mapcomponent.java

《j2ee经典实例详解》的源代码。原书无附带光盘。介绍的是一个在线银行系统的例子。绝对难得

/*
 * Copyright (c) 2005 Sun Microsystems, Inc.  All rights reserved.  U.S.
 * Government Rights - Commercial software.  Government users are subject
 * to the Sun Microsystems, Inc. standard license agreement and
 * applicable provisions of the FAR and its supplements.  Use is subject
 * to license terms.
 *
 * This distribution may include materials developed by third parties.
 * Sun, Sun Microsystems, the Sun logo, Java and J2EE are trademarks
 * or registered trademarks of Sun Microsystems, Inc. in the U.S. and
 * other countries.
 *
 * Copyright (c) 2005 Sun Microsystems, Inc. Tous droits reserves.
 *
 * Droits du gouvernement americain, utilisateurs gouvernementaux - logiciel
 * commercial. Les utilisateurs gouvernementaux sont soumis au contrat de
 * licence standard de Sun Microsystems, Inc., ainsi qu'aux dispositions
 * en vigueur de la FAR (Federal Acquisition Regulations) et des
 * supplements a celles-ci.  Distribue par des licences qui en
 * restreignent l'utilisation.
 *
 * Cette distribution peut comprendre des composants developpes par des
 * tierces parties. Sun, Sun Microsystems, le logo Sun, Java et J2EE
 * sont des marques de fabrique ou des marques deposees de Sun
 * Microsystems, Inc. aux Etats-Unis et dans d'autres pays.
 */


package components;

import listeners.AreaSelectedEvent;
import javax.faces.component.UICommand;
import javax.faces.context.FacesContext;
import javax.faces.el.MethodBinding;
import javax.faces.event.AbortProcessingException;
import javax.faces.event.ActionEvent;
import javax.faces.event.ActionListener;
import javax.faces.event.FacesEvent;
import javax.faces.event.PhaseId;
import java.io.IOException;


/**
 * <p>{@link MapComponent} is a JavaServer Faces component that corresponds
 * to a client-side image map.  It can have one or more children of type
 * {@link AreaComponent}, each representing hot spots, which a user can
 * click on and mouse over.</p>
 *
 * <p>This component is a source of {@link AreaSelectedEvent} events,
 * which are fired whenever the current area is changed.</p>
 */
public class MapComponent extends UICommand {
    // ------------------------------------------------------ Instance Variables
    private String current = null;

    // --------------------------------------------------------------Constructors 
    public MapComponent() {
        super();
    }

    // -------------------------------------------------------------- Properties

    /**
     * <p>Return the alternate text label for the currently selected
     * child {@link AreaComponent}.</p>
     */
    public String getCurrent() {
        return (this.current);
    }

    /**
     * <p>Set the alternate text label for the currently selected child.
     * If this is different from the previous value, fire an
     * {@link AreaSelectedEvent} to interested listeners.</p>
     *
     * @param current The new alternate text label
     */
    public void setCurrent(String current) {
        String previous = this.current;
        this.current = current;

        // Fire an {@link AreaSelectedEvent} if appropriate
        if ((previous == null) && (current == null)) {
            return;
        } else if ((previous != null) &&
                (current != null) &&
                (previous.equals(current))) {
            return;
        } else {
            this.queueEvent(new AreaSelectedEvent(this));
        }
    }

    /**
     * <p>Return the component family for this component.</p>
     */
    public String getFamily() {
        return ("Map");
    }

    // ----------------------------------------------------- StateHolder Methods

    /**
     * <p>Return the state to be saved for this component.</p>
     *
     * @param context <code>FacesContext</code> for the current request
     */
    public Object saveState(FacesContext context) {
        Object[] values = new Object[2];
        values[0] = super.saveState(context);
        values[1] = current;

        return (values);
    }

    /**
     * <p>Restore the state for this component.</p>
     *
     * @param context <code>FacesContext</code> for the current request
     * @param state   State to be restored
     *
     * @throws IOException if an input/output error occurs
     */
    public void restoreState(FacesContext context, Object state) {
        Object[] values = (Object[]) state;
        super.restoreState(context, values[0]);
        current = (String) values[1];
    }
}