1 | package org.apollo.audio.util;
|
---|
2 |
|
---|
3 | import java.util.LinkedList;
|
---|
4 | import java.util.List;
|
---|
5 |
|
---|
6 | import org.apollo.audio.ApolloPlaybackMixer;
|
---|
7 | import org.apollo.audio.ApolloSubjectChangedEvent;
|
---|
8 | import org.apollo.mvc.Observer;
|
---|
9 | import org.apollo.mvc.Subject;
|
---|
10 | import org.apollo.mvc.SubjectChangedEvent;
|
---|
11 | import org.apollo.util.AudioMath;
|
---|
12 | import org.expeditee.gui.DisplayController;
|
---|
13 | import org.expeditee.settings.audio.AudioSettings;
|
---|
14 |
|
---|
15 | /**
|
---|
16 | * The audio playback clock ticks at {@link #CLOCK_RESOLUTION} milliseconds and
|
---|
17 | * invokes all registered clock listeners <b>on the same thread as the clock<b>.
|
---|
18 | * Thus the clock is not entirely accurate: its intention of use is for updating
|
---|
19 | * a GUI according to the live frame position in the software mixer.
|
---|
20 | *
|
---|
21 | * Thus all thread safety precautions and efficiencies are at the users discretion.
|
---|
22 | * The ideal usage would be to simply update some data without the need of locking
|
---|
23 | * and returning ASAP
|
---|
24 | *
|
---|
25 | * @see {@link ApolloPlaybackMixer}
|
---|
26 | *
|
---|
27 | * @author Brook Novak
|
---|
28 | *
|
---|
29 | */
|
---|
30 | public class PlaybackClock {
|
---|
31 |
|
---|
32 | //public static final long CLOCK_RESOLUTION = 50; // used to be 300, then 50, now retrieved from Settings
|
---|
33 |
|
---|
34 | private Clock clockThread = null;
|
---|
35 |
|
---|
36 | private List<PlaybackClockListener> playbackClockListeners = new LinkedList<PlaybackClockListener>();
|
---|
37 |
|
---|
38 | private static PlaybackClock instance = new PlaybackClock();
|
---|
39 | public static PlaybackClock getInstance() {
|
---|
40 | return instance;
|
---|
41 | }
|
---|
42 |
|
---|
43 | /**
|
---|
44 | * Singleton constructor preps the PlaybackClock for listening for
|
---|
45 | * audio events from the software mixer
|
---|
46 | *
|
---|
47 | */
|
---|
48 | private PlaybackClock() {
|
---|
49 |
|
---|
50 | ApolloPlaybackMixer.getInstance().addObserver(new Observer() {
|
---|
51 |
|
---|
52 | public Subject getObservedSubject() {
|
---|
53 | return ApolloPlaybackMixer.getInstance();
|
---|
54 | }
|
---|
55 | public void setObservedSubject(Subject parent) {
|
---|
56 | }
|
---|
57 |
|
---|
58 | public void modelChanged(Subject source, SubjectChangedEvent event) {
|
---|
59 |
|
---|
60 | if (event.getID() == ApolloSubjectChangedEvent.PLAYBACK_STARTED) {
|
---|
61 |
|
---|
62 | // Start the clock
|
---|
63 | assert(clockThread == null);
|
---|
64 | clockThread = new Clock();
|
---|
65 | clockThread.start();
|
---|
66 |
|
---|
67 | } else if (event.getID() == ApolloSubjectChangedEvent.PLAYBACK_STOPPED) {
|
---|
68 |
|
---|
69 | // Kill the clock
|
---|
70 | clockThread.interrupt();
|
---|
71 | clockThread = null; // it will die in its own time
|
---|
72 | }
|
---|
73 | }
|
---|
74 |
|
---|
75 | });
|
---|
76 | }
|
---|
77 |
|
---|
78 | /**
|
---|
79 | * Adds a PlaybackClockListener for receiving notifications whenever audio is played.
|
---|
80 | *
|
---|
81 | * @param listener
|
---|
82 | * The listener to add. If already added then it won't be added again.
|
---|
83 | *
|
---|
84 | * @throws NullPointerException
|
---|
85 | * If listener is null.
|
---|
86 | */
|
---|
87 | public void addPlaybackClockListener(PlaybackClockListener listener) {
|
---|
88 | if (listener == null) throw new NullPointerException("listener");
|
---|
89 | synchronized(playbackClockListeners) {
|
---|
90 | if (!playbackClockListeners.contains(listener))
|
---|
91 | playbackClockListeners.add(listener);
|
---|
92 | }
|
---|
93 | }
|
---|
94 |
|
---|
95 | /**
|
---|
96 | * Removes a listener such that it will stop receiving notifications.
|
---|
97 | *
|
---|
98 | * @param listener
|
---|
99 | * The listener to remove.
|
---|
100 | *
|
---|
101 | * @throws NullPointerException
|
---|
102 | * If listener is null.
|
---|
103 | */
|
---|
104 | public void removePlaybackClockListener(PlaybackClockListener listener) {
|
---|
105 | if (listener == null) throw new NullPointerException("listener");
|
---|
106 | synchronized(playbackClockListeners) {
|
---|
107 | playbackClockListeners.remove(listener);
|
---|
108 | }
|
---|
109 | }
|
---|
110 |
|
---|
111 | /**
|
---|
112 | * The clock periodically wakes and updates playback-related GUI according to the
|
---|
113 | * live position of the playback.
|
---|
114 | *
|
---|
115 | * The clock thread dies once its interrupted.
|
---|
116 | *
|
---|
117 | * @author Brook Novak
|
---|
118 | *
|
---|
119 | */
|
---|
120 | private class Clock extends Thread {
|
---|
121 |
|
---|
122 | Clock() {
|
---|
123 | super("Playback Clock");
|
---|
124 | }
|
---|
125 |
|
---|
126 | public void run() {
|
---|
127 |
|
---|
128 | try {
|
---|
129 | long framePos, msPos;
|
---|
130 | boolean shouldRepaint;
|
---|
131 |
|
---|
132 | int CLOCK_RESOLUTION = AudioSettings.PlaybackClockResolution.get();
|
---|
133 |
|
---|
134 | while (!interrupted()) {
|
---|
135 |
|
---|
136 | // Get the live time in frames - directly from the hardware
|
---|
137 | framePos = ApolloPlaybackMixer.getInstance().getLiveFramePosition();
|
---|
138 |
|
---|
139 | shouldRepaint = false;
|
---|
140 |
|
---|
141 | if (framePos >= 0) { // is playing still?
|
---|
142 |
|
---|
143 | msPos = AudioMath.framesToMilliseconds(
|
---|
144 | framePos,
|
---|
145 | ApolloPlaybackMixer.getInstance().getLiveAudioFormat());
|
---|
146 |
|
---|
147 | // Update the GUI. Because the clock awakes in small time slices must
|
---|
148 | // avoid updating the GUI on the swing thread: otherwise the AWT Event
|
---|
149 | // queue could easily become saturated.
|
---|
150 | synchronized(playbackClockListeners) { // arg, the most expensive operation!
|
---|
151 |
|
---|
152 | for (PlaybackClockListener listener : playbackClockListeners) {
|
---|
153 |
|
---|
154 | listener.onTick(framePos, msPos); // trusting that an exception does not occur
|
---|
155 | // If one does occur the worst that can happen is the the user doesn't
|
---|
156 | // have playback feedback.
|
---|
157 | shouldRepaint = true;
|
---|
158 | }
|
---|
159 |
|
---|
160 | }
|
---|
161 |
|
---|
162 | }
|
---|
163 |
|
---|
164 | // Do a repaint is something was listening
|
---|
165 | if (shouldRepaint) {
|
---|
166 | DisplayController.requestRefresh(true); // later - should not congest AWT queue
|
---|
167 | }
|
---|
168 |
|
---|
169 | sleep(CLOCK_RESOLUTION);
|
---|
170 |
|
---|
171 | } // Keep updating GUI until interrupted
|
---|
172 | } catch (InterruptedException e) { // consume
|
---|
173 | // Done
|
---|
174 | }
|
---|
175 |
|
---|
176 | // Notify that have completed
|
---|
177 | synchronized(playbackClockListeners) {
|
---|
178 |
|
---|
179 | for (PlaybackClockListener listener : playbackClockListeners) {
|
---|
180 |
|
---|
181 | listener.onTick(-1, -1);
|
---|
182 |
|
---|
183 | }
|
---|
184 |
|
---|
185 | }
|
---|
186 |
|
---|
187 | }
|
---|
188 |
|
---|
189 | }
|
---|
190 |
|
---|
191 | /**
|
---|
192 | * A PlaybackClockListener is periodically notified while there is playback occuring.
|
---|
193 | *
|
---|
194 | * @author Brook Novak
|
---|
195 | *
|
---|
196 | */
|
---|
197 | public interface PlaybackClockListener {
|
---|
198 |
|
---|
199 | /**
|
---|
200 | * At every tick, this is invoked <i>directly from the clock thread</i>
|
---|
201 | *
|
---|
202 | * @see {@link PlaybackClock} for implementation considerations.
|
---|
203 | *
|
---|
204 | * @param framePosition
|
---|
205 | * The current position of the playback in frames.
|
---|
206 | * Negative if playback has finished.
|
---|
207 | *
|
---|
208 | * @param msPosition
|
---|
209 | * The current position of the playback in milliseconds.
|
---|
210 | * Negative if playback has finished.
|
---|
211 | *
|
---|
212 | */
|
---|
213 | public void onTick(long framePosition, long msPosition);
|
---|
214 |
|
---|
215 | }
|
---|
216 | }
|
---|