<Swing Dev> [Accessibility]Focus unable to traverse in the menubar

Frank Ding dingxmin at linux.vnet.ibm.com
Thu Dec 13 09:01:54 UTC 2012 

Hi Alexandr,
   I made another change according to your comment @ 
http://cr.openjdk.java.net/~dingxmin/8000326/webrev.02 .  Please review it.
   I submitted a bug whose internal review ID is 2401619 about one 
wording mistake in ContainerOrderFocusTraversalPolicy.  But since the 
bug system transition, newly submitted bugs cannot pass review and get 
publicly available.  Can you help me to have somebody review it?

   Thanks and Best regards,
   Frank

On 12/12/2012 10:07 PM, Alexander Scherbatiy wrote:
> On 12/10/2012 11:08 AM, Frank Ding wrote:
>> Hi Pavel,
>>   I think pointing out the special behavior in javadoc makes more 
>> sense.  Could you please take a look at my draft below?
>>   http://cr.openjdk.java.net/~dingxmin/8000326/webrev.01
>      I think that It has more sense to point this special behavior in 
> the JMenuBar class itself.
>      It looks more naturally to read about the JMenuBar focus 
> traversal behaviour from the JMenuBar javadoc.
>
>>   Note that I think in the sentence "By default, methods of this 
>> class with return a Component only if it is" it should be "will" not 
>> "with", shouldn't it?
>      Thank you that you point it out. Could you create an issue on it?
>
>     Thanks,
>     Alexandr.
>>
>>   Expecting your reply.
>> Best regards,
>> Frank
>>
>> On 10/8/2012 7:47 PM, pavel porvatov wrote:
>>> Hi Jonathan,
>>>> Hi Pavel,
>>>>
>>>> On 10/02/2012 11:31 PM, Pavel Porvatov wrote:
>>>>> Hi Jonathan,
>>>>>> Hi Pavel,
>>>>>>
>>>>>> I've filed bug 7198816 for this problem,
>>>>>>
>>>>>> Regards, Pavel
>>>>>> http://bugs.sun.com/view_bug.do?bug_id=7198816
>>>>> This bug was not ported to jira, so I created another bug:
>>>>> https://jbs.oracle.com/bugs/browse/JDK-8000326
>>>>
>>>> Thanks for porting, but I have trouble with opening that link.
>>> Sorry, use the following link:
>>> http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=8000326
>>>
>>> but the bug is not available yet... It contains the same description 
>>> as the original bug.
>>>
>>>> Any comments on the patch?
>>> The fix looks dangerous for me. After the fix the 
>>> setFocusTraversalKeysEnabled method doesn't work for JMenuBar (when 
>>> ContainerOrderFocusTraversalPolicy is used) - it ignores this 
>>> property...
>>>
>>> Regards, Pavel
>>>>
>>>> best regards
>>>> Jonathan
>>>>
>>>>>
>>>>> Regards, Pavel
>>>>>>
>>>>>> On 11/09/2011 07:25 PM, Pavel Porvatov wrote:
>>>>>>> Hi Jing,
>>>>>>>> Thanks Pavel,
>>>>>>>>
>>>>>>>>      It seems fine to me, if no other suggestions/opinions, I 
>>>>>>>> guess we can move on with this?
>>>>>>> Yes, we can. Could you please file a bug for the problem as well?
>>>>>>>
>>>>>>> Thanks, Pavel
>>>>>>>>
>>>>>>>> On 2011/11/2 19:58, Pavel Porvatov wrote:
>>>>>>>>> Hi Jing,
>>>>>>>>>>
>>>>>>>>>> Hello Anton,
>>>>>>>>>>
>>>>>>>>>>     Thanks for the review. I am still trying to figure out 
>>>>>>>>>> some real case and provide more detail the customer may fail.
>>>>>>>>>>     Anyway, I agree we'd better update the java spec to make 
>>>>>>>>>> it clear for the customers. I'd like to know if anyone can 
>>>>>>>>>> help with that?
>>>>>>>>> I'm not sure that javadoc changing is a good decision in this 
>>>>>>>>> case. ContainerOrderFocusTraversalPolicy is designed for AWT, 
>>>>>>>>> but I don't know why that policy cannot be used for Swing 
>>>>>>>>> components as well. I see several problems:
>>>>>>>>> 1. We cannot change javadoc of 
>>>>>>>>> ContainerOrderFocusTraversalPolicy because of backward 
>>>>>>>>> compatibility
>>>>>>>>> 2. We cannot remove setFocusTraversalKeysEnabled(false) from 
>>>>>>>>> the JMenuBar#JMenuBar() constructor because of backward 
>>>>>>>>> compatibility
>>>>>>>>>
>>>>>>>>> May be the best decision is to specify, that JMenuBar creates 
>>>>>>>>> menu with the focusTraversalKeysEnabled = false
>>>>>>
>>>>>> Did you mean that for the new menu 
>>>>>> setFocusTraversalKeysEnabled(false) ? I've tried, but it does not 
>>>>>> seem to work for this problem.
>>>>>>
>>>>>>  if my understanding is incorrect, please help to fix me.
>>>>>>
>>>>>>>>>
>>>>>>>>> Regards, Pavel
>>>>>>>>>>
>>>>>>>>>> On 2011/10/12 20:54, Anton Tarasov wrote:
>>>>>>>>>>> Hi Neil,
>>>>>>>>>>>
>>>>>>>>>>> On 10/10/2011 7:01 PM, Neil Richards wrote:
>>>>>>>>>>>> On Mon, 2011-10-10 at 16:56 +0400, Anton Tarasov wrote:
>>>>>>>>>>>>> Hi Neil and Jing,
>>>>>>>>>>>>> I'm afraid that it's wrong to use 
>>>>>>>>>>>>> ContainerOrderFocusTraversalPolicy
>>>>>>>>>>>>> for swing components. This policy is designed for AWT.
>>>>>>>>>>>>> JMenuBar calls setFocusTraversalKeysEnabled(false) in its 
>>>>>>>>>>>>> ctor which
>>>>>>>>>>>>> means that it "swallows" focus traversal keys (like 
>>>>>>>>>>>>> TAB/SHIFT-TAB
>>>>>>>>>>>>> etc.)
>>>>>>>>>>>>> and so it can't be a member of a focus traversal chain. 
>>>>>>>>>>>>> Swing's
>>>>>>>>>>>>> default traversal policy (LayoutFocusTraversalPolicy) 
>>>>>>>>>>>>> excludes
>>>>>>>>>>>>> JMenuBar
>>>>>>>>>>>>> from a focus traversal cycle. 
>>>>>>>>>>>>> ContainerOrderFocusTraversalPolicy is
>>>>>>>>>>>>> not "aware" about JMenuBar and so it allows it.
>>>>>>>>>>>>>
>>>>>>>>>>>>> So, either a default Swing policy should be used, or a 
>>>>>>>>>>>>> custom policy.
>>>>>>>>>>>>> At worst, ContainerOrderFocusTraversalPolicy should be 
>>>>>>>>>>>>> overriden
>>>>>>>>>>>>> to exclude JMenuBar from a cycle (override its 
>>>>>>>>>>>>> accept(Component)
>>>>>>>>>>>>> method).
>>>>>>
>>>>>> I agree that backward compatibility should not be broken by the 
>>>>>> fix, so here's a patch from me for the worst case, could you 
>>>>>> please help to take a look?
>>>>>>
>>>>>> http://cr.openjdk.java.net/~luchsh/7198816/
>>>>>>
>>>>>> Thanks
>>>>>> Jonathan
>>>>>>
>>>>>>>>>>>>>
>>>>>>>>>>>>> Thanks,
>>>>>>>>>>>>> Anton.
>>>>>>>>>>>> Hi Anton,
>>>>>>>>>>>> Thanks for reviewing the suggestion, and for your insights 
>>>>>>>>>>>> into this
>>>>>>>>>>>> scenario.
>>>>>>>>>>>>
>>>>>>>>>>>> > From the Javadoc, it seems that 
>>>>>>>>>>>> setFocusTraversalKeysEnabled() is mainly
>>>>>>>>>>>> concerned with choosing whether focus traversal key presses 
>>>>>>>>>>>> (normally
>>>>>>>>>>>> TAB and SHIFT-TAB) are processed "automatically" (when 
>>>>>>>>>>>> 'true') or are
>>>>>>>>>>>> delivered to the Component as key events (for the 
>>>>>>>>>>>> component's code to
>>>>>>>>>>>> process "manually").
>>>>>>>>>>>>
>>>>>>>>>>>> (In the case of JMenuBar, it makes them come through as key 
>>>>>>>>>>>> events, but
>>>>>>>>>>>> doesn't do anything special to process these events, which 
>>>>>>>>>>>> is why they
>>>>>>>>>>>> get discarded.)
>>>>>>>>>>>
>>>>>>>>>>> That is right, though it doesn't directly relate to the 
>>>>>>>>>>> issue we're talking about =)
>>>>>>>>>>>
>>>>>>>>>>>> Your description above, though, seems to suggest that it is 
>>>>>>>>>>>> generally
>>>>>>>>>>>> undesirable for the JMenuBar to be given the focus, as all the
>>>>>>>>>>>> Swing-aware focus traversal policies make a point of not 
>>>>>>>>>>>> giving focus to
>>>>>>>>>>>> JMenuBar items.
>>>>>>>>>>>>
>>>>>>>>>>>> If this is so, then wouldn't it make sense to call 
>>>>>>>>>>>> setFocusable(false)
>>>>>>>>>>>> from its constructor (too), to ensure it doesn't get focus ?
>>>>>>>>>>>>
>>>>>>>>>>>> Or, to put it another way, could you explain a little of 
>>>>>>>>>>>> the reasoning
>>>>>>>>>>>> or scenario behind why it is desirable for JMenuBar items 
>>>>>>>>>>>> to be
>>>>>>>>>>>> generally focusable, even though they aren't 
>>>>>>>>>>>> focus-traversable ?
>>>>>>>>>>>>
>>>>>>>>>>>> I think such an explanation would be really helpful in 
>>>>>>>>>>>> clearing up my
>>>>>>>>>>>> confusion on this point.
>>>>>>>>>>>>
>>>>>>>>>>>> Thanks, Neil
>>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>> Well, I suspect that the core of the problem is that adding 
>>>>>>>>>>> JMenuBar as JComponent to a swing
>>>>>>>>>>> container doesn't make much sense. Though it is not directly 
>>>>>>>>>>> prohibited, doing so may cause
>>>>>>>>>>> side effects like the one you've discovered. When JMenuBar 
>>>>>>>>>>> is set properly onto a JFrame its focus
>>>>>>>>>>> is managed by JRootPane and its focusability just isn't 
>>>>>>>>>>> taken into account. That's may be the reason
>>>>>>>>>>> it's not declared unfocusable. Honestly, I can't tell you 
>>>>>>>>>>> exactly.
>>>>>>>>>>>
>>>>>>>>>>> If you do it, you probably won't make any harm, but I 
>>>>>>>>>>> personally don't think this is a vital fix
>>>>>>>>>>> (unless you have a good use case of the scenario you've 
>>>>>>>>>>> provided). Anyway, this is a swing question
>>>>>>>>>>> (I'm, as an AWT dev member, leaving the decision to swing 
>>>>>>>>>>> guys).
>>>>>>>>>>>
>>>>>>>>>>> Thanks,
>>>>>>>>>>> Anton.
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>
>>>>>>>>
>>>>>>>
>>>>>>
>>>>>
>>>>
>>>
>>
>

More information about the swing-dev mailing list