import java.applet.*;
import java.awt.*;
import java.util.*;

public class TimedLineCanvas extends Canvas {

    private String s = "";
    private Vector lines = new Vector();

    private static int statusLineHeight = 20;

    public void paint (Graphics g) {

	// Draw the status bar and message s, if any:
	g.setColor(Color.blue);
	Dimension canvasSize = getSize();
	int canvasHeight = canvasSize.height;
	int canvasWidth = canvasSize.width;
	g.fillRect(0, canvasHeight - statusLineHeight, 
                   canvasWidth, canvasHeight);
	if (! (s == "")) {
	    g.setColor(Color.white);
	    g.drawString(s,20,canvasHeight - 5);
	}

	// Draw all the lines in red:
	g.setColor(Color.red);
	for (Enumeration lineEnum = lines.elements();
	     lineEnum.hasMoreElements();) {
	    ((LCLine) lineEnum.nextElement()).paint(g);
	}
    }

    public void addLine(int x1, int y1, int x2, int y2) {
	lines.addElement(new LCLine(x1, y1, x2, y2));
	repaint();
    }
    public void clear() {
	lines.removeAllElements();
	s = "";
	repaint();
    }
    public void setString(String s) {
	this.s = s;
	repaint();
    }
    class LCLine {
	int x1, y1, x2, y2;
	public LCLine(int x1, int y1, int x2, int y2) {
	    this.x1 = x1; this.y1 = y1; this.x2 = x2; this.y2 = y2;
	}
	public void paint(Graphics g) {
	    g.drawLine(x1, y1, x2, y2);
	}
    }
}