[OpenLayers-Users] Custom Controls

[Christopher Schmidt]

On Thu, Dec 18, 2008 at 05:44:23PM -0000, André Matos wrote:
> Hi Guys!
> 
>  
> 
> I am starting on OpenLayers API and I have two questions
 
> 
>  
> 
> I am  studing the controls and I have notice that, there’s no API methods or
> API properties in Control type. That means the open layers developers can
> change it, without any advise. 
> 
> The way I am doing my controls is this:
> 
> Is this the best way to implement custom controls? 

I think so.

> Will OpenLayers
> developers change the not API methods, initialize, draw, destroy or the div
> property defined at Control Class?

I think it's fair to say we won't change any of those. I'll wait for
dissenting opinions before changing the docs.

> description in the Control Class destroy method: 
> 
>  
> 
> Method: destroy
> 
>      * The destroy method is used to perform any clean up before the control
> 
>      * is dereferenced.  Typically this is where event listeners are removed
> 
>      * to prevent memory leaks.
> 
>  
> 
> But it Is never called. The control is dereferenced at Map.removeControl
> method, and this method does not call control.destroy method


Generally speaking, we try not to .destroy() anything we don't create --
meaning it would be up to application designers to destroy things.

When the map itself is destroyed, we do destroy any control associated
with it -- but removing a control is not equivilant to wanting it
destroyed. Instead, it's a sign that the control should no longer be
visible on the map. The user might then take that same control and addi
t back to the map later.

So, this is just representative of our conservative destruction
philosophy.

Regards,
-- 
Christopher Schmidt
MetaCarta