diff options
Diffstat (limited to 'jpa/plugins/org.eclipse.jpt.utility/src/org/eclipse/jpt/utility/internal/model/value/CachingTransformationPropertyValueModel.java')
| -rw-r--r-- | jpa/plugins/org.eclipse.jpt.utility/src/org/eclipse/jpt/utility/internal/model/value/CachingTransformationPropertyValueModel.java | 112 |
1 files changed, 0 insertions, 112 deletions
diff --git a/jpa/plugins/org.eclipse.jpt.utility/src/org/eclipse/jpt/utility/internal/model/value/CachingTransformationPropertyValueModel.java b/jpa/plugins/org.eclipse.jpt.utility/src/org/eclipse/jpt/utility/internal/model/value/CachingTransformationPropertyValueModel.java deleted file mode 100644 index a2d1e6157d..0000000000 --- a/jpa/plugins/org.eclipse.jpt.utility/src/org/eclipse/jpt/utility/internal/model/value/CachingTransformationPropertyValueModel.java +++ /dev/null @@ -1,112 +0,0 @@ -/******************************************************************************* - * Copyright (c) 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 org.eclipse.jpt.utility.internal.Transformer; -import org.eclipse.jpt.utility.model.value.PropertyValueModel; - -/** - * A <code>CachingTransformationPropertyValueModel</code> wraps another - * <code>PropertyValueModel</code> and uses a <code>Transformer</code> - * to transform the wrapped value before it is returned by <code>getValue()</code>. - * The transformed value is calculated and cached during initialization and every - * time the wrapped value changes. This can be useful when the old value - * passed in to <code>valueChanged(PropertyChangeEvent)</code> can no longer - * be "transformed" because its state is no longer valid. - * This caching can also improve time performance in some situations. - * <p> - * As an alternative to building a <code>Transformer</code>, - * a subclass of <code>CachingTransformationPropertyValueModel</code> can - * either override the <code>transform_(Object)</code> method or, - * if something other than null should be returned when the wrapped value - * is null, override the <code>transform(Object)</code> method. - */ -public class CachingTransformationPropertyValueModel<T1, T2> - extends TransformationPropertyValueModel<T1, T2> -{ - - /** - * Cache the transformed value so that during property change event notification - * we do not have to transform the old value. The old value could no longer be valid in - * the model; as a result, transforming it would not be valid. - */ - protected T2 cachedValue; - - - // ********** constructors/initialization ********** - - /** - * Construct a property value model with the specified nested - * property value model and the default transformer. - * Use this constructor if you want to override the - * <code>transform_(Object)</code> or <code>transform(Object)</code> - * method instead of building a <code>Transformer</code>. - */ - public CachingTransformationPropertyValueModel(PropertyValueModel<? extends T1> valueHolder) { - super(valueHolder); - } - - /** - * Construct an property value model with the specified nested - * property value model and transformer. - */ - public CachingTransformationPropertyValueModel(PropertyValueModel<? extends T1> valueHolder, Transformer<T1, T2> transformer) { - super(valueHolder, transformer); - } - - - // ********** behavior ********** - - /** - * We have listeners, transform the nested value and cache the result. - */ - @Override - protected void engageValueHolder() { - super.engageValueHolder(); - this.cachedValue = this.transform(this.valueHolder.getValue()); - } - - /** - * We have no more listeners, clear the cached value. - */ - @Override - protected void disengageValueHolder() { - this.cachedValue = null; - super.disengageValueHolder(); - } - - /** - * No need to transform the nested value, simply return the cached value, - * which is already transformed. - */ - @Override - public T2 getValue() { - return this.cachedValue; - } - - /** - * Transform the specified new value, caching it before returning it. - */ - @Override - protected T2 transformNew(T1 value) { - this.cachedValue = super.transformNew(value); - return this.cachedValue; - } - - /** - * No need to transform the old value, simply return the cached value, - * which is already transformed. - */ - @Override - protected T2 transformOld(T1 value) { - return this.cachedValue; - } - -} |