In the debugger component, I see that I overrode setWidth, to do this
<method name="setWidth" args="w" >
super.setWidth( Math.max( 170 , Math.min( w , canvas.width) ) );
</method>
On 9/25/06, [EMAIL PROTECTED] <[EMAIL PROTECTED]> wrote:
> I'll be damned. It works. I swear that I tried this yesterday and it
> didn't work. I must be losing it.
>
>
>
>
> Quoting P T Withington <[EMAIL PROTECTED]>:
>
> > You can do the same thing in Javascript, since true -> 1 and false -> 0
> > in a numeric context.
> >
> > On 2006-09-25, at 20:34 EDT, [EMAIL PROTECTED] wrote:
> >
> >> Hmmm. I have an idea. In my situation, I just need to stop the width
> >> from going below zero.
> >>
> >> In C I'd do something like this...
> >>
> >> width = (parentwidth-20} * (parentwidth-20 > 0);
> >>
> >> Is there some mathematical trickery I can use to convert true/false to
> >> 1/0 in a constraint?
> >>
> >> The best I can come up with is the ternary operator...
> >>
> >> width="${(parent.width-20) * (parent.width-20 > 0)?1:0}"
> >>
> >>
> >>
> >>
> >>
> >> Quoting P T Withington <[EMAIL PROTECTED]>:
> >>
> >>> If I wanted to be a pedant (ok, I do) I would tell you that
> >>> [functions](http://en.wikipedia.org/wiki/
> >>> Functional_programming#Pure_functions) are just fine in constraints,
> >>> it is 'procedures' that are not.
> >>>
> >>> On 2006-09-25, at 16:21 EDT, John Sundman wrote:
> >>>
> >>>> Please consult the Developer's Guide on the hazards of using
> >>>> functions within constraints.
> >>>>
> >>>> http://labs.openlaszlo.org/trunk-nightly/docs/guide/
> >>>> constraints.html#d0e13355
> >>>>
> >>>> It can sometimes be done, but there be dangers there, and you do so
> >>>> at your own risk.
> >>>>
> >>>> jrs
> >>>>
> >>>> On Sep 23, 2006, at 2:48 PM, Benjamin Shine wrote:
> >>>>
> >>>>>
> >>>>> Constraints can hold complex javascript. To cap constraints to a
> >>>>> range (100-500 in this example), I use something like
> >>>>> width="{max(100, min(500, sizeslider.value))}"
> >>>>>
> >>>>> A nest of trinary ? expressions would probably be faster by avoiding
> >>>>> two function calls. With whitespace added for clarity:
> >>>>> width="${ sizeslider.value < 100
> >>>>> ? 100
> >>>>> : ( sizeslider.value > 500 ?
> >>>>> 500
> >>>>> : sizeslider.value)) }"
> >>>>>
> >>>>> It is sometimes clearer to express this as a handler for
> >>>>> sizeslider.onvalue, something like this:
> >>>>> <handler reference="sizeslider" event="onvalue"
> >>>>> method="setClampedSize" />
> >>>>> <method name="setClampedSize" args="x">
> >>>>> var xclamp = min(100, max(500, x));
> >>>>> mybox.setAttribute("width", xclamp);
> >>>>> </method>
> >>>>>
> >>>>> The compiler probably turns the first and third forms above into the
> >>>>> same thing; if the compiler has an optimization for min and max (but
> >>>>> I don't think it does) then all three forms would be equivalent.
> >>>>>
> >>>>> -ben
> >>>>>
> >>>>> On Sep 22, 2006, at 10:25 PM, [EMAIL PROTECTED] wrote:
> >>>>>
> >>>>>> In my example below, I create a view with a smaller nested view.
> >>>>>> The
> >>>>>> inner view gets its size from constraints based on the its parent.
> >>>>>> The problem is, when the parent is resized too small, the
> >>>>>> constraints
> >>>>>> on the inner view become negative. If you run my app, you can
> >>>>>> adjust
> >>>>>> the size with the slider and see what happens. Basically, I need
> >>>>>> some
> >>>>>> way to have a constraint that tracks the parent, but cannot become
> >>>>>> negative. Is there some way to do this in a contstraint? Or
> >>>>>> possibly
> >>>>>> a different solution that doesn't have the negative constraint
> >>>>>> problem?
> >>>>>>
> >>>>>>
> >>>>>> <canvas>
> >>>>>>
> >>>>>> <view x="20" y="20" layout="axis:y">
> >>>>>> <view layout="axis:x">
> >>>>>> <text text="outer view size: "/>
> >>>>>> <slider id="sizeslider" width="100" showvalue="true"
> >>>>>> value="50"/>
> >>>>>> </view>
> >>>>>> <view layout="axis:x">
> >>>>>> <text text="inner view size: "/>
> >>>>>> <text text="${box.subviews[0].height}" bgcolor="silver"/>
> >>>>>> </view>
> >>>>>> </view>
> >>>>>>
> >>>>>> <view id="box" x="20" y="80" bgcolor="blue"
> >>>>>> width="${sizeslider.value}" height="${sizeslider.value}">
> >>>>>> <view bgcolor="green" x="10" y="10"
> >>>>>> width="${parent.width - 20}" height="${parent.height -
> >>>>>> 20}"/>
> >>>>>> </view>
> >>>>>>
> >>>>>>
> >>>>>> </canvas>
> >>>>>>
> >>>>>>
> >>
> >>
> >>
> >> _______________________________________________
> >> Laszlo-user mailing list
> >> [email protected]
> >> http://www.openlaszlo.org/mailman/listinfo/laszlo-user
>
>
>
>
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>
--
Henry Minsky
Software Architect
[EMAIL PROTECTED]
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