[Laszlo-dev] For Review: Change 20080623-ptw-Y Summary: Fix meassure{Width, Height}

[Sarah Allen]

yes, I misread... resourcewidth/height should be zero if there is no 
resource.  But the same null Number issue applies to width/height.  If a 
view has nothing in it, I assume the width/height are zero.  How do you 
know if they are set deliberately to zero or just happen to be zero?   
When designing a component, you often want to set a default width/height 
based on the contents if the developer doesn't set one (like with window).

Thanks,
Sarah

P T Withington wrote:
> resourcewidth/height are read-only and represent the size of the 
> resource of the view.  They are declared to be of type Number.  null 
> is not a Number.  Having an initial value of null was what was 
> breaking the measurement code.  The rest of the view system uses 0 
> when you don't have a resource (e.g., when a resource fails to load).  
> So, it seemed expedient and proper.
>
> Since these are read-only, it would be an error for the developer to 
> set them to 0 (although we don't have any way of preventing that in 
> JS1 runtimes).
>
> [The _real_ bug is that swf8 does not implement coercion of null to a 
> Number correctly.  They coerce it to NaN, it is supposed to coerce to 
> +0.  But I don't have any easy way to fix that other than to wait for 
> us to stop supporting swf8...]
>
> On 2008-06-23, at 10:51 EDT, Sarah Allen wrote:
>
>> Why is the default 0 now, not null?  (I seem to remember hearing 
>> about the desire to change this but I forget the details.)  How does 
>> someone check if a developer intentionally set the size to 0 or it 
>> just happens to be zero?  (This is especially important in writing 
>> components.)
>>
>> Sarah
>>
>>
>> P T Withington wrote:
>>> Change 20080623-ptw-Y by ptw at dueling-banjos.local on 2008-06-23 
>>> 04:54:06 EDT
>>>    in /Users/ptw/OpenLaszlo/ringding-clean
>>>    for http://svn.openlaszlo.org/openlaszlo/trunk
>>>
>>> Summary: Fix meassure{Width,Height}
>>>
>>> Bugs Fixed:
>>> LPP-6339: '<view> component. measureWidth and measureHeight 
>>> functions for a view return null unless a resource is attached to 
>>> that view.'
>>>
>>> Technical Reviewer: max (pending)
>>> QA Reviewer: mwilde (pending)
>>> Doc Reviewer: sallen (Message-ID: <485F1F44.3060907 at laszlosystems.com>)
>>>
>>> Details:
>>>    Default resource dimensions to 0, not null.  Update measureSize to
>>>    mimmic __LZcheckSize.  Update documentation.
>>>
>>> Tests:
>>>    ant lztest, smokecheck, test case from bug
>>>
>>> Files:
>>> M      WEB-INF/lps/lfc/views/LaszloView.lzs
>>>
>>> Changeset: 
>>> http://svn.openlaszlo.org/openlaszlo/patches/20080623-ptw-Y.tar
>>
>