org.eclipse.jface.action.AbstractAction.java Source code

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Here is the source code for org.eclipse.jface.action.AbstractAction.java

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/*******************************************************************************
 * Copyright (c) 2005, 2015 IBM Corporation and others.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/

package org.eclipse.jface.action;

import org.eclipse.core.commands.common.EventManager;
import org.eclipse.jface.util.IPropertyChangeListener;
import org.eclipse.jface.util.PropertyChangeEvent;

/**
 * <p>
 * Some common functionality to share between implementations of
 * <code>IAction</code>. This functionality deals with the property change
 * event mechanism.
 * </p>
 * <p>
 * Clients may neither instantiate nor extend this class.
 * </p>
 *
 * @since 3.2
 */
public abstract class AbstractAction extends EventManager implements IAction {

    @Override
    public void addPropertyChangeListener(final IPropertyChangeListener listener) {
        addListenerObject(listener);
    }

    /**
     * Notifies any property change listeners that a property has changed. Only
     * listeners registered at the time this method is called are notified.
     *
     * @param event
     *            the property change event
     *
     * @see org.eclipse.jface.util.IPropertyChangeListener#propertyChange(PropertyChangeEvent)
     */
    protected final void firePropertyChange(final PropertyChangeEvent event) {
        final Object[] list = getListeners();
        for (Object element : list) {
            ((IPropertyChangeListener) element).propertyChange(event);
        }
    }

    /**
     * Notifies any property change listeners that a property has changed. Only
     * listeners registered at the time this method is called are notified. This
     * method avoids creating an event object if there are no listeners
     * registered, but calls
     * <code>firePropertyChange(PropertyChangeEvent)</code> if there are.
     *
     * @param propertyName
     *            the name of the property that has changed
     * @param oldValue
     *            the old value of the property, or <code>null</code> if none
     * @param newValue
     *            the new value of the property, or <code>null</code> if none
     *
     * @see org.eclipse.jface.util.IPropertyChangeListener#propertyChange(PropertyChangeEvent)
     */
    protected final void firePropertyChange(final String propertyName, final Object oldValue,
            final Object newValue) {
        if (isListenerAttached()) {
            firePropertyChange(new PropertyChangeEvent(this, propertyName, oldValue, newValue));
        }
    }

    @Override
    public void removePropertyChangeListener(final IPropertyChangeListener listener) {
        removeListenerObject(listener);
    }

}