| /******************************************************************************* |
| * Copyright (c) 2006, 2008 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 |
| * Matthew Hall - bug 118516 |
| *******************************************************************************/ |
| |
| package org.eclipse.core.databinding.observable; |
| |
| import org.eclipse.core.runtime.Assert; |
| import org.eclipse.core.runtime.ListenerList; |
| |
| /** |
| * Listener management implementation. Exposed to subclasses in form of |
| * {@link AbstractObservable} and {@link ChangeSupport}. |
| * |
| * @since 1.0 |
| * |
| */ |
| /* package */ class ChangeManager { |
| |
| ListenerList[] listenerLists = null; |
| Object listenerTypes[] = null; |
| private Realm realm; |
| |
| /** |
| * @param realm |
| * |
| */ |
| /* package */ ChangeManager(Realm realm) { |
| Assert.isNotNull(realm, "Realm cannot be null"); //$NON-NLS-1$ |
| this.realm = realm; |
| } |
| |
| /** |
| * @param listenerType |
| * @param listener |
| */ |
| protected void addListener(Object listenerType, |
| IObservablesListener listener) { |
| int listenerTypeIndex = findListenerTypeIndex(listenerType); |
| if (listenerTypeIndex == -1) { |
| int length; |
| if (listenerTypes == null) { |
| length = 0; |
| listenerTypes = new Object[1]; |
| listenerLists = new ListenerList[1]; |
| } else { |
| length = listenerTypes.length; |
| System.arraycopy(listenerTypes, 0, |
| listenerTypes = new Object[length + 1], 0, length); |
| System |
| .arraycopy(listenerLists, 0, |
| listenerLists = new ListenerList[length + 1], |
| 0, length); |
| } |
| listenerTypes[length] = listenerType; |
| listenerLists[length] = new ListenerList(); |
| boolean hadListeners = hasListeners(); |
| listenerLists[length].add(listener); |
| if (!hadListeners) { |
| this.firstListenerAdded(); |
| } |
| return; |
| } |
| ListenerList listenerList = listenerLists[listenerTypeIndex]; |
| boolean hadListeners = true; |
| if (listenerList.size() == 0) { |
| hadListeners = hasListeners(); |
| } |
| listenerList.add(listener); |
| if (!hadListeners) { |
| firstListenerAdded(); |
| } |
| } |
| |
| /** |
| * @param listenerType |
| * @param listener |
| */ |
| protected void removeListener(Object listenerType, |
| IObservablesListener listener) { |
| int listenerTypeIndex = findListenerTypeIndex(listenerType); |
| if (listenerTypeIndex != -1) { |
| listenerLists[listenerTypeIndex].remove(listener); |
| if (listenerLists[listenerTypeIndex].size() == 0) { |
| if (!hasListeners()) { |
| this.lastListenerRemoved(); |
| } |
| } |
| } |
| } |
| |
| protected boolean hasListeners() { |
| if (listenerTypes == null) { |
| return false; |
| } |
| for (int i = 0; i < listenerTypes.length; i++) { |
| if (listenerLists[i].size() > 0) { |
| return true; |
| } |
| } |
| return false; |
| } |
| |
| private int findListenerTypeIndex(Object listenerType) { |
| if (listenerTypes != null) { |
| for (int i = 0; i < listenerTypes.length; i++) { |
| if (listenerTypes[i] == listenerType) { |
| return i; |
| } |
| } |
| } |
| return -1; |
| } |
| |
| protected void fireEvent(ObservableEvent event) { |
| Object listenerType = event.getListenerType(); |
| int listenerTypeIndex = findListenerTypeIndex(listenerType); |
| if (listenerTypeIndex != -1) { |
| Object[] listeners = listenerLists[listenerTypeIndex] |
| .getListeners(); |
| for (int i = 0; i < listeners.length; i++) { |
| event.dispatch((IObservablesListener) listeners[i]); |
| } |
| } |
| } |
| |
| /** |
| * |
| */ |
| protected void firstListenerAdded() { |
| } |
| |
| /** |
| * |
| */ |
| protected void lastListenerRemoved() { |
| } |
| |
| /** |
| * |
| */ |
| public void dispose() { |
| listenerLists = null; |
| listenerTypes = null; |
| realm = null; |
| } |
| |
| /** |
| * @return Returns the realm. |
| */ |
| public Realm getRealm() { |
| return realm; |
| } |
| |
| } |