Q: Padding props -- fixed lengths?

[Andreas L Delmelle <a_...@pandora.be>]

Hi,

A question: I noticed that the warning about tables having padding and 
border-collapse="collapse" has been commented out recently, since 
"hasPadding() now requires context".

Can anyone explain why precisely this was done? IOW: why does a 
PercentBaseContext *always* need to be provided? Why is hasPadding() 
not simply overloaded --one with a context, and one without?

It almost makes it seem as if padding always needs to be specified as a 
percentage-width, or somehow a fixed-length is always interpreted as 
"the specified fixed-length * 100%"...?


Thanks,

Andreas

Re: Q: Padding props -- fixed lengths?

[Manuel Mall <mm...@arcus.com.au>]

On Sat, 24 Sep 2005 05:22 pm, Andreas L Delmelle wrote:
> On Sep 24, 2005, at 10:39, Andreas L Delmelle wrote:
> > On Sep 24, 2005, at 03:36, Manuel Mall wrote:
> >> <snip />
> >
> > Thanks for the info Manuel.
>
> Ok then:
> Instead of using hasPadding(), which tries to evaluate the specified
> value, we could also provide a method hasPaddingInfo() (analogous to
> the hasBorderInfo() method I added yesterday).
>
> This method would just check if the padding is null for every side,
> without doing any evaluation. It would allow the check to remain in
> the FOTree --the user would get a warning *if* padding was specified,
> no matter whether it ultimately evaluates to zero or not, just as a
> hint that the eventual value will be ignored by layout.
>
Yes, that's certainly an option and will probably catch 90% or more of 
real life cases.
>
>
> Cheers,
>
> Andreas

Rgds

Manuel

Re: Q: Padding props -- fixed lengths?

[Andreas L Delmelle <a_...@pandora.be>]

On Sep 24, 2005, at 10:39, Andreas L Delmelle wrote:

> On Sep 24, 2005, at 03:36, Manuel Mall wrote:
>
>> <snip />
>
> Thanks for the info Manuel.

Ok then:
Instead of using hasPadding(), which tries to evaluate the specified 
value, we could also provide a method hasPaddingInfo() (analogous to 
the hasBorderInfo() method I added yesterday).

This method would just check if the padding is null for every side, 
without doing any evaluation. It would allow the check to remain in the 
FOTree --the user would get a warning *if* padding was specified, no 
matter whether it ultimately evaluates to zero or not, just as a hint 
that the eventual value will be ignored by layout.



Cheers,

Andreas

Re: Q: Padding props -- fixed lengths?

[Andreas L Delmelle <a_...@pandora.be>]

On Sep 24, 2005, at 03:36, Manuel Mall wrote:

> <snip />

Thanks for the info Manuel.

Cheers,

Andreas

Re: Q: Padding props -- fixed lengths?

[Manuel Mall <mm...@arcus.com.au>]

On Sat, 24 Sep 2005 03:45 am, Andreas L Delmelle wrote:
> On Sep 23, 2005, at 18:12, Andreas L Delmelle wrote:
> > <snip />
> > It almost makes it seem as if padding always needs to be specified
> > as a percentage-width, or somehow a fixed-length is always
> > interpreted as "the specified fixed-length * 100%"...?
>
> Or, more correctly: as if the fixed-length is converted to a
> percentage only to be recalculated, so that you end up with the exact
> same value...?
>
> Somehow this seems suboptimal. Let me know if I'm missing anything.
>
Andreas,

I think this is a misunderstanding. Firstly you can specify a padding 
width in any way allowed by the spec. However, if you want to get the 
computed/absolute value anywhere you need to provide a context for 
percentage evaluation as the width in question could have been 
specified by the user as a percentage. The property system will only 
use the context if the specified value is a percentage otherwise it 
will ignore it.

The case in question is tricky as the context is only available during 
layout but in this case a padding width is attempted to be evaluated 
during fo tree parsing. In the general case that can not be done as if 
the width is specified as a percentage you have to wait until layout to 
get typically the ipd on which the percentage is based. Therefore the 
whole logic of trying to determine "hasPadding" during fo tree 
construction is misplaced. This is further complicated by the 
possibility that the specified value  can be an expression containing a 
percentage (eg. 5% - 5pt). There is no way to determine if this 
expression evaluates to 0 or not until layout.

> Thanks,
>
> Andreas

HTH

Manuel

Re: Q: Padding props -- fixed lengths?

[Andreas L Delmelle <a_...@pandora.be>]

On Sep 23, 2005, at 18:12, Andreas L Delmelle wrote:

> <snip />
> It almost makes it seem as if padding always needs to be specified as 
> a percentage-width, or somehow a fixed-length is always interpreted as 
> "the specified fixed-length * 100%"...?

Or, more correctly: as if the fixed-length is converted to a percentage 
only to be recalculated, so that you end up with the exact same 
value...?

Somehow this seems suboptimal. Let me know if I'm missing anything.

Thanks,

Andreas