Question

Perhaps I am going about this the wrong way. Let me know
Using Swing and AWT, I have several buttons set up on a frame and they each have an ActionListener corresponding to their specific function I.E.

JButton foo_button = new JButton("Foo-Me");
foo_button.addActionListener(new ActionListener() {
    public void actionPerformed(ActionEvent evt) {
        //Fancy schmancy code work
    } 
})
JButton bar_button = new JButton("Bar None");
bar_button.addActionListener(new ActionListener() {
    public void actionPerformed(ActionEvent evt) {
        //Fancy schmancy code work
    } 
})

So each of these buttons do their own thing. However, what if I want all the buttons to do a certain thing (the same exact method for each), in my case, clear a label, before they do their own thing.

Obviously I could add whatever_label.setText(“”) to each actionPerformed() but that entails a lot of duplication, something I’m not so much a fan of.

Oh Java and Swing gurus come to my aid.

Answer 1

You can subclass your own implementation of ActionListener:

private static abstract class MyListener implements ActionListener {

    @Override
    final public void actionPerformed(ActionEvent evt) {
        theSameTask();
        uniqueTask(evt);
    } 
    private void theSameTask() {
        // the identical task
    }
    public abstract void uniqueTask(ActionEvent evt);
}

And then, the new listeners will look like this:

JButton bar_button = new JButton("Bar None");
bar_button.addActionListener(new MyListener() {
    @Override public void uniqueTask(ActionEvent evt) {
        //Fancy schmancy code work
    } 
});