<Swing Dev> Approved: 7189299 DefaultButtonModel instance keeps stale listeners of JButton in case of multiple SwingUtilities.updateComponentTreeUI() calls
Alexander Scherbatiy
alexandr.scherbatiy at oracle.com
Fri Feb 15 11:12:34 UTC 2013
The fix is pushed to JDK 8:
http://hg.openjdk.java.net/jdk8/awt/jdk/rev/4bf242def958
The java incident 7189299 has not been migrated yet to the new bug
system so the bug is pushed with the new id 8008289.
Thanks,
Alexandr.
On 2/13/2013 6:26 PM, Sergey Malenkov wrote:
> The fix looks like a hack, but it is acceptable in this case.
>
> Thanks,
> SAM
>
> On 29.01.2013 9:31, Frank Ding wrote:
>> Hi Alexandr,
>> Please review my 9th attempt @
>> http://cr.openjdk.java.net/~dingxmin/7189299/webrev.09/
>> The revision also passed test LoadingWebPageToJEditorPane.
>>
>> Thanks && Best regards,
>> Frank
>>
>> On 1/28/2013 5:04 PM, Frank Ding wrote:
>>> Hi Alexandr,
>>> Thanks for your suggestion. I will prepare a patch according to it
>>> soon.
>>>
>>> Best regards,
>>> Frank
>>>
>>> On 1/21/2013 9:41 PM, Alexander Scherbatiy wrote:
>>>> On 1/18/2013 10:50 AM, Frank Ding wrote:
>>>>> Hi Alexandr,
>>>>> Do you have any idea?
>>>>
>>>> What about one more way removing listeners:
>>>> - disadvantage: listeners are hardcoded
>>>> - advantage: there is no need to override JButton, JList,...
>>>> classes
>>>>
>>>> ------------------------------------------
>>>> private void clearModel(Object model) {
>>>> if (model instanceof DefaultButtonModel) {
>>>> DefaultButtonModel buttonModel = (DefaultButtonModel)
>>>> model;
>>>> String listenerClass =
>>>> "javax.swing.AbstractButton$Handler";
>>>>
>>>> for (ActionListener listener :
>>>> buttonModel.getActionListeners()) {
>>>> if
>>>> (listenerClass.equals(listener.getClass().getName())) {
>>>> buttonModel.removeActionListener(listener);
>>>> }
>>>> }
>>>> // remove change listeners
>>>> // remove item listeners
>>>>
>>>> } else if(model instanceof ListModel){
>>>> // remove list listeners
>>>> }
>>>> }
>>>> ------------------------------------------
>>>>
>>>> Thanks,
>>>> Alexandr.
>>>>
>>>>>
>>>>> Best regards,
>>>>> Frank
>>>>>
>>>>> On 12/28/2012 11:16 AM, Frank Ding wrote:
>>>>>> Hi Alexandr,
>>>>>> I did some more investigations.
>>>>>> 1. The model can be accessed as below which is also illustrated
>>>>>> in the jtreg test
>>>>>> http://cr.openjdk.java.net/~dingxmin/7189299/webrev.07/test/javax/swing/text/html/7189299/bug7189299.java.html
>>>>>>
>>>>>>
>>>>>>
>>>>>> HTMLEditorKit htmlEditorKit = (HTMLEditorKit) html.getEditorKit();
>>>>>> StyleContext.NamedStyle style = ((StyleContext.NamedStyle)
>>>>>> htmlEditorKit.getInputAttributes());
>>>>>> DefaultButtonModel model = ((DefaultButtonModel)
>>>>>> style.getAttribute(StyleConstants.ModelAttribute));
>>>>>>
>>>>>> Though it needs type conversion, model can be exposed to client
>>>>>> code. This implies client code has the chance to add listeners.
>>>>>> Another way of updating listener in model is by first getting
>>>>>> JButton or other html Swing components and then call listener
>>>>>> related api that affects model. I dumped vars above but did not
>>>>>> find out possibility for application to get Swing component
>>>>>> reference.
>>>>>>
>>>>>> 2. As of swing.text.html library, I searched 'ModelAttribute'
>>>>>> under javax/swing directory with command "grep -R 'ModelAttribute'
>>>>>> ." which shows aside from FormView and StyleConstants, the classes
>>>>>> referencing it are HTMLDocument, HTMLWriter. This means only
>>>>>> FormView adds listeners to model.
>>>>>>
>>>>>> My first attempt at fixing the problem (only for JButton listener
>>>>>> leak) is trying to remove all listeners completely. See
>>>>>> http://cr.openjdk.java.net/~dingxmin/7189299/webrev.01/. Pavel
>>>>>> argued that it may cause existing application to malfunction. Then
>>>>>> I came up with
>>>>>> http://cr.openjdk.java.net/~dingxmin/7189299/webrev.02/ where only
>>>>>> stale listeners are identified and removed using reflection. But
>>>>>> Pavel insisted reflection should be prohibited. So I tried to work
>>>>>> around it by extending JButton in FormView to access the private
>>>>>> listener instance such that only stale listener is removed. The
>>>>>> perfect revision is
>>>>>> http://cr.openjdk.java.net/~dingxmin/7189299/webrev.07/.
>>>>>>
>>>>>> I propose we fix JButton issue as it leads to NPE visible to
>>>>>> application. Bug in other components can be put off if Swing team
>>>>>> intend to fix it elegantly or duplicate code like what is in v.07.
>>>>>> Any idea or comment, please let me know.
>>>>>>
>>>>>> Thanks and best regards,
>>>>>> Frank
>>>>>>
>>>>>> On 12/10/2012 6:40 PM, Alexander Scherbatiy wrote:
>>>>>>> On 12/6/2012 12:39 PM, Frank Ding wrote:
>>>>>>>> Hi Alexandr,
>>>>>>>> I did several attempts but still have hang issues somewhere.
>>>>>>>> It seems the new approach of caching gui components created each
>>>>>>>> time is not practical because of the threading restriction
>>>>>>>> already imposed on HTMLDocument.
>>>>>>>> Can we make compromise by turning to previous solution (v7 in
>>>>>>>> particular) and generalize it to other gui components (which
>>>>>>>> means there would be JCheckBoxWrapper, JRadioButtonWrapper,
>>>>>>>
>>>>>>> The issue is that models contain listeners from all previous
>>>>>>> components. Models are used to store data and state of components
>>>>>>> when form view is recreated.
>>>>>>> FormView adds it's own listeners to components (and as result
>>>>>>> to the models). Could you make a little investigation to check
>>>>>>> which other listeners can the models hold?
>>>>>>> Can a user adds a listener? Can listeners be added by other
>>>>>>> parts of the swing.text.html library?
>>>>>>>
>>>>>>> If old listeners does not play role, it is possible just to
>>>>>>> remove them all.
>>>>>>>
>>>>>>> Thanks,
>>>>>>> Alexandr.
>>>>>>>
>>>>>>>> JPasswordFieldWrapper, JTextFieldWrapper, JListWrapper,
>>>>>>>> JComboBoxWrapper, and JButtonWrapper). Or shall we fix JButton
>>>>>>>> only because it causes obvious exception visible to client? I am
>>>>>>>> short of ideas...
>>>>>>>> http://cr.openjdk.java.net/~dingxmin/7189299/webrev.07/
>>>>>>>>
>>>>>>>> Best regards,
>>>>>>>> Frank
>>>>>>>>
>>>>>>>> On 12/5/2012 2:12 PM, Frank Ding wrote:
>>>>>>>>> Hi Alexandr,
>>>>>>>>> I observed the same issue in my environment as well. My
>>>>>>>>> proposed patch would cause severe regression issues. I am
>>>>>>>>> looking into the locking issue.
>>>>>>>>>
>>>>>>>>> Thanks,
>>>>>>>>> Frank
>>>>>>>>>
>>>>>>>>> On 12/3/2012 6:53 PM, Alexander Scherbatiy wrote:
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> Could you check the following sample with your latest fix? It
>>>>>>>>>> just hangs on my side.
>>>>>>>>>>
>>>>>>>>>> - put the sample.html and the response.html files on a
>>>>>>>>>> server
>>>>>>>>>> - update path to the html files in the
>>>>>>>>>> LoadingWebPageToJEditorPane class
>>>>>>>>>>
>>>>>>>>>> ------------- sample.html ------------
>>>>>>>>>> <form name="input" action="response.html" method="get">
>>>>>>>>>> Username: <input type="text" name="user">
>>>>>>>>>> <input type="submit" value="Submit">
>>>>>>>>>> </form>
>>>>>>>>>> ------------- response.html ------------
>>>>>>>>>> <html>
>>>>>>>>>> <body>
>>>>>>>>>> Hello World!
>>>>>>>>>> </body>
>>>>>>>>>> </html>
>>>>>>>>>> ------------- LoadingWebPageToJEditorPane.html ------------
>>>>>>>>>> import java.net.URL;
>>>>>>>>>> import javax.swing.JEditorPane;
>>>>>>>>>> import javax.swing.JFrame;
>>>>>>>>>> import javax.swing.JScrollPane;
>>>>>>>>>> import javax.swing.SwingUtilities;
>>>>>>>>>>
>>>>>>>>>> public class LoadingWebPageToJEditorPane {
>>>>>>>>>>
>>>>>>>>>> private static final String HTML_PATH =
>>>>>>>>>> "http://serever/path/sample.html";
>>>>>>>>>>
>>>>>>>>>> public static void main(String[] a) throws Exception {
>>>>>>>>>>
>>>>>>>>>> SwingUtilities.invokeAndWait(new Runnable() {
>>>>>>>>>>
>>>>>>>>>> @Override
>>>>>>>>>> public void run() {
>>>>>>>>>> try {
>>>>>>>>>>
>>>>>>>>>> JFrame frame = new JFrame();
>>>>>>>>>> frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
>>>>>>>>>>
>>>>>>>>>> JEditorPane editorPane = new JEditorPane();
>>>>>>>>>> editorPane.setPage(new URL(HTML_PATH));
>>>>>>>>>>
>>>>>>>>>> frame.add(new JScrollPane(editorPane));
>>>>>>>>>> frame.setSize(300, 200);
>>>>>>>>>> frame.setVisible(true);
>>>>>>>>>> SwingUtilities.updateComponentTreeUI(editorPane);
>>>>>>>>>> } catch (Exception ex) {
>>>>>>>>>> throw new RuntimeException(ex);
>>>>>>>>>> }
>>>>>>>>>> }
>>>>>>>>>> });
>>>>>>>>>> }
>>>>>>>>>> }
>>>>>>>>>> ---------------------------------------
>>>>>>>>>>
>>>>>>>>>> Thanks,
>>>>>>>>>> Alexandr.
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> On 11/28/2012 10:29 AM, Frank Ding wrote:
>>>>>>>>>>> Hi Alexandr,
>>>>>>>>>>> I created a new patch v8 @
>>>>>>>>>>> http://cr.openjdk.java.net/~dingxmin/7189299/webrev.08/. It
>>>>>>>>>>> uses the newly proposed approach mentioned in my last email.
>>>>>>>>>>> Could you please help to review it again?
>>>>>>>>>>>
>>>>>>>>>>> The patch, of course, passed jtreg test bug7189299.java in
>>>>>>>>>>> the patch. What's more, I did additional tests for JComboBox,
>>>>>>>>>>> JTextField and JList in my IDE by comparing listener numbers
>>>>>>>>>>> observed during debugging with/without my patch. The listener
>>>>>>>>>>> numbers were doubled without the fix. This proves that v8
>>>>>>>>>>> patch works for all components. I think I can write those
>>>>>>>>>>> additional tests as jtreg tests after the patch passes review.
>>>>>>>>>>>
>>>>>>>>>>> One notable change is that I had to restrict the scope of
>>>>>>>>>>> holding a write lock in DefaultStyledDocument because
>>>>>>>>>>> otherwise, we cannot store the new component created in
>>>>>>>>>>> FormView.createComponent(). The stack trace is pasted below
>>>>>>>>>>> for reference.
>>>>>>>>>>>
>>>>>>>>>>> Exception in thread "main"
>>>>>>>>>>> java.lang.reflect.InvocationTargetException
>>>>>>>>>>> at java.awt.EventQueue.invokeAndWait(EventQueue.java:1270)
>>>>>>>>>>> at
>>>>>>>>>>> javax.swing.SwingUtilities.invokeAndWait(SwingUtilities.java:1350)
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>> at bug7189299.main(bug7189299.java:116)
>>>>>>>>>>> Caused by: java.lang.IllegalStateException: Attempt to mutate
>>>>>>>>>>> in notification
>>>>>>>>>>> at
>>>>>>>>>>> javax.swing.text.AbstractDocument.writeLock(AbstractDocument.java:1357)
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>> at
>>>>>>>>>>> javax.swing.text.html.HTMLDocument.obtainLock(HTMLDocument.java:1708)
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>> at
>>>>>>>>>>> javax.swing.text.html.FormView.createComponent(FormView.java:211)
>>>>>>>>>>>
>>>>>>>>>>> ......(omitted)......
>>>>>>>>>>> at
>>>>>>>>>>> javax.swing.plaf.basic.BasicTextUI$RootView.insertUpdate(BasicTextUI.java:1602)
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>> at
>>>>>>>>>>> javax.swing.plaf.basic.BasicTextUI$UpdateHandler.insertUpdate(BasicTextUI.java:1861)
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>> at
>>>>>>>>>>> javax.swing.text.AbstractDocument.fireInsertUpdate(AbstractDocument.java:201)
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>> at
>>>>>>>>>>> javax.swing.text.DefaultStyledDocument.create(DefaultStyledDocument.java:155)
>>>>>>>>>>>
>>>>>>>>>>> <------ FormView.createComponent is triggered by this call
>>>>>>>>>>> which has already held the lock
>>>>>>>>>>> at
>>>>>>>>>>> javax.swing.text.html.HTMLDocument.create(HTMLDocument.java:469)
>>>>>>>>>>>
>>>>>>>>>>> ......(omitted)......
>>>>>>>>>>>
>>>>>>>>>>> This change did violate what is documented in
>>>>>>>>>>> AbstractDocument.writeLock that "This situation violates the
>>>>>>>>>>> bean event model where order of delivery is not guaranteed and
>>>>>>>>>>> all listeners should be notified before further mutations are
>>>>>>>>>>> allowed. " However, without the change of shrinking lock
>>>>>>>>>>> scope, the component cannot be saved once it is created in
>>>>>>>>>>> FormView.createComponent(). I found it is even harder to save
>>>>>>>>>>> it later in code but perhaps there does exist a more
>>>>>>>>>>> appropriate place to do this. If you have any better
>>>>>>>>>>> suggestion, I am glad to know.
>>>>>>>>>>>
>>>>>>>>>>> Also I searched references to
>>>>>>>>>>> 'StyleConstants.ComponentAttribute' as you asked. The result
>>>>>>>>>>> is listed below. Note that the command 'grep' is invoked
>>>>>>>>>>> under openjdk 8 top directory.
>>>>>>>>>>> $ grep -R 'ComponentAttribute' .
>>>>>>>>>>> ./jdk/src/share/classes/javax/swing/text/StyleConstants.java:
>>>>>>>>>>> public static final Object ComponentAttribute = new
>>>>>>>>>>> CharacterConstants("component");
>>>>>>>>>>> ./jdk/src/share/classes/javax/swing/text/StyleConstants.java:
>>>>>>>>>>> return (Component) a.getAttribute(ComponentAttribute);
>>>>>>>>>>> ./jdk/src/share/classes/javax/swing/text/StyleConstants.java:
>>>>>>>>>>> a.addAttribute(ComponentAttribute, c);
>>>>>>>>>>> ./jdk/src/share/classes/javax/swing/text/StyleConstants.java:
>>>>>>>>>>> Background, ComponentAttribute, IconAttribute,
>>>>>>>>>>> ./jdk/src/share/classes/javax/swing/text/StyledEditorKit.java:
>>>>>>>>>>> set.removeAttribute(StyleConstants.ComponentAttribute);
>>>>>>>>>>> Binary file ./jdk/test/sun/tools/jhat/jmap.bin matches
>>>>>>>>>>>
>>>>>>>>>>> So ComponentAttribute is not referenced by other classes
>>>>>>>>>>> except StyledEditorKit. StyleConstants exposes
>>>>>>>>>>> ComponentAttribute in getComponent() and setComponent()
>>>>>>>>>>> methods. References to StyleConstants.getComponent and
>>>>>>>>>>> StyleConstants.setComponent are further searched in repo.
>>>>>>>>>>>
>>>>>>>>>>> $ grep -R 'StyleConstants.getComponent' .
>>>>>>>>>>> ./jdk/src/share/classes/javax/swing/text/ComponentView.java: *
>>>>>>>>>>> the element (by calling StyleConstants.getComponent). A
>>>>>>>>>>> ./jdk/src/share/classes/javax/swing/text/ComponentView.java:
>>>>>>>>>>> Component comp = StyleConstants.getComponent(attr);
>>>>>>>>>>>
>>>>>>>>>>> $ grep -R 'StyleConstants.setComponent' .
>>>>>>>>>>> ./jdk/src/share/classes/javax/swing/JTextPane.java:
>>>>>>>>>>> StyleConstants.setComponent(inputAttributes, c);
>>>>>>>>>>>
>>>>>>>>>>> From the facts above, I think we are sufficiently confident to
>>>>>>>>>>> use ComponentAttribute.
>>>>>>>>>>>
>>>>>>>>>>> Please let me know if you have any comments and I can do more
>>>>>>>>>>> regression tests and provide more jtreg test cases as next
>>>>>>>>>>> step.
>>>>>>>>>>>
>>>>>>>>>>> Thanks and regards,
>>>>>>>>>>> Frank
>>>>>>>>>>>
>>>>>>>>>>> On 11/15/2012 5:18 PM, Alexander Scherbatiy wrote:
>>>>>>>>>>>> On 11/14/2012 10:22 AM, Frank Ding wrote:
>>>>>>>>>>>>> Hi Alexandr,
>>>>>>>>>>>>> After a couple of hours investigating the possibility of
>>>>>>>>>>>>> fixing JComboBox.setModel(null) and
>>>>>>>>>>>>> JTextComponent.setComponent(null), I found that
>>>>>>>>>>>>> 1. In JComboBox.setModel, the new model, null in this case,
>>>>>>>>>>>>> is eventually passed to BasicComboPopup.propertyChange where
>>>>>>>>>>>>> JList.setModel is called. JList.setModel rejects the null
>>>>>>>>>>>>> model because of its api restriction. Below I listed the
>>>>>>>>>>>>> offending call stacks in my IDE. This makes sense as the
>>>>>>>>>>>>> associated drop down JList needs new model. However, it
>>>>>>>>>>>>> makes fixing JComboBox.setModel(null) hard or impossible.
>>>>>>>>>>>>> Exception in thread "main"
>>>>>>>>>>>>> java.lang.IllegalArgumentException: model must be non null
>>>>>>>>>>>>> at javax.swing.JList.setModel(JList.java:1674)
>>>>>>>>>>>>> at
>>>>>>>>>>>>> javax.swing.plaf.basic.BasicComboPopup$Handler.propertyChange(BasicComboPopup.java:939)
>>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>>>>>>>> at
>>>>>>>>>>>>> java.beans.PropertyChangeSupport.fire(PropertyChangeSupport.java:335)
>>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>>>>>>>> at
>>>>>>>>>>>>> java.beans.PropertyChangeSupport.firePropertyChange(PropertyChangeSupport.java:327)
>>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>>>>>>>> at
>>>>>>>>>>>>> java.beans.PropertyChangeSupport.firePropertyChange(PropertyChangeSupport.java:263)
>>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>>>>>>>> at
>>>>>>>>>>>>> java.awt.Component.firePropertyChange(Component.java:8413)
>>>>>>>>>>>>> at javax.swing.JComboBox.setModel(JComboBox.java:322)
>>>>>>>>>>>>>
>>>>>>>>>>>>> 2. JTextComponent.setComponent(null) can be fixed but code
>>>>>>>>>>>>> change in BasicTextUI is also required.
>>>>>>>>>>>>>
>>>>>>>>>>>>> Since setting null model to JComboBox, JList and
>>>>>>>>>>>>> JTextComponent is impossible or dangerous, just as you
>>>>>>>>>>>>> mentioned, we could set a non null new model to these UI
>>>>>>>>>>>>> components just for the purpose of having the side effect of
>>>>>>>>>>>>> removing listeners from old model. Are you ok with this
>>>>>>>>>>>>> approach?
>>>>>>>>>>>> Yes. Please, try this and run the html swing automated
>>>>>>>>>>>> tests from the test/javax/swing/text/html diroctory to check
>>>>>>>>>>>> possible regressions.
>>>>>>>>>>>>
>>>>>>>>>>>> Thanks,
>>>>>>>>>>>> Alexandr.
>>>>>>>>>>>>
>>>>>>>>>>>>> By the way, I will investigate your another question "Could
>>>>>>>>>>>>> you also check that the StyleConstants.ComponentAttribute
>>>>>>>>>>>>> property value can't be rewritten by the JDK code or by
>>>>>>>>>>>>> public methods." and reply soon.
>>>>>>>>>>>>>
>>>>>>>>>>>>> Best regards,
>>>>>>>>>>>>> Frank
>>>>>>>>>>>>>
>>>>>>>>>>>>> On 11/13/2012 7:49 PM, Alexander Scherbatiy wrote:
>>>>>>>>>>>>>> On 11/13/2012 11:53 AM, Frank Ding wrote:
>>>>>>>>>>>>>>> Hi Alexandr,
>>>>>>>>>>>>>>> As for your comment "Could you create an issue that a
>>>>>>>>>>>>>>> JComboBox.setModel(null) call throws NPE? You could fix it
>>>>>>>>>>>>>>> before the 7189299 issue. ", I created a bug with internal
>>>>>>>>>>>>>>> review ID of 2381499 on JComboBox.setModel(null). But
>>>>>>>>>>>>>>> test shows that JPasswordField.setDocument(null),
>>>>>>>>>>>>>>> JTextField.setDocument(null), JList.setModel(null) and
>>>>>>>>>>>>>>> JTextArea.setDocument(null) all throw NPE. Particularly,
>>>>>>>>>>>>>>> JList.setModel(null) has null check and throws
>>>>>>>>>>>>>>> IllegalArgumentException("model" must be non null"). Shall
>>>>>>>>>>>>>>> I include those components as well?
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> There is the javadoc for the JList setModel() method:
>>>>>>>>>>>>>> Throws IllegalArgumentException - if model is null. So it
>>>>>>>>>>>>>> is undesirable to change the public API.
>>>>>>>>>>>>>> However, it is possible to set a new empty model for
>>>>>>>>>>>>>> the JList. The list listeners should be removed from the
>>>>>>>>>>>>>> old model in this case.
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> You could have only 2 issues: one for components that
>>>>>>>>>>>>>> allow to set a null model but throws NPE (like JComboBox)
>>>>>>>>>>>>>> and another for components that does not allow to set null
>>>>>>>>>>>>>> model but they do not remove listeners from the old model
>>>>>>>>>>>>>> in case if a new model is set.
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> Thanks,
>>>>>>>>>>>>>> Alexandr.
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> Thanks for your guidance in advance.
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> Best regards,
>>>>>>>>>>>>>>> Frank
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> On 11/8/2012 10:55 PM, Alexander Scherbatiy wrote:
>>>>>>>>>>>>>>>> On 11/7/2012 10:56 AM, Frank Ding wrote:
>>>>>>>>>>>>>>>>> Hi Alexandr,
>>>>>>>>>>>>>>>>> Unfortunately, all the JComponents involved in
>>>>>>>>>>>>>>>>> FormView.createComponent() have bugs!
>>>>>>>>>>>>>>>>> I have done tests for all other swing components, i.e.
>>>>>>>>>>>>>>>>> JCheckBox, JRadioButton, JPasswordField, JTextField,
>>>>>>>>>>>>>>>>> JList, JComboBox and JTextField. Sadder news is that if
>>>>>>>>>>>>>>>>> we fix all components in the same way as I did for
>>>>>>>>>>>>>>>>> JButton, we need to subclass them all, resulting in
>>>>>>>>>>>>>>>>> JCheckBoxWrapper, JRadioButtonWrapper,
>>>>>>>>>>>>>>>>> JPasswordFieldWrapper, JTextFieldWrapper, JListWrapper,
>>>>>>>>>>>>>>>>> JComboBoxWrapper, JTextFieldWrapper plus
>>>>>>>>>>>>>>>>> JButtonWrapper! This approach becomes unacceptable when
>>>>>>>>>>>>>>>>> all swing components are affected.
>>>>>>>>>>>>>>>>> Shall we fix it in other way illustrated below?
>>>>>>>>>>>>>>>>> 1. Whenever a swing component is created, it is kept in
>>>>>>>>>>>>>>>>> AttributeSet, as what is now for model.
>>>>>>>>>>>>>>>>> 2. In FormView.createComponent(), the old swing
>>>>>>>>>>>>>>>>> component can be retrieved via
>>>>>>>>>>>>>>>>> attr.getAttribute(StyleConstants.ComponentAttribute).
>>>>>>>>>>>>>>>>> Note that ComponentAttribute is newly added.
>>>>>>>>>>>>>>>> This way should be carefully investigated that it
>>>>>>>>>>>>>>>> does not introduce new memory leaks.
>>>>>>>>>>>>>>>> Could you also check that the
>>>>>>>>>>>>>>>> StyleConstants.ComponentAttribute property value can't be
>>>>>>>>>>>>>>>> rewritten by the JDK code or by public methods.
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> 3. Before setting shared model to a newly initialized
>>>>>>>>>>>>>>>>> swing component, call oldComp.setModel(null), delegating
>>>>>>>>>>>>>>>>> deregistration to setModel method.
>>>>>>>>>>>>>>>>> 4. Seems some setModel such as AbstractButton.setModel()
>>>>>>>>>>>>>>>>> can function well when the param, new model, is null
>>>>>>>>>>>>>>>>> while JComboBox.setModel() will throw NPE in case of
>>>>>>>>>>>>>>>>> null param.
>>>>>>>>>>>>>>>> Could you create an issue that a
>>>>>>>>>>>>>>>> JComboBox.setModel(null) call throws NPE? You could fix
>>>>>>>>>>>>>>>> it before the 7189299 issue.
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> Thanks,
>>>>>>>>>>>>>>>> Alexandr.
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> 5. Add null check code in those problematic setModel or
>>>>>>>>>>>>>>>>> setDocument methods.
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> Any idea is appreciated. Thanks.
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> Best regards,
>>>>>>>>>>>>>>>>> Frank
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> On 11/6/2012 9:26 PM, Alexander Scherbatiy wrote:
>>>>>>>>>>>>>>>>>> On 11/5/2012 11:20 AM, Frank Ding wrote:
>>>>>>>>>>>>>>>>>>> Hi Alexander,
>>>>>>>>>>>>>>>>>>> Based on your comments last time, I refined my patch
>>>>>>>>>>>>>>>>>>> of v6 and offered v7 @
>>>>>>>>>>>>>>>>>>> http://cr.openjdk.java.net/~dingxmin/7189299/webrev.07/
>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>> This version of the fix looks good for me.
>>>>>>>>>>>>>>>>>> It seems that it is the only good way to check
>>>>>>>>>>>>>>>>>> that a button model contains AbstarctButton.Handler
>>>>>>>>>>>>>>>>>> listener.
>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>> Could you also check that others models used in the
>>>>>>>>>>>>>>>>>> createComponent() method do not have such memory leaks
>>>>>>>>>>>>>>>>>> (even the NPE is not thrown)?
>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>> 4. Could you add the check that the action listener
>>>>>>>>>>>>>>>>>>> is invoked only once after a component tree updating
>>>>>>>>>>>>>>>>>>> and the action does the same that it does before a
>>>>>>>>>>>>>>>>>>> component tree updating?
>>>>>>>>>>>>>>>>>>> Answer: I am afraid I could not make it in the auto
>>>>>>>>>>>>>>>>>>> test (bug7189299.java) but I can achieve it to some
>>>>>>>>>>>>>>>>>>> degree in manual test FormSubmit, the one you
>>>>>>>>>>>>>>>>>>> illustrated below.
>>>>>>>>>>>>>>>>>>> My idea of checking it in FormSubmit.java is
>>>>>>>>>>>>>>>>>>> subclassing JEditorPane and overriding 'public
>>>>>>>>>>>>>>>>>>> EditorKit getEditorKit()' where stack traces can be
>>>>>>>>>>>>>>>>>>> examined in the overridden method to make sure
>>>>>>>>>>>>>>>>>>> FormView.submitData occurs only once. This approach
>>>>>>>>>>>>>>>>>>> works because FormView.submitData() calls
>>>>>>>>>>>>>>>>>>> JEditorPane.getEditorKit but is tricky. However, it's
>>>>>>>>>>>>>>>>>>> the only way I can think of without any additional
>>>>>>>>>>>>>>>>>>> framework support. If you are in favor of adding the
>>>>>>>>>>>>>>>>>>> check in FormSubmit.java, I am willing to do that.
>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>> At least a separated manual test can be added
>>>>>>>>>>>>>>>>>> that asks a user to put a response.html file to a
>>>>>>>>>>>>>>>>>> server and according to the server url checks that
>>>>>>>>>>>>>>>>>> JTeditor pane show the response text after a button
>>>>>>>>>>>>>>>>>> pressing.
>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>> html = new JEditorPane("text/html",
>>>>>>>>>>>>>>>>>> "<html><body><form action=\"" + userURL + "\">"
>>>>>>>>>>>>>>>>>> + "<input type=submit
>>>>>>>>>>>>>>>>>> name=submit value=\"submit\"/>"
>>>>>>>>>>>>>>>>>> + "</form></body></html>");
>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>> response.html:
>>>>>>>>>>>>>>>>>> <html> <body> Hello World! </body> </html>
>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>> Thanks,
>>>>>>>>>>>>>>>>>> Alexandr.
>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>> Thanks again for all your comments and your support.
>>>>>>>>>>>>>>>>>>> Once again, if you have any further concern or
>>>>>>>>>>>>>>>>>>> comment, please don't hesitate to let me know.
>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>> Best regards,
>>>>>>>>>>>>>>>>>>> Frank
>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>
>>>>>>>>
>>>>>>>
>>>>>>
>>>>>
>>>>
>>>
>>
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