\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 (mobile-application-2.pdf)
  /Creator (Cheatography)
  /Author ({[}deleted{]})
  /Subject (Mobile Application 2 Cheat Sheet)
}

% Lengths and widths
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\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{Mobile Application 2 Cheat Sheet}}}} \\
    \normalsize{by \textcolor{DarkBackground}{{[}deleted{]}} via \textcolor{DarkBackground}{\uline{cheatography.com/96251/cs/22163/}}}
\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 25th 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}{Basics}}  \tn
\SetRowColor{white}
\mymulticolumn{1}{x{5.377cm}}{Flutter has Stateful and Stateless Widgets. Stateful widgets (Checkbox, Slider) can display a state, Stateless widgets (Text, IconButton) can't.% Row Count 3 (+ 3)
} \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}{Override build method in state}}  \tn
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{5.377cm}}{//override build method to return an IconButton which displays different icons based on \_isFavorited, and a Text which displays \_favoriteCount \newline @override \newline   Widget build(BuildContext context) \{ \newline     return Row( \newline       mainAxisSize: MainAxisSize.min, \newline       children: {[} \newline         Container( \newline           padding: EdgeInsets.all(0), \newline           child: IconButton( \newline             icon: (\_isFavorited ? Icon(Icons.star) : \seqsplit{Icon(Icons.star\_border))}, \newline             color: Colors.red{[}500{]}, \newline             onPressed: \_toggleFavorite, \newline           ), \newline         ), \newline         SizedBox( \newline           width: 18, \newline           child: Container( \newline             child: \seqsplit{Text('\$\_favoriteCount')}, \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}{Creating a stateful widget}}  \tn
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{5.377cm}}{When createState() is called (which is overridden from StatefulWidget, a new \_FavoriteWidgetState is created. \newline  \newline class FavoriteWidget extends StatefulWidget \{ \newline   @override \newline   \_FavoriteWidgetState createState() =\textgreater{} \_FavoriteWidgetState(); \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}{Add toggle method}}  \tn
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{5.377cm}}{//sets the state when \_toggleFavorite is invoked so the widget refreshes; Increase favorite count \newline void \_toggleFavorite() \{ \newline   setState(() \{ \newline     if (\_isFavorited) \{ \newline       \_favoriteCount -= 1; \newline       \_isFavorited = false; \newline     \} else \{ \newline       \_favoriteCount += 1; \newline       \_isFavorited = true; \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}{Create state}}  \tn
\SetRowColor{LightBackground}
\mymulticolumn{1}{x{5.377cm}}{Create \_FavoriteWidgetState which holds properties like isFavorited and favoriteCount \newline  \newline class \_FavoriteWidgetState extends State\textless{}FavoriteWidget\textgreater{} \{ \newline   bool \_isFavorited = true; \newline   int \_favoriteCount = 41; \newline    \newline \}} \tn 
\hhline{>{\arrayrulecolor{DarkBackground}}-}
\end{tabularx}
\par\addvspace{1.3em}

\begin{tabularx}{5.377cm}{x{2.4885 cm} x{2.4885 cm} }
\SetRowColor{DarkBackground}
\mymulticolumn{2}{x{5.377cm}}{\bf\textcolor{white}{Types of state managment}}  \tn
% Row 0
\SetRowColor{LightBackground}
Widget manages its own state & Sometimes it makes sense to manage state internally. ListView scrolls automatically if content exceeds render box, this is managed internally so the developer doesnt have to handle it \tn 
% Row Count 10 (+ 10)
% Row 1
\SetRowColor{white}
Parent widget manages the widget's state & Parent manages state of children and tells child widget when to update. \tn 
% Row Count 14 (+ 4)
% Row 2
\SetRowColor{LightBackground}
Mix-and-match approach & Some of the state is managed by the widget, some of it is managed by the parent widget. \tn 
% Row Count 19 (+ 5)
\hhline{>{\arrayrulecolor{DarkBackground}}--}
\end{tabularx}
\par\addvspace{1.3em}


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

\end{document}