[OpenLayers-Users] Event registration in activate function

[Eric Lemoine]

On Wed, Jan 7, 2009 at 10:02 PM, Alexandre Dube <adube at mapgears.com> wrote:
> Dear list,
>
>  I'm writing my own Control and I need to register some events.  Doing
> so in the initialize function isn't good because some objects are not
> created yet ( like the map object ).  So I thought I could register them
> in the activate() func and unregister them in the deactivate() func.
>
>  So far it was ok to do so, but now I'm facing a problem.  I need to
> register events that, when triggered, deactivate the control, and other
> events that, when triggered, reactivate the control. It's a control
> that can contain multiple layers that come from the same source but have
> been normalized to render faster, so the user sees no difference when
> zooming.  The control change the opacity of a layer when the mouse is
> over it and because the features generated come from different sources,
> I need to deactivate the control while I'm zooming ( deactivate on
> loadstart, activate on loadend ).  This looks like this :
>
> // inside the activate function()
>        for (var key in this.layers){
>            this.layers[key].events.register(
>                "loadstart", this, this.deactivate);
>            this.layers[key].events.register(
>                "loadend", this, this.activate);
>        }
>
>  So basically I should unregister them in the deactivate function(),
> right ?  The problem is : if I deactivate the control, it will
> unregister the loadend event so it will not be reactivated in the end.
> Is there an other place I should register my events to avoid that
> behavior ?  I see in some other control registration on events in a
> draw() function.  Could I do something similar ?

Defining events that activate and deactivate a control in the control
itself seems weird to me. Have you thought about implementing an
external component controlling your control?

--
Eric