| /******************************************************************************* |
| * Copyright (c) 2006 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 |
| ******************************************************************************/ |
| |
| package org.eclipse.jface.internal.databinding.provisional.observable.value; |
| |
| import java.util.ArrayList; |
| import java.util.Collection; |
| import java.util.HashSet; |
| |
| import org.eclipse.jface.internal.databinding.provisional.observable.AbstractObservable; |
| import org.eclipse.jface.internal.databinding.provisional.observable.ObservableTracker; |
| |
| /** |
| * @since 1.0 |
| * |
| */ |
| abstract public class AbstractObservableValue extends AbstractObservable |
| implements IObservableValue { |
| |
| private Collection valueChangeListeners = null; |
| |
| public void addValueChangeListener(IValueChangeListener listener) { |
| if (valueChangeListeners == null) { |
| boolean hadListeners = hasListeners(); |
| valueChangeListeners = new ArrayList(); |
| valueChangeListeners.add(listener); |
| if (!hadListeners) { |
| firstListenerAdded(); |
| } |
| } else if (valueChangeListeners.size() > 16) { |
| HashSet listenerList = new HashSet(); |
| listenerList.addAll(valueChangeListeners); |
| valueChangeListeners = listenerList; |
| valueChangeListeners.add(listener); |
| } else { |
| valueChangeListeners.add(listener); |
| } |
| } |
| |
| public void removeValueChangeListener(IValueChangeListener listener) { |
| if (valueChangeListeners == null) { |
| return; |
| } |
| valueChangeListeners.remove(listener); |
| if (valueChangeListeners.size() == 0) { |
| valueChangeListeners = null; |
| } |
| if (!hasListeners()) { |
| lastListenerRemoved(); |
| } |
| } |
| |
| public void setValue(Object value) { |
| throw new UnsupportedOperationException(); |
| } |
| |
| protected void fireValueChange(ValueDiff diff) { |
| // fire general change event first |
| super.fireChange(); |
| if (valueChangeListeners != null) { |
| IValueChangeListener[] listeners = (IValueChangeListener[]) valueChangeListeners |
| .toArray(new IValueChangeListener[valueChangeListeners |
| .size()]); |
| for (int i = 0; i < listeners.length; i++) { |
| listeners[i].handleValueChange(this, diff); |
| } |
| } |
| } |
| |
| public final Object getValue() { |
| ObservableTracker.getterCalled(this); |
| return doGetValue(); |
| } |
| |
| abstract protected Object doGetValue(); |
| |
| public boolean isStale() { |
| return false; |
| } |
| |
| /** |
| * @return |
| */ |
| protected boolean hasListeners() { |
| return super.hasListeners() || valueChangeListeners != null; |
| } |
| |
| protected void fireChange() { |
| throw new RuntimeException( |
| "fireChange should not be called, use fireValueChange() instead"); //$NON-NLS-1$ |
| } |
| |
| /* |
| * (non-Javadoc) |
| * |
| * @see org.eclipse.jface.provisional.databinding.observable.AbstractObservable#dispose() |
| */ |
| public void dispose() { |
| valueChangeListeners = null; |
| super.dispose(); |
| } |
| } |