Re: swing design questions

From:

conrad <conrad@lawyer.com>

Newsgroups:

comp.lang.java.programmer

Date:

Sat, 20 Sep 2008 12:35:23 -0700 (PDT)

Message-ID:

<055d1b79-e017-469d-bcc2-e7a5c11fdfe7@c58g2000hsc.googlegroups.com>

On Sep 20, 2:02 pm, Lew <no...@lewscanon.com> wrote:

conrad wrote:

2) In terms of populating your content pane with
swing components, I've seen the method of
following a has-a relationship. You might
start out with a class that creates a panel and
adds some buttons. Another class, say for
creating a check box, would extend your

Mark Space wrote:

You started out good, then lost me. I'm not sure that "class" is the
right level of decomposition here. Methods work fine. It's also a b=

odd to me that a whole class would be devoted just to a checkbox.
Although, if you had a very specialzied sort of checkbox, I guess it
might be worth while.

conrad wrote:

panel/button class. In the case from 1) above,
where a menu system creates a branching
effect for different kinds of interfaces(content
panes with different components that are removed
when a different menu item is selected), what kind
of design methodology should be followed? It
doesn't seem like the above panel/button <-- checkbox
containment example would work here.

Mark Space wrote:

Again I'm not following. A simple example might help. Could you =

post

up an SCCEE? I don't see anything wrong with adding a checkbox to
panel, but the whole "checkbox needs a second class" thing has me conf=

used.

<http://www.pscode.org/sscce.html>

conrad wrote:

Adapted from Introduction to Java Programming by
Y. Daniel Liang:

ButtonDemo.java:

public class ButtonDemo extends JFrame {
  protected MessagePanel messagePanel =
    new MessagePanel("Welcome to Java");

  private JButton jbtLeft = new JButton("<=");
  private JButton jbtRight = new JButton("=>");

  public static void main(String[] args) {
    ButtonDemo frame = new ButtonDemo();
    /* init frame stuff */
    frame.setVisible(true);
  } // main

  public ButtonDemo() {
    messagePanel.setBackground(Color.White);

    // Create Panel to hold JButtons
    // omitted for brevity

    // Set layout
    // omitted for brevity

    // register listeners
    // omitted for brevity
  } // Constructor

} // ButtonDemo

CheckBoxDemo.java:

public class CheckBoxDemo extends ButtonDemo {
  private JCheckBox jchkCentered = new JCheckBox("Centered");
  private JCheckBox jchkBold = new JCheckBox("Bold");
  private JCheckBox jchkItalic = new JCheckBox("Italic");

  public static void main(String[] args) {
    CheckBoxDemo frame = new CheckBoxDemo();
    /* init frame - omitted for brevity */
    frame.setVisible(true);
  } // main

  public CheckBoxDemo() {
    // Set mnemonic keys
    // omitted for brevity

    // Create Panel to hold check boxes
    // omitted for brevity

    // register listeners
    // omitted for brevity
  } // Constructor

} // CheckBoxDemo

The author continues with this method a step further
and extends CheckBoxDemo with a RadioButtonDemo.

That doesn't answer Mark Space's question, AFAICT. He was asking about=

whole class [that] would be devoted just to a checkbox." You show a cl=

ass

that contains not just a checkbox but a JFrame, mnemonics, [J]Panels,
listeners, /ad infinitum/.

I was clarifying what I was originally
asking about in terms of design. Is this
a common approach when building GUI
applications in Java?

In terms of my first solution proposed,
a menu item corresponding to a unique
content pane, it doesn't seem like such
an approach is doable.

Maybe I need to think about it more.

--
conrad