Explicit member method reference in Java

Question

Based on the following example :

import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.SwingConstants;

public class ExempleJFrame extends JFrame {

    public ExempleJFrame() {
        super("JFrame example");
        setLocation(50, 50);
        setSize(200, 200);
        getContentPane().add(new JLabel("This is a text label!", SwingConstants.CENTER));
        setDefaultCloseOperation(EXIT_ON_CLOSE);
    }

    public static void main(String[] args) {
        ExempleJFrame frame = new ExempleJFrame();
        frame.setVisible(true);
    }

}

Is there a way to make it more explicit that I am calling a member method (see setLocation() and setSize())?

I am looking for something in the lines of this.setLocation() to make it explicit that I call a member method and not something from outer space.

Answer 1

If you're using Eclipse, you can set a Save Action (Additional Save Actions -> Member Accesses -> Use 'this' qualifier for method accesses'), which will automatically convert setLocation to this.setlocation on save.

Personally I don't find it particularly useful, because a non-prefixed method call can only be either

• a static method call (which will be italic in Eclipse)
• a this member call
• a super member call

The last two rarely need to be distinguished IMHO, because of run time dispatch.

Answer 2

The good practice is to favour composition over inheritance: don't extend JFrame but delare a JFrame yourFrame; member in your class instead. Then you call the JFrame methods naturally with:

yourFrame.someMethod();

ps: and call your GUI methods from the EDT:

public static void main(String[] args) {
    SwingUtilities.invokeLater(new Runnable() {
        public void run() {
            yourFrame = new JFrame("JFrame example");
            initFrame();
            yourFrame.setVisible(true);
        }
    }
}

Answer 3

as other said in the comments you could use this.setwatever(). usually it is considered a good practice to use this.membervariable but never really came accross code using this.method().but it works perfectly fine.