( 改良点 )

1. windowを閉じたり、開いたりするボタンだけでなく時計もつけた．
2. window上に線を描けるようにした．しかも線の色は描いていく本数によって変わっていく．

( ソース )

import java.awt.*;
import java.util.Date;
public class window extends java.applet.Applet implements Runnable{
	Frame window;
	Thread runner;
	Font theFont = new Font("TimesRoman", Font.BOLD+Font.ITALIC, 20);
	Date theDate;
	public void start(){
		if(runner == null){
			runner = new Thread(this);
			runner.start();
		}
	}
	public void stop(){
		if(runner != null){
			runner.stop();
			runner = null;
		}
	}
	public void run(){
		while(true){
			theDate = new Date();
			repaint();
			try{
				Thread.sleep(1000);
			}
			catch (InterruptedException e){
			}
		}
	}
	public void paint(Graphics g){
		FontMetrics fm = getFontMetrics(theFont);
		setBackground(Color.black);
		g.setColor(Color.white);
		g.setFont(theFont);
		int xstart = (this.size().width - fm.stringWidth(theDate.toString())) / 2;
		int ystart = (this.size().height + fm.getAscent()) / 2;
		g.drawString(theDate.toString(), xstart, ystart);
	}
	public void init(){
		add(new Button("Open Window"));
		add(new Button("Close Window"));
		window = new MyFrame("A Popup Window");
		window.resize(400,400);
		window.show();
	}
	public boolean action(Event evt , Object obj){
		if(evt.target instanceof Button){
			String label = (String) obj;
			if(label.equals("Open Window")){
				if(!window.isShowing())
					window.show();
			}else if(label == "Close Window"){
				if(window.isShowing())
					window.hide();
			}
			return true;
		}else
			return false;
	}
}
class MyFrame extends Frame{
	Label l = new Label("This is a window", Label.CENTER);
	Dialog dl;
	TextField tf;
	MyFrame(String title){
		super(title);
		setLayout(new FlowLayout(FlowLayout.CENTER));
		add(l);
		MenuBar mbar = new MenuBar();
		Menu m = new Menu("Back");
		m.add(new MenuItem("Red"));
		m.add(new MenuItem("Blue"));
		m.add(new MenuItem("Green"));
		m.add(new MenuItem("Gray"));
		m.add(new MenuItem("Black"));
		Menu e = new Menu("Text");
		e.add(new MenuItem("Set Text"));
		e.add(new CheckboxMenuItem("Reverse Text"));
		mbar.add(m);
		mbar.add(e);
		setMenuBar(mbar);
		dl = new Dialog(this, "Enter Text",true);
		dl.setLayout(new GridLayout(2,1,30,30));
		tf = new TextField(l.getText(),20);
		dl.add(tf);
		dl.add(new Button("OK"));
		dl.setBackground(Color.gray);
		dl.resize(200,150);
	}
	public boolean action(Event evt, Object obj){
		String label = (String)obj;
		if(evt.target instanceof MenuItem){
			if(label.equals("Red")){
				setBackground(Color.red);
				repaint();
			}else if(label.equals("Blue")){
				setBackground(Color.blue);
				repaint();
			}else if(label.equals("Green")){
				setBackground(Color.green);
				repaint();
			}else if(label.equals("Gray")){
				setBackground(Color.gray);
				repaint();
			}else if(label.equals("Black")){
				setBackground(Color.black);
				repaint();
			}else if(label.equals("Set Text")){
				dl.show();
			}
			return false;
		}
		if(evt.target instanceof CheckboxMenuItem){
			if(l.getForeground()==Color.black){
				l.setForeground(Color.white);
				l.setBackground(Color.black);
				l.repaint();
			}else{
				l.setForeground(Color.black);
				l.setBackground(Color.white);
				l.repaint();
			}
			return false;
		}
		if(evt.target instanceof Button){
			if(label == "OK"){
				l.setText(tf.getText());
				dl.hide();
			}
			return false;
		}
		return true;
	}
	final int MAXLINES = 60;
	Point starts[] = new Point[MAXLINES];
	Point ends[] = new Point[60];
	Point anchor;
	Point current_point;
	int current_line = 0;
	int f[];
	public boolean mouseDown(Event evt, int x, int y){
		anchor = new Point (x, y);
		return true;
	}
	public boolean mouseUp(Event evt, int x, int y){
		if(current_line < MAXLINES){
			addline(x, y);
		}else{
			System.out.println("Too many lines.");
		}
		current_point = null;
		repaint();
		return true;
	}
 	public boolean mouseDraw(Event evt, int x, int y){
		current_point = new Point(x, y);
		repaint();
		return true;
	}	
	void addline(int x, int y){
		starts[current_line] = anchor;
		ends[current_line] = new Point(x, y);
		current_line++;
	}	
	public void paint(Graphics g){
		int i;	
		for ( i=0; i<current_line; i++ ){
			g.drawLine(starts[i].x, starts[i].y, ends[i].x, ends[i].y);
			g.setColor(new Color(i*i,i+4*i,i*i+3));
		}
		if(current_point != null)
	      		g.drawLine(anchor.x, anchor.y, current_point.x, current_point.y);
	}
}