Remove whitespace around own environment

Question

Does anyone know how to remove the whitespace which is created by TeX everytime I use my own created environment? I tried the tricks with \ignorespaces and \ignorespacesafterend but that doesn't seem to work. I want to make use of labels to cross-reference to included code parts later on, and I have a feeling that this labeling issue might be responsible for the white-space I'm generating? Thanks in advance.

\document{book}
\usepackage{listings}
\newcounter{codeexcerptcounter}
\newcommand{\CEN}{Code excerpt~\thecodeexcerptcounter}

\newenvironment{codeexcerpt}[1][]{
\refstepcounter{codeexcerptcounter}%
}{%
}

\newcommand{\addcodeexcerpt}[1][]%
{\begin{center}
\begin{codeexcerpt}
#1
\end{codeexcerpt}
\end{center}}%

\begin{document}

\chapter{First Chapter}

Here goes some explanation.

\addcodeexcerpt[\label{codeex:first}]
\lstinputlisting[title=\CEN: Mirror.java]{code/Mirror.java}

\end{document}

Answer 1

You are adding lots of space, so just don't add it. For example

\newenvironment{codeexcerpt}[1][]{
\refstepcounter{codeexcerptcounter}%
}{%
}

should be

\newenvironment{codeexcerpt}[1][]{%
\refstepcounter{codeexcerptcounter}%
}{%
}

to avoid adding a space at the start of the environment.

also in

\newcommand{\addcodeexcerpt}[1][]%
{\begin{center}
\begin{codeexcerpt}
#1
\end{codeexcerpt}
\end{center}}%


\addcodeexcerpt[\label{codeex:first}]

The content of the displayed codeexcerpt environment is just \label{codeex:first} which is no visible output and will just look like vertical space on the page.

So something like

\documentclass{book}
\usepackage{listings}
\newcounter{codeexcerptcounter}
\newcommand{\CEN}{Code excerpt~\thecodeexcerptcounter}



\newcommand{\addcodeexcerpt}[2][]%
{\par\refstepcounter{codeexcerptcounter}#1#2}

\begin{document}

\chapter{First Chapter}

Here goes some explanation.

\addcodeexcerpt[\label{codeex:first}]
{\lstinputlisting[title=\CEN: Mirror.java]{xxx.txt}}

\end{document}