/**
 * Copyright (c) 2011, The University of Southampton and the individual contributors.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 *
 *   *  Redistributions of source code must retain the above copyright notice,
 *      this list of conditions and the following disclaimer.
 *
 *   *  Redistributions in binary form must reproduce the above copyright notice,
 *      this list of conditions and the following disclaimer in the documentation
 *      and/or other materials provided with the distribution.
 *
 *   *  Neither the name of the University of Southampton nor the names of its
 *      contributors may be used to endorse or promote products derived from this
 *      software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
package org.openimaj.demos.sandbox.video.gt;

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.ItemEvent;
import java.awt.event.ItemListener;
import java.util.ArrayList;
import java.util.List;

import javax.swing.AbstractButton;

/**
 * A replacement for the AWT ButtonGroup class.
 * 
 * @author David Dupplaw (dpd@ecs.soton.ac.uk)
 * @created 17 Jul 2012
 * @version $Author$, $Revision$, $Date$
 */
public class ButtonGroup 
{
        /** The buttons */
        private final List<AbstractButton> buttons = new ArrayList<AbstractButton>();
        
        /** The listeners */
        private final List<ItemListener> listeners = new ArrayList<ItemListener>();

        /**
         * Add a button
         * 
         * @param b
         */
        public void add(final AbstractButton b) {
                this.buttons.add(b);
                b.addActionListener(new ActionListener()
                {
                        @Override
                        public void actionPerformed(final ActionEvent e)
                        {
                                ButtonGroup.this.updateButtons(b);
                                ButtonGroup.this.fireListenerEvent( b );
                        }
                });
        }

        /**
         * Remove the given button from the group.
         * 
         * @param b The button to remove
         */
        public void remove(final AbstractButton b) {
                this.buttons.remove(b);
        }

        /**
         * Make sure only the given button is selected.
         * 
         * @param b The button to select.
         */
        private void updateButtons(final AbstractButton b) {
                for (final AbstractButton button : this.buttons)
                        button.setSelected(button == b);
        }

        /**
         * Returns the selected button in the group.
         * 
         * @return The selected button in the group or null if no buttons are
         *         selected.
         */
        public AbstractButton getSelected() {
                for (final AbstractButton button : this.buttons)
                        if (button.isSelected())
                                return button;
                return null;
        }

        /**
         * Sets all buttons in the group to unselected.
         */
        public void selectNone() {
                for (final AbstractButton button : this.buttons)
                        button.setSelected(false);
        }

        /**
         * Set the selected button to the given one. Note that this method will
         * select the button whether or not the button is in the button group.
         * 
         * @param b The button to select
         */
        public void setSelected(final AbstractButton b) {
                b.setSelected(true);
                this.updateButtons(b);
        }
        
        /**
         *      Add the given item listener to listen for button change events from
         *      this button group.
         *      @param il the item listener
         */
        public void addItemListener( final ItemListener il )
        {
                this.listeners.add( il );
        }
        
        /**
         *      Remove the given item listener from this button group.
         *      @param il The item listener to remove.
         */
        public void removeItemListener( final ItemListener il )
        {
                this.listeners.remove( il );
        }
        
        /**
         *      Fire an itemStateChange event to the item listeners.
         *      @param b The button that was selected
         */
        protected void fireListenerEvent( final AbstractButton b )
        {
                if( b.isSelected() )
                        for( final ItemListener il : this.listeners )
                        {
                                final ItemEvent ie = new ItemEvent( b, b.hashCode(), b, 
                                                ItemEvent.SELECTED );
                                il.itemStateChanged( ie );
                        }
        }
        
        /**
         *      Removes all the buttons being controlled by this button group.
         */
        public void clear()
        {
                this.buttons.clear();
        }
}