[WebMIDI] Introduce MidiManagerUsb

media/midi/midi_manager_usb.cc

+// 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.
+
+#include "media/midi/midi_manager_usb.h"
+
+#include "base/callback.h"
+#include "base/logging.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/message_loop/message_loop.h"
+#include "media/midi/usb_midi_descriptor_parser.h"
+#include "media/midi/usb_midi_device.h"
+#include "media/midi/usb_midi_input_stream.h"
+#include "media/midi/usb_midi_jack.h"
+#include "media/midi/usb_midi_output_stream.h"
+
+namespace media {
+
+namespace {
+
+void Noop(bool result) {

[Takashi Toyoshima, 2013/12/24 04:33:23]

Placeholder for something?

[yhirano, 2013/12/24 04:42:50]

Added a comment.

+}
+
+}  // namespace
+
+MIDIManagerUsb::MIDIManagerUsb(scoped_ptr<UsbMidiDevice::Factory> factory)
+    : device_factory_(factory.Pass()) {
+}
+
+MIDIManagerUsb::~MIDIManagerUsb() {
+}
+
+bool MIDIManagerUsb::Initialize() {
+  Initialize(base::Bind(Noop));
+  return true;
+}
+
+void MIDIManagerUsb::Initialize(base::Callback<void(bool result)> callback) {
+  initialize_callback_ = callback;
+  // This is safe because EnumerateDevices cancels the operation on destruction.
+  device_factory_->EnumerateDevices(
+      this,
+      base::Bind(&MIDIManagerUsb::OnEnumerateDevicesDone,
+                 base::Unretained(this)));
+}
+
+void MIDIManagerUsb::DispatchSendMIDIData(MIDIManagerClient* client,
+                                          uint32_t port_index,
+                                          const std::vector<uint8>& data,
+                                          double timestamp) {
+  DCHECK_LT(port_index, output_streams_.size());
+  output_streams_[port_index]->Send(data);
+  // TODO(yhirano): Call AccumulateMIDIBytesSent.
+}
+
+
+void MIDIManagerUsb::ReceiveUsbMidiData(UsbMidiDevice* device,
+                                        int endpoint_number,
+                                        const uint8* data,
+                                        size_t size,
+                                        double timestamp) {
+  if (!input_stream_)
+    return;
+  input_stream_->OnReceivedData(device,
+                                endpoint_number,
+                                data,
+                                size,
+                                timestamp);
+}
+
+void MIDIManagerUsb::OnReceivedData(size_t jack_index,
+                                    const uint8* data,
+                                    size_t size,
+                                    double timestamp) {
+  ReceiveMIDIData(jack_index, data, size, timestamp);
+}
+
+
+void MIDIManagerUsb::OnEnumerateDevicesDone(bool result,
+                                            UsbMidiDevice::Devices* devices) {
+  if (!result) {
+    initialize_callback_.Run(false);
+    return;
+  }
+  devices->swap(devices_);
+  for (size_t i = 0; i < devices_.size(); ++i) {
+    UsbMidiDescriptorParser parser;
+    std::vector<uint8> descriptor = devices_[i]->GetDescriptor();
+    bool parse_result = parser.Parse(devices_[i],
+                                     descriptor.data(),
+                                     descriptor.size());
+    if (!parse_result) {
+      initialize_callback_.Run(false);
+      return;
+    }
+    const std::vector<UsbMidiJack>& jacks = parser.jacks();
+    std::vector<UsbMidiJack> input_jacks;
+    for (size_t j = 0; j < jacks.size(); ++j) {
+      if (jacks[j].GetDirection() == UsbMidiJack::OUT) {
+        output_streams_.push_back(new UsbMidiOutputStream(jacks[j]));
+        // TODO(yhirano): Set appropriate properties.
+        AddOutputPort(MIDIPortInfo());
+      } else {
+        DCHECK_EQ(jacks[j].GetDirection(), UsbMidiJack::IN);
+        input_jacks.push_back(jacks[j]);
+        // TODO(yhirano): Set appropriate properties.
+        AddInputPort(MIDIPortInfo());
+      }
+    }
+    input_stream_.reset(new UsbMidiInputStream(input_jacks, this));
+  }
+  initialize_callback_.Run(true);
+}
+
+}  // namespace media