<div dir="ltr"><div>if you are using pdftex rather than classic tex you can use \pdfsavepos then write \pdflastxpos and ypos in \everyjob and complain if the saved coordinates match the position of the first line of the page and parindent.<br><br></div>David<br><br></div><div class="gmail_extra"><br><div class="gmail_quote">On 25 August 2016 at 15:41, Philip Taylor <span dir="ltr"><<a href="mailto:P.Taylor@rhul.ac.uk" target="_blank">P.Taylor@rhul.ac.uk</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div bgcolor="#FFFFFF" text="#000000">
In a book on which I am currently working, and following the example
I established in earlier books, I have adopted the convention of
"minimal indentation" -- \parindent is suppressed whenever it adds
nothing significant (IMHO) to the page. So, for example \parindent
is suppressed (a) after full-width inserts, (b) at the start of a
paragraph that commences at the same level as the top line of an
part-width insert floated left, and so on. And, in particular,
\parindent is (manually) suppressed at the top of a new page. Now,
it is (relatively) easy to detect when \parindent suppression occurs
in the <u><i><b>wrong</b></i></u> place (i.e., when a manually
inserted \noindent does <i><b>not</b></i> end up at the top of a
page, using TeX's intrinsic top-of-page discard behaviour w.r.t.
leaders) [1], but I have not yet found a way to detect when
(automatic) paragraph indentation occurs (wrongly) at the top of a
page. Any suggestions as to how to accomplish this will be
gratefully received. Note that I am not attempting the impossible
-- I know that without a multi-pass approach, or the use of an
adjunct programming language such as that offered by LuaTeX, I
cannot automatically /suppress/ paragraph indentation at top of page
: I merely want to be warned (either in the log file, or even in
the PDF itself) if such paragraph indentation has in fact occurred.<br>
<br>
[1] <br>
<br>
<tt>
</tt><tt>
</tt>
<p style="margin-top:0px;margin-bottom:0px;margin-left:0px;margin-right:0px;text-indent:0px"><tt>\newbox
\errorbox</tt></p>
<tt>
</tt>
<p style="margin-top:0px;margin-bottom:0px;margin-left:0px;margin-right:0px;text-indent:0px"><tt>\setbox
\errorbox = \leftline {+++ NOT AT TOP OF PAGE +++}</tt></p>
<tt>
</tt>
<p style="margin-top:0px;margin-bottom:0px;margin-left:0px;margin-right:0px;text-indent:0px"><tt><br>
</tt></p>
<tt>
</tt>
<p style="margin-top:0px;margin-bottom:0px;margin-left:0px;margin-right:0px;text-indent:0px"><tt>\def
\errormsgbox {\copy \errorbox}</tt></p>
<tt>
</tt>
<p style="margin-top:0px;margin-bottom:0px;margin-left:0px;margin-right:0px;text-indent:0px"><tt><br>
</tt></p>
<tt>
</tt>
<p style="margin-top:0px;margin-bottom:0px;margin-left:0px;margin-right:0px;text-indent:0px"><tt>\def
\assert #1%</tt></p>
<tt>
</tt>
<p style="margin-top:0px;margin-bottom:0px;margin-left:0px;margin-right:0px;text-indent:0px"><tt> {%</tt></p>
<tt>
</tt>
<p style="margin-top:0px;margin-bottom:0px;margin-left:0px;margin-right:0px;text-indent:0px"><tt>
\endgraf \leaders \errormsgbox \vskip 2 \ht \errorbox \relax</tt></p>
<tt>
</tt>
<p style="margin-top:0px;margin-bottom:0px;margin-left:0px;margin-right:0px;text-indent:0px"><tt>
\noindent \ignorespaces</tt></p>
<tt>
</tt>
<p style="margin-top:0px;margin-bottom:0px;margin-left:0px;margin-right:0px;text-indent:0px"><tt> }</tt></p>
<br>
<tt>% Usage : \assert {newpage}</tt><span class="HOEnZb"><font color="#888888"><tt><br>
</tt><br>
<div>-- <br>
<img src="cid:part1.02030903.06040700@Rhul.Ac.Uk"><br>
Philip Taylor</div>
</font></span></div>
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