\documentclass[10pt,a4paper]{article}

% Packages
\usepackage{fancyhdr}           % For header and footer
\usepackage{multicol}           % Allows multicols in tables
\usepackage{tabularx}           % Intelligent column widths
\usepackage{tabulary}           % Used in header and footer
\usepackage{hhline}             % Border under tables
\usepackage{graphicx}           % For images
\usepackage{xcolor}             % For hex colours
%\usepackage[utf8x]{inputenc}    % For unicode character support
\usepackage[T1]{fontenc}        % Without this we get weird character replacements
\usepackage{colortbl}           % For coloured tables
\usepackage{setspace}           % For line height
\usepackage{lastpage}           % Needed for total page number
\usepackage{seqsplit}           % Splits long words.
%\usepackage{opensans}          % Can't make this work so far. Shame. Would be lovely.
\usepackage[normalem]{ulem}     % For underlining links
% Most of the following are not required for the majority
% of cheat sheets but are needed for some symbol support.
\usepackage{amsmath}            % Symbols
\usepackage{MnSymbol}           % Symbols
\usepackage{wasysym}            % Symbols
%\usepackage[english,german,french,spanish,italian]{babel}              % Languages

% Document Info
\author{{[}deleted{]}}
\pdfinfo{
  /Title (flutter.pdf)
  /Creator (Cheatography)
  /Author ({[}deleted{]})
  /Subject (Flutter Cheat Sheet)
}

% Lengths and widths
\addtolength{\textwidth}{6cm}
\addtolength{\textheight}{-1cm}
\addtolength{\hoffset}{-3cm}
\addtolength{\voffset}{-2cm}
\setlength{\tabcolsep}{0.2cm} % Space between columns
\setlength{\headsep}{-12pt} % Reduce space between header and content
\setlength{\headheight}{85pt} % If less, LaTeX automatically increases it
\renewcommand{\footrulewidth}{0pt} % Remove footer line
\renewcommand{\headrulewidth}{0pt} % Remove header line
\renewcommand{\seqinsert}{\ifmmode\allowbreak\else\-\fi} % Hyphens in seqsplit
% This two commands together give roughly
% the right line height in the tables
\renewcommand{\arraystretch}{1.3}
\onehalfspacing

% Commands
\newcommand{\SetRowColor}[1]{\noalign{\gdef\RowColorName{#1}}\rowcolor{\RowColorName}} % Shortcut for row colour
\newcommand{\mymulticolumn}[3]{\multicolumn{#1}{>{\columncolor{\RowColorName}}#2}{#3}} % For coloured multi-cols
\newcolumntype{x}[1]{>{\raggedright}p{#1}} % New column types for ragged-right paragraph columns
\newcommand{\tn}{\tabularnewline} % Required as custom column type in use

% Font and Colours
\definecolor{HeadBackground}{HTML}{333333}
\definecolor{FootBackground}{HTML}{666666}
\definecolor{TextColor}{HTML}{333333}
\definecolor{DarkBackground}{HTML}{A3A3A3}
\definecolor{LightBackground}{HTML}{F3F3F3}
\renewcommand{\familydefault}{\sfdefault}
\color{TextColor}

% Header and Footer
\pagestyle{fancy}
\fancyhead{} % Set header to blank
\fancyfoot{} % Set footer to blank
\fancyhead[L]{
\noindent
\begin{multicols}{3}
\begin{tabulary}{5.8cm}{C}
    \SetRowColor{DarkBackground}
    \vspace{-7pt}
    {\parbox{\dimexpr\textwidth-2\fboxsep\relax}{\noindent
        \hspace*{-6pt}\includegraphics[width=5.8cm]{/web/www.cheatography.com/public/images/cheatography_logo.pdf}}
    }
\end{tabulary}
\columnbreak
\begin{tabulary}{11cm}{L}
    \vspace{-2pt}\large{\bf{\textcolor{DarkBackground}{\textrm{Flutter Cheat Sheet}}}} \\
    \normalsize{by \textcolor{DarkBackground}{{[}deleted{]}} via \textcolor{DarkBackground}{\uline{cheatography.com/96251/cs/21925/}}}
\end{tabulary}
\end{multicols}}

\fancyfoot[L]{ \footnotesize
\noindent
\begin{multicols}{3}
\begin{tabulary}{5.8cm}{LL}
  \SetRowColor{FootBackground}
  \mymulticolumn{2}{p{5.377cm}}{\bf\textcolor{white}{Cheatographer}}  \\
  \vspace{-2pt}{[}deleted{]} \\
  \uline{cheatography.com/deleted-96251} \\
  \end{tabulary}
\vfill
\columnbreak
\begin{tabulary}{5.8cm}{L}
  \SetRowColor{FootBackground}
  \mymulticolumn{1}{p{5.377cm}}{\bf\textcolor{white}{Cheat Sheet}}  \\
   \vspace{-2pt}Not Yet Published.\\
   Updated 4th March, 2020.\\
   Page {\thepage} of \pageref{LastPage}.
\end{tabulary}
\vfill
\columnbreak
\begin{tabulary}{5.8cm}{L}
  \SetRowColor{FootBackground}
  \mymulticolumn{1}{p{5.377cm}}{\bf\textcolor{white}{Sponsor}}  \\
  \SetRowColor{white}
  \vspace{-5pt}
  %\includegraphics[width=48px,height=48px]{dave.jpeg}
  Measure your website readability!\\
  www.readability-score.com
\end{tabulary}
\end{multicols}}




\begin{document}
\raggedright
\raggedcolumns

% Set font size to small. Switch to any value
% from this page to resize cheat sheet text:
% www.emerson.emory.edu/services/latex/latex_169.html
\footnotesize % Small font.

\begin{multicols*}{3}

\begin{tabularx}{5.377cm}{X}
\SetRowColor{DarkBackground}
\mymulticolumn{1}{x{5.377cm}}{\bf\textcolor{white}{Simple Hello World App}}  \tn
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{5.377cm}}{import \seqsplit{'package:flutter/material}.dart';  {\bf{import the material component package}} \newline  \newline void main() =\textgreater{} runApp(MyApp()); {\bf{create and run the app}} \newline  \newline class MyApp extends StatelessWidget \{ {\bf{the main widget which is launched}} \newline   @override \newline   Widget build(BuildContext context) \{ {\bf{overriden build method which holds the content}} \newline     return MaterialApp( \newline       title: 'Welcome to Flutter', {\bf{title}} \newline       home: Scaffold( \newline         appBar: AppBar( \newline           title: Text('Welcome to Flutter'), {\bf{set the appbar-text}} \newline         ), \newline         body: Center( \newline           child: Text('Hello World'), {\bf{set the body to center and add text}} \newline         ), \newline       ), \newline     ); \newline   \} \newline \}} \tn 
\hhline{>{\arrayrulecolor{DarkBackground}}-}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{5.377cm}{X}
\SetRowColor{DarkBackground}
\mymulticolumn{1}{x{5.377cm}}{\bf\textcolor{white}{Infinite scrolling listview}}  \tn
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{5.377cm}}{class RandomWordsState extends State\textless{}RandomWords\textgreater{} \{ \newline   final \_suggestions = \textless{}WordPair\textgreater{}{[}{]}; {\bf{adds a suggestion list}} \newline   final \_biggerFont = const TextStyle(fontSize: 18.0); {\bf{increases the font size}} \newline   @override \newline Widget build(BuildContext context) \{ \newline   return Scaffold( \newline     appBar: AppBar( \newline       title: Text('Startup Name Generator'), \newline     ), \newline     body: \_buildSuggestions(), {\bf{sets the body to the build suggestions method which generates the list}} \newline   ); \newline \} \newline \} \newline  \newline Widget \_buildSuggestions() \{ \newline   return ListView.builder( \newline       padding: const EdgeInsets.all(16.0), \newline       itemBuilder: (context, i) \{ {\bf{creates the items}} \newline         if (i.isOdd) return Divider(); {\bf{adds a divider between items}} \newline  \newline         final index = i \textasciitilde{}/ 2; {\bf{calculates number of word parings in the list without counting dividers}} \newline         if (index \textgreater{}= \_suggestions.length) \{ \newline           \seqsplit{\_suggestions.addAll(generateWordPairs().take(10));} {\bf{add ten more words when the end of the list is reached}} \newline         \} \newline         return \_buildRow(\_suggestions{[}index{]}); {\bf{build the row using the widget below}} \newline  \newline Widget \_buildRow(WordPair pair) \{ \newline   return ListTile( \newline     title: Text( \newline       pair.asPascalCase, {\bf{sets the word as text \newline       style: \_biggerFont, }}changes the fontsize** \newline     ), \newline   ); \newline \} \newline       \}); \newline \}} \tn 
\hhline{>{\arrayrulecolor{DarkBackground}}-}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{5.377cm}{X}
\SetRowColor{DarkBackground}
\mymulticolumn{1}{x{5.377cm}}{\bf\textcolor{white}{External packages}}  \tn
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{5.377cm}}{edit pubspec.yaml, to add english\_words \newline  \newline    dependencies: \newline     flutter: \newline       sdk: flutter \newline     cupertino\_icons: \textasciicircum{}0.1.2 \newline +   english\_words: \textasciicircum{}3.1.5  \newline  \newline after that, run flutter pub get to get the new dependencies \newline and then add the new dependency to lib/main.dart \newline  \newline import \seqsplit{'package:english\_words/english\_words}.dart';} \tn 
\hhline{>{\arrayrulecolor{DarkBackground}}-}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{5.377cm}{X}
\SetRowColor{DarkBackground}
\mymulticolumn{1}{x{5.377cm}}{\bf\textcolor{white}{Generate random words}}  \tn
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{5.377cm}}{class MyApp extends StatelessWidget \{ \newline     @override \newline     Widget build(BuildContext context) \{ \newline +     final wordPair = WordPair.random(); {\bf{create a new wordpair}} \newline       return MaterialApp( \newline         title: 'Welcome to Flutter', \newline         home: Scaffold( \newline @@ -16,7 +18,7 @@ \newline             title: Text('Welcome to Flutter'), \newline           ), \newline           body: Center( \newline -           child: Text('Hello World'), {\bf{remove the hello world text}} \newline +           child: \seqsplit{Text(wordPair.asPascalCase)}, {\bf{show random word as text}} \newline           ), \newline         ), \newline       );} \tn 
\hhline{>{\arrayrulecolor{DarkBackground}}-}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{5.377cm}{X}
\SetRowColor{DarkBackground}
\mymulticolumn{1}{x{5.377cm}}{\bf\textcolor{white}{Stateful widgets}}  \tn
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{5.377cm}}{class RandomWordsState extends State\textless{}RandomWords\textgreater{} \{ \newline   @override \newline   Widget build(BuildContext context) \{ \newline     final wordPair = WordPair.random(); \newline     return \seqsplit{Text(wordPair.asPascalCase);} \newline   \} \newline \} \newline  \newline {\bf{this creates a "state" which saves the generated word and displays it as text}} \newline  \newline class RandomWords extends StatefulWidget \{ \newline   @override \newline   RandomWordsState createState() =\textgreater{} RandomWordsState(); \newline \} \newline  \newline {\bf{add the state to the statefull widget}} \newline  \newline class MyApp extends StatelessWidget \{ \newline     @override \newline     Widget build(BuildContext context) \{ \newline -     final wordPair = WordPair.random(); \newline       return MaterialApp( \newline         title: 'Welcome to Flutter', \newline         home: Scaffold( \newline @@ -18,8 +17,8 @@ \newline             title: Text('Welcome to Flutter'), \newline           ), \newline           body: Center( \newline -           child: \seqsplit{Text(wordPair.asPascalCase)}, \newline +           child: RandomWords(), \newline           ), \newline         ), \newline       ); \newline     \}  \newline  \newline {\bf{remove the previous random word generation and replace it with the stateful widget}}} \tn 
\hhline{>{\arrayrulecolor{DarkBackground}}-}
\end{tabularx}
\par\addvspace{1.3em}


% That's all folks
\end{multicols*}

\end{document}