Web MIDI API back-end (work-in-progress)

content/renderer/media/midi_message_filter.h

+// Copyright (c) 2013 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CONTENT_RENDERER_MEDIA_MIDI_MESSAGE_FILTER_H_
+#define CONTENT_RENDERER_MEDIA_MIDI_MESSAGE_FILTER_H_
+
+#include "base/memory/scoped_ptr.h"
+#include "content/common/content_export.h"
+#include "ipc/ipc_channel_proxy.h"
+#include <vector>
+
+#include "third_party/WebKit/Source/Platform/chromium/public/WebMIDIAccessor.h"
+
+namespace base {
+class MessageLoopProxy;
+}
+
+namespace content {
+
+// MessageFilter that handles MIDI messages.
+class CONTENT_EXPORT MIDIMessageFilter
+    : public IPC::ChannelProxy::MessageFilter {
+ public:
+  explicit MIDIMessageFilter(
+      const scoped_refptr<base::MessageLoopProxy>& io_message_loop);
+
+  // Getter for the one MIDIMessageFilter object.
+  static MIDIMessageFilter* Get();
+
+  // IO message loop associated with this message filter.
+  scoped_refptr<base::MessageLoopProxy> io_message_loop() const {
+    return io_message_loop_;
+  }
+
+  void AddClient(WebKit::WebMIDIAccessor::Client* client);
+  void RemoveClient(WebKit::WebMIDIAccessor::Client* client);
+
+ protected:
+  virtual ~MIDIMessageFilter();
+
+ private:
+  // Sends an IPC message using |channel_|.
+  void Send(IPC::Message* message);
+
+  // IPC::ChannelProxy::MessageFilter override. Called on |io_message_loop|.
+  virtual bool OnMessageReceived(const IPC::Message& message) OVERRIDE;
+  virtual void OnFilterAdded(IPC::Channel* channel) OVERRIDE;
+  virtual void OnFilterRemoved() OVERRIDE;
+  virtual void OnChannelClosing() OVERRIDE;
+
+  // Called when browser process has approved (or denied)
+  // access to MIDI hardware.
+  void OnAccessApproved(int access, bool success);
+
+  // Called when the browser process has sent MIDI data containing one or
+  // more messages.
+  void OnDataReceived(int port,
+                      const std::vector<uint8>& data,
+                      double timestamp);
+
+
+
+  void HandleDataReceived(int port,
+                      const std::vector<uint8>& data,
+                      double timestamp);
+
+
+  // IPC channel for Send(); must only be accesed on |io_message_loop_|.
+  IPC::Channel* channel_;
+
+  // Message loop on which IPC calls are driven.
+  const scoped_refptr<base::MessageLoopProxy> io_message_loop_;
+
+  // The singleton instance for this filter.
+  static MIDIMessageFilter* g_filter;
+  
+  WebKit::WebMIDIAccessor::Client* client_;
+  // For main thread!!!!!!!!!!
+  base::MessageLoop* message_loop_;
+
+  DISALLOW_COPY_AND_ASSIGN(MIDIMessageFilter);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_RENDERER_MEDIA_MIDI_MESSAGE_FILTER_H_