[PATCH -perfbook 6/7] Tweak TOC width params

[Akira Yokosawa <akiyks@gmail.com>]

We now have Section 15.5.10, (five digits + two periods).
Default of the book class can not afford that much digits in
subsection count.
Increase width parameters to accomodate it.

Also, as for -sf builds, the Helvetica clone font needs slightly
wider spaces in the "em" unit.  Add settings for -sf builds.

Mention default widths in the comment block for future reference.

Signed-off-by: Akira Yokosawa <akiyks@gmail.com>
---
 perfbook-lt.tex | 21 +++++++++++++++++++--
 1 file changed, 19 insertions(+), 2 deletions(-)

diff --git a/perfbook-lt.tex b/perfbook-lt.tex
index cdac9d495a3a..af5e0bf30032 100644
--- a/perfbook-lt.tex
+++ b/perfbook-lt.tex
@@ -158,11 +158,28 @@
 \setboolean{indexhier}{true}
 \newcommand{\IfIndexHier}[2]{\ifthenelse{\boolean{indexhier}}{#1}{#2}}
 
-% Widen pnumwidth in TOC for ebook size build (more than 1000 pages)
+% Tweak width params of TOC
 \makeatletter
-\IfEbookSize{
+\IfEbookSize{ % for ebook size build (more than 1000 pages)
 \renewcommand*\@pnumwidth{2.2em}
 }{}
+% default params defined in book.sty:
+%  width of chapter (two digits):			1.5em
+%  indent of section:					1.5em
+%  width of section (three digits + one periods):	2.3em
+%  indent of subsection:	  			3.8em
+%  width of subsection (four digits + two periods):	3.2em
+\IfSansSerif{	% sans serif (Helvetica clone)
+		%  to cover section "E.10" and subsection "15.5.10",
+		%  width of section:      2.4em
+		%  width of subsection:   3.7em
+\renewcommand*\l@section{\@dottedtocline{1}{1.5em}{2.4em}}
+\renewcommand*\l@subsection{\@dottedtocline{2}{3.9em}{3.7em}}
+}{		% serif (Times Roman clone)
+		%  to cover subsection "15.5.10",
+		%  width of subsection:   3.4em
+\renewcommand*\l@subsection{\@dottedtocline{2}{3.8em}{3.4em}}
+}
 \makeatother
 
 \IfEbookSize{
-- 
2.25.1