Form: 'TextField's and digsigfield in a table

Question

Note: Question is kin to Form: Tabular arrangement of 'TextField's and digsigfield

I use digsig.sty from Martin Lottermoser http://home.htp-tel.de/lottermose2/tex/dist/digsig.sty

---

How can I arrange two 'TextField's and one digsigfield in this shape, as seamlessly as possible?

I think, I have to set a correct value into
\renewcommand{\tabcolsep}{\dimexpr 0\fboxsep+1\fboxrule+\arrayrulewidth} ?

BTW: I have to implement this with a table, because the picture is only a possible special case.

Actual:

\documentclass[fontsize=14pt]{scrreprt}
\usepackage[margin=1.75cm,
 includefoot, 
showframe=false
%headheight=2\baselineskip,
]{geometry}

\usepackage{tabularx}
\usepackage{xcolor}
\usepackage{calc}
\usepackage[]{hyperref}
\usepackage{digsig} 

\begin{document}
\begin{Form}
  \setlength\arrayrulewidth{1pt}
  \setlength\fboxrule{\arrayrulewidth}
  \setlength{\fboxsep}{0pt}
\renewcommand{\tabcolsep}{\dimexpr 0\fboxsep+1\fboxrule+\arrayrulewidth}
\noindent\begin{tabularx}{\textwidth}{b{0.5\textwidth}  X }
\noindent\color{blue}\fbox{\noindent\digsigfield{0.5\textwidth}{10cm}{test}} & \TextField[multiline,borderstyle=S, value=Text 1, height=10cm]{}\\
\TextField[multiline,borderstyle=S, value=Text 2, height=7cm, width=\textwidth]{}{} 
\end{tabularx}
\end{Form}
\end{document}

Answer 1

Textfields must have a name!

\documentclass[fontsize=14pt]{scrreprt}
\usepackage[margin=1.75cm,
 includefoot,
showframe=false
%headheight=2\baselineskip,
]{geometry}

\usepackage{tabularx}
\usepackage{xcolor}
\usepackage{calc}
\usepackage[]{hyperref}
\usepackage{digsig}
\usepackage{tikz}
\begin{document}
\begin{Form}

\def\LayoutTextField#1#2{#2} % yes you need this
  \setlength\arrayrulewidth{1pt}
  \setlength\fboxrule{\arrayrulewidth}
  \setlength{\fboxsep}{0pt}
\renewcommand{\tabcolsep}{0.5\fboxrule}
\noindent\begin{tabularx}{\textwidth}{b{0.5\textwidth}  X }
\noindent\color{blue}\fbox{\noindent\digsigfield{\dimexpr0.5\textwidth-2\fboxrule}{10cm}{test}} &
\noindent\TextField[name=box1,multiline,borderstyle=S, value=Text 1, height=10cm]{}\\[-0.3\normalbaselineskip]
\hspace{\fboxrule}\TextField[name=box2,multiline,borderstyle=S, 
             value=Text 2, height=7cm, width=\textwidth]{}{}
\end{tabularx}
\end{Form}
\end{document}