From af869a65a43a1a9df4a2510ba291e928d1dea266 Mon Sep 17 00:00:00 2001
From: Alexandre Dupas <alexandre.dupas@gmail.com>
Date: Sun, 19 Feb 2012 17:53:12 +0100
Subject: [PATCH] Add importantdiagramonly option to the crepbook document
 class

The importonlydiagramonly option allows to print only chord diagrams
that have been flagged as important by the author of the song. The
important chords are generally complicated uncommon chords and their
diagram is registered with the starred version of the gtab macro.
---
 tex/crepbook.cls | 22 +++++++++++++++++++++-
 1 file changed, 21 insertions(+), 1 deletion(-)

diff --git a/tex/crepbook.cls b/tex/crepbook.cls
index 98b3d00e..6a1ffa0a 100644
--- a/tex/crepbook.cls
+++ b/tex/crepbook.cls
@@ -10,12 +10,14 @@
 \newif{\iftabs}
 \newif{\iflilypond}
 \newif{\ifnodiagram}
+\newif{\ifimportantdiagramonly}
 \newif{\ifpictures}
 
 \tabsfalse
 \lilypondfalse
 \nodiagramtrue
 \picturesfalse
+\importantdiagramonlyfalse
 
 % Options
 \DeclareOption{tabs}{\tabstrue}
@@ -24,6 +26,7 @@
 \DeclareOption{nolilypond}{\lilypondfalse}
 \DeclareOption{nodiagram}{\nodiagramtrue}
 \DeclareOption{diagram}{\nodiagramfalse}
+\DeclareOption{importantdiagramonly}{\importantdiagramonlytrue\nodiagramfalse}
 \DeclareOption{pictures}{\picturestrue}
 \DeclareOption{nopictures}{\picturesfalse}
 
@@ -217,8 +220,25 @@
   \fi%
 }%
 
+\let\gtab@Original\gtab
+\newcommand{\gtab@Hidden}[2]{}%
 \ifnodiagram%
-  \renewcommand{\gtab}[2]{}%
+\renewcommand{\gtab}{\@ifstar
+  \gtab@Hidden%
+  \gtab@Hidden%
+}
+\else%
+\ifimportantdiagramonly%
+\renewcommand{\gtab}{\@ifstar
+  \gtab@Original%
+  \gtab@Hidden%
+}
+\else%
+\renewcommand{\gtab}{\@ifstar
+  \gtab@Original%
+  \gtab@Original%
+}
+\fi%
 \fi%
 
 \newcommand{\lilypond}[1]{%