| // 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. |
| virtual void DispatchSendMIDIData(MIDIManagerClient* client, |
| uint32 port_index, |
| const std::vector<uint8>& data, |
| double timestamp) = 0; |
| |
| // 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; |
| |
| 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_ |