/* ComboBoxDemo.java */

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

/* This class demonstrates the use of a Combo box to control the speed of a
 * falling ball.  Adapted from example in Bruce et al.
 */
public class ComboBoxDemo extends WindowController implements ActionListener {
    
    // location of instructions
    private static final Location INSTR_LOCATION = new Location(100,25);
    
    private static final int SLOW_SPEED = 1,   // slow setting
                             MEDIUM_SPEED = 3, // medium setting
                             FAST_SPEED = 10;   // fast setting
    
    private FallingBall droppedBall; // the falling ball
    
    private JComboBox speedChoice;   // Combo box to select ball speed
    private int speed;               // Current speed setting
    
    // display instructions and combo box
    public void begin() {
        new Text( "Click to make a falling ball...", INSTR_LOCATION, canvas );

        speed = SLOW_SPEED;

        speedChoice = new JComboBox();         //construct combo box
        
        speedChoice.addItem ( "Slow" );        // Add 3 entries
        speedChoice.addItem ( "Medium" );
        speedChoice.addItem ( "Fast" );
        speedChoice.setSelectedItem( "Medium" ); // Display "Medium" initially

        speedChoice.addActionListener ( this );    // this class is listener
        
        Container contentPane = getContentPane(); // Add combo box to south
        contentPane.add( speedChoice, BorderLayout.SOUTH );
        contentPane.validate();
    }
    
    // make a new ball when the player clicks
    public void onMouseClick( Location point ) {
        droppedBall = new FallingBall( point, speed, canvas );
    }
    
    // reset ball speed from combo box setting
    public void actionPerformed( ActionEvent evt ) {
        Object newLevel = speedChoice.getSelectedItem ();
        if ( newLevel.equals( "Slow" )) {
            speed = SLOW_SPEED;
        } else if ( newLevel.equals( "Medium" )) {
            speed = MEDIUM_SPEED;
        } else if ( newLevel.equals( "Fast" )) {
            speed = FAST_SPEED;
        }
        if ( droppedBall != null ) {
            droppedBall.setSpeed( speed );
        }
    }
    
    // Main program for application
    public static void main(String [] args) {
       ComboBoxDemo theDemo = new ComboBoxDemo();
       theDemo.startController(500, 500);
    }
    
	/** Animate a falling ball
	 */
	class FallingBall extends ActiveObject {
		
		private static final int BALLSIZE = 30;
		private static final int DELAY_TIME = 33;
		
		private DrawingCanvas canvas; // canvas to draw on
		private FilledOval ball;      // Image of ball as circle
		private int speed;            // current speed of ball
		
		// Draw ball at location and w/speed given in parameters
		public FallingBall( Location ballLocation, int initSpeed, 
							DrawingCanvas aCanvas ) {
			canvas = aCanvas;
			ball = new FilledOval( ballLocation, BALLSIZE, BALLSIZE, canvas );
			speed = initSpeed;
			start();
		}
		
		// Move ball down until off of canvas
		public void run() {
			while ( ball.getY() < canvas.getHeight() ) {
				ball.move( 0, speed );
				pause( DELAY_TIME );
			}
			ball.removeFromCanvas();
		}
		
		// reset speed of ball
		public void setSpeed( int newSpeed ) {
			speed = newSpeed;
		}
	} 
}