Phil,

If you elect to go with plan (a), I could help if you like.

- Don

On Jul 7, 2011, at 8:26 AM, P T Withington wrote:

> Ah.  Not so easy.
> 
> I'm pretty sure that literal % constraints on width/height are handled in the 
> compiler.  This is mostly for legacy reasons -- we used to try to do as much 
> as possible at compile time to make things faster (at a loss of dynamicity).
> 
> Nowadays we have a lot more power at runtime so we should dispense with the 
> compiler "optimization" and just let these things be handled at runtime.  
> (With the added benefit that you could change the percentage dynamically at 
> run time.)
> 
> The short/kludge answer is:
> 
> a) Find the place in the compiler that handles %'s and make it store a copy 
> of the original % in something like _source_width, or
> 
> b) Just know that it is a percent and back-calculate it.
> 
> The long/right answer is:
> 
> 2) Use CSS and write a presentation type that parses both absolute and 
> percent dimensions and can unparse those same dimensions.  (See the color 
> presentation type for instance, for a p-t that has multiple representations.  
> The unparser has an optional argument that lets you specify the desired 
> representation format.)
> 
> 
> On 2011-07-07, at 08:15, [email protected] wrote:
> 
>> I'm looking for something different. If the user enters '79%' for the width, 
>> I want to obtain the string '79%', not the size which represents 79% of the 
>> canvas width.
>> 
>> Thanks!
>> 
>> Phil
>> 
>> 
>> 
>> On Wed, Jul 6, 2011 at 7:43 PM, P T Withington wrote:
>> 
>>> Well a constraint is really just a handler for the dependent variables that 
>>> updates the actual value, so in this case if you ask for the elements width 
>>> or height, you will get the current real value.  The best way to forward 
>>> those values (and track them) is to make another constraint.  Constraints 
>>> are easy to write in OL, but hard to write in JS.  You can get an inkling 
>>> of a hand-written constraint by looking at the implementation of the align 
>>> and valign attributes that let you say things like 'center', 'top', etc.  
>>> Those get interpreted into constraints on the parent bound.
>>> 
>>> Hope that helps.
>>> 
>>> On 2011-07-06, at 19:30, [email protected] wrote:
>>> 
>>>> Hi Tucker,
>>>> 
>>>> Is it possible to retrieve the raw constraint values of an attribute? For 
>>>> example,
>>>> 
>>>> <html width="100%" height="100%" .../>
>>>> 
>>>> I'd like to obtain the 100% values for width and height so I can forward 
>>>> them to the iframemanager.
>>>> 
>>>> Thanks!
>>>> 
>>>> Phil
> 
> 


--

Don Anderson
Java/C/C++, Berkeley DB, systems consultant

voice: 617-306-2057
email: [email protected]
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