[lively-kernel] startStepping error

[Patrick Shouse]

Thanks, Dan! That works great now.

On Mon, Jul 12, 2010 at 1:42 AM, Dan Ingalls <danhhingalls at gmail.com> wrote:

>  Hi, Patrick -
>
> I don't have time to actually debug this, and others may be able to help
> you.  But, assuming you got morph.stepByVelocities to work once, I think the
> problem is that it's required for a morph to be in a world before you can
> use stepping.  Normally you would do this by calling super at the beginning,
> but I don't think your commented version of that will work.  Try instead...
>
> BoxMorph.subclass("LauncherMorph", {
>         addMorph: function($super, morph) {
>                 $super(morph);
>                 morph.velocity=pt(10,0);
>                 morph.angularVelocity=Math.PI/16;
>                 morph.moveOriginBy(morph.innerBounds().center());
>                 //morph.stepByVelocities();
>                 morph.startStepping(1000,"stepByVelocities");
>         }
> });
>
> The rule is: if you wish to call an overridden method, then add the
> pseudo-argument '$super' at the beginning of the declared arguments.
> Thereafter you can use $super to refer to the overridden procedure.
>
> If the problem is what I think it is, this should help.
>
> Good luck
>         - Dan
> -------------------------------
>
> Hi, Folks. I have this script (below) in a TextMorph. When I evaluate each
> line it seems to work fine, until the last line which causes this error
> "Type Error: Cannot call method 'startSteppingFor' of null". How do I debug
> this?
>
>
> BoxMorph.subclass("LauncherMorph", {
>
>         addMorph: function(morph) {
>
>                 //super(morph);
>
>                 morph.velocity=pt(10,0);
>
>                 morph.angularVelocity=Math.PI/16;
>
>                 morph.moveOriginBy(morph.innerBounds().center());
>
>                 //morph.stepByVelocities();
>
>                 morph.startStepping(1000,"stepByVelocities");
>
>         }
>
> });
>
> morph1 = new LauncherMorph(new Rectangle(50,100,80,360));
>
> morph1.openInWorld();
>
> morph2 = Morph.makeRectangle(new Rectangle(20,20,40,40));
>
> morph1.addMorph(morph2);
>
>
> Here's a link to my test page:
> http://www.lively-kernel.org/repository/lively-wiki/users/pshouse/te
> st.xhtml
>
>
> Thanks,
>
> Patrick
>
>
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>
>
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