[cp-patches] FYI: MetalLookAndFeel.setCurrentTheme

[David Gilbert]

The 1.5.0 spec states that this method should throw a NullPointerException if the 
supplied theme is null:

2005-09-23  David Gilbert  <address@hidden>

        * javax/swing/plaf/metal/MetalLookAndFeel.java
        (setCurrentTheme): throw exception if argument is null, improved API
        docs.

I also did some investigation of the procedure for changing the theme - this has 
been implemented in such a way that it requires setting a new theme then creating 
and installing a new instance of the MetalLookAndFeel.  It could have been done 
better, but that is the way it is and we match the reference implementation.  I've 
added some comments to the API docs to describe the procedure, since the steps 
required are not immediately obvious.

Regards,

Dave

Index: javax/swing/plaf/metal/MetalLookAndFeel.java
===================================================================
RCS file: 
/cvsroot/classpath/classpath/javax/swing/plaf/metal/MetalLookAndFeel.java,v
retrieving revision 1.59
diff -u -r1.59 MetalLookAndFeel.java
--- javax/swing/plaf/metal/MetalLookAndFeel.java        22 Sep 2005 17:31:30 
-0000      1.59
+++ javax/swing/plaf/metal/MetalLookAndFeel.java        23 Sep 2005 08:22:00 
-0000
@@ -42,7 +42,9 @@
 import java.awt.Font;
 import java.awt.Insets;
 
+import javax.swing.LookAndFeel;
 import javax.swing.UIDefaults;
+import javax.swing.UIManager;
 import javax.swing.plaf.BorderUIResource;
 import javax.swing.plaf.ColorUIResource;
 import javax.swing.plaf.FontUIResource;
@@ -602,12 +604,21 @@
   }
 
   /**
-   * Sets the current theme for the look and feel.
+   * Sets the current theme for the look and feel.  Note that the theme must 
be 
+   * set <em>before</em> the look and feel is installed.  To change the theme 
+   * for an already running application that is using the 
+   * address@hidden MetalLookAndFeel}, first set the theme with this method, 
then 
+   * create a new instance of address@hidden MetalLookAndFeel} and install it 
in the 
+   * usual way (see address@hidden UIManager#setLookAndFeel(LookAndFeel)}).
    * 
-   * @param theme  the theme.
+   * @param theme  the theme (<code>null</code> not permitted).
+   * 
+   * @throws NullPointerException if <code>theme</code> is <code>null</code>.
    */
   public static void setCurrentTheme(MetalTheme theme)
   {
+    if (theme == null)
+      throw new NullPointerException("Null 'theme' not permitted.");
     MetalLookAndFeel.theme = theme;
   }