Further generalized the Interaction/Delegate pattern by introducing the

Doable annotation.

TULIP/config/externalization.properties

 ABOUT_NODE=about
-ACTION_ATTRIBUTE=action
 ACTIVATE_WITH_HANDLE_NODE=activateWithHandle
 ALPHA_NODE=alpha
 ANIMATED_PROPERTIES_ELEMENT=animatedProperties
@@ -50,6 +49,7 @@ DESELECTED_ELEMENT=deselected
 DISPLAY_NAME_NODE=displayName
 DISPLAY_TIME_NODE=displayTime
 DISTANCE_NODE=distance
+DO_ATTRIBUTE=do
 DRAGGABLE_NODE=draggable
 DRAW_BORDER_NODE=drawBorder
 DRAW_PRIORITY_NODE=drawPriority
@@ -129,6 +129,7 @@ NAMESPACE_SEPARATOR=.
 NETWORK_ADAPTER_NODE=networkAdapter
 OBJECT_NODE=object
 OBJECTS_NODE=objects
+ON_ATTRIBUTE=on
 OPACITY_NODE=opacity
 ORIGIN_NODE=origin
 ORIGIN_OFFSET_NODE=originOffset

TULIP/config/signature.properties

 UNDEFINED=undefined
 
-ON_DROP=onDrop
-ON_TRANSLATE_BEGIN=onTranslateBegin
-ON_TRANSLATE_END=onTranslateEnd
-ON_ROTATE_BEGIN=onRotateBegin
-ON_ROTATE_END=onRotateEnd
-ON_LIFT=onLift
+ON_DROP=drop
+ON_TRANSLATE_BEGIN=translateBegin
+ON_TRANSLATE_END=translateEnd
+ON_ROTATE_BEGIN=rotateBegin
+ON_ROTATE_END=rotateEnd
+ON_LIFT=lift
 
-ON_TOUCHED=onTouched
-ON_DRAG_BEGIN=onDragBegin
-ON_DRAG_END=onDragEnd
-ON_RELEASED=onReleased
+ON_TOUCHED=touched
+ON_DRAG_BEGIN=dragBegin
+ON_DRAG_END=dragEnd
+ON_RELEASED=released
 
-ON_TETHER_ESTABLISHED=onTetherEstablished
-ON_TETHER_TORN_DOWN=onTetherTornDown
\ No newline at end of file
+ON_TETHER_ESTABLISHED=tetherEstablished
+ON_TETHER_TORN_DOWN=tetherTornDown
\ No newline at end of file

TULIP/src/lu/list/itis/dkd/tui/event/interaction/builder/BaseInteractionBuilder.java

@@ -70,7 +70,7 @@ public abstract class BaseInteractionBuilder<B extends BaseInteractionBuilder<B>
     // ---------------------------------------------------------------------------
 
     private void buildFromBootstrap(@Nullable Element rootElement, BootstrapContext context, BootstrapCallback callback) throws BuildException {
-        action = BootstrappingUtils.getAttributeAsString(rootElement, Externalization.ACTION_ATTRIBUTE, BootstrappingUtils.OPTIONAL, Signature.UNDEFINED);;
+        action = BootstrappingUtils.getAttributeAsString(rootElement, Externalization.ON_ATTRIBUTE, BootstrappingUtils.OPTIONAL, Signature.UNDEFINED);;
     }
 
     // ---------------------------------------------------------------------------

TULIP/src/lu/list/itis/dkd/tui/event/interaction/delegate/AudioDelegate.java

@@ -24,7 +24,9 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 import java.io.IOException;
+import java.lang.reflect.Method;
 import java.net.URL;
+import java.util.Map;
 
 import javax.media.Controller;
 import javax.media.Format;
@@ -49,6 +51,7 @@ import javax.media.format.AudioFormat;
 public class AudioDelegate extends MediaDelegate implements Playable {
 
     private Player player;
+    private Map<String, Method> doableMethods;
 
     // ***************************************************************************
     // * Constants *
@@ -90,6 +93,9 @@ public class AudioDelegate extends MediaDelegate implements Playable {
     // ---------------------------------------------------------------------------
 
     private void setupFromProperties() {
+
+        doableMethods = Delegate.getDoableMethods(AudioDelegate.class);
+
         StringBuilder urlBuilder = new StringBuilder(this.baseUrl.toString());
         urlBuilder.append(this.media);
         try {
@@ -107,25 +113,34 @@ public class AudioDelegate extends MediaDelegate implements Playable {
     // ***************************************************************************
     // * Class Body *
     // ***************************************************************************
+    // ---------------------------------------------------------------------------
 
     @Override
     public boolean handle(Interaction action) {
 
-        Runnable play = () -> {
-            play();
-        };
+        if (doableMethods.containsKey(this.doable)) {
+
+            Runnable doIt = () -> {
+                Delegate.invokeDoableMethod(doableMethods.get(this.doable), this, null);
+            };
 
-        Thread playThread = new Thread(play);
-        playThread.start();
+            Thread playThread = new Thread(doIt);
+            playThread.start();
 
-        return true;
+            return true;
+        }
+        LOGGER.warn("Don't know how to do {}!", this.doable); //$NON-NLS-1$
+
+        return false;
     }
 
     // ---------------------------------------------------------------------------
     /** {@inheritDoc} */
     // ---------------------------------------------------------------------------
 
+    @Doable(identifier = "play")
     @Override
+
     public void play() {
         if (this.player != null) {
             this.player.setMediaTime(BEGIN);
@@ -137,7 +152,9 @@ public class AudioDelegate extends MediaDelegate implements Playable {
     /** {@inheritDoc} */
     // ---------------------------------------------------------------------------
 
+    @Doable(identifier = "pause")
     @Override
+
     public void pause() {
         if ((this.player != null) && (player.getState() == Controller.Started)) {
             this.player.stop();
@@ -148,7 +165,9 @@ public class AudioDelegate extends MediaDelegate implements Playable {
     /** {@inheritDoc} */
     // ---------------------------------------------------------------------------
 
+    @Doable(identifier = "stop")
     @Override
+
     public void stop() {
         if ((this.player != null) && (player.getState() == Controller.Started)) {
             this.player.stop();
@@ -156,4 +175,10 @@ public class AudioDelegate extends MediaDelegate implements Playable {
         }
     }
 
+    // ---------------------------------------------------------------------------
+    // ***************************************************************************
+    // * End of Class *
+    // ***************************************************************************
+    // ---------------------------------------------------------------------------
+
 }
\ No newline at end of file

TULIP/src/lu/list/itis/dkd/tui/event/interaction/delegate/Delegate.java

@@ -19,6 +19,14 @@ package lu.list.itis.dkd.tui.event.interaction.delegate;
 import lu.list.itis.dkd.tui.event.interaction.Handler;
 import lu.list.itis.dkd.tui.event.interaction.delegate.builder.BaseDelegateBuilder;
 
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
+import java.util.HashMap;
+import java.util.Map;
+
 /**
  * @author Nico Mack [nico.mack@list.lu]
  * @since 2.5
@@ -31,6 +39,13 @@ import lu.list.itis.dkd.tui.event.interaction.delegate.builder.BaseDelegateBuild
 public abstract class Delegate implements Handler<Delegate> {
 
     protected String name;
+    protected String doable;
+
+    // ***************************************************************************
+    // * Constants *
+    // ***************************************************************************
+
+    private static final Logger LOGGER = LoggerFactory.getLogger(Delegate.class.getSimpleName());
 
     // ---------------------------------------------------------------------------
     // ***************************************************************************
@@ -44,6 +59,7 @@ public abstract class Delegate implements Handler<Delegate> {
 
     public Delegate(BaseDelegateBuilder<?> builder) {
         this.name = builder.name;
+        this.doable = builder.doable;
     }
 
     // ---------------------------------------------------------------------------
@@ -54,6 +70,42 @@ public abstract class Delegate implements Handler<Delegate> {
 
     public Delegate(Delegate original) {
         this.name = original.name;
+        this.doable = original.doable;
+    }
+
+    // ---------------------------------------------------------------------------
+    // ***************************************************************************
+    // * Primitive(s) *
+    // ***************************************************************************
+    // ---------------------------------------------------------------------------
+
+    protected static Map<String, Method> getDoableMethods(Class<?> clazz) {
+        Map<String, Method> doables = new HashMap<>();
+
+        try {
+            for (Method method : clazz.getDeclaredMethods()) {
+                Doable doable = method.getAnnotation(Doable.class);
+                if (doable != null) {
+                    String identifier = doable.identifier();
+                    doables.put(identifier, method);
+                }
+            }
+        } catch (Exception e) {
+            LOGGER.error("Failed to lookup doable methods for class {}!", clazz.getSimpleName()); //$NON-NLS-1$
+        }
+        return doables;
+    }
+
+    // ---------------------------------------------------------------------------
+
+    protected static Object invokeDoableMethod(Method method, Delegate delegate, Object[] parameters) {
+        Object result = null;
+        try {
+            result = method.invoke(delegate, parameters);
+        } catch (IllegalAccessException | IllegalArgumentException | InvocationTargetException e) {
+            LOGGER.error("Failed to invoke method {} on Delegate {}!", method.getName(), delegate.getClass(), e); //$NON-NLS-1$
+        }
+        return result;
     }
 
     // ---------------------------------------------------------------------------
@@ -69,6 +121,9 @@ public abstract class Delegate implements Handler<Delegate> {
             throw new NullPointerException();
         String clazzName = this.getClass().getName();
         int comparison = clazzName.compareTo(delegate.getClass().getName());
+        if (comparison == 0) {
+            comparison = this.doable.compareTo(delegate.doable);
+        }
         if (comparison == 0) {
             comparison = this.name.compareTo(delegate.name);
         }

TULIP/src/lu/list/itis/dkd/tui/event/interaction/delegate/Doable.java

+/**
+ * Copyright Luxembourg Institute of Science and Technology, 2018. All rights reserved.
+ * 
+ * This file is part of TULIP.
+ * 
+ * TULIP is free software: you can redistribute it and/or modify it under the terms of the GNU
+ * Lesser General Public License as published by the Free Software Foundation, version 3 of the
+ * License.
+ * 
+ * TULIP is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even
+ * the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser
+ * General Public License for more details.
+ * 
+ * You should have received a copy of the GNU Lesser General Public License along with TULIP. If
+ * not, see <http://www.gnu.org/licenses/lgpl-3.0.html>.
+ */
+package lu.list.itis.dkd.tui.event.interaction.delegate;
+
+import static java.lang.annotation.ElementType.METHOD;
+import static java.lang.annotation.RetentionPolicy.RUNTIME;
+
+import java.lang.annotation.Retention;
+import java.lang.annotation.Target;
+
+@Retention(RUNTIME)
+@Target(METHOD)
+/**
+ * @author mack
+ * @since [major].[minor]
+ * @version [major].[minor].[micro]
+ */
+public @interface Doable {
+    String identifier() default "";
+}

TULIP/src/lu/list/itis/dkd/tui/event/interaction/delegate/builder/BaseDelegateBuilder.java

@@ -26,6 +26,7 @@ import org.jdom2.Element;
 public abstract class BaseDelegateBuilder<B extends BaseDelegateBuilder<B>> {
     /** The name that will be given to the delegate. */
     public String name;
+    public String doable;
 
     // ---------------------------------------------------------------------------
     // ***************************************************************************
@@ -36,6 +37,7 @@ public abstract class BaseDelegateBuilder<B extends BaseDelegateBuilder<B>> {
     /** Constructor initialising the fields. */
     public BaseDelegateBuilder() {
         name = Externalization.EMPTY_STRING;
+        doable = Externalization.EMPTY_STRING;
     }
 
     // ---------------------------------------------------------------------------
@@ -69,6 +71,7 @@ public abstract class BaseDelegateBuilder<B extends BaseDelegateBuilder<B>> {
     // ---------------------------------------------------------------------------
 
     private void buildFromBootstrap(@Nullable Element rootElement, BootstrapContext context, BootstrapCallback callback) throws BuildException {
+        doable = BootstrappingUtils.getAttributeAsString(rootElement, Externalization.DO_ATTRIBUTE, BootstrappingUtils.MANDATORY, null);
         name = BootstrappingUtils.getContentAsString(rootElement, Externalization.NAME_NODE, BootstrappingUtils.OPTIONAL, Externalization.EMPTY_STRING, context);
     }
 

TULIP/src/lu/list/itis/dkd/tui/utility/Externalization.java

@@ -34,7 +34,6 @@ public class Externalization extends NLS {
     private static final String BUNDLE_NAME = "externalization"; //$NON-NLS-1$
 
     public static String ABOUT_NODE;
-    public static String ACTION_ATTRIBUTE;
     public static String ACTIVATE_WITH_HANDLE_NODE;
     public static String ALPHA_NODE;
     public static String ANIMATED_PROPERTIES_ELEMENT;
@@ -85,6 +84,7 @@ public class Externalization extends NLS {
     public static String DISPLAY_NAME_NODE;
     public static String DISPLAY_TIME_NODE;
     public static String DISTANCE_NODE;
+    public static String DO_ATTRIBUTE;
     public static String DRAGGABLE_NODE;
     public static String DRAW_BORDER_NODE;
     public static String DRAW_PRIORITY_NODE;
@@ -165,6 +165,7 @@ public class Externalization extends NLS {
     public static String OBJECT_NODE;
     public static String OBJECTS_NODE;
     public static String OPACITY_NODE;
+    public static String ON_ATTRIBUTE;
     public static String ORIGIN_NODE;
     public static String ORIGIN_OFFSET_NODE;
     public static String OUTER_RADIUS_NODE;