PropertyChangeEvent.java

/*******************************************************************************
 * Copyright (c) 2012-2017 Codenvy, S.A.
 * 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:
 *   Codenvy, S.A. - initial API and implementation
 *******************************************************************************/
package org.eclipse.che.ide.api.action;

/**
 * A "PropertyChange" event gets delivered whenever a bean changes a "bound"
 * or "constrained" property.  A PropertyChangeEvent object is sent as an
 * argument to the PropertyChangeListener and VetoableChangeListener methods.
 * <p/>
 * Normally PropertyChangeEvents are accompanied by the name and the old
 * and new value of the changed property.  If the new value is a primitive
 * type (such as int or boolean) it must be wrapped as the
 * corresponding java.lang.* Object type (such as Integer or Boolean).
 * <p/>
 * Null values may be provided for the old and the new values if their
 * true values are not known.
 * <p/>
 * An event source may send a null object as the name to indicate that an
 * arbitrary set of if its properties have changed.  In this case the
 * old and new values should also be null.
 *
 * @author <a href="mailto:evidolob@codenvy.com">Evgen Vidolob</a>
 * @version $Id:
 */
public class PropertyChangeEvent {


    /** The object on which the Event initially occurred. */
    protected Object source;

    /**
     * name of the property that changed.  May be null, if not known.
     *
     * @serial
     */
    private String propertyName;

    /**
     * New value for property.  May be null if not known.
     *
     * @serial
     */
    private Object newValue;

    /**
     * Previous value for property.  May be null if not known.
     *
     * @serial
     */
    private Object oldValue;

    /**
     * Constructs a new <code>PropertyChangeEvent</code>.
     *
     * @param source
     *         The bean that fired the event.
     * @param propertyName
     *         The programmatic name of the property
     *         that was changed.
     * @param oldValue
     *         The old value of the property.
     * @param newValue
     *         The new value of the property.
     */
    public PropertyChangeEvent(Object source, String propertyName,
                               Object oldValue, Object newValue) {
        this.source = source;
        this.propertyName = propertyName;
        this.newValue = newValue;
        this.oldValue = oldValue;
    }

    /**
     * Gets the programmatic name of the property that was changed.
     *
     * @return The programmatic name of the property that was changed.
     * May be null if multiple properties have changed.
     */
    public String getPropertyName() {
        return propertyName;
    }

    /**
     * Gets the new value for the property, expressed as an Object.
     *
     * @return The new value for the property, expressed as an Object.
     * May be null if multiple properties have changed.
     */
    public Object getNewValue() {
        return newValue;
    }

    /**
     * Gets the old value for the property, expressed as an Object.
     *
     * @return The old value for the property, expressed as an Object.
     * May be null if multiple properties have changed.
     */
    public Object getOldValue() {
        return oldValue;
    }

    /**
     * Returns a string representation of the object.
     *
     * @return a string representation of the object
     */
    @Override
    public String toString() {
        StringBuilder sb = new StringBuilder(getClass().getName());
        sb.append("[propertyName=").append(getPropertyName());
        sb.append("; oldValue=").append(getOldValue());
        sb.append("; newValue=").append(getNewValue());
        sb.append("; source=").append(getSource());
        return sb.append("]").toString();
    }

    /**
     * The object on which the Event initially occurred.
     *
     * @return The object on which the Event initially occurred.
     */
    public Object getSource() {
        return source;
    }
}