I think you're reaching a point where you should understand exactly how
the Knuth model works. I haven't looked at how conditionality is
implemented very closely. Without diving deeper into this myself I'm
unable to help right now other than to point you to
BlockStackingLayoutManager again which contains at least part of the
code that deals with space conditionality. If the comments are right in
BlockStackingLayoutManager conditionality has not even been implemented
for blocks in the b-p-d.

If you really want to go down that road I suggest you get Donald Knuth's
"Digital Typography" or another book that contains the essay "Breaking
Paragraphs into Lines". There may also be a little information about
handling conditionality in the mailing list archives. Sorry that I can't
help more, but we're getting into complicated terrain here.

On 05.09.2005 14:52:23 Manuel Mall wrote:
> On Mon, 5 Sep 2005 03:08 pm, Manuel Mall wrote:
> > Jeremias,
> >
> > thanks for your patience in answering my questions.
> >
> > On Mon, 5 Sep 2005 02:51 pm, Jeremias Maerki wrote:
> > > On 04.09.2005 16:34:35 Manuel Mall wrote:
> <snip/>
> > > > Another question for the "Knuth" experts. It appears the inline
> > > > LMs don't make provisions in the IPD for borders/padding on
> > > > inlines. I assume border/padding is logically like a &nbsp; (with
> > > > the width of the border + padding) in front of the first and
> > > > after the last character of the inline assuming
> > > > .conditionality=discard, that is we don't want to have let's say
> > > > a left border alone on the end of a line with the text starting
> > > > on the next. For .conditionality=retain this width needs to be
> > > > reserved as well at the beginning and end of each intermediate
> > > > line. Any suggestions how this can/should be integrated into the
> > > > linebreaking algorithm?
> > >
> > > Exactly like spaces, borders and padding in b-p-d for block-level
> > > objects: additional auxiliary boxes and penalties. See
> > > BlockStackingLayoutManager.addKnuthElementsFor*(). Line breaking is
> > > the same as page breaking, only in a different direction.
> >
> > Thanks for the pointer. I'll have a look at that.
> >
> 
> That seem to have done the trick. I have copied the Border/Padding 
> before/after logic from BlockStackingLayoutManager and made it into a 
> Border/Padding start/end for the Inline LM. There were some side 
> effects in that the Line LM expectd only KnuthInlineBoxes and now we 
> have some KnuthBoxes as well but I think I solved that ok.
> 
> Next problem: border conditionality - how do I model that with the Knuth 
> approach? At the time I add the Border/Padding start/end boxes we don't 
> have line breaks so they really only cover the .conditionality=discard 
> case. How do I tell the algorithm to leave enough space at the end of 
> each line (and the beginning of the next line) for the borders (in the 
> case of .conditionality=retain)?
> 
> > > <snip/>
> > >
> > >
> > > Jeremias Maerki
> >
> > Manuel
> 
> Manuel



Jeremias Maerki

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