Re: Unicode labels, fonts for components?

From:
RedGrittyBrick <RedGrittyBrick@SpamWeary.foo>
Newsgroups:
comp.lang.java.programmer
Date:
Mon, 21 Jan 2008 10:30:00 +0000
Message-ID:
<4794742a$0$13935$fa0fcedb@news.zen.co.uk>
Peter Duniho wrote:

The main problem I'm having is that the "2 R" (left arrow) and "2 " (right
arrow) characters are not displaying property under Windows (Java 6).
They are displayed correctly on the Mac (Java 5). (I mentioned the JRE
version in case it's relevant, but I'd hope it wouldn't be).

I wondering if this is a consequence of me not setting some property or
setting or otherwise not configuring my application or Java correctly.
If so, how do I get it to work? If not, what might be wrong? Is it a
known limitation of the Windows Java implementation?

I had expected that Java would be fully Unicode-enabled. Eclipse seems
to support it just fine, under Windows and on the Mac. And the Java
runtime on the Mac supports it fine. (In fact, even on the Eclipse
version of Windows the arrows show up fine in the source, and since
Eclipse is practically all Java (right?) I expect that demonstrates that
there is _some_ way to get Unicode characters to work right in a Java
application).

Related to this is that Component.getFont() doesn't appear to behave as
documented. The docs imply that _some_ font will be returned; if the
Component doesn't have one set, the parent's font will be returned.
Now, I suppose read literally this means that if the parent doesn't have
a font, you get null. But I would have thought that "font will be
returned" really means "the result of Component.getFont() on the parent
will be returned", implying that it will work its way up the containment
hierarchy until a font is found and returned.

I ran into this because I wondered if the arrows weren't displaying
properly because of a font issue. The font being displayed _looks_ like
Arial, but my installed Arial font has those characters so I figured I'd
double-check to see what font was being used. But calling getFont() on
the Component (it's a Button...not sure if that matters) returns null,
which is not at all what I expected.

Is there any way programmatically to reliably get the actual font that's
current being used to display text in a Component?

But mostly I just want to know how to get my arrow characters to display
properly. :)


The following displays fine on Windows XP with JRE 1.6

--------------------------8<---------------------------------
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;

public class TestGetFont {
     public static void main(String[] args) {
         SwingUtilities.invokeLater(new Runnable() {
             public void run() {
                 new TestGetFont();
             }
         });
     }

     TestGetFont() {
         String arrows = "left \u2190 right \u2192 arrows";

         JButton b = new JButton(arrows);
         System.out.println("JButton font is " + b.getFont());

         JPanel p = new JPanel();
         p.add(b);

         JFrame f = new JFrame("Test Component.getFont()");
         f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
         f.add(p);
         f.pack();
         f.setLocationRelativeTo(null);
         f.setVisible(true);
     }

}
--------------------------8<---------------------------------

The console output from println is:
JButton font is
javax.swing.plaf.FontUIResource[family=Dialog,name=Dialog,style=bold,size=12]

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