/*

 * 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.awt.*;

import java.awt.event.*;

import javax.swing.JPanel;

/**

 * The {@code AutoHidePanel} is a {@code JPanel} whose visibility is

 * automatically set to {@code false} when it contains no visible child {@code

 * Component}s, {@code true} otherwise.

 */

@SuppressWarnings({"serial"})

public class AutoHidePanel extends JPanel {

    public static class AutoHideListener implements ContainerListener {

	//

	// Instance data

	//

	private ComponentListener CHILD_LISTENER =

	    new ComponentAdapter() {

		@Override

		public void componentHidden(ComponentEvent event) {

		    Component comp = event.getComponent();

		    setVisible(comp.getParent());

		}

		@Override

		public void componentShown(ComponentEvent event) {

		    Component comp = event.getComponent();

		    setVisible(comp.getParent());

		}

	    };

	//

	// ContainerListener methods

	//

	@Override

	public void componentAdded(ContainerEvent event) {

	    event.getChild().addComponentListener(CHILD_LISTENER);

	    setVisible(event.getContainer());

	}

	@Override

	public void componentRemoved(ContainerEvent event) {

	    event.getChild().removeComponentListener(CHILD_LISTENER);

	    setVisible(event.getContainer());

	}

	//

	// AutoHideListener methods

	//

	public void deinit(Container container) {

	    container.removeContainerListener(this);

	    for (Component comp : container.getComponents()) {

		comp.removeComponentListener(CHILD_LISTENER);

	    }

	}

	public void init(Container container) {

	    container.addContainerListener(this);

	    for (Component comp : container.getComponents()) {

		comp.addComponentListener(CHILD_LISTENER);

	    }

	    setVisible(container);

	}

	//

	// Private methods

	//

	/**

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

	 * it has any visible child {@code Component}s.

	 */

	private void setVisible(Container container) {

	    boolean visible = false;

	    for (Component comp : container.getComponents()) {

		if (comp.isVisible()) {

		    visible = true;

		    break;

		}

	    }

	    container.setVisible(visible);

	}

    }

    //

    // Static data

    //

    private static final AutoHideListener LISTENER = new AutoHideListener();

    //

    // Constructors

    //

    public AutoHidePanel() {

	init();

    }

    public AutoHidePanel(boolean isDoubleBuffered) {

	super(isDoubleBuffered);

	init();

    }

    public AutoHidePanel(LayoutManager layout) {

	super(layout);

	init();

    }

    public AutoHidePanel(LayoutManager layout, boolean isDoubleBuffered) {

	super(layout, isDoubleBuffered);

	init();

    }

    //

    // Private methods

    //

    private void init() {

	autoHide(this);

    }

    //

    // Static methods

    //

    /**

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

     * automatically set its visibility whenever its text or icon properties

     * change.

     *

     * @return	    the added {@link AutoHideListener}

     */

    public static AutoHideListener autoHide(Container container) {

	LISTENER.init(container);

	return LISTENER;

    }

}