Height and text in rectangle split

Question

I'm working from the code given here. I've got this:

\newcommand\Textbox[2]{%
    \parbox[c][\dimexpr#1-7.7pt][c]{2cm}{\centering#2}}

\tikzstyle{partition}=[draw,
        align=center,
        color=blue,
        rectangle split,]

\begin{tikzpicture}[font=\footnotesize]
    \node[partition,
    rectangle split parts=7,
    rectangle split part fill={gray!30, blue!15}] (start) {
        \textbf{Start}
        \nodepart{two}  \Textbox{30.0pt}{300 KB}
        \nodepart{three}\Textbox{60.0pt}{600 KB}
        \nodepart{four} \Textbox{35.0pt}{350 KB}
        \nodepart{five} \Textbox{20.0pt}{200 KB}
        \nodepart{six}  \Textbox{75.0pt}{750 KB}
        \nodepart{seven}\Textbox{12.5pt}{125 KB}
        };

    % 115 KB
    \node[right=0.5em of start,
    partition,
    rectangle split parts=8, 
    rectangle split part fill={
        gray!30,
        blue!15, blue!15, blue!15, blue!15, blue!15, green!15, blue!15
    }] (step1) {
        \textbf{Step 1}
        \nodepart{two}  \Textbox{30.0pt}{300 KB}
        \nodepart{three}\Textbox{60.0pt}{600 KB}
        \nodepart{four} \Textbox{35.0pt}{350 KB}
        \nodepart{five} \Textbox{20.0pt}{200 KB}
        \nodepart{six}  \Textbox{75.0pt}{750 KB}
        \nodepart{seven}\Textbox{11.5pt}{115 KB}
        \nodepart{eight}\Textbox{01.0pt}{10 KB}
        };

    % 500 KB
    \node[right=0.5em of step1,
    partition,
    rectangle split parts=9, 
    rectangle split part fill={
        gray!30,
        blue!15, green!15, blue!15,blue!15,blue!15,blue!15, green!15, blue!15
    }] (step2) {
        \textbf{Step 2}
        \nodepart{two}  \Textbox{30.0pt}{300 KB}
        \nodepart{three}\Textbox{50.0pt}{500 KB}
        \nodepart{four} \Textbox{10.0pt}{100 KB}
        \nodepart{five} \Textbox{35.0pt}{350 KB}
        \nodepart{six}  \Textbox{20.0pt}{200 KB}
        \nodepart{seven}\Textbox{75.0pt}{750 KB}
        \nodepart{eight}\Textbox{11.5pt}{115 KB}
        \nodepart{nine} \Textbox{01.0pt}{10 KB}
        };
        
    % 358 KB
    \node[right=0.5em of step2,
    partition,
    rectangle split parts=10, 
    rectangle split part fill={
        gray!30,
        blue!15, green!15, blue!15, blue!15, blue!15, green!15, blue!15, green!15, blue!15
    }] (step3) {
        \textbf{Step 3}
        \nodepart{two}  \Textbox{30.0pt}{300 KB}
        \nodepart{three}\Textbox{50.0pt}{500 KB}
        \nodepart{four} \Textbox{10.0pt}{100 KB}
        \nodepart{five} \Textbox{35.0pt}{350 KB}
        \nodepart{six}  \Textbox{20.0pt}{200 KB}
        \nodepart{seven}\Textbox{35.8pt}{358 KB}
        \nodepart{eight}\Textbox{39.2pt}{392 KB}
        \nodepart{nine} \Textbox{11.5pt}{115 KB}
        \nodepart{ten}  \Textbox{01.0pt}{10 KB}
        };
        
    % 200 KB
    \node[right=0.5em of step3,
    partition,
    rectangle split parts=10, 
    rectangle split part fill={
        gray!30,
        blue!15, green!15, blue!15, blue!15, green!15, green!15, blue!15, green!15, blue!15
    }] (step4) {
        \textbf{Step 4}
        \nodepart{two}  \Textbox{30.0pt}{300 KB}
        \nodepart{three}\Textbox{50.0pt}{500 KB}
        \nodepart{four} \Textbox{10.0pt}{100 KB}
        \nodepart{five} \Textbox{35.0pt}{350 KB}
        \nodepart{six}  \Textbox{20.0pt}{200 KB}
        \nodepart{seven}\Textbox{35.8pt}{358 KB}
        \nodepart{eight}\Textbox{39.2pt}{392 KB}
        \nodepart{nine} \Textbox{11.5pt}{115 KB}
        \nodepart{ten}  \Textbox{01.0pt}{10 KB}
        };
        
    % 375 KB
    \node[right=0.5em of step4,
    partition,
    rectangle split parts=11, 
    rectangle split part fill={
        gray!30,
        blue!15, green!15, blue!15, blue!15, green!15, green!15, green!15, blue!15, green!15, blue!15
    }] (step5) {
        \textbf{Step 5}
        \nodepart{two}   \Textbox{30.0pt}{300 KB}
        \nodepart{three} \Textbox{50.0pt}{500 KB}
        \nodepart{four}  \Textbox{10.0pt}{100 KB}
        \nodepart{five}  \Textbox{35.0pt}{350 KB}
        \nodepart{six}   \Textbox{20.0pt}{200 KB}
        \nodepart{seven} \Textbox{35.8pt}{358 KB}
        \nodepart{eight} \Textbox{37.5pt}{375 KB}
        \nodepart{nine}  \Textbox{1.7pt}{17 KB}
        \nodepart{ten}   \Textbox{11.5pt}{115 KB}
        \nodepart{eleven}\Textbox{01.0pt}{10 KB}
        };
\end{tikzpicture}

What can I do to clean it up so that it works for the very smallest slices?

Answer 1

It might be better not to place the labels as contents to the nodes, because nodes will always try to be as large as their contents. Also, I am not sure whether a multipart node such as rectangle split is really the best choice for this, because rectangle split nodes don't allow you to easily define specific heights for the different parts.

I would probably use a pic for this:

\documentclass[border=5pt]{standalone}
\usepackage{tikz}
\usetikzlibrary{positioning}

\newcounter{multipartblockvalue}
\newcounter{multipartblocklabel}
\newcounter{multipartblockfill}
\tikzset{
    pics/multipart block/.style={
        code={
            \tikzset{multipart block/.cd, reset counters, #1}
            \node (-head) at (0,0)
                [multipart block/head]
                {\pgfkeysvalueof{/tikz/multipart block/head content}};
            \foreach \v/\c/\f [count=\i] in {1,...,\pgfkeysvalueof{/tikz/multipart block/parts count}} {
                \pgfmathtruncatemacro{\lasti}{\i-1}
                \tikzset{
                    multipart block/part \i/.initial={},
                    multipart block/part label \i/.initial={}
                }
                \ifnum\lasti=0\relax
                    \node (-part \i) at ([yshift={\pgflinewidth}]-head.south)
                    [anchor=north, multipart block/parts, multipart block/part \i] 
                    {};
                \else
                    \node (-part \i) at ([yshift={\pgflinewidth}]-part \lasti.south)
                    [anchor=north, multipart block/parts, multipart block/part \i] 
                    {};
                \fi
                \node (-part label \i)  at (-part \i)
                [multipart block/part label \i]
                {};
            }
        }
    },
    multipart block/reset counters/.code={
        \setcounter{multipartblockvalue}{0}
        \setcounter{multipartblocklabel}{0}
        \setcounter{multipartblockfill}{0}
    },
    multipart block/step value counter/.code={
        \stepcounter{multipartblockvalue}
    },
    multipart block/step label counter/.code={
        \stepcounter{multipartblocklabel}
    },
    multipart block/step fill counter/.code={
        \stepcounter{multipartblockfill}
    },
    multipart block/parts count/.initial={1},
    multipart block/parts value/.style={
        /tikz/multipart block/step value counter,
        /tikz/multipart block/part \themultipartblockvalue/.append style={
            text height={#1 pt}, inner sep=0pt
        }
    },
    multipart block/parts label/.style={
        /tikz/multipart block/step label counter,
        /tikz/multipart block/part label \themultipartblocklabel/.append style={
            node contents={#1}
        }
    },
    multipart block/parts fill/.style={
        /tikz/multipart block/step fill counter,
        /tikz/multipart block/part \themultipartblockfill/.append style={
            fill={#1}
        }
    },
    multipart block/parts value/.initial={},
    multipart block/parts label/.initial={},
    multipart block/parts fill/.initial={},
    multipart block/parts/.style={draw, fill=blue!15},
    multipart block/head content/.initial={header},
    multipart block/head/.style={draw, fill=gray!30, text depth=0pt},
}

\begin{document}

\begin{tikzpicture}

\pic[draw=blue, minimum width=2cm] (column 1) {
    multipart block={
        head content={\textbf{Start}},
        parts count=6, 
        parts label/.list={300 KB, 600 KB, 350 KB, 200 KB, 750 KB, 125 KB},
        parts value/.list={30, 60, 35, 20, 75, 12.5},
    }
};

\pic[draw=blue, minimum width=2cm] (column 2) at ([xshift=2.5cm]column 1-head) {
    multipart block={
        head content={\textbf{Step 1}},
        parts count=7, 
        parts label/.list={300 KB, 600 KB, 350 KB, 200 KB, 750 KB, 115 KB, 10 KB},
        parts value/.list={30, 60, 35, 20, 75, 11.5, 1},
        parts fill/.list={,,,,,green!15,}
    }
};

\pic[draw=blue, minimum width=2cm] (column 3) at ([xshift=2.5cm]column 2-head) {
    multipart block={
        head content={\textbf{Step 2}},
        parts count=8, 
        parts label/.list={300 KB, 500 KB, 100 KB, 350 KB, 200 KB, 750 KB, 115 KB, 10 KB},
        parts value/.list={30, 50, 10, 35, 20, 75, 11.5, 1},
        parts fill/.list={,green!15,,,,,green!15,},
        part label 8/.append style={
            xshift=1.25cm,
            minimum width=0pt,
            anchor=west,
            append after command={
                \pgfextra{
                    \draw (-part label 8.west) -- (-part 8.east);
                }
            },
        }
    }
};

\end{tikzpicture}

\end{document}