Style implementation question

[CBrand]

Hello all,

I would like to implement events on the same level as the component
that is listening for them. Is there any problem with subclassing a
Component that implements its own listeners? For example:

public class Foo extends JTextField implements KeyListener {

public Foo() {

super(32);
addKeyListener(this);

}

public void keyPressed(KeyEvent e) {
//Do stuff here.
}

public void keyReleased(KeyEvent e) {
//Do stuff here.
}

public void keyTyped(KeyEvent e) {
//Do stuff here.
}

}

 

[Daniel Pitts]

Hello all,

I would like to implement events on the same level as the component
that is listening for them. Is there any problem with subclassing a
Component that implements its own listeners? For example:

public class Foo extends JTextField implements KeyListener {

public Foo() {

super(32);
addKeyListener(this);

}

public void keyPressed(KeyEvent e) {
//Do stuff here.
}

public void keyReleased(KeyEvent e) {
//Do stuff here.
}

public void keyTyped(KeyEvent e) {
//Do stuff here.
}

}

There is no "problem", but it leads to bad design an unmaintainable code.

First, you should separate behavior from UI, search for the MVC pattern.
Second, you shouldn't let the "this" pointer escape until after your
constructor finishes (consider a static factory instead of constructor).
Third, it is common, and often cleaner IMO, to use Anonymous classes as
listeners/callbacks.

 

[CBrand]

Hi Daniel,

Thanks for the info. That was exactly what I was wanting to know.

- Corey



On Oct 11, 2:31 pm, Daniel Pitts

[snip]