Cannot programatically distinguish between Steel and Ocean with 1.4 methods

Name: jl125535 Date: 09/27/2004


FULL PRODUCT VERSION :
java version "1.5.0"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.5.0-b64)
Java HotSpot(TM) Client VM (build 1.5.0-b64, mixed mode)


A DESCRIPTION OF THE PROBLEM :
What I would like to be able to do is programatically figure out what the look and feel is. I would like to be able to programmatically tell the difference between Metal/Steel and Metal/Ocean.

I can do this using Java 1.5 and the method
    MetalLookAndFeel.getCurrentTheme().getName()
But in Java 1.4 I cannot do this because there is no method
    MetalLookAndFeel.getCurrentTheme().

Because my program must continue to compile and run under Java 1.4, I cannot use that method. The preferable way to detect the current theme is using the method LookAndFeel.getName(), which is supposed to return a different value for different variants of the same look and feel. Unfortunately the MetalLookAndFeel returns "Metal" for both Steel and Ocean.

API for javax.swing.LookAndFeel.getName()
Return a short string that identifies this look and feel, e.g. "CDE/Motif". This string should be appropriate for a menu item. Distinct look and feels should have different names, e.g. a subclass of MotifLookAndFeel that changes the way a few components are rendered should be called "CDE/Motif My Way"; something that would be useful to a user trying to select a L&F from a list of names.


EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
The output of the program when run under Java 1.4 will be "Metal".
    $ java -Dswing.defaultlaf=javax.swing.plaf.metal.MetalLookAndFeel LNFWriter
       Metal

I would expect that since Java 1.5 changed the look and feel, it should
also change what it reports by this test program to be "Metal/Ocean":
    $ java -Dswing.defaultlaf=javax.swing.plaf.metal.MetalLookAndFeel LNFWriter
       Metal/Ocean

Therefore a program can detect whether the current theme is Steel ("Metal")
or Ocean ("Metal/Ocean").

ACTUAL -
The output of the program when run under Java 1.5 will be "Metal", but
the look and feel is NOT the same look and feel as in Java 1.4.
    $ java -Dswing.defaultlaf=javax.swing.plaf.metal.MetalLookAndFeel LNFWriter
       Metal


REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
import javax.swing.UIManager;

public class LNFWriter {
    public static void main(String[] args) {
         System.out.println(UIManager.getLookAndFeel().getName());
    }
}
---------- END SOURCE ----------

CUSTOMER SUBMITTED WORKAROUND :
I have developed a workaround that uses reflection to determine the look and feel.
This method has many drawbacks - it requires that a NoSuchMethodException be
thrown every time it is run on Java 1.4, and it does not support themes other than
"Steel" on Java 1.4:

    /**
     * Workaround method to get the metal theme, either "Steel" or "Ocean". This is because the
     * Metal look and feel's getName() property does not distinguish between versions correctly.
     * A bug has been submitted to the Sun Java bug database and will be reviewed. If fixed, we
     * can get rid of this ugly hack method.
     */
    private static String getMetalTheme() {
        try {
            if(!UIManager.getLookAndFeel().getName().equals("Metal")) return UIManager.getLookAndFeel().getName();
            MetalLookAndFeel metalLNF = (MetalLookAndFeel)UIManager.getLookAndFeel();
            Method getCurrentTheme = metalLNF.getClass().getMethod("getCurrentTheme", new Class[0]);
            MetalTheme currentTheme = (MetalTheme)getCurrentTheme.invoke(metalLNF, new Object[0]);
            return "Metal/" + currentTheme.getName();
        } catch(NoSuchMethodException e) {
            // must be Java 1.4 because getCurrentTheme() method does not exist
            // therefore the theme of interest is "Steel"
            return "Metal/Steel";
        } catch(Exception e) {
            e.printStackTrace();
            return "Metal/Steel";
        }
    }
(Incident Review ID: 311764)
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