On Thu, Mar 1, 2012 at 2:38 PM, Shaun Tarves <shaun@tarves.net> wrote:
> It still seems like an extra "event" at the very least. User selects, which
> fires selection change, which fires new place, which then "reselects" the
> item (the loop ends here since there no selection change would be fired
> given that the item is already selected).
>
> BUT, in the case of history movement (back/forward), new place is requested,
> place change is fired, which selects item, which fires selectionchange,
> which then again goes to new place.
>
> How would you not get an extra item on the history stack with this approach?
>
>
> On Thu, Mar 1, 2012 at 9:31 AM, Chris Price <price.c@gmail.com> wrote:
>>
>> In my example this is caught by the following in
>> SingleSelectionManager, which traps setting the selected value to be
>> itself -
>>
>> http://code.google.com/codesearch#T04cSGC7sWI/trunk/user/src/com/google/gwt/view/client/SingleSelectionModel.java&q=abstractselectionmodel%20package:http://google-web-toolkit%5C.googlecode%5C.com&l=106
>>
>> However, Jens raises a very good point about the potential downside of
>> this approach.
>>
>> Chris
>>
>> On Thu, Mar 1, 2012 at 2:23 PM, Shaun Tarves <shaun@tarves.net> wrote:
>> > @Thomas - In the example you pointed me to, what prevents this from
>> > essentially creating an infinite loop? OnSelectionChange fires a new
>> > history
>> > event. The history handler responds, gets info and changes the
>> > selection,
>> > which would in turn fire a new history event. No?
>> >
>> > @Chris - I think it's the same situation...your selection handler fires
>> > a
>> > new place, which selects and item, which would in turn fire a new place
>> > request. Right?
>> >
>> > Am I missing something here?
>> >
>> >
>> > On Thu, Mar 1, 2012 at 5:14 AM, Jens <jens.nehlmeier@gmail.com> wrote:
>> >>
>> >> You may also want to
>> >>
>> >> read: https://groups.google.com/d/topic/google-web-toolkit/dTwvMbxlFgI/discussion
>> >>
>> >> Its not directly related to your problem but as you are firing place
>> >> changes by listening on the selection model it could happen that your
>> >> UI may
>> >> gets inconsistent. This can happen if you use Activity.mayStop() to
>> >> provide
>> >> warning messages and the user chooses to cancel a place change. Without
>> >> considering this case your list will have the new item selected
>> >> (because you
>> >> clicked on it and CellList updates the selection model) while your
>> >> details
>> >> view still shows the old item (because the user cancels the place
>> >> change).
>> >>
>> >> -- J.
>> >>
>> >>
>> >> Am Mittwoch, 29. Februar 2012 14:30:21 UTC+1 schrieb Shaun Tarves:
>> >>>
>> >>> Hi all -
>> >>>
>> >>> First off, thanks for all the great info on this board. I've gotten so
>> >>> much out of it. However, I'm having a problem I haven't seen addressed
>> >>> before. Here's my scenario:
>> >>>
>> >>> 1) I have 2 places, 2 separate activity managers/mappers (one for a
>> >>> "menu" display area and one for "content" display area).
>> >>>
>> >>> 2) In the menu area is a basic CellList, with an attached selection
>> >>> handler that fires an event registered on the app's event bus to go to
>> >>> a new
>> >>> place. It also naturally "selects" the item in the menu.
>> >>>
>> >>> Selection of items/going to new places works naturally when the user
>> >>> is
>> >>> clicking around.
>> >>>
>> >>> My problem:
>> >>>
>> >>> When any history action is involved (via a direct URL or using
>> >>> back/forward in the browser), how to I handle selecting the
>> >>> appropriate item
>> >>> in the menu?
>> >>>
>> >>> The obvious choice is a place change handler in the menu, which, in
>> >>> turn,
>> >>> uses the menu's selection handler to select the appropriate item. BUT,
>> >>> since
>> >>> the selection handler fires an event to go to a new place upon
>> >>> selection, it
>> >>> introduces circular logic. (onPlaceChange does setSelected, then
>> >>> onSelection
>> >>> fires an event to change places)
>> >>>
>> >>> It's disconcerting that none of the sample apps (expenses,
>> >>> mobilewebapp)
>> >>> do any kind of item selection when you navigate DIRECTLY to a place
>> >>> via URL,
>> >>> but this seems like a really basic feature of a web application.
>> >>>
>> >>> Thoughts?
>> >>
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