Sublist without bullets

Question

I know that I can suppress indentation bullets using \item[], but nonetheless, the vertical space taken up by the bullet still stays empty. I thought of using a custom list environment, but this did neither adjust the space nor the font size. Arrows mark some of the questionable spots in the following example.

\documentclass{beamer}
\begin{document}
\begin{frame}
  \begin{itemize}
    \item A sub-itemize
      \begin{itemize}
        \item an item with a bullet
        \item[] items without a bullet waste space
        \item[] \(\leftarrow\) here
      \end{itemize}
    \item A sub-list
      \begin{list}{}{}
        \item these items are too big
        \item the sublist font should be smaller
        \item[] \(\leftarrow\) still too much space
      \end{list}
  \end{itemize}
\end{frame}
\end{document}

How can I close the gap? Or, alternatively, how can a new environment be created, that works like itemize but only adds an indent and decreases the font size without adding any bullets?

Answer 1

If you want a list of bullets but have some of the un-bulleted items not indented as far as the regular ones, you need to manually push them back using a negative indent. If you want an entire list to not have bullets and not have as big an indent, then you can set the appropriate beamer template for that (possibly nested) list, as well as the list margin.

Here's an example:

\documentclass{beamer}% http://ctan.org/pkg/beamer
\let\Tiny\tiny% http://tex.stackexchange.com/q/58087/5764
\begin{document}
\begin{frame}
  \begin{itemize}
    \item A sub-itemize
      \begin{itemize}
        \item an item with a bullet
        \item[] items without a bullet waste space
        \item[] \hspace*{-1em}\(\leftarrow\) here
      \end{itemize}
    \item A sub-list
      \begin{list}{}{}
        \item these items are too big
        \item the sublist font should be smaller
        \item[] \(\leftarrow\) still too much space
      \end{list}
  \end{itemize}

  \setbeamertemplate{itemize subitem}{}% Remove bullets frp, ote,oze sinote,
  \setlength\leftmarginii{0.5em}% Left margin of subitems

  \begin{itemize}
    \item A sub-itemize
    \begin{itemize}
      \item an item with a bullet
      \item items without a bullet waste space
      \item \(\leftarrow\) here
    \end{itemize}
  \end{itemize}
\end{frame}

\end{document}

For the third subitem, a negative \hspace{-1em} pushes the content back by 1em. The final list has a itemize subitem template set to nothing (meaning the bullets will not appear), but also the left margin is set to 0.5em, making the items appear with less of an indent.

The default intent for the respective nested lists are 2em each (with a \labelsep of .5em). The following detail is taken from beamerbaselocalstructure.sty:

%
% List stuff
%

\setlength\leftmargini  {2em}
\setlength\leftmarginii  {2em}
\setlength\leftmarginiii  {2em}
\setlength  \labelsep  {.5em}
\setlength  \labelwidth{\leftmargini}
\addtolength\labelwidth{-\labelsep}

Answer 2

I took the definition of the itemize environment and modified it to my liking.

The incorporated \list avoids creating any bullet at all with an empty first parameter and the current margin is set to a fixed width.

\documentclass{beamer}
\makeatletter
% This is itemize, stolen from beamer/base/beamerbaselocalstructure.sty
% but stripped from the bullets and their indentation.
\newcommand{\sub}[1][]{%
  \beamer@ifempty{#1}{}{\def\beamer@defaultospec{#1}}%
  \ifnum \@itemdepth >2\relax\@toodeep\else
    \advance\@itemdepth\@ne
    \beamer@computepref\@itemdepth% sets \beameritemnestingprefix
    \usebeamerfont{itemize/enumerate \beameritemnestingprefix body}%
    \usebeamercolor[fg]{itemize/enumerate \beameritemnestingprefix body}%
    \usebeamertemplate{itemize/enumerate \beameritemnestingprefix body begin}%
    \setlength{\csname leftmargin\romannumeral\@itemdepth\endcsname}{.5em}%
    \list{}%
      {\def\makelabel##1{%
          {%
            \hss\llap{{%
                \usebeamerfont*{itemize \beameritemnestingprefix item}%
                \usebeamercolor[fg]{itemize \beameritemnestingprefix item}##1}}%
          }%
        }%
      }
  \fi%
  \beamer@cramped%
  \raggedright%
  \beamer@firstlineitemizeunskip%
}
\def\endsub{\enditemize} % recycle identical itemize end.
\makeatother


\begin{document}
\begin{frame}
  \begin{itemize}
    \item A sub-itemize
      \begin{itemize}
        \item an item with a bullet
        \item[] items without a bullet waste space
        \item[] \(\leftarrow\) here
      \end{itemize}
    \item A custom sublist
      \begin{sub}
        \item these items work like sub-itemize
        \item but they waste no space
        \item \(\leftarrow\) here
          \begin{sub}
            \item they even work when nested
          \end{sub}
      \end{sub}
  \end{itemize}
\end{frame}
\end{document}