materialize.tex

\documentclass{standalone}
\usepackage{tikz,rxmarbles}
\usetikzlibrary[arrows,shapes,positioning,matrix]

\begin{document}
\begin{tikzpicture}

\matrix[row sep=0.5cm]
{
  \draw [time] (0,0) -- (7,0);
  \node[marble,circle,red] (0x0) at (1,0) {};
  \node[marble,circle,green] (1x0) at (3,0) {};
  \node[complete] (2x0) at (5.25,0) {};
  \\
  
  \node[box,minimum width=7cm] (op) {Materialize};
  \\
  
  \draw [time] (0,0) -- (7,0);
  \node[notification] (0x2) at (1,0) {onNext \tikz[baseline=-1mm] \node[marble,circle,red] {};};
  \node[notification] (1x2) at (3,0) {onNext \tikz[baseline=-1mm] \node[marble,circle,green] {};};
  \node[notification] (2x2) at (5.25,0) {onCompleted};
  \node[complete] (3x2) at (6.5,0) {};
  \\
};

\draw [fdash] (0x0) -- (0x0|-op.north);
\draw [fdash] (1x0) -- (1x0|-op.north);
\draw [fdash] (2x0) -- (2x0|-op.north);

\draw [rdash] (0x2) -- (0x2|-op.south);
\draw [rdash] (1x2) -- (1x2|-op.south);
\draw [rdash] (2x2) -- (2x2|-op.south);
\draw [rdash] (3x2) -- (3x2|-op.south);

\end{tikzpicture}
\end{document}