Replace TikZ's standard overlay specification from only to onslide

Question

In beamer, the standard overlay specification seems to be onslide. In below code, \item<2-> reserves space for the second item on all slides. Inside a tikz environment, however, the standard overlay specification is only, which does not reserve space and causes these "jumping" or "dancing" slides. Is there a way to change the standard overlay specification to onslide so that the rest of the slide does not shift between slides 2 and 3?

I know I could use an overlayarea with sufficiently large height or, equivalently, draw an invisible rectangle on slides 1-2, but that requires manual effort that can accumulate to be quite costly in a lifetime of creating lecture slides. The overlay option for the tikzpicture has the desired effect only if there is no other content on the slide. I could use \onslide<3->{\draw (0, 0) rectangle (-1, -1);} instead, which has the desired effect, but is rather ugly. Is there no way to change the default behavior of the \draw and other beamer commands so that \draw<> ... produces \onslide<>{\draw ...}?

\documentclass{beamer}
\usepackage{tikz}

\begin{document}

\begin{frame}
\begin{center}
\begin{tikzpicture}
\draw (0, 0) rectangle (1, 1);
\draw<3-> (0, 0) rectangle (-1, -1);
\end{tikzpicture}
\end{center}

\begin{itemize}
\item Some text
\item<2-> More text
\end{itemize}
\end{frame}

\end{document}

Answer 1

An easy solution is to use \path to replace the missing \draw features. You can also use [opacity=0] for nodes or even an entire scope.

\documentclass{beamer}
\usepackage{tikz}

\begin{document}

\begin{frame}
\begin{center}
\begin{tikzpicture}
\draw (0, 0) rectangle (1, 1);
\draw<3-> (0, 0) rectangle (-1, -1);
\path (0, 0) rectangle (-1, -1);%***** added line *****
\end{tikzpicture}
\end{center}

\begin{itemize}
\item Some text
\item<2-> More text
\end{itemize}
\end{frame}

\end{document}

Answer 2

I figured it out. Posting this as an answer in the hope that others will find it useful. TikZ resets the \draw and similar commands to \path[draw] in the beginning of every tikzpicture to prevent the user from accidentally overwriting it. This allows us to simply redefine \draw and others within an every picture/.code, checking whether there is an overlay specification with \futurelet and, if there is one, parsing it with \def. I think this solution should be quite robust and quite quick.

\documentclass{beamer}
\usepackage{tikz}

\makeatletter
\newcommand{\fixtikzpath}[1]{
    \expandafter\def\csname #1@standard@btkz\endcsname{\path[#1]}
    \expandafter\def\csname #1@gobble@btkz\endcsname<##1>##2;{
        \def\overlay@btkz{<##1>}
        \expandafter\onslide\overlay@btkz{\path[#1] ##2;}
    }
    \expandafter\def\csname #1@check@btkz\endcsname{
        \ifx\next@btkz<
            \expandafter\expandafter\csname #1@gobble@btkz\endcsname
        \else
            \expandafter\expandafter\csname #1@standard@btkz\endcsname
        \fi
    }
    \expandafter\def\csname #1\endcsname{\expandafter\futurelet\expandafter\next@btkz\csname #1@check@btkz\endcsname}
}
\newcommand{\fixtikznode}{
    \def\node@standard@btkz{\tikz@path@overlay{node}}
    \def\node@gobble@btkz<##1>##2;{
        \def\overlay@btkz{<##1>}
        \expandafter\onslide\overlay@btkz{\tikz@path@overlay{node} ##2;}
    }
    \def\node@check@btkz{
        \ifx\next@btkz<
            \expandafter\node@gobble@btkz
        \else
            \expandafter\node@standard@btkz
        \fi
    }
    \def\node{\futurelet\next@btkz\node@check@btkz}
}
\tikzset{every picture/.code={
    \fixtikzpath{draw}
    \fixtikzpath{fill}
    \fixtikzpath{clip}
    \fixtikznode
}}
\makeatother

\begin{document}
\begin{frame}
\begin{center}
\begin{tikzpicture}
\draw (0, 0) rectangle (1, 1);
\draw<2-> (0, 0) rectangle (1.2, -1.2);
\fill<3-> (0, 0) rectangle (-1.4, -1.4);
\node<4-> at (-1.4, 1.4) {It works};
\end{tikzpicture}
\end{center}
\end{frame}
\end{document}