Manuel Mall wrote:
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)?
The sequence of elements representing the inline content starts and ends
with a box .
Adding another box at the beginning and at the end of the sequence
implements "retain", as a line break is never allowed to separate two
adjacent boxes: so, the left border and padding will always be in same
line as the first piece of content, and the breaking algorithm will always
reserve enough space.
In order to implement "discard", glue elements must be used instead: these
elements are discarded if they are chosen as a line break or they are
adjacent to a line break, and in this case borders and padding will not be
I think that a single box or glue element could be created, representing
both border and padding, unless the conditionalities of these properties
can be different: for example, if it were possible to have
border-start.conditionality = "discard" and padding-start.conditionality =
"retain" two distinct elements should necessarily be created.
 Or, better, everything should work well if the first and last elements
are boxes. Should there be spaces at the beginning and at the end of the
inline having borders, they should be handled as non-breaking spaces, in
order to avoid a break between the start border and the first word, or
between the last word and the end border.
- Re: e-g with padding and borders Luca Furini