/*

 * CDDL HEADER START

 *

 * The contents of this file are subject to the terms of the

 * Common Development and Distribution License (the "License").

 * You may not use this file except in compliance with the License.

 *

 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE

 * or http://www.opensolaris.org/os/licensing.

 * See the License for the specific language governing permissions

 * and limitations under the License.

 *

 * When distributing Covered Code, include this CDDL HEADER in each

 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.

 * If applicable, add the following below this CDDL HEADER, with the

 * fields enclosed by brackets "[]" replaced with your own identifying

 * information: Portions Copyright [yyyy] [name of copyright owner]

 *

 * CDDL HEADER END

 */

/*

 * Copyright (c) 2010, 2012, Oracle and/or its affiliates. All rights reserved.

 */

package com.oracle.solaris.vp.util.swing;

import java.beans.*;

import javax.swing.*;

/**

 * The {@code AutoHideLabel} is a {@code JLabel} whose visibility is

 * automatically set to {@code false} when its text and icon are {@code null} or

 * empty, {@code true} otherwise.

 */

@SuppressWarnings({"serial"})

public class AutoHideLabel extends JLabel {

    public static class AutoHideListener implements PropertyChangeListener {

	//

	// PropertyChangeListener methods

	//

	@Override

	public void propertyChange(PropertyChangeEvent event) {

	    setVisible((JLabel)event.getSource());

	}

	//

	// AutoHideListener methods

	//

	public void deinit(JLabel label) {

	    label.removePropertyChangeListener("text", this);

	    label.removePropertyChangeListener("icon", this);

	}

	public void init(JLabel label) {

	    label.addPropertyChangeListener("text", this);

	    label.addPropertyChangeListener("icon", this);

	    setVisible(label);

	}

	//

	// Private methods

	//

	/**

	 * Sets the visibility of the given {@code label} based on whether it

	 * has a non-{@code null}/empty icon or text.

	 */

	private void setVisible(JLabel label) {

	    String text = label.getText();

	    label.setVisible((text != null && !text.isEmpty()) ||

		label.getIcon() != null);

	}

    }

    //

    // Static data

    //

    private static final AutoHideListener LISTENER = new AutoHideListener();

    //

    // Constructors

    //

    public AutoHideLabel() {

	init();

    }

    public AutoHideLabel(Icon icon) {

	super(icon);

	init();

    }

    public AutoHideLabel(Icon icon, int horizontalAlignment) {

	super(icon, horizontalAlignment);

	init();

    }

    public AutoHideLabel(String text) {

	super(text);

	init();

    }

    public AutoHideLabel(String text, Icon icon, int horizontalAlignment) {

	super(text, icon, horizontalAlignment);

	init();

    }

    public AutoHideLabel(String text, int horizontalAlignment) {

	super(text, horizontalAlignment);

	init();

    }

    //

    // Private methods

    //

    private void init() {

	autoHide(this);

    }

    //

    // Static methods

    //

    /**

     * Add an {@link AutoHideListener} to the given {@code JLabel} to

     * automatically set its visibility whenever its text or icon properties

     * change.

     *

     * @return	    the added {@link AutoHideListener}

     */

    public static AutoHideListener autoHide(JLabel label) {

	LISTENER.init(label);

	return LISTENER;

    }

}