package howto;

import java.awt.*;

public class FigLine extends java.applet.Applet implements Figure
{
   private TextField tfx1, tfy1, tfx2, tfy2;

   private NewCanvas nc;

   public void init()
   {
      setBackground(Color.white);

      setLayout(new BorderLayout());

      Panel p = new Panel();

      p.setLayout(new FlowLayout(FlowLayout.CENTER, 0, 0));

      p.add(new Label("drawLine ("));
      p.add(tfx1 = new TextField(2));
      p.add(new Label(","));
      p.add(tfy1 = new TextField(2));
      p.add(new Label(","));
      p.add(tfx2 = new TextField(2));
      p.add(new Label(","));
      p.add(tfy2 = new TextField(2));
      p.add(new Label(")"));

      add("North", p);

      nc = new NewCanvas(this);

      add("Center", nc);

      p = new Panel();

      p.add(new Button("Draw"));

      add("South", p);

      tfx1.setText("10");
      tfy1.setText("10");
      tfx2.setText("100");
      tfy2.setText("100");
   }

   private int parseTextField(TextField tf)
   {
      int n;

      try
      {
         n = Integer.parseInt(tf.getText());
      }
      catch (NumberFormatException nfe)
      {
         tf.setText("0");
         n = 0;
      }

      return n;
   }

   public void paintCallback(Graphics g)
   {
      int x1 = parseTextField(tfx1);
      int y1 = parseTextField(tfy1);
      int x2 = parseTextField(tfx2);
      int y2 = parseTextField(tfy2);

      g.drawLine(x1, y1, x2, y2);
   }

   public boolean action(Event e, Object o)
   {
      if (o.equals("Draw"))
      {
         nc.repaint();

         return true;
      }

      return false;
   }

   public Dimension preferredSize()
   {
      return new Dimension(500, 200);
   }

   public static void main(String [] args)
   {
      Frame f = new Frame("Line");

      FigLine fl = new FigLine();

      fl.init();

      f.add("Center", fl);

      f.pack();
      f.show();
   }
}