UML messy diagram

Question

I have 7 classes and wanted to make a UML-diagram of these in latex. I did manage to code it but take a look at the result (I did even try to rescale and rearrange): You can't even identify all the lines showing the relationships. The UML is very messy as you can see so I would like to know if it is possible to make this UML in Latex such that it looks more clean? Code:

\documentclass{article}
\usepackage[utf8]{inputenc}
\usepackage{fullpage}
\usepackage[schoo,simplified]{pgf-umlcd}
\date{January 2019}

\begin{document}



\maketitle

\section{UML-diagram (se næste side)}
\newpage
\begin{tikzpicture}
\begin{package}{Chess}
\begin{class}[text width = 5cm]{chessPiece}{0,0}
    \attribute{\textit{nameOfType : string}}
    \attribute{color : Color}
    \attribute{position : Position option with get/set = None}
    \attribute{\textit{candidateRelativeMoves : Position list list}}
    \attribute{}
    \operation{}
    \operation{ToString : unit $\rightarrow$ string}
    \operation{availableMoves : Board $\rightarrow$ Position list}
    \operation{isThreatened : Board : chessPiece : Position $\rightarrow$ bool}
    \operation{}
\end{class}
\begin{class}[text width = 5cm]{Board}{-5.5,0}
    \attribute{Item : : chessPiece option with set}
    \operation{static validPositionWrap : Position $\rightarrow$ Position option}
    \operation{ToString : unit $\rightarrow$ string}
    \operation{move : Position : Position $\rightarrow$ unit}
    \operation{getVacantNOccupied : chessPiece : Position list $\rightarrow$ unit}
    \operation{getVacantNNeighbours : chessPiece : Position list $\rightarrow$ unit}
\end{class}
\end{package}
\begin{package}{Pieces}
\begin{class}[text width = 3cm]{king}{-11,-1}
\inherit{chessPiece}
\attribute{nameOfType : string= "king"}
\attribute{candidateRelativeMoves = [[(-1,0)];[(-1,1)];[(0,1)];[(1,1)];
      [(1,0)];[(1,-1)];[(0,-1)];[(-1,-1)]]}
\end{class}
\begin{class}[text width = 3cm]{rook}{-11,-5}
    \inherit{chessPiece}
    \attribute{nameOfType : string= "rook"}
    \attribute{candidateRelativeMoves = List.map (swap List.map [1..7]) indToRel}
\end{class}
\end{package}
\begin{package}{Interactives}
\begin{class}[text width = 5cm]{Player}{0,-8}
    \attribute{pieceToMove : chessPiece option = None}
    \operation{nextMove : Board $\rightarrow$ string}
\end{class}
\begin{class}[text width = 5 cm]{Human}{0, -11}
    \inherit{Player}
\end{class}
\end{package}
\begin{class}[text width = 5cm]{Game}{-8,-10}
    \attribute{player1 : Human}
    \attribute{player2 : Human}
    \attribute{\_board : Board}
    \operation{setup : unit}
    \operation{run : unit}
    \operation{valid : string [] $\rightarrow$ Human $\rightarrow$ bool}
\end{class}
\unidirectionalAssociation {chessPiece}{}{}{Board}
\unidirectionalAssociation{Game}{}{}{chessPiece}
\unidirectionalAssociation{Game}{}{}{Player}
\composition{Game}{}{}{king}
\composition{Game}{}{}{rook}
\composition{Game}{}{}{Human}
\composition{Game}{}{}{Board}
\composition{Player}{}{}{chessPiece}
\end{tikzpicture}
\end{document}

Example of a way better version, with example of a modified arrow:

Answer 1

How does this look? Mostly I just repositioned things a bit, changed some text widths and the font size. Note I positioned some of the classes relative to other classes (see Is there any method to create UML using LaTeX without giving (x,y) co-ordinate? for more about that), which makes aligning things easier.

If you have suggestions for modifications, feel free to add them in comments. For example, it would certainly be possible to draw the various arrows differently, they need not be straight lines, but it might require some more manual work, rather than pgf-umlcds macro (\composition etc.).

The code below show a few methods for making the inherit-arrow between king and chessPiece go around the Chess package. This is done "manually", using a standard TikZ \draw macro.

They mostly make use of defining named coordinates at the corner points of the path, and using -|/|- path specifications (see TikZ: What EXACTLY does the the |- notation for arrows do?) to draw the line. To get the correct look, I add the umlcd style inherit line style. Some of the methods require specific TikZ libraries, mentioned in comments.

\documentclass{article}
\usepackage[school,simplified]{pgf-umlcd}
\usetikzlibrary{calc}
\usetikzlibrary{positioning}
\usepackage{fullpage}

\begin{document}   
\begin{tikzpicture}[font=\footnotesize] % reduce fontsize
\begin{package}{Chess}
\begin{class}[text width = 3.3cm]{chessPiece}{0,0}
    \attribute{\textit{nameOfType : string}}
    \attribute{color : Color}
    \attribute{position : Position option with get/set = None}
    \attribute{\textit{candidateRelativeMoves : Position list list}}
    \attribute{}
    \operation{}
    \operation{ToString : unit $\rightarrow$ string}
    \operation{availableMoves : Board $\rightarrow$ Position list}
    \operation{isThreatened : Board : chessPiece : Position $\rightarrow$ bool}
    \operation{}
\end{class}
\begin{class}[text width = 3cm, xshift=-3cm]{Board}{chessPiece.north west}
    \attribute{Item : : chessPiece option with set}
    \operation{static validPositionWrap : Position $\rightarrow$ Position option}
    \operation{ToString : unit $\rightarrow$ string}
    \operation{move : Position : Position $\rightarrow$ unit}
    \operation{getVacantNOccupied : chessPiece : Position list $\rightarrow$ unit}
    \operation{getVacantNNeighbours : chessPiece : Position list $\rightarrow$ unit}
\end{class}
\end{package}
\begin{package}{Pieces}
\begin{class}[text width = 3.3cm, xshift=-4cm]{king}{Board.north west}
%\inherit{chessPiece}
\attribute{nameOfType : string= "king"}
\attribute{candidateRelativeMoves = [[(-1,0)];[(-1,1)];[(0,1)];[(1,1)];
      [(1,0)];[(1,-1)];[(0,-1)];[(-1,-1)]]}
\end{class}
\begin{class}[text width = 3.3cm, yshift=-5mm]{rook}{king.south}
    \inherit{chessPiece}
    \attribute{nameOfType : string= "rook"}
    \attribute{candidateRelativeMoves = List.map (swap List.map [1..7]) indToRel}
\end{class}
\end{package}
\begin{package}{Interactives}
\begin{class}[text width = 3.3cm, yshift=-2cm]{Player}{chessPiece.south}
    \attribute{pieceToMove : chessPiece option = None}
    \operation{nextMove : Board $\rightarrow$ string}
\end{class}
\begin{class}[text width = 3.3cm, yshift=-1cm]{Human}{Player.south}
    \inherit{Player}
\end{class}
\end{package}
\begin{class}[text width = 4cm, xshift=-4cm]{Game}{Player.north west}
    \attribute{player1 : Human}
    \attribute{player2 : Human}
    \attribute{\_board : Board}
    \operation{setup : unit}
    \operation{run : unit}
    \operation{valid : string [] $\rightarrow$ Human $\rightarrow$ bool}
\end{class}
\unidirectionalAssociation {chessPiece}{}{}{Board}
\unidirectionalAssociation{Game}{}{}{chessPiece}
\unidirectionalAssociation{Game}{}{}{Player}
\composition{Game}{}{}{king}
\composition{Game}{}{}{rook}
\composition{Game}{}{}{Human}
\composition{Game}{}{}{Board}
\composition{Player}{}{}{chessPiece}

%% method 1
%\path (king.east) ++(1cm,0) coordinate (m1)
%      (chessPiece.north) ++(0,1.2cm) coordinate(m2);
%\draw [umlcd style inherit line] (chessPiece.north) -- (m2) -| (m1) -- (king.east);

%% method 2 -- requires \usetikzlibrary{calc}
%\draw [umlcd style inherit line]
%     let
%         \p1=(king.east),\p2=(Board.west)
%     in
%     (chessPiece.north) -- ++(0,1.2cm) -| ($(\x1,\y1)!0.5!(\x2,\y1)$) -- (king.east);

%% method 3 -- requires \usetikzlibrary{calc}
%\draw [umlcd style inherit line] (chessPiece.north) -- ++(0,1.2cm) -| ($(king.east)+(1.2cm,0)$) -- (king.east);

%% method 4 -- requires \usetikzlibrary{positioning}
%\coordinate [above left=of Chess] (m3);
%\draw [umlcd style inherit line] (chessPiece) |- (m3) |- (king);

%% method 5
\coordinate (m4) at ([shift={(-4mm,7mm)}]Chess.north west);
\draw [umlcd style inherit line] (chessPiece) |- (m4) |- (king);
\end{tikzpicture}
\end{document}