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 MEDIA_MIDI_MIDI_MANAGER_H_
6 #define MEDIA_MIDI_MIDI_MANAGER_H_
11 #include "base/basictypes.h"
12 #include "base/memory/ref_counted.h"
13 #include "base/synchronization/lock.h"
14 #include "base/time/time.h"
15 #include "media/midi/midi_export.h"
16 #include "media/midi/midi_port_info.h"
17 #include "media/midi/result.h"
20 class SingleThreadTaskRunner
;
26 // A MidiManagerClient registers with the MidiManager to receive MIDI data.
27 // See MidiManager::RequestAccess() and MidiManager::ReleaseAccess()
29 class MIDI_EXPORT MidiManagerClient
{
31 virtual ~MidiManagerClient() {}
33 // AddInputPort() and AddOutputPort() are called before CompleteStartSession()
34 // is called to notify existing MIDI ports, and also called after that to
35 // notify new MIDI ports are added.
36 virtual void AddInputPort(const MidiPortInfo
& info
) = 0;
37 virtual void AddOutputPort(const MidiPortInfo
& info
) = 0;
39 // SetInputPortState() and SetOutputPortState() are called to notify a known
40 // device gets disconnected, or connected again.
41 virtual void SetInputPortState(uint32 port_index
, MidiPortState state
) = 0;
42 virtual void SetOutputPortState(uint32 port_index
, MidiPortState state
) = 0;
44 // CompleteStartSession() is called when platform dependent preparation is
46 virtual void CompleteStartSession(Result result
) = 0;
48 // ReceiveMidiData() is called when MIDI data has been received from the
50 // |port_index| represents the specific input port from input_ports().
51 // |data| represents a series of bytes encoding one or more MIDI messages.
52 // |length| is the number of bytes in |data|.
53 // |timestamp| is the time the data was received, in seconds.
54 virtual void ReceiveMidiData(uint32 port_index
,
57 double timestamp
) = 0;
59 // AccumulateMidiBytesSent() is called to acknowledge when bytes have
60 // successfully been sent to the hardware.
61 // This happens as a result of the client having previously called
62 // MidiManager::DispatchSendMidiData().
63 virtual void AccumulateMidiBytesSent(size_t n
) = 0;
66 // Manages access to all MIDI hardware.
67 class MIDI_EXPORT MidiManager
{
69 static const size_t kMaxPendingClientCount
= 128;
72 virtual ~MidiManager();
74 // The constructor and the destructor will be called on the CrBrowserMain
76 static MidiManager
* Create();
78 // A client calls StartSession() to receive and send MIDI data.
79 // If the session is ready to start, the MIDI system is lazily initialized
80 // and the client is registered to receive MIDI data.
81 // CompleteStartSession() is called with Result::OK if the session is started.
82 // Otherwise CompleteStartSession() is called with proper Result code.
83 // StartSession() and EndSession() can be called on the Chrome_IOThread.
84 // CompleteStartSession() will be invoked on the same Chrome_IOThread.
85 void StartSession(MidiManagerClient
* client
);
87 // A client calls EndSession() to stop receiving MIDI data.
88 void EndSession(MidiManagerClient
* client
);
90 // Invoke AccumulateMidiBytesSent() for |client| safely. If the session was
91 // already closed, do nothing.
92 void AccumulateMidiBytesSent(MidiManagerClient
* client
, size_t n
);
94 // DispatchSendMidiData() is called when MIDI data should be sent to the MIDI
96 // This method is supposed to return immediately and should not block.
97 // |port_index| represents the specific output port from output_ports().
98 // |data| represents a series of bytes encoding one or more MIDI messages.
99 // |length| is the number of bytes in |data|.
100 // |timestamp| is the time to send the data, in seconds. A value of 0
101 // means send "now" or as soon as possible.
102 // The default implementation is for unsupported platforms.
103 virtual void DispatchSendMidiData(MidiManagerClient
* client
,
105 const std::vector
<uint8
>& data
,
109 friend class MidiManagerUsb
;
111 // Initializes the platform dependent MIDI system. MidiManager class has a
112 // default implementation that synchronously calls CompleteInitialization()
113 // with Result::NOT_SUPPORTED on the caller thread. A derived class for a
114 // specific platform should override this method correctly.
115 // This method is called on Chrome_IOThread thread inside StartSession().
116 // Platform dependent initialization can be processed synchronously or
117 // asynchronously. When the initialization is completed,
118 // CompleteInitialization() should be called with |result|.
119 // |result| should be Result::OK on success, otherwise a proper Result.
120 virtual void StartInitialization();
122 // Called from a platform dependent implementation of StartInitialization().
123 // It invokes CompleteInitializationInternal() on the thread that calls
124 // StartSession() and distributes |result| to MIDIManagerClient objects in
125 // |pending_clients_|.
126 void CompleteInitialization(Result result
);
128 void AddInputPort(const MidiPortInfo
& info
);
129 void AddOutputPort(const MidiPortInfo
& info
);
130 void SetInputPortState(uint32 port_index
, MidiPortState state
);
131 void SetOutputPortState(uint32 port_index
, MidiPortState state
);
133 // Dispatches to all clients.
134 // TODO(toyoshim): Fix the mac implementation to use
135 // |ReceiveMidiData(..., base::TimeTicks)|.
136 void ReceiveMidiData(uint32 port_index
,
141 void ReceiveMidiData(uint32 port_index
,
144 base::TimeTicks time
) {
145 ReceiveMidiData(port_index
, data
, length
,
146 (time
- base::TimeTicks()).InSecondsF());
149 size_t clients_size_for_testing() const { return clients_
.size(); }
150 size_t pending_clients_size_for_testing() const {
151 return pending_clients_
.size();
154 const MidiPortInfoList
& input_ports() const { return input_ports_
; }
155 const MidiPortInfoList
& output_ports() const { return output_ports_
; }
158 void CompleteInitializationInternal(Result result
);
159 void AddInitialPorts(MidiManagerClient
* client
);
161 // Keeps track of all clients who wish to receive MIDI data.
162 typedef std::set
<MidiManagerClient
*> ClientSet
;
165 // Keeps track of all clients who are waiting for CompleteStartSession().
166 ClientSet pending_clients_
;
168 // Keeps a SingleThreadTaskRunner of the thread that calls StartSession in
169 // order to invoke CompleteStartSession() on the thread.
170 scoped_refptr
<base::SingleThreadTaskRunner
> session_thread_runner_
;
172 // Keeps true if platform dependent initialization is already completed.
175 // Keeps the platform dependent initialization result if initialization is
176 // completed. Otherwise keeps Result::NOT_INITIALIZED.
179 // Keeps all MidiPortInfo.
180 MidiPortInfoList input_ports_
;
181 MidiPortInfoList output_ports_
;
183 // Protects access to |clients_|, |pending_clients_|, |initialized_|,
184 // |result_|, |input_ports_| and |output_ports_|.
187 DISALLOW_COPY_AND_ASSIGN(MidiManager
);
193 #endif // MEDIA_MIDI_MIDI_MANAGER_H_