/*
 *  File:  ListDynTest.java
 *
 *  Create a scrolling List with multiple selections, using ItemEvents
 *    for (singly) selected items.  Shows how the user can add and
 *    remove items (with TextFields).
 *
 *  Copyright:  Northeast Parallel Architectures Center
 *  
 */

import java.awt.List;
import java.awt.Label;
import java.awt.Color;
import java.awt.Font;
import java.awt.TextField;
import java.awt.event.ItemListener;
import java.awt.event.ActionListener;
import java.awt.event.ItemEvent;
import java.awt.event.ActionEvent;

public class ListDynTest extends java.applet.Applet
                      implements ItemListener, ActionListener
{
  // Allow five visible items in the list, 
  //    and allow multiple selections:
  private List wordList = new List( 5, true );
  
  private String resultstring;
  private Label resultlabel;
  private Label newlabel = new Label("Add an adjective:     ");
  private TextField newitemtext = new TextField (20);
  private Label oldlabel = new Label("      Remove one:     ");
  private TextField olditemtext = new TextField (20);
  private Font f = new Font ( "Dialog", Font.PLAIN, 18 );

  public void init() {
    setBackground( Color.white );
    setFont (f);

    // Color the scrolling list:
    Color purple = new Color( 127, 0, 255);
    wordList.setBackground( purple );
    wordList.setForeground( Color.white );
    
      
    // Add items to the scrolling list:
    wordList.addItem( "Snowy" );
    wordList.addItem( "Cold" );
    wordList.addItem( "Icy" );
    wordList.addItem( "Cloudy" );
    wordList.addItem( "Windy" );
    wordList.addItem( "Horrible" );
    wordList.addItem( "Damp" );
    wordList.addItem( "Extra Snowy" );
    wordList.addItem( "Insalubrious" );

    // Register the applet to listen for events:
    wordList.addItemListener( this );
    
    // Construct a text label:
    resultstring  = "            Welcome to winters in Syracuse!             ";
    resultlabel = new Label( resultstring, Label.CENTER );

    newitemtext.addActionListener(this);    
    olditemtext.addActionListener(this);    

    add( wordList );
    add( resultlabel );
    add ( newlabel );
    add ( newitemtext );
    add ( oldlabel );
    add ( olditemtext );
    
  }
  
  public void itemStateChanged( ItemEvent event ) 
  { // if an item has either been selected or deselected    
    updateLabel();
   }

  public void actionPerformed( ActionEvent event ) 
  { // if a textfield has been entered, determine which one:
    if (event.getSource() == newitemtext) 
         wordList.add ( newitemtext.getText());
    if (event.getSource() == olditemtext) 
	try {  wordList.remove ( olditemtext.getText()); }
          catch (IllegalArgumentException ex)
	      { olditemtext.setText ("No such item to remove!"); }
    updateLabel();
  }

  

  public void updateLabel() 
  { 
    //  get the String array of the labels of selected items
    String itemlabels[] = wordList.getSelectedItems();

    // Build string of comma-separated items:
    String str = "Welcome to ";
    for ( int i = 0; i < itemlabels.length; i++ ) 
    { 
         str += itemlabels[i] + ",";
    }
    // Insert "and" in the appropriate place:
    if ( !str.equals( "" ) ) {
      str += " winters in Syracuse!";
      int pos = str.lastIndexOf( "," );
      if ( pos != -1 )
        str = str.substring( 0, pos )  + str.substring( pos + 1 );
    }
    resultlabel.setText( str );  // update label
  }
  
}