[Laszlo-dev] disabling delegates

[Jim Grandy]

We don't just use this technique here. In LaszloView.as, we clear  
__LZcheckwidth and __LZcheckheight to null in certain situations, and  
then call them without checking for null.

On Apr 12, 2006, at 5:50 AM, Henry Minsky wrote:

> OK will do.
>
>
> On 4/12/06, P T Withington <ptw at openlaszlo.org> wrote:
> This looks like a 'stupid AS trick' to me.  Don't try this at home.
>
> I would just change the loop to test d.enabled, and change
> LzDelegate.disable to just set the flag and not muck with the innards
> of the delegate.
>
> [This is why nullable types suck.]
>
> On 2006-04-11, at 11:50 EDT, Henry Minsky wrote:
>
> > There is a method for disabling a delegate which is currently
> > implemented as
> >
> > LzDelegate.prototype.disable = function (){
> >     if ( !this.enabled ) return;
> >     this.enabled = false;
> >     this.disc = this.c;
> >     this.c = null;
> > }
> >
> > This has the unfortunate side effect of causing an error in DHTML
> > runtime if
> > you then try to call
> > this delegate, because the inner loop of LzEvent.sendEvent does
> >
> >     for (var i = dll; i >= 0; i--){
> >         d = this.delegateList[ i ];
> >         //pointer may be bad due to deletions
> >         if ( d && ! d.event_called){
> >             d.event_called = true; //this delegate has been called
> >             calledDelegates.push( d );
> >             // d.execute( sd ); inlined
> >             // We don't worry about deleted contexts here, because
> >             // we assume that delegates registered on events are
> >             // properly managed
> >             d.c[d.f]( sd );
> >         }
> >     }
> >
> > And d.c will be null, causing an error in 'real' javascript. Should
> > I put a
> > check here for the disabled flag,
> > or should we bind d.c in LzDelegate to some inert event while it is
> > disabled?
> >
> >
> >
> > --
> > Henry Minsky
> > Software Architect
> > hminsky at laszlosystems.com
> > _______________________________________________
> > Laszlo-dev mailing list
> > Laszlo-dev at openlaszlo.org
> > http://www.openlaszlo.org/mailman/listinfo/laszlo-dev
>
>
>
>
> -- 
> Henry Minsky
> Software Architect
> hminsky at laszlosystems.com
>
> _______________________________________________
> Laszlo-dev mailing list
> Laszlo-dev at openlaszlo.org
> http://www.openlaszlo.org/mailman/listinfo/laszlo-dev

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