fiore@0: /*  
fiore@0:  CCmI Editor - A Collaborative Cross-Modal Diagram Editing Tool
fiore@0:   
fiore@0:  Copyright (C) 2011  Queen Mary University of London (http://ccmi.eecs.qmul.ac.uk/)
fiore@0: 
fiore@0:  This program is free software: you can redistribute it and/or modify
fiore@0:  it under the terms of the GNU General Public License as published by
fiore@0:  the Free Software Foundation, either version 3 of the License, or
fiore@0:  (at your option) any later version.
fiore@0: 
fiore@0:  This program is distributed in the hope that it will be useful,
fiore@0:  but WITHOUT ANY WARRANTY; without even the implied warranty of
fiore@0:  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
fiore@0:  GNU General Public License for more details.
fiore@0: 
fiore@0:  You should have received a copy of the GNU General Public License
fiore@0:  along with this program.  If not, see <http://www.gnu.org/licenses/>.
fiore@0: */
fiore@0: package uk.ac.qmul.eecs.ccmi.gui;
fiore@0: 
fiore@0: import java.awt.event.ItemEvent;
fiore@0: import java.awt.event.KeyEvent;
fiore@0: import java.util.Vector;
fiore@0: 
fiore@0: import javax.swing.ComboBoxModel;
fiore@0: import javax.swing.JComboBox;
fiore@0: 
fiore@0: /**
fiore@0:  * A ComboBox component which overrides the default behaviour when selecting items by the keyboard
fiore@0:  * up and down arrow keys. When the top is reached, if the user presses the up arrow key  
fiore@0:  * instead of blocking on the first item, the LoopComboBox loops forward to the last item. Likewise,
fiore@0:  * when the bottom is reached and the user presses the down arrow key the LoopComboBox 
fiore@0:  * loops back to the first item.  
fiore@0:  *
fiore@0:  */
fiore@0: @SuppressWarnings("serial")
fiore@0: public class LoopComboBox extends JComboBox {
fiore@0: 	public LoopComboBox(){
fiore@0: 		super();
fiore@0: 	}
fiore@0: 	
fiore@0: 	public LoopComboBox(Object[] items){
fiore@0: 		super(items);
fiore@0: 	}
fiore@0: 	
fiore@0: 	public LoopComboBox(ComboBoxModel aModel){
fiore@0: 		super(aModel);
fiore@0: 	}
fiore@0: 	
fiore@0: 	public LoopComboBox(Vector<?> items){
fiore@0: 		super(items);
fiore@0: 	}
fiore@0: 	
fiore@0: 	@Override
fiore@0: 	public void	processKeyEvent(KeyEvent e) {
fiore@0: 		if(dataModel.getSize() == 0){
fiore@0: 			super.processKeyEvent(e);
fiore@0: 		}else{
fiore@0: 			if(e.getKeyCode() == KeyEvent.VK_DOWN 
fiore@0: 					&& e.getID()==KeyEvent.KEY_PRESSED 
fiore@0: 					&& getSelectedIndex() == getItemCount()-1){
fiore@0: 				setSelectedIndex(0);
fiore@0: 				if(getItemCount() == 1)
fiore@0: 					fireOneItemStateChanged();
fiore@0: 			}else if(e.getKeyCode() == KeyEvent.VK_UP 
fiore@0: 					&& e.getID()==KeyEvent.KEY_PRESSED 
fiore@0: 					&& getSelectedIndex() == 0){
fiore@0: 				setSelectedIndex(getItemCount()-1);
fiore@0: 				if(getItemCount() == 1)
fiore@0: 					fireOneItemStateChanged();
fiore@0: 			}else
fiore@0: 				super.processKeyEvent(e);
fiore@0: 		}
fiore@0: 	}
fiore@0: 	
fiore@5: 	/*
fiore@0: 	 * when the comboBox has only one item the ItemStateChanged listeners ain't fired by default.
fiore@0: 	 * This behaviour has to be forced in order to have the item label to be spoken out by  
fiore@0: 	 * the narrator, in spite of the item number .  
fiore@0: 	 */
fiore@0: 	private void fireOneItemStateChanged(){
fiore@0: 		fireItemStateChanged(new ItemEvent(
fiore@0: 				this,
fiore@0: 				ItemEvent.ITEM_STATE_CHANGED,
fiore@0: 				getSelectedItem(),
fiore@0: 				ItemEvent.SELECTED
fiore@0: 		));
fiore@0: 	}
fiore@0: }