allocates a new PluginObject and returns it as a PP_Var with a
  30   // refcount of 1.
  31   static PP_Var Create(PepperPluginInstanceImpl* instance,
  32                        const PPP_Class_Deprecated* ppp_class,
  33                        void* ppp_class_data);
  34
  35   PepperPluginInstanceImpl* instance() const { return instance_; }
  36
  37   const PPP_Class_Deprecated* ppp_class() { return ppp_class_; }
  38   void* ppp_class_data() {
  39     return ppp_class_data_;
  40   };
  41
  42   NPObject* GetNPObject() const;
  43
  44   // Returns true if the given var is an object implemented by the same plugin
  45   // that owns the var object, and that the class matches. If it matches,
  46   // returns true and places the class data into |*ppp_class_data| (which can
  47   // optionally be NULL if no class data is desired).
  48   static bool IsInstanceOf(NPObject* np_object,
  49                            const PPP_Class_Deprecated* ppp_class,
  50                            void** ppp_class_data);
  51
  52   // Converts the given NPObject to the corresponding ObjectVar.
  53   //
  54   // The given NPObject must be one corresponding to a PluginObject or this
  55   // will crash. If the object is a PluginObject but the plugin has gone
  56   // away (the object could still be alive because of a reference from JS),
  57   // then the return value will be NULL.
  58   static PluginObject* FromNPObject(NPObject* object);
  59
  60   // Allocates a plugin wrapper object and returns it as an NPObject. This is
  61   // used internally only.
  62   static NPObject* AllocateObjectWrapper();
  63
  64  private:
  65   struct NPObjectWrapper;
  66
  67   // This object must be created using the CreateObject function of the which
  68   // will set up the correct NPObject.
  69   //
  70   // The NPObjectWrapper (an NPObject) should already have the reference
  71   // incremented on it, and this class will take ownership of that reference.
  72   PluginObject(PepperPluginInstanceImpl* instance,
  73                NPObjectWrapper* object_wrapper,
  74                const PPP_Class_Deprecated* ppp_class,
  75                void* ppp_class_data);
  76
  77   PepperPluginInstanceImpl* instance_;
  78
  79   // Holds a pointer to the NPObject wrapper backing the var. This class
  80   // derives from NPObject and we hold a reference to it, so it must be
  81   // refcounted. When the type is not an object, this value will be NULL.
  82   //
  83   // We don't actually own this pointer, it's the NPObject that actually
  84   // owns us.
  85   NPObjectWrapper* object_wrapper_;
  86
  87   const PPP_Class_Deprecated* ppp_class_;
  88   void* ppp_class_data_;
  89
  90   DISALLOW_COPY_AND_ASSIGN(PluginObject);
  91 };
  92
  93 }  // namespace content
  94
  95 #endif  // CONTENT_RENDERER_PEPPER_PLUGIN_OBJECT_H_