How can I apply a style to existing tikz node on specific slides

Question

This is what I'm trying to do

    \begin{tikzpicture}
    [node distance = 1cm, auto,font=\footnotesize,
    % STYLES
    every node/.style={node distance=1.3cm},
    comment/.style={rectangle, inner sep= 5pt, text width=4cm, node distance=0.25cm, font=},
    module/.style={rectangle, drop shadow, draw, fill=black!10, inner sep=5pt, text width=3cm, text badly centered, minimum height=0.8cm, font=\bfseries\footnotesize\sffamily,rounded corners},
    selected/.style={fill=red!40}]

    \node [module] (nodeA) {node A};
    \node [module, below of=nodeA] (nodeA) {node B};

    \only<1>{
      \node [comment, text width=6cm, right=0.25 of nodeA] {short description of Node A};
      \node [comment, text width=6cm, right=0.25 of nodeB] {short description of Node B};
     }

    \only<2>{
      \node [selected] (nodeA) {};
      \node [comment, text width=6cm, right=0.25 of nodeA] {long description of node A};
    }
    \only<3>{
      \node [selected] (nodeB) {};
      \node [comment, text width=6cm, right=0.25 of nodeA] {long description of node B};
    }
    \end{tikzpicture}

The problem is

      \node [selected] (nodeB) {};

creates a new node, but I want it to apply the style for the existing node. Is there any way to do so?

Of course I could have copies of every node in selected state and not-selected state, but I really want to have a normal solution.

Eratosthenes

What is "the style for the existing node"? – Irita

Answer 1

I don't think you can do this the way you want to (assuming I understand the question correctly), because once a node is drawn, there's no way to change its appearance. I'd suggest using Beamer's \alt macro:

\alt<2>{\node[module,selected] at (nodeA) {node A};}{\node[module] at (nodeA) {node A};}
\alt<3>{\node[module,selected] at (nodeB) {node B};}{\node[module] at (nodeB) {node B};}
\node[comment,text width=6cm,right=0.25 of nodeA]{\alt<2>{short description}{long description}};
\node[comment,text width=6cm,right=0.25 of nodeB]{\alt<3>{short description}{long description}};

Or something like that (you might have to tinker with the semicolons to get it to work, I can't test that at the moment).

Another option would be to actually just draw a new node. If you include

\node[module,selected] at (nodeA) {node A};

inside \only<2>, that will draw a node that looks just like node A, except with a red background, at the same position at node A. The new node will cover up the original node A.

Irradiant

Oh, that will help me heaps! I once had to draw a white box covering the bit of my figure I had to change and redraw what I wanted to get the result :) – Cheat

Answer 2

Sometimes, to avoid repetitions, it may be nice to do something like this:

% #1    Overlay specs.
% #2    Style name.
% #4    Style properties.
\def\onlystyle<#1>#2#3{%
    \alt<#1>{%
        \tikzset{#2/.style = {#3}}
    }{%
        \tikzset{#2/.style = {}}
    }%
}

Then, if you put, for example, this within a frame:

\onlystyle<2>{selected}{fill = red}

the style selected will be defined as fill = red on the second slide of the animation, and as a style with no effect whatsoever on every other slide. Then, you can write a readable figure such as:

\begin{tikzpicture}
    \node           at (0, 0) {A};
    \node[selected] at (1, 0) {B};
    \node           at (2, 0) {C};
\end{tikzpicture}

and the “B” node will be highlighted on the second slide. This way, you don't have to copy-paste tons of node definitions. Of course, it cannot be applied to every single animation need, but I like to keep this technique up my sleeve.

Kirstinkirstyn

Answer 3

I found yet another solution, which has advantages (more functionality!) compared to all previous solutions, including the one I posted before.

First I mention the improved solution, then I explain why it actually shows more functionality than all other solutions.

The following solution, adapted from How can I make Beamer overlays with TikZ node attributes?, uses an additional tikz library and uses a parameter for the slide number-dependent attribute (for the slide numbers, of course). Note that the tikz setting has to be done outside the frame now.

\documentclass{beamer}
\usepackage{tikz}
\usetikzlibrary{overlay-beamer-styles}
\begin{document}

\begin{frame}{With code/node duplication (explicit frame numbers)}
  \begin{tikzpicture}
  [every node/.style={draw,circle},
   redStyle/.style={fill=red},
   blueStyle/.style={fill=blue}]
   
  \node<1> [] (A) {A};          % no style
  \node<2> [redStyle]  (A) {A}; % red style
  \node<3> [blueStyle] (A) {A}; % blue style

  \node [right of=A] (B) {B};
  \draw [-latex] (A) -- (B) ;
  \end{tikzpicture}
\end{frame}


\tikzset{
  every node/.style={draw,circle},
  redStyle/.style={fill=red},     redStyle on/.style={alt=#1{redStyle}{}},
  blueStyle/.style={fill=blue}, blueStyle on/.style={alt=#1{blueStyle}{}}}
\begin{frame}{\textbf{Without} code/node duplication (explicit frame numbers)}
  \begin{tikzpicture}
  \node [redStyle on=<2>,blueStyle on=<3>] (A) {A};   
  \node [right of=A] (B) {B};
  \draw [-latex] (A) -- (B) ;
  \end{tikzpicture}
\end{frame}


\tikzset{
  every node/.style={draw,circle},
  redStyle/.style={fill=red},     redStyle on/.style={alt=#1{redStyle}{}},
  blueStyle/.style={fill=blue}, blueStyle on/.style={alt=#1{blueStyle}{}}}
\begin{frame}{\textbf{Without} code/node duplication (relative frame numbers)}
  \begin{tikzpicture}
  \node [redStyle on=<+(1)>,blueStyle on=<+(1)>] (A) {A};   
  \node [right of=A] (B) {B};
  \draw [-latex] (A) -- (B) ;
  \end{tikzpicture}
\end{frame}

\end{document}

Now the explanation why this solution is the best mentioned so far, i.e. which additional features it has and why (or when) they are relevant. Well, simply because the respective property does not have to show at the same slide number for different usages within the same frame. Simple example:

Let's say you have a simple tree, i.e. nodes with directed edges connecting them. Say you want to make some of the edges bold in specific slides. Of course you have multiple edges, so clearly they do not all become bold at the very same time! Some edges get bold at frame numbers m to n, others get bold at x and y. This can now be trivially realized with using the node (or edge, in this case) properties timedBold on=<m-n> and timedBold on=<x,y>.

Okubo

Answer 4

Note that there is yet another possibility, which to me seems a bit better than the previous two suggestions, because it has less code duplication (compared to David Z's solution), and because (compared to Alice M.'s solution) you do not need to define a new command that you had to define outside the frame (though defining this additional command is probably not an issue to anybody). In principle, the following suggestion seems to be closely related to the suggestion by Alice M.

Anyway, the solution is a direct application of How to modify a node in TikZ when using beamer's overlays.

Is basically just re-defines a style based on the frame number. See the following minimal example, second or third frame. (I re-did the minimal example since I regard the given one extremely complicated; it was certainly not a minimal example, and also not working on its own.)

\documentclass{beamer}
\usepackage{tikz}
\begin{document}

\begin{frame}{With code/node duplication (explicit frame numbers)}
  \begin{tikzpicture}
  [every node/.style={draw,circle},
   redStyle/.style={fill=red},
   blueStyle/.style={fill=blue}]
   
  \node<1> [] (A) {A};          % no style
  \node<2> [redStyle]  (A) {A}; % red style
  \node<3> [blueStyle] (A) {A}; % blue style

  \node [right of=A] (B) {B};
  \draw [-latex] (A) -- (B) ;
  \end{tikzpicture}
\end{frame}

\begin{frame}{\textbf{Without} code/node duplication (explicit frame numbers)}
  \only<1>{\tikzset{colorStyle/.style={}}}          % no style
  \only<2>{\tikzset{colorStyle/.style={fill=red}}}  % red style
  \only<3>{\tikzset{colorStyle/.style={fill=blue}}} % blue style

  \begin{tikzpicture}
  [every node/.style={draw,circle}]
    
  \node [colorStyle] (A) {A}; % frame-dependent style
  \node [right of=A] (B) {B};
  \draw [-latex] (A) -- (B) ;
  \end{tikzpicture}
\end{frame}

\begin{frame}{\textbf{Without} code/node duplication (relative frame numbers)}
  \only<+>{\tikzset{colorStyle/.style={}}}          % no style
  \only<+>{\tikzset{colorStyle/.style={fill=red}}}  % red style
  \only<+>{\tikzset{colorStyle/.style={fill=blue}}} % blue style

  \begin{tikzpicture}
  [every node/.style={draw,circle}]
    
  \node [colorStyle] (A) {A}; % frame-dependent style
  \node [right of=A] (B) {B};
  \draw [-latex] (A) -- (B) ;
  \end{tikzpicture}
\end{frame}

\end{document}

Okubo