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. 4 5 #ifndef CONTENT_BROWSER_MEDIA_MIDI_HOST_H_ 6 #define CONTENT_BROWSER_MEDIA_MIDI_HOST_H_ 7 8 #include <vector> 9 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" 18 19 namespace media { 20 class MidiManager; 21 class MidiMessageQueue; 22 } 23 24 namespace content { 25 26 class CONTENT_EXPORT MidiHost 27 : public BrowserMessageFilter, 28 public media::MidiManagerClient { 29 public: 30 // Called from UI thread from the owner of this object. 31 MidiHost(int renderer_process_id, media::MidiManager* midi_manager); 32 33 // BrowserMessageFilter implementation. 34 virtual void OnDestruct() const OVERRIDE; 35 virtual bool OnMessageReceived(const IPC::Message& message) OVERRIDE; 36 37 // MidiManagerClient implementation. 38 virtual void CompleteStartSession(int client_id, 39 media::MidiResult result) OVERRIDE; 40 virtual void ReceiveMidiData(uint32 port, 41 const uint8* data, 42 size_t length, 43 double timestamp) OVERRIDE; 44 virtual void AccumulateMidiBytesSent(size_t n) OVERRIDE; 45 46 // Start session to access MIDI hardware. 47 void OnStartSession(int client_id); 48 49 // Data to be sent to a MIDI output port. 50 void OnSendData(uint32 port, 51 const std::vector<uint8>& data, 52 double timestamp); 53 54 private: 55 FRIEND_TEST_ALL_PREFIXES(MidiHostTest, IsValidWebMIDIData); 56 friend class base::DeleteHelper<MidiHost>; 57 friend class BrowserThread; 58 59 virtual ~MidiHost(); 60 61 // Returns true if |data| fulfills the requirements of MidiOutput.send API 62 // defined in the WebMIDI spec. 63 // - |data| must be any number of complete MIDI messages (data abbreviation 64 // called "running status" is disallowed). 65 // - 1-byte MIDI realtime messages can be placed at any position of |data|. 66 static bool IsValidWebMIDIData(const std::vector<uint8>& data); 67 68 int renderer_process_id_; 69 70 // Represents if the renderer has a permission to send/receive MIDI SysEX 71 // messages. 72 bool has_sys_ex_permission_; 73 74 // |midi_manager_| talks to the platform-specific MIDI APIs. 75 // It can be NULL if the platform (or our current implementation) 76 // does not support MIDI. If not supported then a call to 77 // OnRequestAccess() will always refuse access and a call to 78 // OnSendData() will do nothing. 79 media::MidiManager* const midi_manager_; 80 81 // Buffers where data sent from each MIDI input port is stored. 82 ScopedVector<media::MidiMessageQueue> received_messages_queues_; 83 84 // The number of bytes sent to the platform-specific MIDI sending 85 // system, but not yet completed. 86 size_t sent_bytes_in_flight_; 87 88 // The number of bytes successfully sent since the last time 89 // we've acknowledged back to the renderer. 90 size_t bytes_sent_since_last_acknowledgement_; 91 92 // Protects access to |sent_bytes_in_flight_|. 93 base::Lock in_flight_lock_; 94 95 DISALLOW_COPY_AND_ASSIGN(MidiHost); 96 }; 97 98 } // namespace content 99 100 #endif // CONTENT_BROWSER_MEDIA_MIDI_HOST_H_ 101