[OpenLayers-Users] Hover control sample (share)

[Eric Lemoine]

Yeah, we can't solve that issue without storing some state in a
location shared by every control, the feature itself seems the good
spot.

Eric

2009/1/21, Alexandre Dube <adube at mapgears.com>:
> Hey Eric, Ivan,
>
>   That issue could occur if both controls would actually change the
> renderIntent of the feature ( without actually selecting the feature ).
>
>   Let's assume that you can only have one feature hovered at a time (
> only one feature can be hovered by the mouse).  That said, we could have
> its renderIntent copied to a this.oldRenderIntent local property, then
> on "beforefeatureunselected" restore the feature with its old
> renderIntent.  What do you think ?  Simple but that could work.
>
>   Also, can we agree on this : 2 SelectFeature controls both doing
> selection by click or both by hover are not compatible with multiple
> styling, so let's forget about this for now.
>
>   I'll definitively have to try all this soon.
>
> Alexandre
>
> Eric Lemoine wrote:
>> Hi
>>
>> A first note. The current select feature implementation should
>> accomodate this use case: two controls on the same layer, one working
>> on click and the other on hover, only one of them actually changing
>> the feature style. This is achievable by registering a
>> beforefeatureselected listener, and have this listener return false.
>> Adding beforefeatureunselected might help fully accomodate that use
>> case.
>>
>> Now if we want the two controls to do feature styling, we need the
>> stuff I mentioned previously - per-control selectedFeatures arrays and
>> events. But this is unfortunately not sufficient. Use case: two
>> controls, one working on click and the other on hover, both doing
>> feature styling but with different render intents. If we have this
>> sequence "mouse goes over feature, mouse clicks feature, mouse goes
>> out of feature", then the feature ends up being rendered with the
>> "default" render intent, while it's still selected from the click
>> control's perspective. In most cases, this isn't desirable I think.
>>
>> At this point I don't have a solution to the above issue.
>>
>> Eric
>>
>> 2009/1/20, Alexandre Dube <adube at mapgears.com>:
>>
>>> Hi Ivan, Eric,
>>>
>>>   I was actually thinking a similar idea.  The more I thought about it,
>>> the more I thought about copying/pasting the SelectFeature control, make
>>> some changes to the copy and name it HighlightFeature.  But Eric's idea
>>> is much better.
>>>
>>>   Having the control itself know which feature it has selected + having
>>> its own events could enable the possibility of having multiple
>>> SelectFeature controls for a single layer.  Having both selecting on
>>> hover and/or click won't matter except for the style and the
>>> renderIntent applied to the selected feature.  I guess the last declared
>>> control would have the last word of determining those...
>>>
>>>   About that, what if we want 2 different colors for each ctrl ?  Having
>>> 2 selectfeature ctrls doing the same thing ( hover and click ) is not
>>> very logic, but let's say one select on hover, the other on click, it
>>> would be nice be able to have 2 different styles for each action.  But
>>> how could we do that ? (I guess I don't fully understand the whole
>>> renderIntent stuff yet...  Could we specify a specific renderIntent for
>>> the selectFeature ?  Could "select" be the default value and we could be
>>> able to set our own ?)  To do so without changing the renderIntent of
>>> the feature is to change its style only, without selecting it.
>>>
>>>   Ivan's idea (selectOnHover:false) sounds good.  I'd like to see the
>>> code and try it.  Ivan, could you share what you've done ?  At the same
>>> time, I'd like to try to add events to the control and its
>>> selectedFeatures array, like Eric said.
>>>
>>>   Finally, I would like to know more about what you think about all this.
>>>
>>> Best regards,
>>>
>>> Alexandre
>>>
>>> Ivan Grcic wrote:
>>>
>>>> On Mon, Jan 19, 2009 at 10:19 PM, Eric Lemoine <eric.c2c at gmail.com>
>>>> wrote:
>>>>
>>>>
>>>>> On Mon, Jan 19, 2009 at 3:30 PM, Alexandre Dube <adube at mapgears.com>
>>>>> wrote:
>>>>>
>>>>>
>>>>>> Hi Eric,
>>>>>>
>>>>>>  I took a look at the SelectFeature control.  Now I understand what
>>>>>> you
>>>>>> meant and it makes sense.  Also, it's also making sense to have this
>>>>>> control
>>>>>> have the possibility to highlight on hover or on click.
>>>>>>
>>>>>>  "beforefeaturehighlighted" and "featurehighlighted" events make
>>>>>> sense,
>>>>>> but
>>>>>> a "featureunhighlighted" (or some other term meaning that the feature
>>>>>> was
>>>>>> highlighted and is now no more) would also be useful.
>>>>>>
>>>>>>
>>>>> Alexandre,
>>>>>
>>>>> The more I think about this highlight feature control the more I think
>>>>> there's no room for both a select feature and a highlight feature
>>>>> controls.
>>>>>
>>>>>
>>>>>
>>>> Same opinion here. We already have a bunch of controls, and now adding
>>>> two very similar ones...
>>>>
>>>> Currently im using slightly modified SelectFeature control, i added
>>>> one more option to it: selectOnHover, thats how i quickly solved the
>>>> problem of only highlighting feature without selecting it.
>>>>
>>>> If selectOnHover is true, feature is selected&higlighted (select
>>>> method is called) on hover, if its false feature is only higlighted,
>>>> not selected.
>>>>
>>>>
>>>>
>>>>> What causes people trouble is that they can't use two select feature
>>>>> controls, one in hover mode and the other in click mode. This is
>>>>> because once a feature is hovered it is selected, and cannot be
>>>>> selected again when it is clicked.
>>>>>
>>>>> Maybe we could modify the select feature control so that (1) it
>>>>> optionally uses its own selectedFeatures array, as opposed to relying
>>>>> on the layer's, and (b) defines its own "beforefeatureselected",
>>>>> "featureselected" and "featureunselected" event types. In this way,
>>>>> one should be able to use two select feature controls, and get
>>>>> "featureselected" events, from the first control when features are
>>>>> hovered and from the second control when features are clicked.
>>>>>
>>>>> Tell me what you think,
>>>>>
>>>>>
>>>>>
>>>>
>>>>> --
>>>>> Eric
>>>>> _______________________________________________
>>>>> Users mailing list
>>>>> Users at openlayers.org
>>>>> http://openlayers.org/mailman/listinfo/users
>>>>>
>>>>>
>>>>>
>>>>
>>>>
>>>>
>>> --
>>> Alexandre Dubé
>>> Mapgears
>>> www.mapgears.com
>>>
>>>
>>>
>
>
> --
> Alexandre Dubé
> Mapgears
> www.mapgears.com
>
>