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29 #ifndef AudioScheduledSourceNode_h
30 #define AudioScheduledSourceNode_h
32 #include "modules/webaudio/AudioSourceNode.h"
38 class AudioScheduledSourceNode : public AudioSourceNode {
40 // These are the possible states an AudioScheduledSourceNode can be in:
42 // UNSCHEDULED_STATE - Initial playback state. Created, but not yet scheduled.
43 // SCHEDULED_STATE - Scheduled to play (via start()), but not yet playing.
44 // PLAYING_STATE - Generating sound.
45 // FINISHED_STATE - Finished generating sound.
47 // The state can only transition to the next state, except for the FINISHED_STATE which can
50 // These must be defined with the same names and values as in the .idl file.
51 UNSCHEDULED_STATE = 0,
57 AudioScheduledSourceNode(AudioContext*, float sampleRate);
60 void start(ExceptionState& exceptionState) { start(0.0, exceptionState); }
61 void start(double when, ExceptionState&);
62 void stop(ExceptionState& exceptionState) { stop(0.0, exceptionState); }
63 void stop(double when, ExceptionState&);
65 unsigned short playbackState() const { return static_cast<unsigned short>(m_playbackState); }
66 bool isPlayingOrScheduled() const { return m_playbackState == PLAYING_STATE || m_playbackState == SCHEDULED_STATE; }
67 bool hasFinished() const { return m_playbackState == FINISHED_STATE; }
69 EventListener* onended() { return getAttributeEventListener(EventTypeNames::ended); }
70 void setOnended(PassRefPtr<EventListener>);
73 // Get frame information for the current time quantum.
74 // We handle the transition into PLAYING_STATE and FINISHED_STATE here,
75 // zeroing out portions of the outputBus which are outside the range of startFrame and endFrame.
77 // Each frame time is relative to the context's currentSampleFrame().
78 // quantumFrameOffset : Offset frame in this time quantum to start rendering.
79 // nonSilentFramesToProcess : Number of frames rendering non-silence (will be <= quantumFrameSize).
80 void updateSchedulingInfo(size_t quantumFrameSize,
82 size_t& quantumFrameOffset,
83 size_t& nonSilentFramesToProcess);
85 // Called when we have no more sound to play or the noteOff() time has been reached.
86 virtual void finish();
90 PlaybackState m_playbackState;
92 // m_startTime is the time to start playing based on the context's timeline (0 or a time less than the context's current time means "now").
93 double m_startTime; // in seconds
95 // m_endTime is the time to stop playing based on the context's timeline (0 or a time less than the context's current time means "now").
96 // If it hasn't been set explicitly, then the sound will not stop playing (if looping) or will stop when the end of the AudioBuffer
98 double m_endTime; // in seconds
100 bool m_hasEndedListener;
102 static const double UnknownTime;
107 #endif // AudioScheduledSourceNode_h