1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
|
// 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_H_
#define MEDIA_MIDI_MIDI_MANAGER_H_
#include <set>
#include <vector>
#include "base/basictypes.h"
#include "base/memory/scoped_ptr.h"
#include "base/message_loop/message_loop_proxy.h"
#include "base/synchronization/lock.h"
#include "media/base/media_export.h"
#include "media/midi/midi_port_info.h"
namespace base {
class Thread;
}
namespace media {
// A MIDIManagerClient registers with the MIDIManager to receive MIDI data.
// See MIDIManager::RequestAccess() and MIDIManager::ReleaseAccess()
// for details.
class MEDIA_EXPORT MIDIManagerClient {
public:
virtual ~MIDIManagerClient() {}
// ReceiveMIDIData() is called when MIDI data has been received from the
// MIDI system.
// |port_index| represents the specific input port from input_ports().
// |data| represents a series of bytes encoding one or more MIDI messages.
// |length| is the number of bytes in |data|.
// |timestamp| is the time the data was received, in seconds.
virtual void ReceiveMIDIData(uint32 port_index,
const uint8* data,
size_t length,
double timestamp) = 0;
// AccumulateMIDIBytesSent() is called to acknowledge when bytes have
// successfully been sent to the hardware.
// This happens as a result of the client having previously called
// MIDIManager::DispatchSendMIDIData().
virtual void AccumulateMIDIBytesSent(size_t n) = 0;
};
// Manages access to all MIDI hardware.
class MEDIA_EXPORT MIDIManager {
public:
static MIDIManager* Create();
MIDIManager();
virtual ~MIDIManager();
// A client calls StartSession() to receive and send MIDI data.
// If the session is ready to start, the MIDI system is lazily initialized
// and the client is registered to receive MIDI data.
// Returns |true| if the session succeeds to start.
bool StartSession(MIDIManagerClient* client);
// A client calls ReleaseSession() to stop receiving MIDI data.
void EndSession(MIDIManagerClient* client);
// DispatchSendMIDIData() schedules one or more messages to be sent
// at the given time on a dedicated thread.
// |port_index| represents the specific output port from output_ports().
// |data| represents a series of bytes encoding one or more MIDI messages.
// |length| is the number of bytes in |data|.
// |timestamp| is the time to send the data, in seconds. A value of 0
// means send "now" or as soon as possible.
void DispatchSendMIDIData(MIDIManagerClient* client,
uint32 port_index,
const std::vector<uint8>& data,
double timestamp);
// input_ports() is a list of MIDI ports for receiving MIDI data.
// Each individual port in this list can be identified by its
// integer index into this list.
const MIDIPortInfoList& input_ports() { return input_ports_; }
// output_ports() is a list of MIDI ports for sending MIDI data.
// Each individual port in this list can be identified by its
// integer index into this list.
const MIDIPortInfoList& output_ports() { return output_ports_; }
protected:
// Initializes the MIDI system, returning |true| on success.
virtual bool Initialize() = 0;
// Implements the platform-specific details of sending MIDI data.
// This function runs on MIDISendThread.
virtual void SendMIDIData(MIDIManagerClient* client,
uint32 port_index,
const std::vector<uint8>& data,
double timestamp) = 0;
void AddInputPort(const MIDIPortInfo& info);
void AddOutputPort(const MIDIPortInfo& info);
// Dispatches to all clients.
void ReceiveMIDIData(uint32 port_index,
const uint8* data,
size_t length,
double timestamp);
// Checks if current thread is MIDISendThread.
bool CurrentlyOnMIDISendThread();
bool initialized_;
// Keeps track of all clients who wish to receive MIDI data.
typedef std::set<MIDIManagerClient*> ClientList;
ClientList clients_;
// Protects access to our clients.
base::Lock clients_lock_;
MIDIPortInfoList input_ports_;
MIDIPortInfoList output_ports_;
// |send_thread_| is used to send MIDI data by calling the platform-specific
// API.
scoped_ptr<base::Thread> send_thread_;
scoped_refptr<base::MessageLoopProxy> send_message_loop_;
DISALLOW_COPY_AND_ASSIGN(MIDIManager);
};
} // namespace media
#endif // MEDIA_MIDI_MIDI_MANAGER_H_
|
