How can I stop content overlapping my footer?

Question

I am trying to use LaTeX to generate PDF versions of cheat sheets people build on my website. They are all three column documents, effectively each containing multiple tables.

For the most part, LaTeX handles the dividing of content into columns really well. However, sometimes some blocks overlap the footer. I have a test document (built with lualatex, based on this tex file), and you can see on page 2 in the first column the "Directives" block overlaps the footer.

I've tried a few different things to resolve this. The closest solution was adding an mbox after each table, as in this PDF (from this tex file). As you can see, there is no longer an overlapping issue. However, on page 3 there is now a gap at the top of column 2.

Does anybody have an idea how I can stop columns overlapping the footer without introducing odd gaps at the top of some columns?

Answer 1

You don't give LaTeX much of a chance here:-) Each of the sections is an unbreakable table (tabularx or tabulary mostly) as LaTeX never re-orders content it is inevitable that you get overfull boxes or big gaps. LaTeX does complain a lot

Overfull \vbox (52.91997pt too high) has occurred while \output is active
Overfull \vbox (51.91997pt too high) has occurred while \output is active
Overfull \vbox (50.91997pt too high) has occurred while \output is active
Overfull \vbox (49.91997pt too high) has occurred while \output is active
Overfull \vbox (48.91997pt too high) has occurred while \output is active
Overfull \vbox (47.91997pt too high) has occurred while \output is active
Overfull \vbox (46.91997pt too high) has occurred while \output is active
Overfull \vbox (45.91997pt too high) has occurred while \output is active
Overfull \vbox (44.91997pt too high) has occurred while \output is active
Overfull \vbox (43.91997pt too high) has occurred while \output is active
Overfull \vbox (42.91997pt too high) has occurred while \output is active
Overfull \vbox (41.91997pt too high) has occurred while \output is active
Overfull \vbox (40.91997pt too high) has occurred while \output is active
Overfull \vbox (39.91997pt too high) has occurred while \output is active
Overfull \vbox (38.91997pt too high) has occurred while \output is active
Overfull \vbox (37.91997pt too high) has occurred while \output is active
Overfull \vbox (36.91997pt too high) has occurred while \output is active

The NgModelController table on page two simply doesn't fit in that column, you could put a \columnbreak before it leaving that column very short, and also causing problems in the next column unless you force a break there as well.

I suspect that in this case the various tables are more or less independent and that a better algorithm for this kind of layout would be to measure each one, and then add whichever table best fits in the current column. It's not impossible to do that but LaTeX doesn't really offer much support for that kind of layout out of the box and if it is just one document rather than an automated printing of thousands of pages of data dumped from some database, it is probably better to re-arrange the tables by hand.

Or of course you could use breakable tables and allow them to wrap to the next column. It's fairly easy to use longtable in multicol (there is some code on this site for example) although it's a bit harder to use the repeating header feature that longtable would normally have.