Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > comp.lang.java.programmer > #6436

Re: A question about some long java code that has getters/setters

Show all headers | View raw

On 7/22/2011 7:12 PM, Chad wrote:
> The following code, which is taken from one of my school books,
> displays 4 different boxes inside a gui
>
>
>
> import java.awt.*;
> import javax.swing.*;
>
> public class TestMessagePanel extends JFrame {
>
>      public TestMessagePanel() {
>          MessagePanel messagePanel1 = new MessagePanel("Top Left");
>          MessagePanel messagePanel2 = new MessagePanel("Top Right");
>          MessagePanel messagePanel3 = new MessagePanel("Bottom Left");
>          MessagePanel messagePanel4 = new MessagePanel("Bottom Right");
>          messagePanel1.setBackground(Color.RED);
>          messagePanel2.setBackground(Color.CYAN);
>          messagePanel3.setBackground(Color.GREEN);
>          messagePanel4.setBackground(Color.WHITE);
>          messagePanel1.setCentered(true);
>
>          setLayout(new GridLayout(2, 2));
>          add(messagePanel1);
>          add(messagePanel2);
>          add(messagePanel3);
>          add(messagePanel4);
>      }
>
>      public static void main(String[] args) {
>          TestMessagePanel frame = new TestMessagePanel();
>          frame.setSize(300, 200);
>          frame.setTitle("TestMessagePanel");
>          frame.setLocationRelativeTo(null);
>          frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
>          frame.setVisible(true);
>
>      }//end main()
> }
>
> class MessagePanel extends JPanel {
>
>      private String message = "Nope";
>      private int xCoordinate = 20;
>      private int yCoordinate = 20;
>      private int interval = 10;
>      private boolean centered;
>
>      public MessagePanel() {
>      }
>
>      public MessagePanel(String message) {
>          this.message = message;
>      }
>
>      public String getMessage() {
>          return message;
>      }
>
>      public void setMessage(String message) {
>          this.message = message;
>          repaint();
>      }
>
>      public int getXCoordinate() {
>          return xCoordinate;
>      }
>
>      public void setXCoordinate(int x) {
>          this.xCoordinate = x;
>          repaint();
>      }
>
>      public int getYCoordinate() {
>          return yCoordinate;
>      }
>
>      public void setYCoordinate(int y) {
>          this.xCoordinate = y;
>          repaint();
>      }
>
>      public boolean isCentered() {
>          return centered;
>      }
>
>      public void setCentered(boolean centered) {
>          this.centered = centered;
>          repaint();
>      }
>
>      public int getInterval() {
>          return interval;
>      }
>
>      public void setInterval(int interval) {
>          this.interval = interval;
>          repaint();
>      }
>
>      protected void paintComponent(Graphics g) {
>          super.paintComponent(g);
>
>          if (centered) {
>              FontMetrics fm = g.getFontMetrics();
>              int stringWidth = fm.stringWidth(message);
>              int stringAscent = fm.getAscent();
>              xCoordinate = getWidth() / 2 - stringWidth / 2;
>              yCoordinate = getWidth() / 2 - stringAscent / 2;
>          }
>          g.drawString(message, xCoordinate, yCoordinate);
>      }
>
>      public void MoveLeft() {
>          xCoordinate -= interval;
>          repaint();
>      }
>
>      public void MoveRight() {
>          xCoordinate += interval;
>          repaint();
>      }
>
>      public void moveUp() {
>          yCoordinate -= interval;
>          repaint();
>      }
>
>      public void moveDown() {
>          yCoordinate += interval;
>          repaint();
>      }
>
>      public Dimension getPreferredSize() {
>          return new Dimension(200, 30);
>      }
> }
>
>
> What I don't get is why the book defines stuff like getXCoordinate(),
> getYCoordinate(), and getInterval() when it doesn't even use them in
> this very long code example. I tried reading over the section in the
> book, but the author gives no explanation on why he included a bunch
> of unused getters/setters. On top of that, the code seems to work fine
> when I comment out these methods.
>
> Ideas?

There are two approaches to getters and setters:
* generate all except when you have a good reason not to
* generate only those you absolutely need

In this case I think the second approach is actually the best, but
I am a lazy bastard so I would like just ask my IDE to add all
the getters and setters anyway.

Arne

Back to comp.lang.java.programmer | Previous | Next — Previous in thread | Next in thread | Find similar

Thread

A question about some long java code that has getters/setters Chad <cdalten@gmail.com> - 2011-07-22 16:12 -0700
  Re: A question about some long java code that has getters/setters Arne Vajhøj <arne@vajhoej.dk> - 2011-07-22 19:28 -0400
  Re: A question about some long java code that has getters/setters Andreas Leitgeb <avl@gamma.logic.tuwien.ac.at> - 2011-07-22 23:31 +0000
  Re: A question about some long java code that has getters/setters markspace <-@.> - 2011-07-22 16:51 -0700
  Re: A question about some long java code that has getters/setters lewbloch <lewbloch@gmail.com> - 2011-07-23 09:02 -0700
    Re: A question about some long java code that has getters/setters blmblm@myrealbox.com <blmblm.myrealbox@gmail.com> - 2011-07-23 17:41 +0000
      Re: A question about some long java code that has getters/setters lewbloch <lewbloch@gmail.com> - 2011-07-23 11:42 -0700
      Re: A question about some long java code that has getters/setters Arne Vajhøj <arne@vajhoej.dk> - 2011-07-23 17:59 -0400
        Re: A question about some long java code that has getters/setters Steve Sobol <sjsobol@JustThe.net> - 2011-07-23 23:39 -0700
          Re: A question about some long java code that has getters/setters blmblm@myrealbox.com <blmblm.myrealbox@gmail.com> - 2011-07-25 19:44 +0000
          Re: A question about some long java code that has getters/setters lewbloch <lewbloch@gmail.com> - 2011-07-26 09:03 -0700
    Re: A question about some long java code that has getters/setters Arne Vajhøj <arne@vajhoej.dk> - 2011-07-23 19:26 -0400
      Re: A question about some long java code that has getters/setters lewbloch <lewbloch@gmail.com> - 2011-07-26 09:00 -0700
    Re: A question about some long java code that has getters/setters Patrick May <patrick@softwarematters.org> - 2011-07-25 16:27 -0400
      Re: A question about some long java code that has getters/setters markspace <-@.> - 2011-07-25 15:14 -0700
      Re: A question about some long java code that has getters/setters lewbloch <lewbloch@gmail.com> - 2011-07-25 15:56 -0700
        Re: A question about some long java code that has getters/setters Patricia Shanahan <pats@acm.org> - 2011-07-25 17:00 -0700
          Re: A question about some long java code that has getters/setters Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-07-25 21:17 -0400
      Re: A question about some long java code that has getters/setters markspace <-@.> - 2011-07-25 16:50 -0700
        Re: A question about some long java code that has getters/setters Gene Wirchenko <genew@ocis.net> - 2011-07-25 18:30 -0700
          Re: A question about some long java code that has getters/setters Patricia Shanahan <pats@acm.org> - 2011-07-25 18:41 -0700
          Re: A question about some long java code that has getters/setters lewbloch <lewbloch@gmail.com> - 2011-07-26 09:05 -0700
          Re: A question about some long java code that has getters/setters Gene Wirchenko <genew@ocis.net> - 2011-07-26 10:48 -0700
            Re: A question about some long java code that has getters/setters Gene Wirchenko <genew@ocis.net> - 2011-07-26 11:56 -0700
              Re: A question about some long java code that has getters/setters Patricia Shanahan <pats@acm.org> - 2011-07-26 13:34 -0700
                Re: A question about some long java code that has getters/setters lewbloch <lewbloch@gmail.com> - 2011-07-26 14:21 -0700
            Re: A question about some long java code that has getters/setters lewbloch <lewbloch@gmail.com> - 2011-07-26 14:20 -0700
        Re: A question about some long java code that has getters/setters Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-07-25 21:35 -0400
        Re: A question about some long java code that has getters/setters Arved Sandstrom <asandstrom3minus1@eastlink.ca> - 2011-07-26 06:59 -0300
    Re: A question about some long java code that has getters/setters Jukka Lahtinen <jtfjdehf@hotmail.com.invalid> - 2011-07-26 12:19 +0300
      Re: A question about some long java code that has getters/setters lewbloch <lewbloch@gmail.com> - 2011-07-26 09:08 -0700
        Re: A question about some long java code that has getters/setters Jukka Lahtinen <jtfjdehf@hotmail.com.invalid> - 2011-07-27 15:56 +0300
          Re: A question about some long java code that has getters/setters lewbloch <lewbloch@gmail.com> - 2011-07-27 14:14 -0700

csiph-web