src/main/java/net/pterodactylus/sonitus/data/source/MultiSource.java

   1 /*
   2  * Sonitus - MultiSource.java - Copyright © 2013 David Roden
   3  *
   4  * This program is free software: you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation, either version 3 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 package net.pterodactylus.sonitus.data.source;
  19
  20 import static com.google.common.base.Preconditions.checkNotNull;
  21
  22 import java.io.EOFException;
  23 import java.io.IOException;
  24 import java.util.Collections;
  25 import java.util.List;
  26 import java.util.concurrent.atomic.AtomicReference;
  27 import java.util.logging.Logger;
  28 import javax.swing.event.EventListenerList;
  29
  30 import net.pterodactylus.sonitus.data.AbstractControlledComponent;
  31 import net.pterodactylus.sonitus.data.Controller;
  32 import net.pterodactylus.sonitus.data.Metadata;
  33 import net.pterodactylus.sonitus.data.Source;
  34
  35 import com.google.inject.Inject;
  36
  37 /**
  38  * {@link Source} implementation that simply forwards another source and
  39  * supports changing the source without letting the {@link
  40  * net.pterodactylus.sonitus.data.Sink} know.
  41  *
  42  * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
  43  */
  44 public class MultiSource extends AbstractControlledComponent implements Source {
  45
  46         /** The logger. */
  47         private static final Logger logger = Logger.getLogger(MultiSource.class.getName());
  48
  49         /** The source finished listeners. */
  50         private final EventListenerList sourceFinishedListeners = new EventListenerList();
  51
  52         /** The current source. */
  53         private final AtomicReference<Source> source = new AtomicReference<Source>();
  54
  55         /** Whether the source was changed. */
  56         private boolean sourceChanged;
  57
  58         /** Creates a new multi source. */
  59         @Inject
  60         public MultiSource() {
  61                 super("Multisource");
  62         }
  63
  64         //
  65         // LISTENER MANAGEMENT
  66         //
  67
  68         /**
  69          * Adds a source finished listener to the list of registered listeners.
  70          *
  71          * @param sourceFinishedListener
  72          *              The source finished listener to add
  73          */
  74         public void addSourceFinishedListener(SourceFinishedListener sourceFinishedListener) {
  75                 sourceFinishedListeners.add(SourceFinishedListener.class, sourceFinishedListener);
  76         }
  77
  78         /**
  79          * Removes a source finished listener from the list of registered listeners.
  80          *
  81          * @param sourceFinishedListener
  82          *              The source finished listener to remove
  83          */
  84         public void removeSourceFinishedListener(SourceFinishedListener sourceFinishedListener) {
  85                 sourceFinishedListeners.remove(SourceFinishedListener.class, sourceFinishedListener);
  86         }
  87
  88         //
  89         // ACTIONS
  90         //
  91
  92         /**
  93          * Sets the new source to use.
  94          *
  95          * @param source
  96          *              The new source to use
  97          */
  98         public void setSource(Source source) {
  99                 checkNotNull(source, "source must not be null");
 100
 101                 Source oldSource = this.source.getAndSet(source);
 102                 if (!source.equals(oldSource)) {
 103                         synchronized (this.source) {
 104                                 sourceChanged = true;
 105                                 this.source.notifyAll();
 106                         }
 107                         metadataUpdated(source.metadata());
 108                         logger.info(String.format("Next Source set: %s", source));
 109                 }
 110         }
 111
 112         //
 113         // EVENT METHODS
 114         //
 115
 116         /**
 117          * Notifies all registered listeners that the current source finished playing
 118          * and that a new source should be {@link #setSource(Source) set}.
 119          *
 120          * @see SourceFinishedListener
 121          */
 122         private void fireSourceFinished() {
 123                 for (SourceFinishedListener sourceFinishedListener : sourceFinishedListeners.getListeners(SourceFinishedListener.class)) {
 124                         sourceFinishedListener.sourceFinished(this);
 125                 }
 126         }
 127
 128         //
 129         // CONTROLLED METHODS
 130         //
 131
 132         @Override
 133         public List<Controller<?>> controllers() {
 134                 return Collections.emptyList();
 135         }
 136
 137         @Override
 138         public Metadata metadata() {
 139                 if (super.metadata() == null) {
 140                         /* no metadata yet, wait for it. */
 141                         waitForNewSource();
 142                         sourceChanged = false;
 143                 }
 144                 return super.metadata();
 145         }
 146
 147         //
 148         // SOURCE METHODS
 149         //
 150
 151         @Override
 152         public byte[] get(int bufferSize) throws EOFException, IOException {
 153                 while (true) {
 154                         try {
 155                                 return source.get().get(bufferSize);
 156                         } catch (EOFException eofe1) {
 157                                 waitForNewSource();
 158                         } finally {
 159                                 synchronized (source) {
 160                                         sourceChanged = false;
 161                                 }
 162                         }
 163                 }
 164         }
 165
 166         //
 167         // PRIVATE METHODS
 168         //
 169
 170         /** Waits for a new source to be {@link #setSource(Source) set}. */
 171         private void waitForNewSource() {
 172                 fireSourceFinished();
 173                 synchronized (source) {
 174                         while (!sourceChanged) {
 175                                 try {
 176                                         logger.info("Waiting for next Source...");
 177                                         source.wait();
 178                                         logger.info("Was notified.");
 179                                 } catch (InterruptedException ioe1) {
 180                                         /* ignore: we’ll end up here again if we were interrupted. */
 181                                 }
 182                         }
 183                 }
 184         }
 185
 186 }