RE: [Groff] The quest for a high-end typesetting system: A few q

[Ted Harding]

On 10-Mar-05 Mats Broberg wrote:
> [...]
> Another general groff question:
> 
> Does groff handle floats, i.e. graphics that does not necessarily need
> to be inserted at a specific point on the page but are allowed to queue
> until there is enough space to put them without getting alot of white
> space? I found a a few references to floats in the UTP book, but only
> in
> relation to something called "displays".
> 
> Best regards,
> Mats Broberg

This depends on the macro package. In the 'ms' macros, for instance,
there is a concept of a "keep" -- a block of material which must
stay together on one page.

Thus the "immediate keep"
.KS
[....]
.KE
will encapsulate the formatted [....] and, if there is room for
it on the current page, will output it there and then; but, if
not, then there will be an immediate break to a new page and
[....] will be placed at the top of this.

There is also the "floating keep" which works like what you are
asking about:
.KF
[....]
.KE
If there is room for the formatted [....] on the current page,
then it goes there immediately. Otherwise, it is kept in
reserve, and subsequent material is output on the current
page until the page is full, whereupon there will be a page
break.

The formatted [....] is then output at the top of the new page,
after which the material from the bottom of the previous page
continues below the [....].

This generally works well, to the point where you can write

.KF
[...1]
.KE
.KF
[...2]
.KE
.KF
[...3]
.KE
etc.,

and (supposing for example that each of these is too big
for more than one of them on a page) you will get [...1]
at the top of the next page as described above, then [...2]
on the following page, then [...3] on the page after that,
in all cases with the surrounding text continuiung smoothly
past the [....]s at the tops of the pages.

However, there can be some conflicts or inconsistencies
with this mechanism. For instance, if [....] is a figure
with a caption and you make an Table-of-Contents entry of
the caption text inside the ".KF ... .KE", then the page
number attached to the index entry will be the page number
on which the "keep" was first encountered, and not the page
number on which it is printed. It is possible to work round
things like this, but it can be subtle!

Hoping this helps,
Ted.


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Date: 10-Mar-05                                       Time: 17:40:39
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