1 // Copyright (c) 2013 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.
5 #ifndef CONTENT_BROWSER_RENDERER_HOST_MEDIA_MIDI_HOST_H_
6 #define CONTENT_BROWSER_RENDERER_HOST_MEDIA_MIDI_HOST_H_
10 #include "base/gtest_prod_util.h"
11 #include "base/memory/ref_counted.h"
12 #include "base/memory/scoped_ptr.h"
13 #include "base/memory/scoped_vector.h"
14 #include "content/common/content_export.h"
15 #include "content/public/browser/browser_message_filter.h"
16 #include "content/public/browser/browser_thread.h"
17 #include "media/midi/midi_manager.h"
21 class MidiMessageQueue;
26 class CONTENT_EXPORT MidiHost
27 : public BrowserMessageFilter,
28 public media::MidiManagerClient {
30 // Called from UI thread from the owner of this object.
31 MidiHost(int renderer_process_id, media::MidiManager* midi_manager);
33 // BrowserMessageFilter implementation.
34 virtual void OnDestruct() const OVERRIDE;
35 virtual bool OnMessageReceived(const IPC::Message& message,
36 bool* message_was_ok) OVERRIDE;
38 // MidiManagerClient implementation.
39 virtual void ReceiveMidiData(uint32 port,
42 double timestamp) OVERRIDE;
43 virtual void AccumulateMidiBytesSent(size_t n) OVERRIDE;
45 // Start session to access MIDI hardware.
46 void OnStartSession(int client_id);
48 // Data to be sent to a MIDI output port.
49 void OnSendData(uint32 port,
50 const std::vector<uint8>& data,
54 FRIEND_TEST_ALL_PREFIXES(MidiHostTest, IsValidWebMIDIData);
55 friend class base::DeleteHelper<MidiHost>;
56 friend class BrowserThread;
60 // Returns true if |data| fulfills the requirements of MidiOutput.send API
61 // defined in the WebMIDI spec.
62 // - |data| must be any number of complete MIDI messages (data abbreviation
63 // called "running status" is disallowed).
64 // - 1-byte MIDI realtime messages can be placed at any position of |data|.
65 static bool IsValidWebMIDIData(const std::vector<uint8>& data);
67 int renderer_process_id_;
69 // Represents if the renderer has a permission to send/receive MIDI SysEX
71 bool has_sys_ex_permission_;
73 // |midi_manager_| talks to the platform-specific MIDI APIs.
74 // It can be NULL if the platform (or our current implementation)
75 // does not support MIDI. If not supported then a call to
76 // OnRequestAccess() will always refuse access and a call to
77 // OnSendData() will do nothing.
78 media::MidiManager* const midi_manager_;
80 // Buffers where data sent from each MIDI input port is stored.
81 ScopedVector<media::MidiMessageQueue> received_messages_queues_;
83 // The number of bytes sent to the platform-specific MIDI sending
84 // system, but not yet completed.
85 size_t sent_bytes_in_flight_;
87 // The number of bytes successfully sent since the last time
88 // we've acknowledged back to the renderer.
89 size_t bytes_sent_since_last_acknowledgement_;
91 // Protects access to |sent_bytes_in_flight_|.
92 base::Lock in_flight_lock_;
94 DISALLOW_COPY_AND_ASSIGN(MidiHost);
97 } // namespace content
99 #endif // CONTENT_BROWSER_RENDERER_HOST_MEDIA_MIDI_HOST_H_