Re: Erasing a String produced using drawString()

From:
Nigel Wade <nmw@ion.le.ac.uk>
Newsgroups:
comp.lang.java.help
Date:
Fri, 23 Feb 2007 11:07:49 +0000
Message-ID:
<ermhu5$sfb$1@south.jnrs.ja.net>
BlackJackal wrote:

This is what I have so far

   import javax.swing.*;
   import java.awt.*;
   import java.awt.event.*;
    public class JBlueGray extends JApplet implements ActionListener
   {
      String fname = "Robert";
      String lname = "McDougal";
      JButton pushme = new JButton("Click Me!");
      Font littlefont = new Font("Helvetica", Font.PLAIN, 12);
      Font bigfont = new Font("Helvetica", Font.PLAIN, 22);
      int x = 20, y = 50, width, count = 0, height;

       public void init()
      {
         Container con = getContentPane();
         con.setLayout(new FlowLayout());
         con.add(pushme);
         pushme.addActionListener(this);
      }

       public void actionPerformed(ActionEvent e)
      {
         Object source = e.getSource();
         if (source == pushme) {
            Graphics gr = getGraphics();
            if (count == 1) {

               gr.setFont(littlefont);
               gr.setColor(Color.BLUE);
               width = gr.getFontMetrics().stringWidth(fname);
               height = gr.getFontMetrics().getHeight();
               gr.drawString(fname, x, y);
               gr.drawString(lname, x + (2 + width), y);
            }
            else if(count == 2) {
               width += gr.getFontMetrics().stringWidth(lname);
               gr.setFont(bigfont);
               gr.setColor(Color.DARK_GRAY);
               gr.fillRect(x, y, width + 4, height);
               gr.drawString(fname, x, y);
               gr.setFont(littlefont);
               gr.setColor(Color.BLUE);
               gr.drawString(lname,
gr.getFontMetrics().stringWidth(fname) + 2, y);
               pushme.setEnabled(false);
            }
         }

      }
   }


Does the homework specify that you use Graphics drawing methods?

Surely it would be much simpler to use JComponents, and alter their visibility
and attributes.

--
Nigel Wade, System Administrator, Space Plasma Physics Group,
            University of Leicester, Leicester, LE1 7RH, UK
E-mail : nmw@ion.le.ac.uk
Phone : +44 (0)116 2523548, Fax : +44 (0)116 2523555

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