content/renderer/pepper/pepper_device_enumeration_host_helper.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 CONTENT_RENDERER_PEPPER_PEPPER_DEVICE_ENUMERATION_HOST_HELPER_H_
   6 #define CONTENT_RENDERER_PEPPER_PEPPER_DEVICE_ENUMERATION_HOST_HELPER_H_
   7
   8 #include <vector>
   9
  10 #include "base/basictypes.h"
  11 #include "base/callback_forward.h"
  12 #include "base/memory/scoped_ptr.h"
  13 #include "content/common/content_export.h"
  14 #include "ppapi/c/dev/ppb_device_ref_dev.h"
  15 #include "ppapi/host/host_message_context.h"
  16 #include "url/gurl.h"
  17
  18 namespace ppapi {
  19 struct DeviceRefData;
  20
  21 namespace host {
  22 class ResourceHost;
  23 }
  24
  25 }  // namespace ppapi
  26
  27 namespace IPC {
  28 class Message;
  29 }
  30
  31 namespace content {
  32
  33 // Resource hosts that support device enumeration can use this class to filter
  34 // and process PpapiHostMsg_DeviceEnumeration_* messages.
  35 // TODO(yzshen): Refactor ppapi::host::ResourceMessageFilter to support message
  36 // handling on the same thread, and then derive this class from the filter
  37 // class.
  38 class CONTENT_EXPORT PepperDeviceEnumerationHostHelper {
  39  public:
  40   class Delegate {
  41    public:
  42     virtual ~Delegate() {}
  43
  44     typedef base::Callback<
  45         void(int /* request_id */,
  46              const std::vector<ppapi::DeviceRefData>& /* devices */)>
  47         EnumerateDevicesCallback;
  48
  49     // Enumerates devices of the specified type. The request ID passed into the
  50     // callback will be the same as the return value.
  51     virtual int EnumerateDevices(PP_DeviceType_Dev type,
  52                                  const GURL& document_url,
  53                                  const EnumerateDevicesCallback& callback) = 0;
  54     // Stop enumerating devices of the specified |request_id|. The |request_id|
  55     // is the return value of EnumerateDevicesCallback.
  56     virtual void StopEnumerateDevices(int request_id) = 0;
  57   };
  58
  59   // |resource_host| and |delegate| must outlive this object.
  60   PepperDeviceEnumerationHostHelper(ppapi::host::ResourceHost* resource_host,
  61                                     Delegate* delegate,
  62                                     PP_DeviceType_Dev device_type,
  63                                     const GURL& document_url);
  64   ~PepperDeviceEnumerationHostHelper();
  65
  66   // Returns true if the message has been handled.
  67   bool HandleResourceMessage(const IPC::Message& msg,
  68                              ppapi::host::HostMessageContext* context,
  69                              int32_t* result);
  70
  71  private:
  72   class ScopedRequest;
  73
  74   // Has a different signature than HandleResourceMessage() in order to utilize
  75   // message dispatching macros.
  76   int32_t InternalHandleResourceMessage(
  77       const IPC::Message& msg,
  78       ppapi::host::HostMessageContext* context,
  79       bool* handled);
  80
  81   int32_t OnEnumerateDevices(ppapi::host::HostMessageContext* context);
  82   int32_t OnMonitorDeviceChange(ppapi::host::HostMessageContext* context,
  83                                 uint32_t callback_id);
  84   int32_t OnStopMonitoringDeviceChange(
  85       ppapi::host::HostMessageContext* context);
  86
  87   void OnEnumerateDevicesComplete(
  88       int request_id,
  89       const std::vector<ppapi::DeviceRefData>& devices);
  90   void OnNotifyDeviceChange(uint32_t callback_id,
  91                             int request_id,
  92                             const std::vector<ppapi::DeviceRefData>& devices);
  93
  94   // Non-owning pointers.
  95   ppapi::host::ResourceHost* resource_host_;
  96   Delegate* delegate_;
  97
  98   PP_DeviceType_Dev device_type_;
  99   GURL document_url_;
 100
 101   scoped_ptr<ScopedRequest> enumerate_;
 102   scoped_ptr<ScopedRequest> monitor_;
 103
 104   ppapi::host::ReplyMessageContext enumerate_devices_context_;
 105
 106   DISALLOW_COPY_AND_ASSIGN(PepperDeviceEnumerationHostHelper);
 107 };
 108
 109 }  // namespace content
 110
 111 #endif  // CONTENT_RENDERER_PEPPER_PEPPER_DEVICE_ENUMERATION_HOST_HELPER_H_