Name: diC59631 Date: 09/15/98


In JList there is a setListData method to fill a JList with one command.
In JComboBox I have to call the JComboBox constructor with a Vector as a
parameter to fill the JComboBox in one command. If I create an empty JComboBox
and I want to fill it later I have to use the addItem method.

Considerations:

1. Why not provide a setListData method also for JComboBox?
2. Why not provide an addItem method for JList?
3. The addItem method in JComboBox is a real performanec bottleneck when you use it.
(Review ID: 38874)
======================================================================
Suggested fix by java.net member leouser:

A DESCRIPTION OF THE FIX :
BUGID: 4173836 RFE: setListData in JComboBox
FILES AFFECTED: javax.swing.JComboBox
JComboBox enhanced with java 6 version:
jdk-6-rc-bin-b64-linux-i586-15_dec_2005.bin

Discusion(embeded in test case as well):
/**
 * BUGID: 4173836 RFE: setListData in JComboBox
 * An old and simple RFE. Ive added two methods to JComboBox:
 * setListData(Object[])
 * setListData(Vector<?>)
 * which makes setting the list data as simple as JLists. Im not
 * touching the other suggestion for a addItem to JList since I think
 * that's out of scope. Maybe needs its own RFE. This one must have
 * been lost over and over again, its 6 lines of code!
 *
 * ANTI-RATIONALE:
 * 1. A subclass may have added methods of the same name.
 * 2. Can already do this with setModel(new DefaultComboBoxModel(...))//yuck...
 *
 * TESTING STRATEGY:
 * Create 2 JComboBoxes, set the data with the new methods, assert that
 * the data returned from getItemAt is in fact equal with the new data.
 *
 *
 * JComboBox enhanced with java 6 version:
 * jdk-6-rc-bin-b64-linux-i586-15_dec_2005.bin
 *
 * test ran succesfully on a SUSE 7.3 Linux distribution
 *
 * Brian Harry
 * ###@###.###
 * jan 24, 2006
 */

UNFIED DIFF:
--- /home/nstuff/java6/jdk1.6.0/javax/swing/JComboBox.java Thu Dec 15 02:17:35 2005
+++ /home/javarefs/javax/swing/JComboBox.java Tue Jan 24 18:50:10 2006
@@ -265,6 +265,30 @@
     }
 
     /**
+ * Constructs a <code>ComboBoxModel</code> from an array of objects and then
+ * applies <code>setModel</code> to it.
+ *
+ * @param listData an array of Objects containing the items to display
+ * in the list
+ * @see #setModel
+ */
+ public void setListData(Object[] listData){
+ setModel(new DefaultComboBoxModel(listData));
+ }
+
+ /**
+ * Constructs a <code>ComboBoxModel</code> from a <code>Vector</code> and then
+ * applies <code>setModel</code> to it.
+ *
+ * @param listData a <code>Vector</code> containing the items to
+ * display in the list
+ * @see #setModel
+ */
+ public void setListData(Vector<?> listData){
+ setModel(new DefaultComboBoxModel(listData));
+ }
+
+ /**
      * Sets the data model that the <code>JComboBox</code> uses to obtain
      * the list of items.
      *


JUnit TESTCASE :
import javax.swing.*;
import java.util.*;
import junit.framework.TestCase;
import junit.textui.TestRunner;
import static java.lang.System.out;

/**
 * BUGID: 4173836 RFE: setListData in JComboBox
 * An old and simple RFE. Ive added two methods to JComboBox:
 * setListData(Object[])
 * setListData(Vector<?>)
 * which makes setting the list data as simple as JLists. Im not
 * touching the other suggestion for a addItem to JList since I think
 * that's out of scope. Maybe needs its own RFE. This one must have
 * been lost over and over again, its 6 lines of code!
 *
 * ANTI-RATIONALE:
 * 1. A subclass may have added methods of the same name.
 * 2. Can already do this with setModel(new DefaultComboBoxModel(...))//yuck...
 *
 * TESTING STRATEGY:
 * Create 2 JComboBoxes, set the data with the new methods, assert that
 * the data returned from getItemAt is in fact equal with the new data.
 *
 *
 * JComboBox enhanced with java 6 version:
 * jdk-6-rc-bin-b64-linux-i586-15_dec_2005.bin
 *
 * test ran succesfully on a SUSE 7.3 Linux distribution
 *
 * Brian Harry
 * ###@###.###
 * jan 24, 2006
 */
public class JCTest4173836 extends TestCase{


    public JCTest4173836(String method){
        super(method);
    }

    public void createGUI(){
        out.println();
        out.println("Testing new methods...");
        JFrame jf = new JFrame();
        JPanel jp = new JPanel();
        jf.add(jp);
        JComboBox jcb1 = new JComboBox();
        jp.add(jcb1);
        JComboBox jcb2 = new JComboBox();
        jp.add(jcb2);
        out.println( "testing the setListData(Object[]) method...");
        Object[] data = new Object[]{ "Java", "is", "cool"};
        jcb1.setListData(data);
        for(int i = 0; i < data.length; i++){
            Object x = jcb1.getItemAt(i);
out.println( i + " is: " + x + ", " + data[i]);
assertEquals(data[i], x);
        }

        Vector<Object> v = new Vector<Object>();
for(Object x: data) v.add(x);
        out.println( "testing the setListData(Vector<?>) method...");
jcb2.setListData(v);
        for(int i = 0; i < data.length; i++){
            Object x = jcb2.getItemAt(i);
out.println( i + " is: " + x + ", " + data[i]);
assertEquals(v.get(i), x);
        }

jf.pack();
jf.setVisible(true);

    }


    public void testCombo(){
        Runnable run = new Runnable(){
public void run(){
                    createGUI();
                }

};
        SwingUtilities.invokeLater(run);
    }


    public static void main(String ... args){
        TestCase tc = new JCTest4173836("testCombo");
TestRunner.run(tc);
    }



}


FIX FOR BUG NUMBER:
4173836