ppapi/host/resource_host.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 PPAPI_HOST_RESOURCE_HOST_H_
   6 #define PPAPI_HOST_RESOURCE_HOST_H_
   7
   8 #include <vector>
   9
  10 #include "base/basictypes.h"
  11 #include "base/memory/ref_counted.h"
  12 #include "ppapi/c/pp_resource.h"
  13 #include "ppapi/host/ppapi_host_export.h"
  14 #include "ppapi/host/resource_message_handler.h"
  15 #include "ppapi/shared_impl/host_resource.h"
  16
  17 namespace IPC {
  18 class Message;
  19 }
  20
  21 namespace ppapi {
  22 namespace host {
  23
  24 struct HostMessageContext;
  25 class PpapiHost;
  26 class ResourceMessageFilter;
  27
  28 // Some (but not all) resources have a corresponding object in the host side
  29 // that is kept alive as long as the resource in the plugin is alive. This is
  30 // the base class for such objects.
  31 class PPAPI_HOST_EXPORT ResourceHost : public ResourceMessageHandler {
  32  public:
  33   ResourceHost(PpapiHost* host, PP_Instance instance, PP_Resource resource);
  34   virtual ~ResourceHost();
  35
  36   PpapiHost* host() { return host_; }
  37   PP_Instance pp_instance() const { return pp_instance_; }
  38   PP_Resource pp_resource() const { return pp_resource_; }
  39
  40   // This runs any message filters in |message_filters_|. If the message is not
  41   // handled by these filters then the host's own message handler is run. True
  42   // is always returned (the message will always be handled in some way).
  43   virtual bool HandleMessage(const IPC::Message& msg,
  44                              HostMessageContext* context) OVERRIDE;
  45
  46   // Sets the PP_Resource ID when the plugin attaches to a pending resource
  47   // host. This will notify subclasses by calling
  48   // DidConnectPendingHostToResource.
  49   //
  50   // The current PP_Resource for all pending hosts should be 0. See
  51   // PpapiHostMsg_AttachToPendingHost.
  52   void SetPPResourceForPendingHost(PP_Resource pp_resource);
  53
  54   virtual void SendReply(const ReplyMessageContext& context,
  55                          const IPC::Message& msg) OVERRIDE;
  56
  57   // Simple RTTI. A subclass that is a host for one of these APIs will override
  58   // the appropriate function and return true.
  59   virtual bool IsFileRefHost();
  60   virtual bool IsFileSystemHost();
  61   virtual bool IsGraphics2DHost();
  62   virtual bool IsMediaStreamVideoTrackHost();
  63
  64  protected:
  65   // Adds a ResourceMessageFilter to handle resource messages. Incoming
  66   // messages will be passed to the handlers of these filters before being
  67   // handled by the resource host's own message handler. This allows
  68   // ResourceHosts to easily handle messages on other threads.
  69   void AddFilter(scoped_refptr<ResourceMessageFilter> filter);
  70
  71   // Called when this resource host is pending and the corresponding plugin has
  72   // just connected to it. The host resource subclass can implement this
  73   // function if it wants to do processing (typically sending queued data).
  74   //
  75   // The PP_Resource will be valid for this call but not before.
  76   virtual void DidConnectPendingHostToResource() {}
  77
  78  private:
  79   // The host that owns this object.
  80   PpapiHost* host_;
  81
  82   PP_Instance pp_instance_;
  83   PP_Resource pp_resource_;
  84
  85   // A vector of message filters which the host will forward incoming resource
  86   // messages to.
  87   std::vector<scoped_refptr<ResourceMessageFilter> > message_filters_;
  88
  89   DISALLOW_COPY_AND_ASSIGN(ResourceHost);
  90 };
  91
  92 }  // namespace host
  93 }  // namespace ppapi
  94
  95 #endif  // PPAPI_HOST_RESOURCE_HOST_H_