[OpenLayers-Users] Add Feature and Pan into View

[Alexandre Dube]

Hi,

  See the example (1).  Use firebug to see the new requests sent (I'm 
getting an error 404 on the example, but only looking at the requests 
should be enough for you to understand what the BBOX does).  When you 
zoom in, since the new extent is within the previous one, no request 
needs to be sent, but if you zoom out or pan, an new request is sent.

  So it would not be enough for you.  You could register your 
"beforefeatureselected" event, keep the feature in a variable, move the 
map to the extent of the feature. 

  If the BBOX strategy invalidated the bounds, that means that a new 
request will be sent resulting to new feature drawn.  So, the feature 
you have in your variable don't exists anymore on your layer, but you 
still have access to its attributes (feature.attributes, see in 
firebug).  If they have a key attribute, you could use it to get your 
feature on your layer and force your selection.

  If the BBOX didn't change the bounds, the original feature should 
still exist so there's nothing needed to be done.

  I may have missed some important details but you should have enough 
stuff to start somewhere.  Take a look at the examples to learn more and 
don't forget to use firebug.  It's a great teacher.

Regards,

Alexandre

(1) http://openlayers.org/dev/examples/strategy-bbox.html

oatley wrote:
> Alexandre,
> Thanks for your reply.
>
> Can you explain the BBOX strategy a little more?  It sounds like it will do
> the trick, but I am still new to OpenLayers.  It sounds like the zoom level
> would change if I set the extent.  (Or am I wrong?)  I would just like it to
> pan, similar to how the Popup pans, in order to get it into view.
>
> Shawn
>
>
> Alexandre Dube wrote:
>   
>> Hi,
>>
>> You could register a "beforefeatureselected" event on your vector layer 
>> and set the map extent according to the feature's extent. I think that 
>> if you use the BBOX strategy, since the feature was already drawn it 
>> should remain the same when the map automatically pan/zoom to the 
>> feature's extent.
>>
>> What do you think ?
>>
>> Alexandre
>>
>> soatley wrote:
>>     
>>> Hello,
>>>
>>> Does anyone know how to have the map pan when adding a feature to a
>>> vector
>>> layer so that the entire feature is in view?
>>>
>>> Here's my code so far that works:
>>>         //define the popup
>>>         infoPopup = new OpenLayers.Popup.FramedCloud("info",
>>>                                      mouseLoc,
>>>                                      null,
>>>                                      "<div
>>> style=\"padding:5px;font-size:0.8em;\">Loading...</div>",
>>>                                      null, true, onPopupClose);
>>>         map.addPopup(infoPopup);
>>>         
>>>          //load the url for the popup data
>>>         OpenLayers.loadURL(infoUrl, '', this, showTip);
>>>
>>>
>>> In the showTip function, I parse the data that is returned, update the
>>> content popup and create a feature.  The feature coordinates (WKT) are
>>> passed with the response.
>>>
>>>             var f = new OpenLayers.Format.WKT();
>>>             infoFeature = f.read(marker.find("points").text());
>>>             infoLayer.addFeatures([infoFeature], { style: "default" });
>>>             infoPopup.contentHTML = marker.find("result").text();
>>>             infoPopup.setContentHTML();
>>>             infoFeature.popup = infoPopup;
>>>
>>> This code works great.  If the popup is off the screen it pans into view. 
>>> Great!  But, how can I do the same if the feature (a parcel) is partially
>>> off the screen?
>>>
>>>
>>>   
>>>       
>> -- 
>> Alexandre Dubé
>> Mapgears
>> www.mapgears.com
>>
>> _______________________________________________
>> Users mailing list
>> Users at openlayers.org
>> http://openlayers.org/mailman/listinfo/users
>>
>>
>>     
>
>   


-- 
Alexandre Dubé
Mapgears
www.mapgears.com