Modify the @tufte@margin@float environment to automatically align floats

Question

The Tufte classes provide the @tufte@margin@float environment which is used for tables and figures, but its result it's not automatically aligned with the text. The \marginnote command provide a margin note that it's aligned with the text on wich you put your note on, but however, it does not take a marginfigure environment as input for example. So how can I modify this environment in order to have a figure that's automatically aligned with the text?

\documentclass[nofonts]{tufte-handout}

\usepackage{graphicx}

    \newcommand*{\fig}
    {
        \marginnote
        {
            \includegraphics[width=\marginparwidth]{image2}
            This is a margin figure.
        }
    }


\begin{document}

test\fig 

\end{document}

Answer 1

Try adding the following code to your preamble:

\makeatletter

\catcode`\V=14 % `V' is a comment character unless [verbose]

\def\FloatBarrier{\begingroup \let\@elt\relax
    V\edef\@tempa{\write\m@ne{Package placeins Info: Float barrier, from
            V  input line \the\inputlineno, processed on page \thepage, lands on
            V  page \noexpand\thepage. }}\@tempa
    \edef\@tempa{\@fb@botlist\@deferlist\@dbldeferlist}%
    \ifx\@tempa\@empty V\PackageInfo{placeins}{No floats held,}%
    \else
    \ifx\@fltovf\relax % my indicator of recursion
    \if@firstcolumn V\PackageWarning{placeins}{Some floats are stuck,}%
    \clearpage 
    \else V\PackageInfo{placeins}{Eject a column and check again:}%
    \null\newpage\FloatBarrier 
    \fi
    \else V\PackageInfo{placeins}{Must dump some floats}%
    \newpage \let\@fltovf\relax V\PackageInfo{placeins}{Check again:}%
    \FloatBarrier % recurse once only
    \fi\fi \endgroup
    \@fb@topbarrier }

\catcode`\V=11

\renewenvironment{@tufte@margin@float}[2][0pt]{%
    \FloatBarrier% process all floats before this point so the figure/table numbers stay in order.
    \begin{lrbox}{\@tufte@margin@floatbox}%
        \begin{minipage}[t]{\marginparwidth}% top-aligned minipage
            \@tufte@caption@font
            \def\@captype{#2}%
            \hbox{}\vspace*{#1}%
            \@tufte@caption@justification
            \@tufte@margin@par
            \noindent
        }{%
    \end{minipage}%
\end{lrbox}%
\marginpar{\usebox{\@tufte@margin@floatbox}}%
}

%%
% Margin figure environment

\renewenvironment{marginfigure}[1][-7pt]%
{\begin{@tufte@margin@float}[#1]{figure}}
    {\end{@tufte@margin@float}}

\makeatother

The only difference between this code and the code from the Tufte-LaTeX document classes is that the minipage environment in the new code is top-aligned as opposed to center-aligned and the default offset was changed from -1.2ex to 0pt.