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Re: Eclipse

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On 6/29/2017 4:49 PM, Eric Douglas wrote:
> On Thursday, June 29, 2017 at 4:34:59 PM UTC-4, Eric Sosman wrote:
>>       The question I'd ask is: What does the Component's presence in (or
>> absence from) the List<MyCustomInterface> tell us?  That is, what will
>> the code do differently if the answer is "Here!" rather than "Huh?"
>> And -- here's the nub -- could the different action be handled more
>> smoothly by overriding focusGained() and/or focusLost() in the
>> MyCustomInterface implementation?
>>
>>       Maybe not, but that's the question I'd ask to start with.
> 
> This component, which is checking for focusGains on this array of components, has it's own list of listeners.  It is reporting a focusGain/focusLost event to those whenever one of these components gains or loses focus except if the focus came from one of these components and went to one of these components.  This custom event needs to treat these components as a group.

     My suggestion is to consider having the MyCustomInterface components
be their own FocusListeners instead of imposing the special treatment
"from the outside" as you seem to be doing now.  That is, a "special"
component would register itself as its own focus listener, and when
receiving a FocusEvent it could check whether the partner is or is not
also a "special" component.  The details depend on whether the special
treatment is applied to all MyCustomInterface implementations or only
to those on the list; you'd have either

	if (partner instanceof MyCustomInterface) ...

or

	if (partner instanceof MyCustomInterface
	    && list.contains((MyCustomInterface) partner)) ...

     If there's a good reason to handle FocusEvents externally to the
focused and unfocused components, well, fine: Just ignore my suggestion,
because I haven't had the reason explained to me.

> The only way I can see to get rid of the warning is to break it up to tell it they're components.
> 
> myComponentArray.contains(focusComponent)
> 
> becomes
> 
> for (MyCustomInterface i : myComponentArray)
>   if (((Component)i).equals(focusComponent)) {
>   }
> }

     Or cast focusComponent and use contains(), as above.

> I don't know any way to tell it for certain that yes any class which implements this interface does also extend Component.

     I can't think of a way off-hand, either.  (Elsethread you've already
rejected replacing MyCustomInterface with an abstract class that extends
Component.)  But even if you think of a way, it wouldn't help.  Your
problem is not that a MyCustomInterface implementation might not be a
Component, but that an unadorned Component (which is what the FocusEvent
gives you) might not implement MyCustomInterface.

-- 
esosman@comcast-dot-net.invalid
Thirteen hundred one days to go.

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Eclipse Eric Douglas <e.d.programmer@gmail.com> - 2017-06-28 07:57 -0700
  Re: Eclipse Eric Douglas <e.d.programmer@gmail.com> - 2017-06-28 09:04 -0700
    Re: Eclipse Eric Douglas <e.d.programmer@gmail.com> - 2017-06-28 12:07 -0700
      Re: Eclipse Eric Douglas <e.d.programmer@gmail.com> - 2017-06-29 06:05 -0700
        Re: Eclipse Jerry Stuckle <jstucklex@attglobal.net> - 2017-06-29 09:32 -0400
          Re: Eclipse Eric Douglas <e.d.programmer@gmail.com> - 2017-06-29 06:42 -0700
        Re: Eclipse Eric Sosman <esosman@comcast-dot-net.invalid> - 2017-06-29 09:47 -0400
          Re: Eclipse Andreas Leitgeb <avl@logic.at> - 2017-06-30 14:47 +0000
            Re: Eclipse Eric Douglas <e.d.programmer@gmail.com> - 2017-06-30 08:22 -0700
              Re: Eclipse Eric Douglas <e.d.programmer@gmail.com> - 2017-07-07 06:19 -0700
                Re: Eclipse Andreas Leitgeb <avl@logic.at> - 2017-07-13 09:29 +0000
        Re: Eclipse Martin Gregorie <martin@address-in-sig.invalid> - 2017-06-29 17:18 +0000
          Re: Eclipse Eric Douglas <e.d.programmer@gmail.com> - 2017-06-29 11:08 -0700
            Re: Eclipse Martin Gregorie <martin@address-in-sig.invalid> - 2017-06-29 18:58 +0000
              Re: Eclipse Eric Douglas <e.d.programmer@gmail.com> - 2017-06-29 12:55 -0700
                Re: Eclipse Martin Gregorie <martin@address-in-sig.invalid> - 2017-06-29 21:31 +0000
                Re: Eclipse Eric Douglas <e.d.programmer@gmail.com> - 2017-06-30 04:55 -0700
                Re: Eclipse Martin Gregorie <martin@address-in-sig.invalid> - 2017-06-30 13:02 +0000
              Re: Eclipse Eric Sosman <esosman@comcast-dot-net.invalid> - 2017-06-29 16:34 -0400
                Re: Eclipse Eric Douglas <e.d.programmer@gmail.com> - 2017-06-29 13:49 -0700
                Re: Eclipse Eric Sosman <esosman@comcast-dot-net.invalid> - 2017-06-29 18:16 -0400
  Re: Eclipse Arne Vajhøj <arne@vajhoej.dk> - 2017-07-02 11:56 -0400

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