I already asked some questions and I wonder if I am to stupid.
There is a nice option called height fill for the last tcolorbox on the page.
Isn't it possible to have height fill as option to the last tcbraster instead to the last box? In my case just two boxes next to each other.
Is the only solution to try it like [tcolorbox: height fill in the middle of the page ?
\documentclass{article}
\usepackage{tcolorbox}
\tcbuselibrary{raster}
\tcbuselibrary{breakable}
\usepackage{pgfplots}
\pgfplotsset{compat=1.9}
\usepackage{tikzscale}
\begin{filecontents}{tikzimage.tikz}
\begin{tikzpicture}
\begin{axis}[xlabel=time,ylabel=value]
\addplot{x^2};
\end{axis}
\end{tikzpicture}
\end{filecontents}
\makeatletter
\tcbset{%
remember height/.style={before upper={%
\iftcb@fixedheight%
\tcbdimto#1{\kvtcb@top@rule@stand+\kvtcb@bottom@rule@stand+\kvtcb@boxsep*2+\kvtcb@top+\kvtcb@bottom}%
\iftcb@hasTitle%
\tcbdimto#1{#1+\ht\tcb@titlebox+\dp\tcb@titlebox+\kvtcb@title@rule+\kvtcb@boxsep*2+\kvtcb@toptitle+\kvtcb@bottomtitle}%
\fi%
\tcbdimto#1{\kvtcb@height@fixed-#1}%
\else%
\tcbdimto#1{4cm}% fallback
\fi%
}},
}
\makeatother
\begin{document}
\begin{tcolorbox}
a\\a\\a\\a\\a\\a\\a\\a\\a\\a\\a\\a\\a\\a\\a\\a\\a\\a
\end{tcolorbox}
\begin{tcolorbox}
b\\b\\b\\b\\b
\end{tcolorbox}
\begin{tcbraster}[%
raster columns=2,
raster rows=1,
% height fill,% this does not work :-(
height=4cm, % want to have height=\vfill
]
\begin{tcolorbox}[%
equal height group=mybox,
title={box 1\\line two},remember height=\myheight]
\includegraphics[width=\linewidth,height=\myheight]{tikzimage.tikz}
\end{tcolorbox}
\begin{tcolorbox}[equal height group=mybox]
This box and the box on the left is extendet to fill the page.
\end{tcolorbox}
\end{tcbraster}
\end{document}
@Thomas F. Sturm
I hope this is my last question sorry and thanks so much for your time!

