Memoir: add chapter headings to 'list of...'

Question

I am seeking to add chapter headings to my list of figures, tables etc. I could not find a solution in the memoir manual, although the solution is probably contained within it I do not know what I am looking for exactly so my apologies.

I have modified RicoRally's EDIT solution here to apply to chapters but memoir is not detecting the titles or they are called something else which I do not know. The code with \documentclass{memoir} produces this lof:

Whereas the code with \documentclass{report} produces this lof:

The code that I am using is:

\documentclass[oneside]{memoir}
\usepackage{lipsum}
\usepackage{etoolbox}
\makeatletter
\def\thischaptertitle{}\def\thischapternumber{}
\newtoggle{noFigs}
\apptocmd{@chapter}%
  {\gdef\thischaptertitle{#1}\gdef\thischapternumber{\thechapter}%
    \global\toggletrue{noFigs}}{}{}
\AtBeginDocument{%
  \AtBeginEnvironment{figure}{%
    \iftoggle{noFigs}{
      \addtocontents{lof}{\protect\contentsline {chapter}%
        {\protect\numberline {\thischapternumber.} {\thischaptertitle}}{}{} }
      \global\togglefalse{noFigs}
    }{}
  }%
}
\long\def@caption#1[#2]#3{%
  \par
  \gdef\my@caption{#2}
  \begingroup
    @parboxrestore
    \if@minipage
      @setminipage
    \fi
    \normalsize
    @makecaption{\csname fnum@#1\endcsname}{\ignorespaces #3}\par
  \endgroup}
\renewenvironment{figure}%
               {@float{figure}}%
               {\end@float
               \addcontentsline{lof}{figure}%
                   {\protect\numberline{\thefigure}{\my@caption}}%
               }%
\renewenvironment{figure*}%
               {@dblfloat{figure}}%
               {\end@dblfloat
               \addcontentsline{lof}{figure}%
                   {\protect\numberline{\thefigure}{\my@caption}}%
               }%
\makeatother
%\usepackage{hyperref}
\begin{document}
\listoffigures
\chapter{Testing}
\lipsum
\section{Hallo}
\begin{figure}[t]
\caption{First figure}
  Test
\end{figure}
\begin{figure}[b]
\caption{Second figure}
  Test
\end{figure}
\chapter{Hallo}
\lipsum
\section{Hallo}
\begin{figure}[t]
\caption{First figure}
  Test
\end{figure}
\begin{figure}[b]
\caption{Second figure}
  Test
\end{figure}
\end{document}

I sort of get the gist of the code between \makeatletter and \makeatother although I do not understand what the \long\def section is doing. If anyone could help me add chapter headings to the memoir lof I would appreciate it.

Neither the memoir or report code works with hyperref either, it gives this error message:

Package hyperref Warning: old lof file detected, not used; run LaTeX again.
[1{c:/texlive/2021/texmf-var/fonts/map/pdftex/updmap/pdftex.map}] [2]
! Undefined control sequence.
<argument> ...umberline {\thefigure }{\my@caption 
                                                  }}{\thepage }{@currentHre...
l.60 \end{figure}

If someone could help me with that in the same breath I would sincerely appreciate it although I could ask it as a separate question if needed.

Answer 1

Use in chapters containing figures:

\addcontentsline{lof}{chapter}{\thechapter.\;~Testing}

after \chapter{Testing} and so on.

UPDATED

Use \chapterlof after any \chapter{..} with figures.

A simple memoir MWE with hyperref

\documentclass[oneside]{memoir}
\usepackage{lipsum} 
\usepackage{hyperref}
%**************************** added
\makeatletter
\def\printchaptertitle#1{\chaptitlefont #1 \gdef\thischaptertitle{#1}}%
\makeatother
\cftsetindents{figure}{1.5em}{2.3em} %indent
\newcommand{\chapterlof}{\addcontentsline{lof}{chapter}{\thechapter.;~\thischaptertitle}}% add chapter to lof
%*****************************************
\begin{document}
\listoffigures
\chapter{Testing}

\chapterlof % add chapter to lof
\lipsum
\section{Hallo}
\begin{figure}[t]
    \caption{First figure}
    Test
\end{figure}
\begin{figure}[b]
    \caption{Second figure}
    Test
\end{figure}
\chapter{Hallo}
\chapterlof
\lipsum
\section{Hallo}
\begin{figure}[t]
    \caption{First figure}
    Test
\end{figure}
\begin{figure}[b]
    \caption{Second figure}
    Test
\end{figure}
\chapter{Bye}
\end{document}

Answer 2

I thank Simon Dispa for his answer and I note your comment about "something more automatic". The following is a version of Simon's answer that automatically adds chapters to the LoF

% chapinlofprob.tex  603616 (A modified version of Simon Dispa's answer)
\documentclass[oneside]{memoir}
\usepackage{lipsum} 
\usepackage{hyperref}
%**************************** added 
\newcommand{\chapterlof}{\addcontentsline{lof}{chapter}{\thechapter.;~\thischaptertitle}}% add chapter to lof
%%%% PW deleted
%\makeatletter
%\def\printchaptertitle#1{\chaptitlefont #1 \gdef\thischaptertitle{#1}}%
%\makeatother
\cftsetindents{figure}{1.5em}{2.3em} %indent
%*****************************************
\begin{document}
\tableofcontents
\listoffigures
%%%% PW added here
\makeatletter
\def\printchaptertitle#1{\chaptitlefont #1 \gdef\thischaptertitle{#1}\chapterlof}%
\makeatother
\chapter{Testing}

%\chapterlof % add chapter to lof PW deleted
\lipsum
\section{Hallo}
\begin{figure}[t]
    \caption{First figure}
    Test
\end{figure}
\begin{figure}[b]
    \caption{Second figure}
    Test
\end{figure}
\chapter{Hallo}
%\chapterlof % PW deleted
\lipsum
\section{Hallo}
\begin{figure}[t]
    \caption{First figure}
    Test
\end{figure}
\begin{figure}[b]
    \caption{Second figure}
    Test
\end{figure}
\chapter{Bye}
\end{document}

Note that if the definition of \printchaptertitle comes before the \listoffigures then various unnumbered chapter-like titles can be added to the LoF; that is why I put it just before the first numbered chapter.