bundles/org.eclipse.ui.workbench/Eclipse UI/org/eclipse/ui/internal/preferences/PropertyMapAdapter.java

/*******************************************************************************
 * Copyright (c) 2004, 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.ui.internal.preferences;

import java.util.ArrayList;

/**
 * @since 3.1
 */
public abstract class PropertyMapAdapter implements IDynamicPropertyMap {

    private PropertyListenerList listeners;
    private int ignoreCount = 0;
    private ArrayList queuedEvents = new ArrayList();
    
    /* (non-Javadoc)
     * @see org.eclipse.ui.internal.preferences.IDynamicPropertyMap#addListener(org.eclipse.ui.internal.preferences.IPropertyMapListener)
     */
    public final void addListener(IPropertyMapListener listener) {
        if (listeners == null) {
            listeners = new PropertyListenerList();
            attachListener();
        }
        listeners.add(listener);
    }
    
    /* (non-Javadoc)
     * @see org.eclipse.ui.internal.preferences.IDynamicPropertyMap#removeListener(org.eclipse.ui.internal.preferences.IPropertyMapListener)
     */
    public final void removeListener(IPropertyMapListener listener) {
        if (listeners != null) {
            listeners.remove(listener);
            if (listeners.isEmpty()) {
                detachListener();
                listeners = null;
            }
        }
    }

    /* (non-Javadoc)
     * @see org.eclipse.ui.internal.preferences.IPropertyMap#isCommonProperty(java.lang.String)
     */
    public final boolean isCommonProperty(String propertyId) {
        return true;
    }

    /**
     * Detaches all listeners which have been registered with other objects
     * 
     * @since 3.1
     */
    public void dispose() {
        if (listeners != null) {
            detachListener();
            listeners = null;
        }
    }
    
    protected final void firePropertyChange(String prefId) {
        if (ignoreCount > 0) {
            queuedEvents.add(prefId);
            return;
        }
        
        if (listeners != null) {
            listeners.firePropertyChange(prefId);
        }
    }
    
    public final void addListener(String[] eventsOfInterest, IPropertyMapListener listener) {
        if (listeners == null) {
            listeners = new PropertyListenerList();
            attachListener();
        }
        listeners.add(eventsOfInterest, listener);
    }
    
    protected final void firePropertyChange(String[] prefIds) {
        if (ignoreCount > 0) {
            for (int i = 0; i < prefIds.length; i++) {
                queuedEvents.add(prefIds[i]);
            }
            return;
        }

        if (listeners != null) {
            listeners.firePropertyChange(prefIds);
        }
    }
    
    public final void startTransaction() {
        ignoreCount++;
    }
    
    public final void endTransaction() {
        ignoreCount--;
        if (ignoreCount == 0 && !queuedEvents.isEmpty()) {
            if (listeners != null) {
                listeners.firePropertyChange((String[]) queuedEvents.toArray(new String[queuedEvents.size()]));
            }
            queuedEvents.clear();
        }
    }
    
    public boolean equals(Object toCompare) {
        return toCompare instanceof IPropertyMap && PropertyUtil.isEqual(this, (IPropertyMap)toCompare);
    }
    
    protected abstract void attachListener();
    protected abstract void detachListener();
}