Add Audio Playback Capability

* Add envoy.client.data.audio package
* Move AudioRecorder to the audio package
* Add AudioPlayer class
* Add AudioControl class that acts as a small media player
* Display the audio control in message controls that contain voice
  messages

src/main/java/envoy/client/data/audio/AudioPlayer.java

@@ -0,0 +1,64 @@
+package envoy.client.data.audio;
+
+import javax.sound.sampled.*;
+
+import envoy.exception.EnvoyException;
+
+/**
+ * Plays back audio from a byte array.
+ * <p>
+ * Project: <strong>envoy-client</strong><br>
+ * File: <strong>AudioPlayer.java</strong><br>
+ * Created: <strong>05.07.2020</strong><br>
+ * 
+ * @author Kai S. K. Engelbart
+ * @since Envoy Client v0.1-beta
+ */
+public final class AudioPlayer {
+
+	private final AudioFormat format;
+	private final DataLine.Info	info;
+
+	private Clip clip;
+
+	/**
+	 * Initializes the player with the default audio format.
+	 * 
+	 * @since Envoy Client v0.1-beta
+	 */
+	public AudioPlayer() { this(AudioRecorder.DEFAULT_AUDIO_FORMAT); }
+
+	/**
+	 * Initializes the player with a given audio format.
+	 * 
+	 * @param format the audio format to use
+	 * @since Envoy Client v0.1-beta
+	 */
+	public AudioPlayer(AudioFormat format) {
+		this.format	= format;
+		info		= new DataLine.Info(Clip.class, format);
+	}
+
+	/**
+	 * @return {@code true} if audio play back is supported
+	 * @since Envoy Client v0.1-beta
+	 */
+	public boolean isSupported() { return AudioSystem.isLineSupported(info); }
+
+	/**
+	 * Plays back an audio clip.
+	 * 
+	 * @param data the data of the clip
+	 * @throws EnvoyException if the play back failed
+	 * @since Envoy Client v0.1-beta
+	 */
+	public void play(byte[] data) throws EnvoyException {
+		try {
+			clip = (Clip) AudioSystem.getLine(info);
+			clip.open(format, data, 0, data.length);
+			clip.start();
+		} catch (LineUnavailableException e) {
+			throw new EnvoyException("Cannot play back audio", e);
+		}
+	}
+}

src/main/java/envoy/client/data/audio/AudioRecorder.java

@@ -1,4 +1,4 @@
-package envoy.client.data;
+package envoy.client.data.audio;
 
 import java.io.IOException;
 import java.nio.file.Files;
@@ -20,21 +20,49 @@ import envoy.exception.EnvoyException;
  */
 public final class AudioRecorder {
 
-	private final AudioFormat format;
+	/**
+	 * The default audio format used for recording and play back.
+	 * 
+	 * @since Envoy Client v0.1-beta
+	 */
+	public static final AudioFormat DEFAULT_AUDIO_FORMAT = new AudioFormat(16000, 16, 1, true, false);
+
+	private final AudioFormat	format;
+	private final DataLine.Info	info;
 
-	private DataLine.Info	info;
 	private TargetDataLine	line;
 	private Path			tempFile;
 
-	public AudioRecorder() { this(new AudioFormat(16000, 16, 1, true, false)); }
+	/**
+	 * Initializes the recorder with the default audio format.
+	 * 
+	 * @since Envoy Client v0.1-beta
+	 */
+	public AudioRecorder() { this(DEFAULT_AUDIO_FORMAT); }
 
+	/**
+	 * Initializes the recorder with a given audio format.
+	 * 
+	 * @param format the audio format to use
+	 * @since Envoy Client v0.1-beta
+	 */
 	public AudioRecorder(AudioFormat format) {
 		this.format	= format;
 		info		= new DataLine.Info(TargetDataLine.class, format);
 	}
 
+	/**
+	 * @return {@code true} if audio recording is supported
+	 * @since Envoy Client v0.1-beta
+	 */
 	public boolean isSupported() { return AudioSystem.isLineSupported(info); }
 
+	/**
+	 * Starts the audio recording.
+	 * 
+	 * @throws EnvoyException if starting the recording failed
+	 * @since Envoy Client v0.1-beta
+	 */
 	public void start() throws EnvoyException {
 		try {
 
@@ -54,6 +82,13 @@ public final class AudioRecorder {
 		}
 	}
 
+	/**
+	 * Stops the recording.
+	 * 
+	 * @return the finished recording
+	 * @throws EnvoyException if finishing the recording failed
+	 * @since Envoy Client v0.1-beta
+	 */
 	public byte[] finish() throws EnvoyException {
 		try {
 			line.stop();

src/main/java/envoy/client/data/audio/package-info.java

@@ -0,0 +1,11 @@
+/**
+ * Contains classes related to recording and playing back audio clips.
+ * <p>
+ * Project: <strong>envoy-client</strong><br>
+ * File: <strong>package-info.java</strong><br>
+ * Created: <strong>05.07.2020</strong><br>
+ * 
+ * @author Kai S. K. Engelbart
+ * @since Envoy Client v0.1-beta
+ */
+package envoy.client.data.audio;

src/main/java/envoy/client/ui/AudioControl.java

@@ -0,0 +1,40 @@
+package envoy.client.ui;
+
+import javafx.scene.control.Button;
+import javafx.scene.layout.HBox;
+
+import envoy.client.data.audio.AudioPlayer;
+import envoy.exception.EnvoyException;
+
+/**
+ * Enables the play back of audio clips through a button.
+ * <p>
+ * Project: <strong>envoy-client</strong><br>
+ * File: <strong>AudioControl.java</strong><br>
+ * Created: <strong>05.07.2020</strong><br>
+ * 
+ * @author Kai S. K. Engelbart
+ * @since Envoy Client v0.1-beta
+ */
+public final class AudioControl extends HBox {
+
+	private AudioPlayer player = new AudioPlayer();
+
+	/**
+	 * Initializes the audio control.
+	 * 
+	 * @param audioData the audio data to play.
+	 * @since Envoy Client v0.1-beta
+	 */
+	public AudioControl(byte[] audioData) {
+		var button = new Button("Play");
+		button.setOnAction(e -> {
+			try {
+				player.play(audioData);
+			} catch (EnvoyException ex) {
+
+			}
+		});
+		getChildren().add(button);
+	}
+}

src/main/java/envoy/client/ui/controller/ChatScene.java

@@ -18,6 +18,7 @@ import javafx.scene.input.KeyEvent;
 import javafx.scene.paint.Color;
 
 import envoy.client.data.*;
+import envoy.client.data.audio.AudioRecorder;
 import envoy.client.event.MessageCreationEvent;
 import envoy.client.net.Client;
 import envoy.client.net.WriteProxy;

src/main/java/envoy/client/ui/listcell/MessageControl.java

@@ -9,7 +9,9 @@ import javafx.scene.image.Image;
 import javafx.scene.image.ImageView;
 import javafx.scene.layout.VBox;
 
+import envoy.client.ui.AudioControl;
 import envoy.client.ui.IconUtil;
+import envoy.data.Attachment.AttachmentType;
 import envoy.data.Message;
 import envoy.data.Message.MessageStatus;
 import envoy.data.User;
@@ -38,6 +40,11 @@ public class MessageControl extends VBox {
 	public MessageControl(Message message) {
 		// Creating the underlying VBox, the dateLabel and the textLabel
 		super(new Label(dateFormat.format(message.getCreationDate())));
+
+		// Voice attachment
+		if (message.hasAttachment() && message.getAttachment().getType() == AttachmentType.VOICE)
+			getChildren().add(new AudioControl(message.getAttachment().getData()));
+
 		final var textLabel = new Label(message.getText());
 		textLabel.setWrapText(true);
 		getChildren().add(textLabel);