// file:   Lesson3.java
// type:   Java code
// note:   Doing a Layout and using images
// author: Gregory C. Walsh
// date:   11/23/97

import java.awt.*;
import java.awt.event.*;
import java.awt.*;
import java.applet.Applet;

public class Lesson3 extends Applet implements ActionListener{
    Image walsh[];
    Button front, top, left, right;
    WalshView view;  // WalshView is an inner class (see details below)...
    Font f1;

    public void init () {
	walsh = new Image[4];

	// Download the four images .....

	for(int i = 0; i < 4; i++) 
	    walsh[i] = getImage(getDocumentBase(), "walsh" + i + ".jpg");

	// Generate the GUI objects with initial states

	front = new Button( "+");
	top   = new Button( "Mug Shot Project" );
	left  = new Button("<");
	right = new Button(">");
	view  = new WalshView(0);

	// Set the font on the GUI

	f1 = new Font("TimesRoman",Font.PLAIN,16);
	front.setFont(f1);
	top.setFont(f1);
	left.setFont(f1);
	right.setFont(f1);

        // Configure the appearance of the GUI

	setLayout(new BorderLayout() );
	add("North",top);
	add("Center",view);
	add("West",left);
	add("East",right);
	add("South",front);

        // Connect buttons to action listeners ....

	front.addActionListener(this);
	top.addActionListener(this);
	right.addActionListener(this);
	left.addActionListener(this);
    }

    // Action listener for the buttons ....

    public void actionPerformed(ActionEvent e) {

	String command = e.getActionCommand();

	if(command == "+") {
	    view.image = 0;
	    view.repaint();
	}

	if(command == "<") {
	    view.image = 1;
	    view.repaint();
	}

	if(command == ">") {
	    view.image = 2;
	    view.repaint();
	}

	if(command == "Mug Shot Project") {
	    view.image = 3;
	    view.repaint();
	}
    }

    // WalshView : This inner class displays an image on a canvas....

    public class WalshView extends Canvas {
	int image;

	public WalshView(int i) {
	    image = i;
	}
	public void paint(Graphics g) {
	    g.drawImage(walsh[image], 0, 0, this);
	}
    }
}