Positioning relative to a \progressbar

Question

I would like illustrate a deliberately overfull progressbar. I am using \progressbar and tikz, but the relative positioning (east) is always off by a bit in the X direction and I don't know why. Consider the following example:

\documentclass{beamer}

\usepackage{progressbar}

\begin{document}

\begin{frame}
  \begin{overprint}
    \begin{tikzpicture}[remember picture]
      \node<1-2> (progressbar) [inner sep=0,outer sep=0] {\progressbar[heightr=1, width=0.3\textwidth, emptycolor=white, filledcolor=red]{1}};
    \end{tikzpicture}
    \tikz[remember picture] \draw<2>[overlay] node at (progressbar.east) [inner sep=0,outer sep=0] {\progressbar[heightr=1, width=0.1\textwidth, linecolor=white!0, emptycolor=white, filledcolor=red, subdivisions=1, roundnessr=0]{1}};
  \end{overprint}
\end{frame}

\end{document}

The first slide (cropped) looks like this:

The second slide (cropped) looks like this (note the second \progressbar at around 85%, not 100):

How can I position the second \progressbar relative to the first so that they don't overlap (disregarding the ugly white border)?

Answer 1

Like this?

The problem is that, by default, it is the center of your second progress bar what is placed at (progressbar.east). You want the left edge at that position, which is achieved by using [anchor=west] for that node. I.e.:

\documentclass{beamer}

\usepackage{progressbar}

\begin{document}

\begin{frame}
  \begin{overprint}
    \begin{tikzpicture}[remember picture]
      \node<1-2> (progressbar) [inner sep=0,outer sep=0] {\progressbar[heightr=1, width=0.3\textwidth, emptycolor=white, filledcolor=red]{1}};
    \end{tikzpicture}
    \tikz[remember picture] \draw<2>[overlay] node[anchor=west] at (progressbar.east) [inner sep=0,outer sep=0] {\progressbar[heightr=1, width=0.1\textwidth, linecolor=white!0, emptycolor=white, filledcolor=red, subdivisions=1, roundnessr=0]{1}};
  \end{overprint}
\end{frame}

\end{document}

Side note: I don't like very much that code, because it uses tikz code inside nodes (\progressbar command is indeed a complete tikzpicture), but I don't know how to avoid that in this case.

Update

The code can be improved a bit. You can draw the second overlay in the same tikzpicture than the first one. This removes the need of remember picture/overlay, and needs one less compilation:

\documentclass{beamer}
\usepackage{progressbar}

\begin{document}
\begin{frame}
  \begin{overprint}
    \begin{tikzpicture}
      \node<1-2> (progressbar) [inner sep=0,outer sep=0] {\progressbar[heightr=1, width=0.3\textwidth, emptycolor=white, filledcolor=red]{1}};
      \node<2>[anchor=west] at (progressbar.east) [inner sep=0,outer sep=0] {\progressbar[heightr=1, width=0.1\textwidth, linecolor=white!0, emptycolor=white, filledcolor=red, subdivisions=1, roundnessr=0]{1}};
    \end{tikzpicture}
  \end{overprint}
\end{frame}
\end{document}