Re: Emacs Survey: Toolbars

[Tomas Hlavaty]

On Tue 22 Dec 2020 at 23:21, Richard Stallman <rms@gnu.org> wrote:
> One interesting question is how to make text flow between pages.  In
> Emacs, a page boundary is a ^L character (formfeed).  To make text
> flow between pages would require deleting and inserting ^L characters
> as needed.  Is that workable?
>
> (I remember when ^L made the line printer skip to the next page.)

In emacs-pdf, I respect ^L and start a new page.  Additionally, a new
pdf page is automatically started when the page gets full (but this is
not indicated in the original text buffer).  It could probably be
feasible to indicate the additional computed page break in the original
text buffer but then there should be a concept of user-entered page
break (e.g. ^L) and computed page break (how to indicated that?).

Another problem with pages is that it requires user configuration (like
emacs has for postcript printing which could be reused) and whole
complexity of fonts and layout.  So far emacs-pdf handles ascii
monospace monochrome buffers only thus in a sense it is already WYSIWYG.
I get the same thing on the paper as on the screen (minus headers and
footers).

Should headers and footers be also displayed in the original text
buffer?  Should they be editable?  How should it be handled at the low
level, e.g. as a text property?

Another problem is inserting computed values, e.g. current page number
or total number of pages, which is often used in headers and footers.
This means that the whole rendering becomes a fixed-point computation.
In emacs-pdf, I simply process the whole document twice and assume that
the layout would not change further anymore but that is not a general
solution.