Re: how to set (preferred) JSlider length?

From:
Knute Johnson <nospam@rabbitbrush.frazmtn.com>
Newsgroups:
comp.lang.java.programmer
Date:
Fri, 08 Aug 2008 09:55:01 -0700
Message-ID:
<489c7a64$0$4025$b9f67a60@news.newsdemon.com>
Mark_Galeck wrote:

Thank you all for your replies, I really appreciate, but... none of
these suggestions work - any calls to setPreferredSize,
setMinimumSize, maximumSize, none of these have any effect, with most
layout managers, they just ignore them

the solution, I found out from an article written by some guru:

To set size of your component and still work with a layout manager:

write your own subclass , and override getPreferredSize, which is what
the layout manager calls.

(He chastises Sun for misleading and lack of documentation. )

Thank you again for your comments.


I'll admit Sun's docs are not that good for telling you how things
really work. But setting preferred size works fine just as I showed you
in the example provided. Most of us stopped overriding
getPreferredSize() years ago because setting it works just fine and we
didn't need the extra code. Java is changing every day and while the
web has some great articles, check the date on them. If they are more
than a couple of years old there may well be new thought on the subject.

Usually problems with layoutmanagers come in two varieties, you have
selected the wrong layoutmanager or you are trying to control the exact
size of your component with a layoutmanager. Unending grief will attach
to both situations. The purpose of the layoutmanager is to help you
make things fit and to compensate for differences in font sizes, native
component sizes and multi-platform quirks. They work great if you let them.

I've converted the code to an applet for you, try it, I guarantee you it
will work. Try playing with the width argument in the <applet> tag. If
you set it to less than 400 the JSlider will be 200 pixels wide.

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class test9 extends JApplet {
     public void init() {
         EventQueue.invokeLater(new Runnable() {
             public void run() {
                 setLayout(new GridBagLayout());
                 GridBagConstraints c = new GridBagConstraints();

                 JSlider s = new JSlider(0,400);
                 Dimension d = s.getPreferredSize();
                 d.width = 400;
                 s.setPreferredSize(d);
                 s.setMinimumSize(new Dimension(200,d.height));

                 add(s,c);
             }
         });
     }
}

<html>
     <head>
     </head>
     <body>
         <applet code=test9.class width=450 height 0>
         </applet>
     </body>
</html>

--

Knute Johnson
email s/nospam/knute2008/

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