1 files changed, 164 insertions, 0 deletions
diff --git a/common/plugins/org.eclipse.jpt.common.utility/src/org/eclipse/jpt/common/utility/internal/model/value/ListValueModelWrapper.java b/common/plugins/org.eclipse.jpt.common.utility/src/org/eclipse/jpt/common/utility/internal/model/value/ListValueModelWrapper.java
new file mode 100644
index 0000000000..7e01a399f3
--- /dev/null
+++ b/common/plugins/org.eclipse.jpt.common.utility/src/org/eclipse/jpt/common/utility/internal/model/value/ListValueModelWrapper.java
@@ -0,0 +1,164 @@
+/*******************************************************************************
+ * Copyright (c) 2007, 2009 Oracle. All rights reserved.
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v1.0, which accompanies this distribution
+ * and is available at http://www.eclipse.org/legal/epl-v10.html.
+ * 
+ * Contributors:
+ *     Oracle - initial API and implementation
+ ******************************************************************************/
+package org.eclipse.jpt.common.utility.internal.model.value;
+
+import org.eclipse.jpt.common.utility.model.event.ListAddEvent;
+import org.eclipse.jpt.common.utility.model.event.ListChangeEvent;
+import org.eclipse.jpt.common.utility.model.event.ListClearEvent;
+import org.eclipse.jpt.common.utility.model.event.ListMoveEvent;
+import org.eclipse.jpt.common.utility.model.event.ListRemoveEvent;
+import org.eclipse.jpt.common.utility.model.event.ListReplaceEvent;
+import org.eclipse.jpt.common.utility.model.listener.ListChangeListener;
+import org.eclipse.jpt.common.utility.model.value.ListValueModel;
+
+/**
+ * This abstract class provides the infrastructure needed to wrap
+ * another list value model, "lazily" listen to it, and propagate
+ * its change notifications. Subclasses must implement the appropriate
+ * {@link ListValueModel}.
+ */
+public abstract class ListValueModelWrapper<E>
+	extends AbstractListValueModel
+{
+	/** The wrapped list value model. */
+	protected final ListValueModel<? extends E> listHolder;
+
+	/** A listener that allows us to synch with changes to the wrapped list holder. */
+	protected final ListChangeListener listChangeListener;
+
+
+	// ********** constructors **********
+
+	/**
+	 * Construct a list value model with the specified wrapped
+	 * list value model.
+	 */
+	protected ListValueModelWrapper(ListValueModel<? extends E> listHolder) {
+		super();
+		if (listHolder == null) {
+			throw new NullPointerException();
+		}
+		this.listHolder = listHolder;
+		this.listChangeListener = this.buildListChangeListener();
+	}
+
+
+	// ********** initialization **********
+
+	protected ListChangeListener buildListChangeListener() {
+		return new ListChangeListener() {
+			public void itemsAdded(ListAddEvent event) {
+				ListValueModelWrapper.this.itemsAdded(event);
+			}
+			public void itemsRemoved(ListRemoveEvent event) {
+				ListValueModelWrapper.this.itemsRemoved(event);
+			}
+			public void itemsReplaced(ListReplaceEvent event) {
+				ListValueModelWrapper.this.itemsReplaced(event);
+			}
+			public void itemsMoved(ListMoveEvent event) {
+				ListValueModelWrapper.this.itemsMoved(event);
+			}
+			public void listCleared(ListClearEvent event) {
+				ListValueModelWrapper.this.listCleared(event);
+			}
+			public void listChanged(ListChangeEvent event) {
+				ListValueModelWrapper.this.listChanged(event);
+			}
+			@Override
+			public String toString() {
+				return "list change listener"; //$NON-NLS-1$
+			}
+		};
+	}
+
+
+	// ********** behavior **********
+
+	/**
+	 * Start listening to the list holder.
+	 */
+	@Override
+	protected void engageModel() {
+		this.listHolder.addListChangeListener(ListValueModel.LIST_VALUES, this.listChangeListener);
+	}
+
+	/**
+	 * Stop listening to the list holder.
+	 */
+	@Override
+	protected void disengageModel() {
+		this.listHolder.removeListChangeListener(ListValueModel.LIST_VALUES, this.listChangeListener);
+	}
+
+	// minimized scope of suppressed warnings
+	@SuppressWarnings("unchecked")
+	protected Iterable<E> getItems(ListAddEvent event) {
+		return (Iterable<E>) event.getItems();
+	}
+
+	// minimized scope of suppressed warnings
+	@SuppressWarnings("unchecked")
+	protected Iterable<E> getItems(ListRemoveEvent event) {
+		return (Iterable<E>) event.getItems();
+	}
+
+	// minimized scope of suppressed warnings
+	@SuppressWarnings("unchecked")
+	protected Iterable<E> getNewItems(ListReplaceEvent event) {
+		return (Iterable<E>) event.getNewItems();
+	}
+
+	// minimized scope of suppressed warnings
+	@SuppressWarnings("unchecked")
+	protected Iterable<E> getOldItems(ListReplaceEvent event) {
+		return (Iterable<E>) event.getOldItems();
+	}
+
+
+	// ********** list change support **********
+
+	/**
+	 * Items were added to the wrapped list holder;
+	 * propagate the change notification appropriately.
+	 */
+	protected abstract void itemsAdded(ListAddEvent event);
+
+	/**
+	 * Items were removed from the wrapped list holder;
+	 * propagate the change notification appropriately.
+	 */
+	protected abstract void itemsRemoved(ListRemoveEvent event);
+
+	/**
+	 * Items were replaced in the wrapped list holder;
+	 * propagate the change notification appropriately.
+	 */
+	protected abstract void itemsReplaced(ListReplaceEvent event);
+
+	/**
+	 * Items were moved in the wrapped list holder;
+	 * propagate the change notification appropriately.
+	 */
+	protected abstract void itemsMoved(ListMoveEvent event);
+
+	/**
+	 * The wrapped list holder was cleared;
+	 * propagate the change notification appropriately.
+	 */
+	protected abstract void listCleared(ListClearEvent event);
+
+	/**
+	 * The value of the wrapped list holder has changed;
+	 * propagate the change notification appropriately.
+	 */
+	protected abstract void listChanged(ListChangeEvent event);
+
+}