Beamer and personal environments

Question

I am trying to create a beamer with personal environments (such as definition, theorem...).

However, when I compile, my personal definitions shows but also an other one definition shows, as if I was using a block (which I don't).

Here is the code that I have :

% Inbuilt themes in beamer
\documentclass[notheorems]{beamer}

% Theme choice:
\usetheme{default}
\usecolortheme{rose}
\usefonttheme{professionalfonts}


\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage{amsgen,amsmath,amstext,amsbsy,amsopn,amsthm,amsfonts,amssymb,makeidx}
\usepackage[inline]{enumitem}%{enumerate}
\usepackage{titlesec}
\usepackage{framed}
\usepackage{lmodern}
\usepackage{mathrsfs}
\usepackage{setspace}
\usepackage[off]{auto-pst-pdf}
\usepackage[french]{babel}
\usepackage{mathtools}
\usepackage{color, xcolor}
\usepackage[all]{xy}

\definecolor{def}{rgb}{0.604,0.196,0.804}

% Personal definition style
% **************
\renewenvironment{leftbar}[1][\hsize]
{% 
\def\FrameCommand 
{%
    {\hspace{0pt}\color{darkgray}\vrule width 2pt}
    \hspace{5pt}%must no space.
    \fboxsep=\FrameSep\makebox%\colorbox{lightgray}
}
\MakeFramed{\hsize#1\advance\hsize-\width\FrameRestore}
}
{\endMakeFramed}

\newcounter{def}

\newtheoremstyle
   {defi}         %1 Nom
   {0ex}          %2 Espace avant
   {0ex}          %3 Espace après
   {\sffamily}  %4 forme des caractères
   {0ex}          %5 indentation
   {\scshape}     %6 Style de l'entête
   {}           %7
   { }            %8 Retour à la ligne après le titre
   {{}}             %9 Comme dans plain ?
\theoremstyle{defi}
\newtheorem{dfplus}[def]{Définition}
\newenvironment{Def}[1][\null]{\begin{leftbar}\begin{dfplus}\textcolor{def}{\scshape{Définition \thedef#1 : }}\color{black}\normalfont\sffamily}{\end{dfplus}\end{leftbar} \vspace*{0.2cm}} 

% **************

\begin{document}

\begin{frame}
\begin{Def}
here is my definition
\end{Def}
\end{frame}

\end{document}

In fact, (it is just about aesthetic), I don't like the blue "definition" showing up.

Thank you for your help !

Answer 1

You can use

\setbeamertemplate{theorem begin}{}
\setbeamertemplate{theorem end}{}

to disable theorem blocks.

% Inbuilt themes in beamer
\documentclass[notheorems]{beamer}

% Theme choice:
%\usetheme{default}
\usecolortheme{rose}
\usefonttheme{professionalfonts}

\setbeamertemplate{theorem begin}{}
\setbeamertemplate{theorem end}{}


\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
%\usepackage{amsgen,amsmath,amstext,amsbsy,amsopn,amsthm,amsfonts,amssymb,makeidx}
%\usepackage[inline]{enumitem}%{enumerate}
%\usepackage{titlesec}
\usepackage{framed}
\usepackage{lmodern}
\usepackage{mathrsfs}
\usepackage{setspace}
\usepackage[off]{auto-pst-pdf}
\usepackage[french]{babel}
\usepackage{mathtools}
%\usepackage{color, xcolor}
\usepackage[all]{xy}

\definecolor{def}{rgb}{0.604,0.196,0.804}

% Personal definition style
% **************
\renewenvironment{leftbar}[1][\hsize]
{% 
\def\FrameCommand 
{%
    {\hspace{0pt}\color{darkgray}\vrule width 2pt}
    \hspace{5pt}%must no space.
    \fboxsep=\FrameSep\makebox%\colorbox{lightgray}
}
\MakeFramed{\hsize#1\advance\hsize-\width\FrameRestore}
}
{\endMakeFramed}

\newcounter{def}

\newtheoremstyle
   {defi}         %1 Nom
   {0ex}          %2 Espace avant
   {0ex}          %3 Espace après
   {\sffamily}  %4 forme des caractères
   {0ex}          %5 indentation
   {\scshape}     %6 Style de l'entête
   {}           %7
   { }            %8 Retour à la ligne après le titre
   {{}}             %9 Comme dans plain ?
\theoremstyle{defi}
\newtheorem{dfplus}[def]{Définition}
\newenvironment{Def}[1][\null]{\begin{leftbar}\begin{dfplus}\textcolor{def}{\scshape{Définition \thedef#1 : }}\color{black}\normalfont\sffamily}{\end{dfplus}\end{leftbar} \vspace*{0.2cm}} 

% **************

\begin{document}

\begin{frame}
\begin{Def}
here is my definition
\end{Def}
\end{frame}

\end{document}

Or you could use the noamsthm class option (however then you will loose overlay-awareness for your theorems)

% Inbuilt themes in beamer
\documentclass[noamsthm]{beamer}

% Theme choice:
%\usetheme{default}
\usecolortheme{rose}
\usefonttheme{professionalfonts}

\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage{amsthm}
%\usepackage{amsgen,amsmath,amstext,amsbsy,amsopn,amsthm,amsfonts,amssymb,makeidx}
%\usepackage[inline]{enumitem}%{enumerate}
%\usepackage{titlesec}
\usepackage{framed}
\usepackage{lmodern}
\usepackage{mathrsfs}
\usepackage{setspace}
\usepackage[off]{auto-pst-pdf}
\usepackage[french]{babel}
\usepackage{mathtools}
%\usepackage{color, xcolor}
\usepackage[all]{xy}

\definecolor{def}{rgb}{0.604,0.196,0.804}

% Personal definition style
% **************
\renewenvironment{leftbar}[1][\hsize]
{% 
\def\FrameCommand 
{%
    {\hspace{0pt}\color{darkgray}\vrule width 2pt}
    \hspace{5pt}%must no space.
    \fboxsep=\FrameSep\makebox%\colorbox{lightgray}
}
\MakeFramed{\hsize#1\advance\hsize-\width\FrameRestore}
}
{\endMakeFramed}

\newcounter{def}

\newtheoremstyle
   {defi}         %1 Nom
   {0ex}          %2 Espace avant
   {0ex}          %3 Espace après
   {\sffamily}  %4 forme des caractères
   {0ex}          %5 indentation
   {\scshape}     %6 Style de l'entête
   {}           %7
   { }            %8 Retour à la ligne après le titre
   {{}}             %9 Comme dans plain ?
\theoremstyle{defi}
\newtheorem{dfplus}[def]{Définition}
\newenvironment{Def}[1][\null]{\begin{leftbar}\begin{dfplus}\textcolor{def}{\scshape{Définition \thedef#1 : }}\color{black}\normalfont\sffamily}{\end{dfplus}\end{leftbar} \vspace*{0.2cm}} 

% **************

\begin{document}

\begin{frame}
\begin{Def}
here is my definition
\end{Def}
\end{frame}

\end{document}