<Swing Dev> [9] Review request for 8074883: Tab key should move to focused button in a button group

[Semyon Sadetsky]

On 24.11.2016 17:08, Sergey Bylokhov wrote:
> On 14.11.16 19:41, Semyon Sadetsky wrote:
>>>>  247      * If this toggle button is a member of the {@link 
>>>> ButtonGroup}
>>>> which has
>>>>  248      * an another ***focusable*** toggle button selected, and the
>>>> focus cause argument
>>>>
>>>> in Swing a component may not receive focus if it is disabled, 
>>>> invisible,
>>>> non-displayable...
>>>> According to the spec the result will be the same if you call
>>>> Component#requestFocus on ***this*** toggle button.
>>>
>>> It just confirms that the new spec is not complete, result of
>>> "Component#requestFocus on ***this*** toggle button" will be different
>>> from the result of "selected#requestFocus(FocusEvent.Cause)" if the
>>> selected component is disabled. Because "Component#requestFocus on
>>> ***this*** toggle button" will select "this", and
>>> "selected#requestFocus(FocusEvent.Cause)" will select nothing.
>> I did not get this. There two results of the call 1)
>> selected.Component#requestFocus 2) this.Component#requestFocus. Of cause
>> they are different.
>
> Yes they are different and can results the different results, but 
> currently spec says the opposite: "(1) method execution is the same as 
> calling (2)". It will be good to rephrase it somehow that we will try 
> to move focus to the selected component.
I still do not understand what inconsistency between the code and the 
spec did you find. I think it would be easier if you just write your 
vision of the spec.
>
>> They cover 100% of outcome. "select nothing" is not
>> mentioned in the spec. Is it really needed?
>>> The property "***focusable***" is a defined in the
>>> Component#isFocusable() and have nothing related to visibility, enable
>>> state/etc. It will return true if component is disabled.
>> I did not mean isFocusable property, but the general capability to get
>> focus. The standard check for focusability is isVisible() &&
>> isDisplayable() && isEnabled() && isFocusable().
>
> What you mean is not "focusable" but possibility to be a "focus owner".
I don't see a big difference between those two. So I'm good with 
replacing "focusable" by "can be a focus owner".
>
>
>>>
>>>>>
>>>>>>>
>>>>>>>>>
>>>>>>>> If a component is disabled it cannot receive input focus, see
>>>>>>>> java.awt.Component#isEnabled specs.  The proposed spec clearly
>>>>>>>> states :
>>>>>>>>
>>>>>>>>  247      * If this toggle button is a member of the {@link
>>>>>>>> ButtonGroup}
>>>>>>>> which has
>>>>>>>>  248      * an another ***focusable*** toggle button selected,
>>>>>>>> and the
>>>>>>>> focus cause argument
>>>>>>>>
>>>>>>>>> It seems that the code in getGroupSelection() will focus the 
>>>>>>>>> first
>>>>>>>>> element in the group, but what elements will be focused if we 
>>>>>>>>> call
>>>>>>>>> Component#requestFocus(FocusEvent.Cause) directly for this 
>>>>>>>>> disabled
>>>>>>>>> compoenent? Will the the same(first) element be selected?
>>>>>>>> I did find any mentions of "first element" in the proposed spec.
>>>>>>>> Please
>>>>>>>> clarify this question.
>>>>>>>> According to the proposed spec the case when
>>>>>>>> Component#requestFocus(FocusEvent.Cause) is called on disabled
>>>>>>>> component
>>>>>>>> will be handled as:
>>>>>>>>
>>>>>>>>  253      * In all other cases the result of the method is the
>>>>>>>> same as
>>>>>>>> calling
>>>>>>>>  254      * {@link Component#requestFocus(FocusEvent.Cause)} on 
>>>>>>>> this
>>>>>>>> toggle button.
>>>>>>>
>>>>>>> The specification states that the call to
>>>>>>> this.requestFocus(FocusEvent.Cause cause);
>>>>>>> and the call to
>>>>>>> selected.requestFocus(FocusEvent.Cause cause);
>>>>>>> produce the same result "If this toggle button is a member of the
>>>>>>> {@link ButtonGroup} which has an another focusable toggle button
>>>>>>> selected, and the focus cause argument denotes window activation or
>>>>>>> focus traversal action of any direction"
>>>>>>>
>>>>>>> The question was "is that always true if the selected element is
>>>>>>> disabled(but focusable)"? I guess that the implementation in the 
>>>>>>> fix
>>>>>>> will select the first "this"(the button on which requestFocus() was
>>>>>>> called), but in the second case something different will be 
>>>>>>> selected.
>>>>>>>
>>>>>>>>>> On 10/25/2016 3:14 PM, Alexandr Scherbatiy wrote:
>>>>>>>>>>> On 10/19/2016 8:14 PM, Semyon Sadetsky wrote:
>>>>>>>>>>>> Hello,
>>>>>>>>>>>>
>>>>>>>>>>>> Please review fix for JDK9:
>>>>>>>>>>>>
>>>>>>>>>>>> bug: https://bugs.openjdk.java.net/browse/JDK-8074883
>>>>>>>>>>>>
>>>>>>>>>>>> webrev: 
>>>>>>>>>>>> http://cr.openjdk.java.net/~ssadetsky/8074883/webrev.00/
>>>>>>>>>>>>
>>>>>>>>>>>> To avoid unexpected selection change the selected button of a
>>>>>>>>>>>> button
>>>>>>>>>>>> group should always grab focus when focus is transferred form
>>>>>>>>>>>> component outside the group to any unselected button inside 
>>>>>>>>>>>> the
>>>>>>>>>>>> group
>>>>>>>>>>>> in case of traversal or initial container activation actions.
>>>>>>>>>>>   - It is better to pass the cause and boolean focusInWindow
>>>>>>>>>>> arguments
>>>>>>>>>>> to the getGroupSelection() method to avoid some code 
>>>>>>>>>>> duplication
>>>>>>>>>>> like
>>>>>>>>>>> switching over the same cause values.
>>>>>>>>>>>   - The fix will require a CCC request because it updates a
>>>>>>>>>>> javadoc
>>>>>>>>>>> for the publci method.
>>>>>>>>>>>
>>>>>>>>>>>   Thanks,
>>>>>>>>>>>   Alexandr.
>>>>>>>>>>>>
>>>>>>>>>>>> --Semyon
>>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>
>>>>>
>>>>>
>>>>
>>>
>>>
>>
>
>