| /******************************************************************************* |
| * Copyright (c) 2006, 2009 IBM Corporation and others. |
| * 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: |
| * IBM Corporation - initial API and implementation |
| * Brad Reynolds - bug 158687 |
| * Brad Reynolds - bug 164653, 147515 |
| * Boris Bokowski - bug 256422 |
| * Matthew Hall - bug 256422 |
| *******************************************************************************/ |
| |
| package org.eclipse.core.databinding.observable.value; |
| |
| import org.eclipse.core.databinding.observable.Diffs; |
| import org.eclipse.core.databinding.observable.Realm; |
| |
| /** |
| * Mutable (writable) implementation of {@link IObservableValue} that will maintain a value and fire |
| * change events when the value changes. |
| * <p> |
| * This class is thread safe. All state accessing methods must be invoked from |
| * the {@link Realm#isCurrent() current realm}. Methods for adding and removing |
| * listeners may be invoked from any thread. |
| * </p> |
| * @since 1.0 |
| */ |
| public class WritableValue extends AbstractObservableValue { |
| |
| private final Object valueType; |
| |
| /** |
| * Constructs a new instance with the default realm, a <code>null</code> |
| * value type, and a <code>null</code> value. |
| */ |
| public WritableValue() { |
| this(null, null); |
| } |
| |
| /** |
| * Constructs a new instance with the default realm. |
| * |
| * @param initialValue |
| * can be <code>null</code> |
| * @param valueType |
| * can be <code>null</code> |
| */ |
| public WritableValue(Object initialValue, Object valueType) { |
| this(Realm.getDefault(), initialValue, valueType); |
| } |
| |
| /** |
| * Constructs a new instance with the provided <code>realm</code>, a |
| * <code>null</code> value type, and a <code>null</code> initial value. |
| * |
| * @param realm |
| */ |
| public WritableValue(Realm realm) { |
| this(realm, null, null); |
| } |
| |
| /** |
| * Constructs a new instance. |
| * |
| * @param realm |
| * @param initialValue |
| * can be <code>null</code> |
| * @param valueType |
| * can be <code>null</code> |
| */ |
| public WritableValue(Realm realm, Object initialValue, Object valueType) { |
| super(realm); |
| this.valueType = valueType; |
| this.value = initialValue; |
| } |
| |
| private Object value = null; |
| |
| public Object doGetValue() { |
| return value; |
| } |
| |
| /** |
| * @param value |
| * The value to set. |
| */ |
| public void doSetValue(Object value) { |
| if (this.value != value) { |
| fireValueChange(Diffs.createValueDiff(this.value, this.value = value)); |
| } |
| } |
| |
| public Object getValueType() { |
| return valueType; |
| } |
| |
| /** |
| * @param elementType can be <code>null</code> |
| * @return new instance with the default realm and a value of <code>null</code> |
| */ |
| public static WritableValue withValueType(Object elementType) { |
| return new WritableValue(Realm.getDefault(), null, elementType); |
| } |
| } |