diff options
Diffstat (limited to 'jpa/plugins/org.eclipse.jpt.utility/src/org/eclipse/jpt/utility/internal/model/value/PropertyCollectionValueModelAdapter.java')
| -rw-r--r-- | jpa/plugins/org.eclipse.jpt.utility/src/org/eclipse/jpt/utility/internal/model/value/PropertyCollectionValueModelAdapter.java | 194 |
1 files changed, 0 insertions, 194 deletions
diff --git a/jpa/plugins/org.eclipse.jpt.utility/src/org/eclipse/jpt/utility/internal/model/value/PropertyCollectionValueModelAdapter.java b/jpa/plugins/org.eclipse.jpt.utility/src/org/eclipse/jpt/utility/internal/model/value/PropertyCollectionValueModelAdapter.java deleted file mode 100644 index 5b09ad161e..0000000000 --- a/jpa/plugins/org.eclipse.jpt.utility/src/org/eclipse/jpt/utility/internal/model/value/PropertyCollectionValueModelAdapter.java +++ /dev/null @@ -1,194 +0,0 @@ -/******************************************************************************* - * Copyright (c) 2007, 2008 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.utility.internal.model.value; - -import java.util.Iterator; -import org.eclipse.jpt.utility.internal.iterators.EmptyIterator; -import org.eclipse.jpt.utility.internal.iterators.SingleElementIterator; -import org.eclipse.jpt.utility.internal.model.AbstractModel; -import org.eclipse.jpt.utility.internal.model.ChangeSupport; -import org.eclipse.jpt.utility.internal.model.SingleAspectChangeSupport; -import org.eclipse.jpt.utility.model.event.PropertyChangeEvent; -import org.eclipse.jpt.utility.model.listener.CollectionChangeListener; -import org.eclipse.jpt.utility.model.listener.PropertyChangeListener; -import org.eclipse.jpt.utility.model.value.CollectionValueModel; -import org.eclipse.jpt.utility.model.value.PropertyValueModel; - -/** - * An adapter that allows us to make a PropertyValueModel behave like - * a read-only, single-element CollectionValueModel, sorta. - * - * If the property's value is null, an empty iterator is returned - * (i.e. you can't have a collection with a null element). - */ -public class PropertyCollectionValueModelAdapter<E> - extends AbstractModel - implements CollectionValueModel<E> -{ - /** The wrapped property value model. */ - protected final PropertyValueModel<? extends E> valueHolder; - - /** A listener that forwards any events fired by the value holder. */ - protected final PropertyChangeListener propertyChangeListener; - - /** Cache the value. */ - protected E value; - - - // ********** constructors/initialization ********** - - /** - * Wrap the specified ListValueModel. - */ - public PropertyCollectionValueModelAdapter(PropertyValueModel<? extends E> valueHolder) { - super(); - if (valueHolder == null) { - throw new NullPointerException(); - } - this.valueHolder = valueHolder; - this.propertyChangeListener = this.buildPropertyChangeListener(); - // postpone building the value and listening to the underlying value - // until we have listeners ourselves... - } - - @Override - protected ChangeSupport buildChangeSupport() { - return new SingleAspectChangeSupport(this, CollectionChangeListener.class, VALUES); - } - - /** - * The wrapped value has changed, forward an equivalent - * collection change event to our listeners. - */ - protected PropertyChangeListener buildPropertyChangeListener() { - return new PropertyChangeListener() { - @SuppressWarnings("unchecked") - public void propertyChanged(PropertyChangeEvent event) { - PropertyCollectionValueModelAdapter.this.valueChanged((E) event.getNewValue()); - } - @Override - public String toString() { - return "property change listener"; - } - }; - } - - - // ********** CollectionValueModel implementation ********** - - public Iterator<E> iterator() { - return (this.value == null) ? - EmptyIterator.<E>instance() - : - new SingleElementIterator<E>(this.value); - } - - public int size() { - return (this.value == null) ? 0 : 1; - } - - - // ********** extend change support ********** - - /** - * Override to start listening to the value holder if necessary. - */ - @Override - public void addCollectionChangeListener(CollectionChangeListener listener) { - if (this.hasNoListeners()) { - this.engageModel(); - } - super.addCollectionChangeListener(listener); - } - - /** - * Override to start listening to the value holder if necessary. - */ - @Override - public void addCollectionChangeListener(String collectionName, CollectionChangeListener listener) { - if (collectionName == VALUES && this.hasNoListeners()) { - this.engageModel(); - } - super.addCollectionChangeListener(collectionName, listener); - } - - /** - * Override to stop listening to the value holder if appropriate. - */ - @Override - public void removeCollectionChangeListener(CollectionChangeListener listener) { - super.removeCollectionChangeListener(listener); - if (this.hasNoListeners()) { - this.disengageModel(); - } - } - - /** - * Override to stop listening to the value holder if appropriate. - */ - @Override - public void removeCollectionChangeListener(String collectionName, CollectionChangeListener listener) { - super.removeCollectionChangeListener(collectionName, listener); - if (collectionName == VALUES && this.hasNoListeners()) { - this.disengageModel(); - } - } - - - // ********** queries ********** - - protected boolean hasListeners() { - return this.hasAnyCollectionChangeListeners(VALUES); - } - - protected boolean hasNoListeners() { - return ! this.hasListeners(); - } - - - // ********** behavior ********** - - protected void engageModel() { - this.valueHolder.addPropertyChangeListener(PropertyValueModel.VALUE, this.propertyChangeListener); - // synch our value *after* we start listening to the value holder, - // since its value might change when a listener is added - this.value = this.valueHolder.getValue(); - } - - protected void disengageModel() { - this.valueHolder.removePropertyChangeListener(PropertyValueModel.VALUE, this.propertyChangeListener); - // clear out the value when we are not listening to the value holder - this.value = null; - } - - /** - * synchronize our internal value with the wrapped value - * and fire the appropriate events - */ - protected void valueChanged(E newValue) { - // put in "empty" check so we don't fire events unnecessarily - if (this.value != null) { - E oldValue = this.value; - this.value = null; - this.fireItemRemoved(VALUES, oldValue); - } - this.value = newValue; - // put in "empty" check so we don't fire events unnecessarily - if (this.value != null) { - this.fireItemAdded(VALUES, this.value); - } - } - - @Override - public void toString(StringBuilder sb) { - sb.append(this.valueHolder); - } - -} |