Name: skT88420 Date: 08/27/99


The JButton( Action x ) constructor and
JButton.setAction( Action x ) method do not behave as expected from the provided documentation.

Basically, the NAME property from the action is not used to set the text of the button; while the SHORT_DESCRIPTION and SMALL_ICON properties are set to the ToolTipText and Icon as exepcted. These methods in the similar classes JCheckBox and JRadioButton work as expected.

 From 'javap -private javax.swing.JButton'

Method void configurePropertiesFromAction(javax.swing.Action)
   0 aload_0
   1 aload_1
   2 ifnull 28
   5 aload_0
   6 ldc #20 <String "displayActionText">
   8 invokevirtual #21 <Method java.lang.Object getClientProperty(java.lang.Object)>
  11 ifnull 28
  14 aload_1
  15 ldc #22 <String "Name">
  17 invokeinterface (args 2) #23 <InterfaceMethod java.lang.Object getValue(java.lang.String)>
  22 checkcast #24 <Class java.lang.String>
  25 goto 29
  28 aconst_null
  29 invokevirtual #25 <Method void setText(java.lang.String)>
  32 aload_0
  33 aload_1
  34 ifnull 51
  37 aload_1
  38 ldc #26 <String "SmallIcon">
  40 invokeinterface (args 2) #23 <InterfaceMethod java.lang.Object getValue(java.lang.String)>
  45 checkcast #27 <Class javax.swing.Icon>
  48 goto 52
  51 aconst_null
  52 invokevirtual #28 <Method void setIcon(javax.swing.Icon)>
  55 aload_0
  56 aload_1
  57 ifnull 69
  60 aload_1
  61 invokeinterface (args 1) #29 <InterfaceMethod boolean isEnabled()>
  66 goto 70
  69 iconst_1
  70 invokevirtual #30 <Method void setEnabled(boolean)>
  73 aload_0
  74 aload_1
  75 ifnull 92
  78 aload_1
  79 ldc #31 <String "ShortDescription">
  81 invokeinterface (args 2) #23 <InterfaceMethod java.lang.Object getValue(java.lang.String)>
  86 checkcast #24 <Class java.lang.String>
  89 goto 93
  92 aconst_null
  93 invokevirtual #32 <Method void setToolTipText(java.lang.String)>
  96 aload_0
  97 iconst_0
  98 invokevirtual #33 <Method void setHorizontalTextPosition(int)>
 101 aload_0
 102 iconst_3
 103 invokevirtual #34 <Method void setVerticalTextPosition(int)>
 106 return

----- End of javap

It appears that the code in JButton looks for a client property called 'displayActionText' (see bytecode 6). There is no documentation describing how to use this; and doing a search on the JDK 1.3 class files reveals that this is the only occurrence of this property.

Specifically with the constructor, there is no way to set this property before requiring it. Also, even with the setAction method this requires the property to be set on every JButton created.

Some code to demonstrate:

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

public class ActionTest extends AbstractAction
{
    public static void main( String[] args )
    {
        JButton button = new JButton( "Button Before Text" );
        button.setToolTipText( "Button Before Tooltip" );
        JCheckBox checkbox = new JCheckBox( "CheckBox Before Text" );
        checkbox.setToolTipText( "CheckBox Before Tooltip" );
        JRadioButton radiobutton = new JRadioButton( "RadioButton Before Text" );
        radiobutton.setToolTipText( "RadioButton Before Tooltip" );
        
        System.out.println( "Button Text: " + button.getText() );
        System.out.println( "Button Tooltip: " + button.getToolTipText() );
        button.setAction( new ActionTest( "Button" ) );
        System.out.println( "Button Text After: " + button.getText() );
        System.out.println( "Button Tooltip After: "
            + button.getToolTipText() );
        button.putClientProperty( "displayActionText" , "true" );
        button.setAction( new ActionTest( "Button (displayActionText)" ) );
        System.out.println( " Set the displayActionText client property" );
        System.out.println( "Button Text After set: " + button.getText() );
        System.out.println( "Button Tooltip After set: "
            + button.getToolTipText() );
        System.out.println();
        
        System.out.println( "CheckBox Text: " + checkbox.getText() );
        System.out.println( "CheckBox Tooltip: " + checkbox.getToolTipText() );
        checkbox.setAction( new ActionTest( "CheckBox" ) );
        System.out.println( "CheckBox Text After: " + checkbox.getText() );
        System.out.println( "CheckBox Tooltip After: "
            + checkbox.getToolTipText() );
        System.out.println();
        
        System.out.println( "RadioButton Text: " + radiobutton.getText() );
        System.out.println( "RadioButton Tooltip: "
            + radiobutton.getToolTipText() );
        radiobutton.setAction( new ActionTest( "RadioButton" ) );
        System.out.println( "RadioButton Text After: "
            + radiobutton.getText() );
        System.out.println( "RadioButton Tooltip After: "
            + radiobutton.getToolTipText() );
        
        System.exit( 0 );
    }
    
    public ActionTest( String type )
    {
        putValue( NAME , type + " After Name" );
        putValue( SHORT_DESCRIPTION , type + " After Short Description" );
    }
    
    public void actionPerformed( ActionEvent evt )
    {
        // Do nothing
    }
}

----- End of Code

Produces output:
Button Text: Button Before Text
Button Tooltip: Button Before Tooltip
Button Text After: null
Button Tooltip After: Button After Short Description
  Set the displayActionText client property
Button Text After set: Button (displayActionText) After Name
Button Tooltip After set: Button (displayActionText) After Short Description

CheckBox Text: CheckBox Before Text
CheckBox Tooltip: CheckBox Before Tooltip
CheckBox Text After: CheckBox After Name
CheckBox Tooltip After: CheckBox After Short Description

RadioButton Text: RadioButton Before Text
RadioButton Tooltip: RadioButton Before Tooltip
RadioButton Text After: RadioButton After Name
RadioButton Tooltip After: RadioButton After Short Description
------ End of output

java -version :>
java version "1.3beta"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.3beta-O)
Java(TM) HotSpot Client VM (build 1.3beta-O, mixed mode)

java -fullversion :>
java full version "1.3beta-O"
(Review ID: 94553)
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