The miracle of weak typing... :P
(Maybe a cache got in your way.)
On 2006-09-25, at 20:49 EDT, [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>
>>>>>>>
>>>>>>>
>>>
>>>
>>>
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>
>
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