<Swing Dev> [8] Review request for 4199622 RFE: JComboBox shouldn't sending ActionEvents for keyboard navigation

[Alexander Potochkin]

Hello Alexander
>
>  - key == PAGE_UP / (key == PAGE_DOWN)
>   Are ui.listBox.getSelectedIndex() and comboBox.getSelectedIndex() 
> the same when the "ComboBox.noActionOnKeyNavigation"
>   property is unset? If so, only the ui.listBox.getSelectedIndex() can 
> be used for both cases.
>
>  - key == HIDE
>    I would suggest to set the ui.listBox.selected index back to the 
> comboBox.selected index to prevent some issues where these two indices 
> are expected to be the same.

I would rather not change this code.
We have experienced a lot of unexpected issues when we made even more 
trivial changes.
The number of scenarios with custom editors, popups and so on is enormous
and sometimes the users can expect those values to be different.

Run the test given below.
Open the combobox and highlight an item in the middle of the popup.
Press backspace.
Notice that those values are not the same.

I strongly believe that old code should behave *exactly* the same when the
"ComboBox.noActionOnKeyNavigation" is off.

Would you agree?

(Yep, this means that I don't approve this fix at this moment.)

Thanks
alexp

import javax.accessibility.AccessibleContext;
import javax.swing.*;
import javax.swing.plaf.basic.ComboPopup;
import javax.swing.plaf.metal.MetalLookAndFeel;
import java.awt.*;
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;

public class ComboTest extends JFrame {

     public ComboTest() {
         setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
         setLayout(new FlowLayout());

         final JComboBox<String> cb = new JComboBox<>(
                 new String[]{"one", "two", "three","one2", "two2", 
"three2","one3", "two3", "three3"});
         cb.setEditable(true);

         cb.getEditor().getEditorComponent().addKeyListener(new 
KeyAdapter() {
             @Override
             public void keyPressed(KeyEvent e) {
                 System.out.println("cb.getSelectedIndex() = " + 
cb.getSelectedIndex());
                 
System.out.println("getComboPopup(cb).getList().getSelectedIndex() = "
                         + getComboPopup(cb).getList().getSelectedIndex());
             }
         });

         add(cb);
         setSize(200, 300);
     }

     private ComboPopup getComboPopup(JComboBox cb) {
         AccessibleContext context = cb.getAccessibleContext();
         for (int i = 0; i < context.getAccessibleChildrenCount(); i++) {
             Object c = context.getAccessibleChild(i);
             if (c instanceof ComboPopup) {
                 return (ComboPopup) c;
             }
         }
         return null;
     }

     public static void main(String... args) throws Exception {
         UIManager.setLookAndFeel(new MetalLookAndFeel());
         SwingUtilities.invokeLater(new Runnable() {
             public void run() {
                 new ComboTest().setVisible(true);
             }
         });
     }
}

>
>  Thanks,
>  Alexandr.
>
> On 1/30/2013 2:36 PM, Vladislav Karnaukhov wrote:
>> Hello Alexandr, all,
>>
>> please find a new version here: 
>> http://cr.openjdk.java.net/~vkarnauk/4199622/webrev.05/
>>
>> On 1/29/2013 07:26 PM, Alexander Scherbatiy wrote:
>>>
>>> - WindowsLookAndFeel and ComboBox.noActionOnKeyNavigation property 
>>> is set
>>>     Press down. Next item is selected and the action listener is
>>> invoked. Is it expected behavior (the drop down list is not shown in
>>> this case)?
>> Yes, it's expected. Customer would like to turn off event firing only 
>> when popup is open. To keep consistency over different LAFs, I only 
>> handle the new flag when drop-down is showing. Under Windows, if drop 
>> list wasn't shown, JComboBox will work as usual even if the flag was 
>> set.
>>
>>>
>>> - It seems that the code below can have a shorter form:
>>>                  if
>>> (UIManager.getBoolean("ComboBox.noActionOnKeyNavigation")) {
>>>                      if (!comboBox.isPopupVisible()) {
>>>                          comboBox.setSelectedIndex(si+1);
>>>                      }
>>>                  } else {
>>>                      comboBox.setSelectedIndex(si+1);
>>>                 }
>>>    ->
>>>      if ( !(UIManager.getBoolean("ComboBox.noActionOnKeyNavigation") &&
>>> comboBox.isPopupVisible()) ) {
>>>            comboBox.setSelectedIndex(si+1);
>>>       }
>> Agree; fixed.
>>
>>>
>>> - doTest() method in the test throws some exception. It can throw robot
>>> and toolkit exceptions as well.
>> Agree; fixed.
>>
>>>
>>> Thanks,
>>>   Alexandr.
>>>
>