Draw relative to right end of node

Question

I'm new to tikz and I guess this is a very easy problem. Still I couldn't find the solution.

I want to use tikz to draw a background for my headlines. Therefore I created the following command:

\documentclass{article}
\usepackage{tikz}
\usepackage{xcolor}
\usetikzlibrary{calc}

\newcommand{\headline}[1]{%
    \begin{tikzpicture}
        \fill[gray] (0,2mm) -- (5mm-2mm,2mm) -- (5mm,0) -- (2mm,0) -- (0,2mm);
        \node (A) at (12mm,1mm) {\Large\textsc{#1}};
        \fill[gray] (A.east|-0,2mm) -- (\textwidth-2mm,2mm) -- (\textwidth,0) -- (A.east|-0,0) -- (A.east|-0,0);
    \end{tikzpicture}%
}

\begin{document}
    \headline{test}
\end{document}

The result is the following:

But I want the left bottom corner of the second line behind the text also to be cut off. Like in this image:

I tried to somehow add the missing 2mm but I didn't find a solution. I tried ([xshift=2mm]A.east|-0,2mm), (A.east|-0+2mm,2mm), \fill[gray] let \p{A}=(A) in (A.east|-0,2mm) -- (\textwidth-2mm,2mm) -- (\textwidth,0) -- (\x{A}+2mm,0) -- (A.east|-0,0); and many other things I came across when searching. But I didn't get it to work.

---

How do I add the missing 2mm relative to the end of the node?

Answer 1

Use the tikz-library calc to calculate the missing coordinate as ($(A.east|-0,0)+(2mm,0)$).

\documentclass{article}
\usepackage{tikz}
\usetikzlibrary{calc}

\newcommand{\headline}[1]{%
    \begin{tikzpicture}
        \fill[gray] (0,2mm) -- (5mm-2mm,2mm) -- (5mm,0) -- (2mm,0) -- cycle;
        \node (A) at (12mm,1mm) {\Large\textsc{#1}};
        \fill[gray] (A.east|-0,2mm) -- (\textwidth-2mm,2mm) -- (\textwidth,0) -- ($(A.east|-0,0)+(2mm,0)$) -- cycle;
    \end{tikzpicture}%
}

\begin{document}
    \noindent
    \headline{test}
\end{document}