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