[Tex/LaTex] TIKZ Matrix nodes filled with colour afterwards and set to background

backgroundsnodespgflayerstikz-matrixtikz-pgf

I have a (maybe easy) problem in formatting a matrix in tikz.
In the first step I ordinary filled my matrix with nodes inside the matrix environment.

After finishing my matrix I use the fit function to draw a rectangle like shape in order to mark for example some columns in the matrix with a colour (I mean to mark a specific arrangement of nodes). For this I use the first node in the row as a anchor point and a second node at the end of the matrix. For the ancor points I just used the names I gave to the nodes inside the matrix.

However, as I draw the shading rectangel after the nodes are drawn the rectangle is placed "in front" of the nodes and therefore hide all text behind.
As I used the nodenames as anchor I cannot put the code for drawing the rectangel before the matrix code.

I searched the PGF manual and there seems to be something like "behind path" and in "front of path" but this seems to work only inside a path command.

For sure I could just draw a rectangle at the beginning but then I have to adjust the anchor points every time I changes my matrix. Using the nodes as ancor points result in a perfect alignment.

Here is some code you could test to see what I meant to achieve:

\documentclass{article}
\usepackage{tikz,amsmath, amssymb,bm,color}
\usepackage[margin=0cm,nohead]{geometry}
\usepackage[active,tightpage]{preview}
\usetikzlibrary{shapes,arrows}
\usetikzlibrary{calc}
\usetikzlibrary{fit,matrix}
\usetikzlibrary{shadings}

\begin{tikzpicture} [auto, remember picture, block/.style ={ rectangle, 
draw, fill=white,  text centered, minimum height=15mm, text width=12em, 
fill=green}]

\matrix (table) [column sep=.8cm,row sep=.5cm, ampersand replacement=\&,  
nodes in empty cells, in front of path]
{
% row 1
\node [block] (11) {\textbf{Kapitelstruktur der Arbeit}};\& 
\node [block] (12) {Theorie}; \&
\node [block] (13) {\\Empirie};  \& 
\node [block] (14) {\textbf{Resultat}};   \\
% row 2
\node [block] (kap1) {Kapitel 1\\Problembeschreibung und Zielsetzung};
\&  \node [block] (22) {Prior theoretical knowledge};
\&  \node [block] (23) {Prior theoretical knowledge};
\&  \node [block] (24) {Prior theoretical knowledge};
\\
% row 3
\node [block] (kap2) {Kapitel 2\\Grundlagen und Definitionen}; \& 
\node [block] (step1) {Prior theoretical knowledge};  
\& \node [block] (33) {Prior theoretical knowledge} ;
\&  \node [block] (34) {Prior theoretical knowledge};\\
};

%%%% THIS SHOULD APPEAR BEHIND THE NODES OF THE MATRIX%%%%
\node[fit=(12)(33), draw, minimum height=1cm, fill=black, fill opacity=.8, 
text=white]{should be behind nodes};
%%%% THIS SHOULD APPEAR BEHIND THE NODES OF THE MATRIX%%%%

\end{tikzpicture}
\end{document}

Many thanks in advance for your help.

Best Answer

You could use backgrounds for that.

\documentclass[border=3.14mm,x11names,dvipsnames,svgnames]{standalone}
\usepackage{tikz,amsmath, amssymb,bm,color}
\usetikzlibrary{shapes,arrows}
\usetikzlibrary{calc}
\usetikzlibrary{fit,matrix}
\usetikzlibrary{shadings}
\usetikzlibrary{backgrounds}
\begin{document}
\begin{tikzpicture}[auto, remember picture, block/.style ={ rectangle, 
draw, fill=white,  text centered, minimum height=15mm, text width=12em, 
fill=green}]

\matrix (table) [column sep=.8cm,row sep=.5cm, ampersand replacement=\&,  
nodes in empty cells, in front of path]
{
% row 1
\node [block] (11) {\textbf{Kapitelstruktur der Arbeit}};\& 
\node [block] (12) {Theorie}; \&
\node [block] (13) {\\Empirie};  \& 
\node [block] (14) {\textbf{Resultat}};   \\
% row 2
\node [block] (kap1) {Kapitel 1\\Problembeschreibung und Zielsetzung};
\&  \node [block] (22) {Prior theoretical knowledge};
\&  \node [block] (23) {Prior theoretical knowledge};
\&  \node [block] (24) {Prior theoretical knowledge};
\\
% row 3
\node [block] (kap2) {Kapitel 2\\Grundlagen und Definitionen}; \& 
\node [block] (step1) {Prior theoretical knowledge};  
\& \node [block] (33) {Prior theoretical knowledge} ;
\&  \node [block] (34) {Prior theoretical knowledge};\\
};

%%%% THIS SHOULD APPEAR BEHIND THE NODES OF THE MATRIX%%%%
\begin{scope}[on background layer]
\node[fit=(12)(33), draw, minimum height=1cm, fill=black, fill opacity=.8, 
text=white]{should be behind nodes};
\end{scope}
%%%% THIS SHOULD APPEAR BEHIND THE NODES OF THE MATRIX%%%%

\end{tikzpicture}
\end{document}

Related Solutions

[Tex/LaTex] How to establish node-anchor-like points on a (tikz) rectangle path (is there a better method than the one described)

I think that the best way to establish node-like anchors is to use a node. I'm guessing that the annoyance of using an actual node to draw the rectangle is that specifying a node rectangle by its coordinates is a little more complicated than just saying (0,0) rectangle (3,2). So here's some code that puts an invisible (rectangular - but that's only because the default is a rectangle) node around the current path. If the path is more complicated then the node is guaranteed to contain the rectangular bounding box.

Here's the code:

\documentclass{article}

\usepackage{tikz}
\usetikzlibrary{fit}
\makeatletter
\tikzset{
  fitting node/.style={
    inner sep=0pt,
    fill=none,
    draw=none,
    reset transform,
    fit={(\pgf@pathminx,\pgf@pathminy) (\pgf@pathmaxx,\pgf@pathmaxy)}
  },
  reset transform/.code={\pgftransformreset}
}
\makeatother

\begin{document}
\begin{tikzpicture}[line width=.5cm]
\draw[thick,green] (-2,-2) -- (4,4);
\draw (0,0) rectangle (3,2) node[fitting node] (rect) {};
\draw[->,red] (5,5) -- (rect.north east);
\draw[->,red] (0,5) -- (rect.north);
\end{tikzpicture}
\end{document}

The green line is to show that the bounding box used is that of the path and not the current picture. The thick lines are to show that the node anchors are on the proper border of the path, not the "theoretical" path[1].

Here's the result:

path with anchors

[1]: With your method of specifying anchors via coordinates, the anchors would be on the "theoretical" path, namely the north west anchor would be at (3,2) not (3 + half line width, 2 + half line width). If you prefer this, it's easy to modify this method to do that.

Edit Now copes with scale=2 as Altermundus asked about. With more complicated transformations then it gets increasingly difficult to keep track since nodes work differently, and it is working on the actual bounding box rather than the path itself. So in those cases, caveat texer.

[Tex/LaTex] How to define the default vertical distance between nodes

I don't really get the question so I hope this is what you wanted. If you include a full document (such that we copy paste and see the problem on our systems) things are much more easier.

Here, you can change the default setting within a scope but your block style had a node distance which was resetting every time it is issued. I've made it 2mm such that we can see the difference easier.

\documentclass[tikz]{standalone}
\usetikzlibrary{arrows,shapes.geometric,positioning}

\begin{document}
\begin{tikzpicture}[decision/.style={diamond, draw, text width=4.5em, text badly centered, node distance=3.5cm, inner sep=0pt},
                    block/.style   ={rectangle, draw, text width=6em, text centered, rounded corners, minimum height=4em, minimum height=2em},
                    cloud/.style   ={draw, ellipse, minimum height=2em},
                    line/.style    ={draw,-latex'},
                    node distance = 1cm, 
                    auto]
    \node [block] (1st) {1st};
    \node [block, right= of 1st]  (2nd1) {2nd1};
\begin{scope}[node distance=2mm and 10mm]%Here we change it for everything inside this scope
    \node [block, above= of 2nd1] (2nd2) {2nd2};
    \node [block, below= of 2nd1] (2nd3) {2nd3};
    \node [block, right= of 2nd1] (3rd1) {3rd1};
    \node [block, above= of 3rd1] (3rd2) {3rd2};
    \node [block, above= of 3rd2] (3rd3) {3rd3};
\end{scope}
    \node [block, below= of 3rd1] (3rd4) {3rd4};
    \node [block, below= of 3rd4] (3rd5) {3rd5};

    \path [line] (1st) -- (2nd1);
    \path [line] (2nd1) -- (2nd2);
    \path [line] (2nd1) -- (2nd3);
    \path [line] (2nd2) -- (3rd3);
    \path [line] (2nd1) -- (3rd1);
    \path [line] (1st) -- (2nd1);
\end{tikzpicture}
\end{document}

enter image description here

Best Answer

Related Solutions

[Tex/LaTex] How to establish node-anchor-like points on a (tikz) rectangle path (is there a better method than the one described)

[Tex/LaTex] How to define the default vertical distance between nodes

Related Question