[ka-Map-users] Controlling the number of points using addObjectGeo

Paul Spencer pspencer at dmsolutions.ca
Tue Feb 28 08:27:09 EST 2006


I think that we should expose two events:


this would potentially allow the interface to expose the number of  
tiles that are 'in the queue' and could be used for other purposes  
to, like fixing overlays etc

KAMAP_TILE_CHANGING would be triggered in the setTile method of  
_layer (and affliates).

KAMAP_TILE_CHANGED would be triggered in the kaMap_imgOnLoad function

One thing to consider is that images do fail to load for various  
reasons and we need to be aware of the difference between an image  
that is loaded the first time and an image that is loaded because of  
an error, otherwise tile counts could be seriously impacted.

Would this meet your needs?



On 28-Feb-06, at 7:58 AM, Stephen Woodbridge wrote:

> This is an excellent question as we have been doing something  
> similar with router overlays. We currently overlay an image just  
> the size of the viewport, but it would make sense to ask for a  
> larger image say the size of the preloaded tile extents and then  
> only update that when additional tiles are requested because the  
> preloaded tile extent needs to change because of panning or  
> zooming. Could this be made an ka-map event that can be easily hooked?
> -Steve
> Base Bloc wrote:
>> Dear all,
>>  First off I would like to say that ka-map 0.2 is a fantastic  
>> piece of kit and thanks for all the work that people have put in  
>> to this.
>>  I am currently building an application using 0.2 and I am using  
>> the addObjectGeo function to add markers along with mouseover  
>> events (pop-up windows) to the map. All is working as it should  
>> and is looking good. My concern now is the number of markers; the  
>> application is covering most of Southeast Asia and the number of  
>> markers is going to be high. I am looking to use Ajax to connect  
>> to a MySQL database to retrieve the point data relevant to the  
>> area of the map being viewed, as if all of the points were to be  
>> retrieved in one go it would result in a serious performance hit  
>> for the user.
>>  I’m no ka-map expert, but I was wondering how ka-map does this  
>> efficiently with the tiles; as in it gets x number of tiles  
>> closest to the area being viewed then moves outwards, is there  
>> anyway to use the variable(s) that are being sent to the server to  
>> request the tiles to also query the database and return the point  
>> data in an equally efficient manor?
>>  Thanks in advance for your thoughts.
>>  Chris
>>   ~~~~~~~~~~~~~~~~~~~~~~~~~~~
>> Christopher Brown
>> Head of Internet Development
>> Base Bloc Cambodia
>> #33, 123, Phnom Penh, Cambodia.
>> P.O. Box 2086
>> www.basebloc.com
>> Tel (+885) 12 315 302
>> --------------------------------------------------------------------- 
>> ---
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|Paul Spencer                           pspencer at dmsolutions.ca   |
|Applications & Software Development                              |
|DM Solutions Group Inc                 http://www.dmsolutions.ca/|

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