我想要一些“翻盖”（实际上，在印刷术中这些是如何称呼的？是“拇指索引”吗？），它是一种填充，延伸到边缘；这样当你“弯曲”一本书时，你可以更容易地看到某个部分在哪里——类似于：
...除了部分 - 所以类似部分标题的垂直颜色背景，除了只有部分的第一行（或一般而言，具有固定宽度的填充，与部分的第一行对齐）。
我认为我可以用tikz它来做这件事，所以我准备了这个 MWE：
\documentclass[10pt,twoside,openright]{book}
\usepackage{titlesec}
\usepackage{tikz}
\usetikzlibrary{calc}
\usetikzlibrary{fit}
\usetikzlibrary{external}
\titleformat*{\section}{%
\normalfont\Large\bfseries\color{black!90}%
\tikzexternaldisable%
%\tikz\node(AA){A};% ! Package titlesec Error: Entered in horizontal mode.
\tikzexternalenable%
}
\begin{document}
\frontmatter
\mainmatter
\part{Introduction}
\chapter*{The first chapter - without thinking anything else}
\section{The first section - and some more text inside; and some more text inside; and some more text inside}
Blah, blah, blah...
\end{document}
输出 - 以及我想要的效果（我:)用红色标记）看起来像这样（单击可获得完整分辨率）：
正如消息来源所述，一旦我开始放入\tikz\node(AA){A};节点进行测试，我就会得到! Package titlesec Error: Entered in horizontal mode.。
是否可以解决这个问题，而不必包含tikzmark或tikzpagenodes包？
作为一个子问题，是否可以解决，以便“翻盖”从部分延伸到外纸边缘 - 无论部分最终位于左手边还是右手边页面？（我仍然主要对“完整”的行边距到边距感兴趣，除了沿着中断\textwidth- 这意味着两个矩形节点）...
答案1
如果您愿意使用tikzpagenodes，您可以使用如下方法：
\documentclass[10pt,twoside,openright]{book}
\usepackage{titlesec}
\usepackage{tikz}
\usetikzlibrary{external}
\usepackage{tikzpagenodes}
\titleformat{\section}[hang]{\normalfont\Large\bfseries\color{black!90}}{\thesection}{1.5em}{\tikzexternaldisable\sectioncolouration{A}}[\tikzexternalenable]
\newcommand*\sectioncolouration[1]{%
\begin{tikzpicture}[baseline=(a.base), overlay, remember picture, inner xsep=0pt, outer sep=0pt]
\node (a) {\phantom{\normalfont\Large\bfseries Xy}};
\path [fill=blue, fill opacity=.2, even odd rule] (current page.west |- a.north) -| (current page.east |- a.south) -| cycle (current page text area.west |- a.north) -| (current page text area.east |- a.south) -| cycle;
\end{tikzpicture}}
\begin{document}
\frontmatter
\mainmatter
\part{Introduction}
\chapter*{The first chapter - without thinking anything else}
\section{The first section - and some more text inside; and some more text inside; and some more text inside}
Blah, blah, blah...
\end{document}
编辑
这是添加了与部分对应的字母标记的版本：
\documentclass[10pt,twoside,openright]{book}
\usepackage{titlesec}
\usepackage{tikz}
\usetikzlibrary{external,calc}
\usepackage{tikzpagenodes}
\titleformat{\section}[hang]{\normalfont\Large\bfseries\color{black!90}}{\thesection}{1.5em}{\tikzexternaldisable\sectioncolouration{\Alph{section}}}[\tikzexternalenable]
\newcommand*\sectioncolouration[1]{%
\begin{tikzpicture}[baseline=(a.base), overlay, remember picture, inner xsep=0pt, outer sep=0pt]
\node (a) {\phantom{\normalfont\Large\bfseries Xy}};
\path [fill=blue, fill opacity=.2, even odd rule] (current page.west |- a.north) -| (current page.east |- a.south) -| cycle (current page text area.west |- a.north) -| (current page text area.east |- a.south) -| cycle;
\ifodd\value{page}
\node at (a -| {$(current page text area.east)!1/2!(current page.east)$}) {#1};
\else
\node at (a -| {$(current page text area.west)!1/2!(current page.west)$}) {#1};
\fi
\end{tikzpicture}}
\begin{document}
\frontmatter
\mainmatter
\part{Introduction}
\chapter*{The first chapter - without thinking anything else}
\newpage
\section{The first section - and some more text inside; and some more text inside; and some more text inside}
Blah, blah, blah...
\newpage
\section{This section starts on an even page}
Some text\dots
\end{document}
答案2
@cfr 的解决方案很棒，但由于我正在研究这个问题，所以我将发布一个替代解决方案；它基于：
...我用的技巧是\vadjust（如何在横屏和竖屏模式间切换？）摆脱“以水平模式进入”（请注意，它是根据宽度等手动调整的，因此@cfr 的解决方案要好得多）：
\documentclass[10pt,twoside,openright]{book}
\usepackage{titlesec}
\usepackage{tikz}
\usetikzlibrary{calc}
\usetikzlibrary{fit}
\usetikzlibrary{external}
\usepackage{lua-visual-debug}
\newcommand{\tikzmarkS}[1]{\tikz[overlay, remember picture]\coordinate(#1){};}
\titleformat*{\section}{%
\normalfont\Large\bfseries\color{black!90}%
\tikzexternaldisable%
%\tikz\node(AA){A};% ! Package titlesec Error: Entered in horizontal mode.
\tikzmarkS{s\arabic{section}}\typeout{s\arabic{section}}%
\begin{tikzpicture}[remember picture,overlay]
\typeout{s\arabic{section}}
\node[rotate=90,minimum width=\baselineskip,minimum height=5.6cm,fill=gray!30,text=white,anchor=south west] at ([yshift=-1.35\baselineskip]s\arabic{section}-|current page.north east) {\arabic{section}};
\node[rotate=90,minimum width=\baselineskip,minimum height=3.6cm,fill=gray!30,text=white,anchor=north east] at ([yshift=-0.28\baselineskip]s\arabic{section}-|current page.south west) {};
\end{tikzpicture}%
\vadjust%
\tikzexternalenable%
}
\begin{document}
\frontmatter
\mainmatter
\part{Introduction}
\chapter*{The first chapter - without thinking anything else}
\section{The first section - and some more text inside; and some more text inside; and some more text inside}
% can be used outside of section, too:
% \begin{tikzpicture}[remember picture,overlay]
% \typeout{s\arabic{section}}
% \node[rotate=90,minimum width=\baselineskip,minimum height=3cm,fill=gray!30,font=\large\bfseries,text=white,anchor=south west] at ([yshift=-2em]s\arabic{section}-|current page.north east) {\arabic{section}};
% \end{tikzpicture}%
Blah, blah, blah...
\end{document}
...输出为（单击可查看完整分辨率）：
