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
  16 namespace ppapi {
  17 struct DeviceRefData;
  18
  19 namespace host {
  20 struct HostMessageContext;
  21 struct ReplyMessageContext;
  22 class ResourceHost;
  23 }
  24 }
  25
  26 namespace IPC {
  27 class Message;
  28 }
  29
  30 namespace content {
  31
  32 // Resource hosts that support device enumeration can use this class to filter
  33 // and process PpapiHostMsg_DeviceEnumeration_* messages.
  34 // TODO(yzshen): Refactor ppapi::host::ResourceMessageFilter to support message
  35 // handling on the same thread, and then derive this class from the filter
  36 // class.
  37 class CONTENT_EXPORT PepperDeviceEnumerationHostHelper {
  38  public:
  39   class Delegate {
  40    public:
  41     virtual ~Delegate() {}
  42
  43     typedef base::Callback<
  44         void (int /* request_id */,
  45               bool /* succeeded */,
  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 EnumerateDevicesCallback& callback) = 0;
  53     // Stop enumerating devices of the specified |request_id|. The |request_id|
  54     // is the return value of EnumerateDevicesCallback.
  55     virtual void StopEnumerateDevices(int request_id) = 0;
  56   };
  57
  58   // |resource_host| and |delegate| must outlive this object.
  59   PepperDeviceEnumerationHostHelper(ppapi::host::ResourceHost* resource_host,
  60                                     Delegate* delegate,
  61                                     PP_DeviceType_Dev device_type);
  62   ~PepperDeviceEnumerationHostHelper();
  63
  64   // Returns true if the message has been handled.
  65   bool HandleResourceMessage(const IPC::Message& msg,
  66                              ppapi::host::HostMessageContext* context,
  67                              int32_t* result);
  68
  69  private:
  70   class ScopedRequest;
  71
  72   // Has a different signature than HandleResourceMessage() in order to utilize
  73   // message dispatching macros.
  74   int32_t InternalHandleResourceMessage(
  75       const IPC::Message& msg,
  76       ppapi::host::HostMessageContext* context,
  77       bool* handled);
  78
  79   int32_t OnEnumerateDevices(ppapi::host::HostMessageContext* context);
  80   int32_t OnMonitorDeviceChange(ppapi::host::HostMessageContext* context,
  81                                 uint32_t callback_id);
  82   int32_t OnStopMonitoringDeviceChange(
  83       ppapi::host::HostMessageContext* context);
  84
  85   void OnEnumerateDevicesComplete(
  86       int request_id,
  87       bool succeeded,
  88       const std::vector<ppapi::DeviceRefData>& devices);
  89   void OnNotifyDeviceChange(
  90       uint32_t callback_id,
  91       int request_id,
  92       bool succeeded,
  93       const std::vector<ppapi::DeviceRefData>& devices);
  94
  95   // Non-owning pointers.
  96   ppapi::host::ResourceHost* resource_host_;
  97   Delegate* delegate_;
  98
  99   PP_DeviceType_Dev device_type_;
 100
 101   scoped_ptr<ScopedRequest> enumerate_;
 102   scoped_ptr<ScopedRequest> monitor_;
 103
 104   scoped_ptr<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_