Cfrgtkky

I wish I could be more specific, but being that I don't understand all of the underlying stuff that's happening, my question will have to be vague (hence the awkward title, I'll edit it to be more specific once I know the details), sorry.

Question: Why does settowidth{hangindent}{some text} not work inside my lemma environment (which is, I think, created using the many option from tcolorbox)?

(I've tried to adjust the parindent, that used to fix some issues with indentation in other tcolorboxes I used, but apparently not here.)

Thanks in advance!

MWE:

documentclass{report}

% Packages used

usepackage[many]{tcolorbox}

% Counter (probably unrelated)

newcounter{lemmacounter}[chapter]

defthelemmacounter{thechapter.arabic{lemmacounter}}



% Where the problem probably lies

    % lemma command for lemma environment using tcolorbox (somehow, I'm not really sure how this is working), with optional "name" argument

DeclareDocumentCommand lemma {o} {%

    IfNoValueTF {#1} {%

        noindentrefstepcounter{lemmacounter}colorbox{black!10}{textbf{L-thelemmacounter}}itshape %

        settowidth{hangindent}{L-00 }hangafter=1 % Why does this not work?

    }{%

        noindentrefstepcounter{lemmacounter}colorbox{black!10}{textbf{L-thelemmacounter}}textbf{ (#1).}itshape

        settowidth{hangindent}{L-00 }hangafter=1 % Why does this not work?

    }%

}



begin{document}



begin{lemma}[Some Lemma]

    Some text some text some text some text some text some text some text some text some text some text some text.

end{lemma}



end{document}

You can achieve your requirement by changing your definitions slightly, here it is:

newenvironment{lemma}[1][empty]{begingroup

if!#1!noindentrefstepcounter{lemmacounter}colorbox{black!10}{textbf{L-thelemmacounter}}itshape

else%

noindentrefstepcounter{lemmacounter}colorbox{black!10}{textbf{L-thelemmacounter}}textbf{ (#1)}itshapefi

settowidth{hangindent}{L-00 }hangafter=1%

}{par%this does the trick for the hangindent

endgroup}