| // 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/synchronization/lock.h" |
| #include "media/base/media_export.h" |
| #include "media/midi/midi_port_info.h" |
| |
| 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() is called when MIDI data should be sent to the MIDI |
| // system. |
| // This method is supposed to return immediately and should not block. |
| // |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. |
| // The default implementation is for unsupported platforms. |
| virtual 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. |
| // The default implementation is for unsupported platforms. |
| virtual bool Initialize(); |
| |
| 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); |
| |
| 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_; |
| |
| DISALLOW_COPY_AND_ASSIGN(MidiManager); |
| }; |
| |
| } // namespace media |
| |
| #endif // MEDIA_MIDI_MIDI_MANAGER_H_ |