Rework SplitButton to not use SWT's internal TypedListener

widgets/splitbutton/org.eclipse.nebula.widgets.splitbutton/src/org/eclipse/nebula/widgets/splitbutton/SplitButton.java

@@ -15,9 +15,9 @@
  *******************************************************************************/
 package org.eclipse.nebula.widgets.splitbutton;
 
-import java.util.Iterator;
 import java.util.LinkedList;
 import java.util.List;
+import java.util.function.Supplier;
 
 import org.eclipse.swt.SWT;
 import org.eclipse.swt.SWTException;
@@ -33,7 +33,6 @@
 import org.eclipse.swt.widgets.Event;
 import org.eclipse.swt.widgets.Listener;
 import org.eclipse.swt.widgets.Menu;
-import org.eclipse.swt.widgets.TypedListener;
 import org.eclipse.swt.widgets.Widget;
 
 /**
@@ -57,7 +56,8 @@ public class SplitButton extends Button {
 
 	private static final int EXTRA_WIDTH = 60;
 
-	private final List<Listener> listeners = new LinkedList<>();
+	private final List<Listener> selectionListeners = new LinkedList<>();
+	private final List<SelectionListener> typedSelectionListeners = new LinkedList<>();
 
 	private int splitButtonAreaLeft = -1;
 	private int splitButtonAreaTop = -1;
@@ -179,30 +179,26 @@ private void drawTriangle() {
 	}
 
 	private void addMouseDownListener() {
-		super.addListener(SWT.MouseDown, new Listener() {
-
-			@Override
-			public void handleEvent(final Event event) {
-				if (shouldShowMenu(event.x, event.y)) {
-					final Button button = (Button) event.widget;
-					final Rectangle rect = button.getBounds();
-					final Point p = button.toDisplay(rect.x, rect.y + rect.height);
-					getMenu().setLocation(p.x - rect.x, p.y - rect.y);
-					getMenu().setVisible(true);
-
-				} else {
-					for (final Listener listener : listeners) {
-						final Event evt = new Event();
-						evt.widget = SplitButton.this;
-						evt.display = getDisplay();
-						evt.type = SWT.Selection;
-						listener.handleEvent(evt);
-					}
+		super.addListener(SWT.MouseDown, event -> {
+			boolean shouldShowMenu = event.x >= splitButtonAreaLeft && event.y >= splitButtonAreaTop
+					&& event.x <= splitButtonAreaRight && event.y <= splitButtonAreaBottom;
+			if (shouldShowMenu) {
+				final Button button = (Button) event.widget;
+				final Rectangle rect = button.getBounds();
+				final Point p = button.toDisplay(rect.x, rect.y + rect.height);
+				getMenu().setLocation(p.x - rect.x, p.y - rect.y);
+				getMenu().setVisible(true);
+			} else {
+				Event evt = new Event();
+				evt.widget = SplitButton.this;
+				evt.display = getDisplay();
+				evt.type = SWT.Selection;
+				for (Listener listener : selectionListeners) {
+					listener.handleEvent(evt);
+				}
+				for (SelectionListener listener : typedSelectionListeners) {
+					listener.widgetSelected(new SelectionEvent(evt));
 				}
-			}
-
-			private boolean shouldShowMenu(final int x, final int y) {
-				return x >= splitButtonAreaLeft && y >= splitButtonAreaTop && x <= splitButtonAreaRight && y <= splitButtonAreaBottom;
 			}
 		});
 	}
@@ -240,8 +236,7 @@ public void addSelectionListener(SelectionListener listener) {
 		if (listener == null) {
 			SWT.error(SWT.ERROR_NULL_ARGUMENT);
 		}
-		final TypedListener typedListener = new TypedListener(listener);
-		listeners.add(typedListener);
+		typedSelectionListeners.add(listener);
 	}
 
 	/**
@@ -271,17 +266,7 @@ public void removeSelectionListener(SelectionListener listener) {
 		if (listener == null) {
 			SWT.error(SWT.ERROR_NULL_ARGUMENT);
 		}
-
-		final Iterator<Listener> it = listeners.iterator();
-		while (it.hasNext()) {
-			final Listener current = it.next();
-			if (current instanceof TypedListener) {
-				final TypedListener tl = (TypedListener) current;
-				if (tl.getEventListener() != null && tl.getEventListener().equals(listener)) {
-					it.remove();
-				}
-			}
-		}
+		typedSelectionListeners.removeIf(listener::equals);
 	}
 
 	/**
@@ -317,7 +302,7 @@ public void addListener(int eventType, Listener listener) {
 			SWT.error(SWT.ERROR_NULL_ARGUMENT);
 		}
 		if (eventType == SWT.Selection) {
-			listeners.add(listener);
+			selectionListeners.add(listener);
 			return;
 		}
 		super.addListener(eventType, listener);
@@ -354,7 +339,7 @@ public void removeListener(int eventType, Listener listener) {
 			SWT.error(SWT.ERROR_NULL_ARGUMENT);
 		}
 		if (eventType == SWT.Selection) {
-			listeners.add(listener);
+			selectionListeners.remove(listener);
 			return;
 		}
 		super.removeListener(eventType, listener);