Logger: extend Listenable interface

Author: maarzt

src/main/java/org/scijava/log/AbstractLogService.java

@@ -72,10 +72,6 @@ public AbstractLogService(final Properties properties) {
 			LogService.LOG_LEVEL_PROPERTY + ":");
 	}
 
-	// -- AbstractLogService methods --
-
-	abstract void notifyListeners(LogMessage message);
-
 	// -- Logger methods --
 
 	@Override
@@ -100,6 +96,8 @@ public void alwaysLog(final int level, final Object msg, final Throwable t) {
 		rootLogger.alwaysLog(level, msg, t);
 	}
 
+	// -- Listenable methods --
+
 	@Override
 	public void addListener(final LogListener listener) {
 		rootLogger.addListener(listener);
@@ -110,6 +108,11 @@ public void removeListener(final LogListener listener) {
 		rootLogger.removeListener(listener);
 	}
 
+	@Override
+	public void notifyListeners(final LogMessage event) {
+		rootLogger.notifyListeners(event);
+	}
+
 	// -- Deprecated --
 
 	/** @deprecated Use {@link LogLevel#prefix(int)} instead. */

src/main/java/org/scijava/log/DefaultLogger.java

@@ -38,6 +38,7 @@
  * Default implementation of {@link Logger}.
  *
  * @author Matthias Arzt
+ * @author Curtis Rueden
  */
 @IgnoreAsCallingClass
 public class DefaultLogger implements Logger {
@@ -54,8 +55,7 @@ public DefaultLogger(final int level)
 	// -- DefaultLogger methods --
 
 	protected void messageLogged(final LogMessage message) {
-		for (LogListener listener : listeners)
-			listener.messageLogged(message);
+		notifyListeners(message);
 	}
 
 	// -- Logger methods --
@@ -70,6 +70,8 @@ public void alwaysLog(final int level, final Object msg, final Throwable t) {
 		messageLogged(new LogMessage(level, msg, t));
 	}
 
+	// -- Listenable methods --
+
 	@Override
 	public void addListener(final LogListener listener) {
 		listeners.add(listener);
@@ -79,4 +81,10 @@ public void addListener(final LogListener listener) {
 	public void removeListener(final LogListener listener) {
 		listeners.remove(listener);
 	}
+
+	@Override
+	public void notifyListeners(final LogMessage message) {
+		for (LogListener listener : listeners)
+			listener.messageLogged(message);
+	}
 }

src/main/java/org/scijava/log/LogListener.java

@@ -35,6 +35,7 @@
  * Callback function used by {@link Logger}.
  *
  * @author Matthias Arzt
+ * @see Logger
  * @see LogMessage
  */
 public interface LogListener {

src/main/java/org/scijava/log/Logger.java

@@ -37,6 +37,8 @@
 import static org.scijava.log.LogLevel.TRACE;
 import static org.scijava.log.LogLevel.WARN;
 
+import org.scijava.Listenable;
+
 /**
  * Interface for objects which can produce log messages.
  * <p>
@@ -49,7 +51,7 @@
  * @see LogService
  */
 @IgnoreAsCallingClass
-public interface Logger {
+public interface Logger extends Listenable<LogListener, LogMessage> {
 
 	default void debug(final Object msg) {
 		log(DEBUG, msg);
@@ -184,15 +186,4 @@ default void log(final int level, final Object msg, final Throwable t) {
 
 	/** Returns the log level of this logger. see {@link LogLevel} */
 	int getLevel();
-
-	/**
-	 * {@link LogListener}s added with this method are notified of every message,
-	 * NB: Messages are only logged, if their level is lower than the logger's
-	 * level.
-	 *
-	 * @param listener
-	 */
-	void addListener(LogListener listener);
-
-	void removeListener(LogListener listener);
 }

src/test/java/org/scijava/log/LogServiceTest.java

@@ -219,7 +219,7 @@ public Throwable exception() {
 		}
 
 		@Override
-		void notifyListeners(LogMessage message) {
+		public void notifyListeners(LogMessage message) {
 			this.message = message.toString();
 			this.exception = message.throwable();
 		}