Implement Web MIDI API back-end

This involves browser-side support and IPC for sending and receiving
MIDI messages.  Initially support for OSX is included.

BUG=163795
R=palmer@chromium.org, piman@chromium.org, scherkus@chromium.org

Review URL: https://codereview.chromium.org/16025005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@207983 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 69 insertions, 0 deletions

diff --git a/media/midi/midi_manager_mac.h b/media/midi/midi_manager_mac.h
new file mode 100644
index 0000000..f513e11
--- /dev/null
+++ b/media/midi/midi_manager_mac.h
@@ -0,0 +1,69 @@
+// 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 MEDIA_MIDI_MIDI_MANAGER_MAC_H_
+#define MEDIA_MIDI_MIDI_MANAGER_MAC_H_
+
+#include <CoreMIDI/MIDIServices.h>
+#include <map>
+#include <string>
+
+#include "base/basictypes.h"
+#include "base/compiler_specific.h"
+#include "media/midi/midi_manager.h"
+#include "media/midi/midi_port_info.h"
+
+namespace media {
+
+class MEDIA_EXPORT MIDIManagerMac : public MIDIManager {
+ public:
+  MIDIManagerMac();
+  virtual ~MIDIManagerMac();
+
+  // MIDIManager implementation.
+  virtual bool Initialize() OVERRIDE;
+  virtual void SendMIDIData(int port_index,
+                            const uint8* data,
+                            size_t length,
+                            double timestamp) OVERRIDE;
+
+ private:
+  // CoreMIDI callback for MIDI data.
+  // Each callback can contain multiple packets, each of which can contain
+  // multiple MIDI messages.
+  static void ReadMidiDispatch(
+      const MIDIPacketList *pktlist,
+      void *read_proc_refcon,
+      void *src_conn_refcon);
+  virtual void ReadMidi(MIDIEndpointRef source, const MIDIPacketList *pktlist);
+
+  // Helper
+  static media::MIDIPortInfo GetPortInfoFromEndpoint(MIDIEndpointRef endpoint);
+  static double MIDITimeStampToSeconds(MIDITimeStamp timestamp);
+  static MIDITimeStamp SecondsToMIDITimeStamp(double seconds);
+
+  // CoreMIDI
+  MIDIClientRef midi_client_;
+  MIDIPortRef coremidi_input_;
+  MIDIPortRef coremidi_output_;
+
+  enum{ kMaxPacketListSize = 512 };
+  char midi_buffer_[kMaxPacketListSize];
+  MIDIPacketList* packet_list_;
+  MIDIPacket* midi_packet_;
+
+  typedef std::map<MIDIEndpointRef, int> SourceMap;
+
+  // Keeps track of the index (0-based) for each of our sources.
+  SourceMap source_map_;
+
+  // Keeps track of all destinations.
+  std::vector<MIDIEndpointRef> destinations_;
+
+  DISALLOW_COPY_AND_ASSIGN(MIDIManagerMac);
+};
+
+}  // namespace media
+
+#endif  // MEDIA_MIDI_MIDI_MANAGER_MAC_H_