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From: =?UTF-8?Q?Arne_Vajh=c3=b8j?= <arne@vajhoej.dk>
Newsgroups: comp.lang.java.programmer
Subject: Re: Event overhead, does it matter?
Date: Wed, 13 Jul 2016 10:45:07 -0400
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On 7/13/2016 9:51 AM, Eric Douglas wrote:
> Is one method more efficient (speed, memory) or is it just a matter of personal preference?

> Method 1:
> public class MyTree extends JTree implements FocusListener {

 > scrollPane.addFocusListener(this);
> addFocusListener(this);

> public void focusGained(final FocusEvent e) {
> if (e.getComponent() == this) {
> // tree gained focus
> }
> if (e.getComponent() == scrollPane) {
> // scroll pane gained focus
> }
> }

> Method 2:
> public class MyTree extends JTree {

> scrollPane.addFocusListener(new FocusListener() {
> public void focusGained(final FocusEvent e) {
> // scroll pane gained focus
> }

> });
> addFocusListener(new FocusListener() {
> public void focusGained(final FocusEvent e) {
> // tree gained focus
> }

> });

You should totally ignore speed and memory considerations.

The difference will be white noise.

Criteria should be readability and a natural design.

I would be inclined to go for method 2, because
it is really two focus listeners, using the same and
having an if within the methods is a design kludge.

Arne