Access controls in a more error-resilient way.

diff --git a/src/main/java/net/pterodactylus/sonitus/data/sink/AudioSink.java b/src/main/java/net/pterodactylus/sonitus/data/sink/AudioSink.java
index b0f0067..bbf24d1 100644 (file)
--- a/src/main/java/net/pterodactylus/sonitus/data/sink/AudioSink.java
+++ b/src/main/java/net/pterodactylus/sonitus/data/sink/AudioSink.java
@@ -17,6 +17,7 @@
 
 package net.pterodactylus.sonitus.data.sink;
 
+import static javax.sound.sampled.BooleanControl.Type.MUTE;
 import static javax.sound.sampled.FloatControl.Type.VOLUME;
 
 import java.io.IOException;
@@ -26,6 +27,9 @@ import java.util.List;
 import java.util.logging.Logger;
 import javax.sound.sampled.AudioFormat;
 import javax.sound.sampled.AudioSystem;
+import javax.sound.sampled.BooleanControl;
+import javax.sound.sampled.Control;
+import javax.sound.sampled.DataLine;
 import javax.sound.sampled.FloatControl;
 import javax.sound.sampled.LineUnavailableException;
 import javax.sound.sampled.SourceDataLine;
@@ -100,28 +104,45 @@ public class AudioSink implements Sink {
 
                        @Override
                        protected void valueSet(Double value) {
-                               if (sourceDataLine != null) {
-                                       FloatControl volumeControl = (FloatControl) sourceDataLine.getControl(VOLUME);
-                                       volumeControl.setValue((float) (value * volumeControl.getMaximum()));
+                               /* search for preferred volume control. */
+                               FloatControl volumeControl = getVolumeControl(sourceDataLine);
+                               if (volumeControl == null) {
+                                       /* could not find volume control! */
+                                       return;
                                }
+
+                               volumeControl.setValue((float) (value * volumeControl.getMaximum()));
                        }
                };
                muteSwitch = new Switch("Mute") {
 
+                       /** The previous value in case we have to emulate the mute control. */
                        private float previousValue;
 
                        @Override
                        protected void valueSet(Boolean value) {
-                               if (sourceDataLine != null) {
-                                       FloatControl volumeControl = (FloatControl) sourceDataLine.getControl(VOLUME);
-                                       if (value) {
-                                               previousValue = volumeControl.getValue();
-                                               volumeControl.setValue(0);
-                                       } else {
-                                               volumeControl.setValue(previousValue);
-                                       }
+                               /* search for mute control. */
+                               BooleanControl muteControl = getMuteControl(sourceDataLine);
+                               if (muteControl != null) {
+                                       muteControl.setValue(value);
+                                       return;
+                               }
+
+                               /* could not find mute control, use volume control! */
+                               FloatControl volumeControl = getVolumeControl(sourceDataLine);
+                               if (volumeControl == null) {
+                                       /* no volume control, either? */
+                                       return;
+                               }
+
+                               if (value) {
+                                       previousValue = volumeControl.getValue();
+                                       volumeControl.setValue(0);
+                               } else {
+                                       volumeControl.setValue(previousValue);
                                }
                        }
+
                };
        }
 
@@ -182,4 +203,57 @@ public class AudioSink implements Sink {
                logger.finest(String.format("AudioSink: Wrote %d Bytes.", buffer.length));
        }
 
+       //
+       // PRIVATE METHODS
+       //
+
+       /**
+        * Returns the {@link FloatControl.Type.VOLUME} control.
+        *
+        * @param dataLine
+        *              The data line to search for the control
+        * @return The control, or {@code null} if no volume control could be found
+        */
+       private static FloatControl getVolumeControl(DataLine dataLine) {
+               return getControl(dataLine, VOLUME, FloatControl.class);
+       }
+
+       /**
+        * Returns the {@link BooleanControl.Type.MUTE} control.
+        *
+        * @param dataLine
+        *              The data line to search for the control
+        * @return The control, or {@code null} if no mute control could be found
+        */
+       private static BooleanControl getMuteControl(DataLine dataLine) {
+               return getControl(dataLine, MUTE, BooleanControl.class);
+       }
+
+       /**
+        * Searches the given data line for a control of the given type and returns it.
+        * If the given data line is {@code null}, {@code null} is returned.
+        *
+        * @param dataLine
+        *              The data line to search for a control
+        * @param controlType
+        *              The type of the control to search
+        * @param controlClass
+        *              The class of the control
+        * @param <T>
+        *              The class of the control
+        * @return The control, or {@code null} if no control could be found
+        */
+       private static <T> T getControl(DataLine dataLine, Control.Type controlType, Class<T> controlClass) {
+               if (dataLine == null) {
+                       return null;
+               }
+               Control[] controls = dataLine.getControls();
+               for (Control control : controls) {
+                       if (control.getType().equals(controlType)) {
+                               return (T) control;
+                       }
+               }
+               return null;
+       }
+
 }