On Sep 23, 2006, at 11:30 AM, P T Withington wrote:
> Constraints are allowed to be arbitrary expressions, so you could
> write:
>
> width="parent.width > 0 ? parent.width - 20 : 0"
I think Tucker means
width="${parent.width > 0 ? parent.width - 20 : 0}"
You need the ${ } to express that it is a constraint.
>
> Or you could create a subclass of view that enforces minimums:
>
> <class name="minview" extends="view">
> <attribute name="minwidth" value="0" />
> <method name="setWidth" args="newwidth">
> super.setWidth(newwidth < minwidth ? minwidth : newwidth);
> </method>
> </class>
I go a little nuts reading code that has '<' where it means '<',
so I would write this as
<method name="setWidth" args="newwidth"><![CDATA[
super.setWidth(newwidth < minwidth ? minwidth : newwidth);
]]></method>
FWIW, when we post code here, we probably just mean it as a sketch.
For more detailed and tested answers, Laszlo Systems offers developer
support; contact [EMAIL PROTECTED]
-ben
>
> Of course, you might also hope that the basic view would not let you
> set your width to a negative number...
>
> On 2006-09-23, at 01:25 EDT, [EMAIL PROTECTED] wrote:
>
>> In my example below, I create a view with a smaller nested view. The
>> inner view gets its size from constraints based on the its parent.
>> The problem is, when the parent is resized too small, the constraints
>> on the inner view become negative. If you run my app, you can adjust
>> the size with the slider and see what happens. Basically, I need
>> some
>> way to have a constraint that tracks the parent, but cannot become
>> negative. Is there some way to do this in a contstraint? Or
>> possibly
>> a different solution that doesn't have the negative constraint
>> problem?
>>
>>
>> <canvas>
>>
>> <view x="20" y="20" layout="axis:y">
>> <view layout="axis:x">
>> <text text="outer view size: "/>
>> <slider id="sizeslider" width="100" showvalue="true"
>> value="50"/>
>> </view>
>> <view layout="axis:x">
>> <text text="inner view size: "/>
>> <text text="${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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