import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
import javax.swing.event.*;
import java.beans.*;

/**
 * DoubleListMain puts together an application that records numbers
 * into a list and reports their average and max.
 * 
 * @author Stuart Hansen
 * @version September 2008
 */

public class DoubleListMain extends JFrame
{
   private JScrollPane pane;
   private JList list;                // the list's display
   private DoubleListModel model;     // the model holding the list
   
   private JLabel add;                // the label for the add field
   private JTextField inputField;     // where the numbers are entered
   private JLabel errorLabel;         // a label to display error messages

   private JLabel avgLabel;           // where the average is displayed
   private Average avg;               // calculates the average
   
   private JLabel maxLabel;           // where the max is displayed
   private Max maximum;               // finds the maximum

   private JButton del;               // deletes the selected element
   private JButton clear;             // clears the entire list

   // The constructor "wires" together the application
   public DoubleListMain ()
   {
      Container cPane = getContentPane();
      cPane.setLayout(null);

      // Set up the list and its model
      model = new DoubleListModel();
      list = new JList();
      list.setModel(model);
      pane = new JScrollPane(list);
      pane.setSize(100, 150);
      pane.setLocation (100, 150);
      cPane.add(pane);
      
      // Set up the label for the add field
      add = new JLabel("Add");
      add.setLocation(50, 50);
      add.setSize(40,30);
      cPane.add(add);

      // Set up the input textField
      inputField = new JTextField();
      inputField.setLocation(100, 50);
      inputField.setSize(100, 30);
      inputField.addActionListener(new AddHandler());
      cPane.add(inputField);
      
      // Set up the label for error messages
      errorLabel = new JLabel("");
      errorLabel.setForeground(Color.red);
      errorLabel.setSize(400, 30);
      errorLabel.setLocation(50, 100);
      cPane.add(errorLabel);
      
      // Set up the delete button
      del = new JButton("Delete");
      del.setSize (100, 30);
      del.setLocation(210, 50);
      del.addActionListener(new DeleteHandler());
      cPane.add(del);

      // Set up the clear button
      clear = new JButton("Clear All");
      clear.setSize (100, 30);
      clear.setLocation(320, 50);
      clear.addActionListener(new ClearHandler());
      cPane.add(clear);

      // Set up the average value and label
      avg = new Average();
      avgLabel = new JLabel("Average = NaN");
      avgLabel.setSize(200, 30);
      avgLabel.setLocation(260, 150);
      list.getModel().addListDataListener(new AverageAdapter());
      avg.addPropertyChangeListener(new AvgPropHandler());
      cPane.add(avgLabel);

      // Set up the maximum value and label
      maximum = new Max();
      maxLabel = new JLabel("Maximum = NaN");
      maxLabel.setSize(200, 30);
      maxLabel.setLocation(260, 200);
      list.getModel().addListDataListener(new MaximumAdapter());
      maximum.addPropertyChangeListener(new MaxPropHandler());
      cPane.add(maxLabel);

      // Set a few windowing parameters and show the frame.
      setSize(500, 400);
      setDefaultCloseOperation(EXIT_ON_CLOSE);
      setVisible(true);
   }
  
   // This class is the handler for adding numbers
   private class AddHandler implements ActionListener
   {
      public void actionPerformed (ActionEvent e)
      {
         try {
            String str = inputField.getText();
            model.addElement(str);
            inputField.setText("");
            errorLabel.setText("");
         }
         catch (Exception ex) {
            errorLabel.setText("Must only add numbers to the list.");
         }
      }
   }

   // This class is the handler for removing numbers
   private class DeleteHandler implements ActionListener
   {
      public void actionPerformed (ActionEvent e)
      {
         try {
            int index = list.getSelectedIndex();
            model.remove(index);
            errorLabel.setText("");
         }
         catch (Exception ex) {
            errorLabel.setText("Error! Use mouse to select element to remove");
         }
      }
   }

   // This class is the handler for clearing the list
   private class ClearHandler implements ActionListener
   {
      public void actionPerformed (ActionEvent e)
      {
         model.clear();
      }
   }

   // This class updates the average
   private class AverageAdapter implements ListDataListener
   {
      public void contentsChanged(ListDataEvent e) {} 
      public void intervalAdded(ListDataEvent e)
      {
         Double[] temp = model.toArray();
         avg.findAverage(temp);        
      } 

      public void intervalRemoved(ListDataEvent e)
      {
         Double[] temp = model.toArray();
         avg.findAverage(temp);        
      } 
   }

   // This class updates the maximum
   private class MaximumAdapter implements ListDataListener
   {
      public void contentsChanged(ListDataEvent e) {} 
      public void intervalAdded(ListDataEvent e)
      {
         Double [] temp = model.toArray();
         maximum.findMax(temp);       
      } 

      public void intervalRemoved(ListDataEvent e)
      {
         Double [] temp = model.toArray();
         maximum.findMax(temp);        
      } 
   }
   
   // This handler updates the JLabel when the average changes
   private class AvgPropHandler implements PropertyChangeListener
   {
	   public void propertyChange (PropertyChangeEvent e)
	   {
		   avgLabel.setText("Average = " + avg.getAverage());
	   }
   }
   
   // This handler updates the JLabel when the maximum changes
   private class MaxPropHandler implements PropertyChangeListener
   {
	   public void propertyChange (PropertyChangeEvent e)
	   {
		   maxLabel.setText("Maximum = " + maximum.getMaximum());
	   }
   }

   // A one line main program
   public static void main (String [] args)
   {
      new DoubleListMain();
   }
}