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From: Joshua Cranmer on 15 Feb 2010 07:53
On 02/14/2010 11:38 PM, Amr wrote:
> my problem is, how do i know whether to give<extends JPanel> or
> <extends JFrame>?
> both extenstions are used in the book.

Traditionally, I make all of my custom panes extend JPanel; I can't
really think of a good case where JFrame needs to be extended: if I need
to make a powerful main window, I would likely just create a Main-ish
class that extends nothing and constructs the elaborate JFrame.

--
Beware of bugs in the above code; I have only proved it correct, not
tried it. -- Donald E. Knuth
From: Arne Vajhøj on 15 Feb 2010 20:21
On 15-02-2010 07:53, Joshua Cranmer wrote:
> On 02/14/2010 11:38 PM, Amr wrote:
>> my problem is, how do i know whether to give<extends JPanel> or
>> <extends JFrame>?
>> both extenstions are used in the book.
>
> Traditionally, I make all of my custom panes extend JPanel; I can't
> really think of a good case where JFrame needs to be extended: if I need
> to make a powerful main window, I would likely just create a Main-ish
> class that extends nothing and constructs the elaborate JFrame.

Extending JFrame is often seen - including in examples from SUN.

Arne

From: Arne Vajhøj on 15 Feb 2010 20:23
On 15-02-2010 02:26, markspace wrote:
> Also, neither should extend ActionListener. Make that a separate class.
> The behavior of being a JPanel (of JFrame) and the behavior of being an
> ActionListener are fairly different. Don't make one object have both
> behaviors, separate those two concepts so they're easier to deal with.
>
> You often see simple teaching examples where one single class does
> everything: it extends ActionListener, extends JFrame, and assembles the
> entire GUI too. This isn't really appropriate for larger programs, where
> this "do it all" behavior would make maintenance more difficult.
> Separate those concerns to different classes. Those do it all classes
> are really only trying to save space so the demo can be as brief as
> possible.

Good advice.

What is good for demo code is not necesarrily good for real world
programs.

Either a separate class or an anonymous class if the code is simple.

Arne

From: Lew on 15 Feb 2010 20:37
Joshua Cranmer wrote:
>> Traditionally, I make all of my custom panes extend JPanel; I can't
>> really think of a good case where JFrame needs to be extended: if I need
>> to make a powerful main window, I would likely just create a Main-ish
>> class that extends nothing and constructs the elaborate JFrame.

Arne Vajhøj wrote:
> Extending JFrame is often seen - including in examples from SUN.

Arne Vajhøj also wrote:
>> What is good for demo code is not necesarrily good
>> for real world programs.

--
Lew
From: Arne Vajhøj on 15 Feb 2010 20:42
On 15-02-2010 20:37, Lew wrote:
> Joshua Cranmer wrote:
>>> Traditionally, I make all of my custom panes extend JPanel; I can't
>>> really think of a good case where JFrame needs to be extended: if I need
>>> to make a powerful main window, I would likely just create a Main-ish
>>> class that extends nothing and constructs the elaborate JFrame.
>
> Arne Vajhøj wrote:
>> Extending JFrame is often seen - including in examples from SUN.
>
> Arne Vajhøj also wrote:
>>> What is good for demo code is not necesarrily good for real world
>>> programs.

:-)

Yes.

Arne

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