Re: textbackground

["dr. Hans van der Meer" <hansm@science.uva.nl>]

On 26-jun-04, at 20:13, Hans Hagen Outside wrote:

> dr. Hans van der Meer wrote:
>
>> Hans,
>>
>> I definitely see problems  with the 
>> \starttextbackground[]-\stoptextbackground environment (discussed in 
>> the "displays"-brochure).
>>
>> When the textbackground falls at a page crossing -- i.e. starts at 
>> the top of a page -- the coloring extends backwards on the page just 
>> left.
>> It can be remedied by putting a \null just in front of 
>> \starttextbackground. The extra vertical space this introduces just 
>> manages to constrain the background to its own page. However, this is 
>> not a general solution, on other places the extra vertical space is 
>> certainly not wanted.
>>
>> I cannot find the exact nature of the problem. I suspect it has to do 
>> with the \output-routines, but these are not my speciality, to say 
>> the least. So, not much help there,
>>
>> Also, the \starttextbackground does not respect footnotes, these are 
>> colored. In contrast, the old \startbackground-\stopbackground does 
>> respect footnotes. The coloring stops at the footnote and restarts at 
>> the next page. I should like that for \starttextbackground as well.
>
> can you make me a minimal example of where things go wrong (keep in 
> mind that there are two methods, tex and paragraph)
> with respect to footnotes, maybe i can make that an option (there are 
> more exceptions)
> Hans
>

Here is the smallest one I could construct that shows the page crossing 
effect. I used the "location=paragraph". With "location=text" I did not 
experiment.
Here follows the code:

% testing textbackgroundcolor
\setupbodyfont[12pt]	% using the default cmr font
\setuppapersize[S6][S6]
\setuplayout[width=middle,location=middle,header=0pt,footer=4ex]
\setuppagenumbering[location={footer,inright},alternative=singlesided]
%
\setupcolors [state=start]
\definecolor [lavender]		[r=.901961,g=.901961,b=.980392]
\definecolor [lavenderblush]	[r=1,g=.941176,b=.960784]
% general page coloring

\setupbackgrounds[page][background=color,backgroundcolor=lavenderblush]
%
% special background coloring for parts of the text
\definetextbackground[A][frame=off,location=paragraph,
	backgroundcolor=lavender,backgroundoffset=0pt]
\starttext
%
\dorecurse{10}{Some text that must fill a portion of the page. }\par
\dorecurse{10}{Some text that must fill a portion of the page. }\par
\dorecurse{10}{Some text that must fill a portion of the page. }\par
%
% WITH 8 AND 9 IN THE NEXT RECURSION THE FIRST PARAGRAPH ON PAGE 2 HAS
% THE BACKGROUND COLORED BUT THE WHITESPACE BELOW THE LAST PARAGRAPH ON
% PAGE 1 IS COLORED TOO.
% CHANGE THE 8/9 TO 10 AND THE COLORING ON PAGE 1 DISPAPPEARS.
% I HAVE BECOME ACROSS SITUATIONS WERE THE COLORING EXTENDED STILL
% FURTHER BACK OVER MORE PRECEDING PARAGRAPHS, BUT IT IS DIFFICULT TO
% CONSTRUCT A MINIMAL EXAMPLE FOR THAT.
\dorecurse{9}{Some text that must fill a portion of the page. }\par
%
% THIS SHOULD COLOR THE FIRST PARAGRAPH ON PAGE 2
\starttextbackground[A]
\dorecurse{5}{Text with the background. }
\stoptextbackground
\dorecurse{10}{Some text that must fill a portion of the page. }\par
%
\stoptext

I hope you can find what causes it, because I like the effects.

Keeping footnotes free from the coloring would be very great if it 
could be accomplished (same as for interposed floats), like:

-- text on page containing reference to footnote, not colored background
-- text on page with colored background
-- footnote not colored (or perhaps the same coloring as where the 
reference occurs?)
-- text on next page goes on with colored background

Hans van der Meer