/*
    *  XNap - A P2P framework and client.
    *
    *  See the file AUTHORS for copyright information.
    *
    *  This program is free software; you can redistribute it and/or modify
    *  it under the terms of the GNU General Public License as published by
    *  the Free Software Foundation.
    *
   *  This program is distributed in the hope that it will be useful,
   *  but WITHOUT ANY WARRANTY; without even the implied warranty of
   *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   *  GNU General Public License for more details.
   *
   *  You should have received a copy of the GNU General Public License
   *  along with this program; if not, write to the Free Software
   *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
   */
  
  package org.xnap.gui.component;
  
  import java.awt.BorderLayout;
  import java.awt.Insets;
  import java.awt.event.ActionEvent;
  
  import javax.swing.AbstractAction;
  import javax.swing.Action;
  import javax.swing.Box;
  import javax.swing.DefaultListModel;
  import javax.swing.JButton;
  import javax.swing.JList;
  import javax.swing.JPanel;
  import javax.swing.JScrollPane;
  import javax.swing.event.ListSelectionEvent;
  import javax.swing.event.ListSelectionListener;
  
  import org.xnap.XNap;
  import org.xnap.gui.util.IconHelper;
  
  /***
   * This class provides a {@link JList} of Strings and a add and remove
   * button.  
   */
  public abstract class AbstractListPanel extends JPanel
      implements ListSelectionListener {
      
      //--- Data field(s) ---
  
      private JList jlItems;
      private DefaultListModel dlmItems;
      private Action acAdd = new AddAction();
      private Action acRemove = new RemoveAction();
      private Box bxInput;
  
      //--- Constructor(s) ---
  	
      public AbstractListPanel(int visibleRows) 
      {
  		setLayout(new BorderLayout());
  
  		dlmItems = new DefaultListModel();
  		jlItems = new JList(dlmItems);
  		jlItems.addListSelectionListener(this);
  		jlItems.setVisibleRowCount(visibleRows);
  		JScrollPane jsp = new JScrollPane(jlItems);
  		add(jsp, BorderLayout.CENTER);
  
  		bxInput = Box.createHorizontalBox();
  		add(bxInput, BorderLayout.NORTH);
  
  		JButton jbAdd = new XNapButton(acAdd);
  		jbAdd.setMargin(new Insets(1, 1, 1, 1));
  		bxInput.add(jbAdd);
  
  		JButton jbRemove = new XNapButton(acRemove);
  		jbRemove.setMargin(new Insets(1, 1, 1, 1));
  		bxInput.add(jbRemove);
      }
  
      // --- Method(s) ---
  
      /***
       * Invoked when the add action is pressed.
       */
      protected abstract Object getInput();
  
      /***
       * Inovked when an item is selected from the list.
       */
      protected abstract void setInput(Object item);
  
      /***
       * Adds the current input to the list.
       */
      public void addInput()
      {
  		Object item = getInput();
  		if (item != null) {
  			if (!dlmItems.contains(item)) {
 				dlmItems.addElement(item);
 				jlItems.ensureIndexIsVisible(dlmItems.getSize() - 1);
 			}
 			setInput(null);
 		}
     }
 
     /***
      * Adds items to the list.
      */
     public void addItems(Object[] items)
     {
 		for (int i = 0; i < items.length; i++) {
 			dlmItems.addElement(items[i]);
 		}
     }
 
     /***
      * Returns the add Action object.
      */
     protected Action getAddAction()
     {
 		return acAdd;
     }
 
     /***
      * Returns the box that is used to display the buttons.
      */
     public Box getInputBox()
     {
 		return bxInput;
     }
 
     /***
      * Returns the list items.
      */
     public Object[] getItems()
     {
 		return dlmItems.toArray();
     }
 
     /***
      * Returns the list items as strings.
      */
     public String[] getStringItems()
     {
 		String[] array = new String[dlmItems.size()];
 		System.arraycopy(dlmItems.toArray(), 0, array, 0, array.length);
 		return array;
     }
 
     /***
      * Returns the remove Action object.
      */
     protected Action getRemoveAction()
     {
 		return acRemove;
     }
 
     /***
      * Invoked when an item from the list is selected. Invokes {@link
      * #setInput(Object)}.
      */
     public void valueChanged(ListSelectionEvent e)
     {
 		if (jlItems.getSelectedValue() != null) {
 			setInput(jlItems.getSelectedValue());
 		}
     }
 
     //--- Inner Class(es) ---
 
     /***
      * Provides an action that adds the current input as an item to
      * the list.
      */
     private class AddAction extends AbstractAction {
 	
         public AddAction() 
 		{
 			putValue(IconHelper.XNAP_ICON, "edit_add.png");
             putValue(Action.SHORT_DESCRIPTION, XNap.tr("Add item."));
 		}
 
         public void actionPerformed(ActionEvent event)
 		{
 			addInput();
 		}
 
     } 
 
     /***
      * Provides an action that removes the currently selected item
      * from the list.  
      */
     private class RemoveAction extends AbstractAction {
 	
         public RemoveAction() 
 		{
 			putValue(IconHelper.XNAP_ICON, "edit_remove.png");
             putValue(Action.SHORT_DESCRIPTION, "Remove selected item.");
 		}
 
         public void actionPerformed(ActionEvent event) 
 		{
 			Object items[] = jlItems.getSelectedValues();
 			for (int i = 0; i < items.length; i++) {
 				dlmItems.removeElement(items[i]);
 			}
 		}
 
     } 
 
 }