1/*
2 * Copyright (C) 2012 Google Inc. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 *
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. Neither the name of Apple Inc. ("Apple") nor the names of
14 * its contributors may be used to endorse or promote products derived
15 * from this software without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
18 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
19 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
20 * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
21 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
22 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
23 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
24 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28
29#pragma once
30
31#include "AudioNode.h"
32
33namespace WebCore {
34
35class AudioScheduledSourceNode : public AudioNode {
36 WTF_MAKE_ISO_ALLOCATED(AudioScheduledSourceNode);
37public:
38 // These are the possible states an AudioScheduledSourceNode can be in:
39 //
40 // UNSCHEDULED_STATE - Initial playback state. Created, but not yet scheduled.
41 // SCHEDULED_STATE - Scheduled to play but not yet playing.
42 // PLAYING_STATE - Generating sound.
43 // FINISHED_STATE - Finished generating sound.
44 //
45 // The state can only transition to the next state, except for the FINISHED_STATE which can
46 // never be changed.
47 enum PlaybackState {
48 // These must be defined with the same names and values as in the .idl file.
49 UNSCHEDULED_STATE = 0,
50 SCHEDULED_STATE = 1,
51 PLAYING_STATE = 2,
52 FINISHED_STATE = 3
53 };
54
55 AudioScheduledSourceNode(AudioContext&, float sampleRate);
56
57 ExceptionOr<void> start(double when);
58 ExceptionOr<void> stop(double when);
59
60 unsigned short playbackState() const { return static_cast<unsigned short>(m_playbackState); }
61 bool isPlayingOrScheduled() const { return m_playbackState == PLAYING_STATE || m_playbackState == SCHEDULED_STATE; }
62 bool hasFinished() const { return m_playbackState == FINISHED_STATE; }
63
64protected:
65 // Get frame information for the current time quantum.
66 // We handle the transition into PLAYING_STATE and FINISHED_STATE here,
67 // zeroing out portions of the outputBus which are outside the range of startFrame and endFrame.
68 // Each frame time is relative to the context's currentSampleFrame().
69 // quantumFrameOffset: Offset frame in this time quantum to start rendering.
70 // nonSilentFramesToProcess: Number of frames rendering non-silence (will be <= quantumFrameSize).
71 void updateSchedulingInfo(size_t quantumFrameSize, AudioBus& outputBus, size_t& quantumFrameOffset, size_t& nonSilentFramesToProcess);
72
73 // Called when we have no more sound to play or the noteOff() time has been reached.
74 virtual void finish();
75
76 PlaybackState m_playbackState { UNSCHEDULED_STATE };
77
78 // 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").
79 double m_startTime { 0 }; // in seconds
80
81 // 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").
82 // 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
83 // has been reached.
84 double m_endTime; // in seconds
85
86 bool m_hasEndedListener { false };
87
88 static const double UnknownTime;
89
90private:
91 bool addEventListener(const AtomicString& eventType, Ref<EventListener>&&, const AddEventListenerOptions&) override;
92 bool removeEventListener(const AtomicString& eventType, EventListener&, const ListenerOptions&) override;
93 void removeAllEventListeners() override;
94};
95
96} // namespace WebCore
97