Add part title in KOMA-Script LoF/LoT

Question

As specified in §3.20. Floating Environments of Tables and Figures on page 128 sq. of KOMA-Script documentation, one can add the option listof=withchapterentry to

Marks chapter starts at the lists of floating environments by a copy of their entries to the table of contents.

I.e. it adds chapter title above figures belonging to this chapter:

List of Figure

Chapter 1
  1.1  My first figure.......................13
  1.2  My second figure......................17

Chapter 42
  42.1 My last figure.......................210

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Question: As I use the scrbook class, what I'd like to do, is to emulate the same behavior yet with part titles, instead of chapter ones. I.e. to kind of create the listof=withpartentry option.
(I only need to make part titles appear, not chapter ones)

How could I do this?

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Some questions already deal with this issue (e.g., Chapters inside LoF and LoT?, Include chapters in List of Figures with titletoc?). However, they are intended for standard classes (book). I think 'dirty' workarounds could be avoided with the scrbook class since the feature is already implemented for chapters.

Answer 1

You could patch \addparttocentry to get an entry for each part in LOF and LOT:

\documentclass{scrbook}

\unsettoc{lof}{chapteratlist}% remove the chapter gap in LOF
\unsettoc{lot}{chapteratlist}% % remove the chapter gap in LOT

\usepackage{xpatch}
\xapptocmd\addparttocentry{%
  \addxcontentsline{lof}{part}[{#1}]{#2}% copy the part entry to LOF
  \addxcontentsline{lot}{part}[{#1}]{#2}% copy the part entry to LOT
}{}{\PatchFailed}

\begin{document}
\listoffigures
\part{Part One}
\chapter{Chapter One}
\captionof{figure}{My first figure}
\captionof{figure}{My second figure}
\chapter{Chapter Two}
\captionof{figure}{A figure in Chapter Two}
\part{Part Two}
\chapter{Chapter Three}
\captionof{figure}{My next figure}
\chapter{Chapter Four}
\addpart{Unnumbered Part}
\chapter{Chapter Five}
\captionof{figure}{My last figure}
\end{document}

Or in all lists controlled by package tocbasic:

\documentclass[listof=ignorechapter]{scrbook}

\usepackage{xpatch}
\makeatletter
\xapptocmd\addparttocentry{%
  \doforeachtocfile{%
    \ifstr{\@currext}{toc}{}{%
      \addxcontentsline{\@currext}{part}[{#1}]{#2}%
    }%
  }%
}{}{\PatchFailed}
\makeatother

\begin{document}
\listoffigures
\part{Part One}
\chapter{Chapter One}
\captionof{figure}{My first figure}
\captionof{figure}{My second figure}
\chapter{Chapter Two}
\captionof{figure}{A figure in Chapter Two}
\part{Part Two}
\chapter{Chapter Three}
\captionof{figure}{My next figure}
\chapter{Chapter Four}
\addpart{Unnumbered Part}
\chapter{Chapter Five}
\captionof{figure}{My last figure}
\end{document}

Result:

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It is also possible to declare a new style for the part entries in the lists. Example without page numbers for the part entries:

\documentclass[listof=ignorechapter]{scrbook}
\usepackage{xpatch}
\makeatletter
\xapptocmd\addparttocentry{%
  \doforeachtocfile{%
    \ifstr{\@currext}{toc}{}{%
        \addxcontentsline{\@currext}{partatlists}[{#1}]{#2}%
    }%
  }%
}{}{\PatchFailed}

\DeclareTOCStyleEntry[
  pagenumberbox=\@gobble,
  level=-1,
  indent=0pt,
  numwidth=0pt,
  dynnumwidth
]{part}{partatlists}
\makeatother

\begin{document}
\listoffigures
\part{Part One}
\chapter{Chapter One}
\captionof{figure}{My first figure}
\captionof{figure}{My second figure}
\chapter{Chapter Two}
\captionof{figure}{A figure in Chapter Two}
\part{Part Two}
\chapter{Chapter Three}
\captionof{figure}{My next figure}
\chapter{Chapter Four}
\addpart{Unnumbered Part}
\chapter{Chapter Five}
\captionof{figure}{My last figure}
\end{document}