Vertically alligned description of acronyms using glossaries package

Question

After spending lots of time searching for a solution, I still haven't found anything that really suits my problem. The goal is pretty simple: I would like to generate a List of Acronyms which consist of a title, description and acronym entries. With the following code I have almost achieved desired results except the distance between acronym entries and the description is not vertically aligned. Here is the code for setting up the glossary design:

% Preamble
\documentclass[11pt, a4paper, twoside]{report}

% Package for acronyms
\usepackage[acronym, automake, nopostdot, nogroupskip]{glossaries}

\makeglossaries

\renewcommand*{\glsnamefont}[1]{\normalfont#1}
\renewcommand\glstreepredesc{\hspace{4cm}}          
\setglossarypreamble[acronym]{\textbf{Acronym}\hspace{3.3cm}\textbf{Description\vspace*{0.3cm}}}

\newacronym{ADF}{ADF}{Automatic Direction Finder}
\newacronym{ADI}{ADI}{Automatic Direction Indicator}

\begin{document}

\printglossary[type=\acronymtype, title={Table of Acronyms}, nonumberlist, style=index]
\bigskip
Here, we use the acronym \acrfull{ADF}. The second acronym is \acrfull{ADI}. After the first usage of the 1st acronym, only the short version is used: \acrshort{ADF}.

\end{document}

In the following result picture one can see that the first letters of both descriptions are not vertically aligned:

The question is: how to make them vertically aligned? Thanks in advance!

Answer 1

The longraggedheader style is what you are looking for. It is similar to the longheader style but aligns everything left.

In order to change the vertical spacing you can redefine \glossaryheader to your liking:

% Set the table's header:
\def\spacing{10pt}% Here you can change the vertical spacing after the header
\renewcommand*{\glossaryheader}{%
    \bfseries Acronym & \bfseries Description \\[\spacing]\endhead%
}%

If you want to change the horizontal spacing, you need to redefine how the style calls longtable:

% put the glossary in a longtable environment:
\def\acrowidth{1cm}% This is the spacing
\renewenvironment{theglossary}%
{\begin{longtable}{p{\acrowidth}p{\glsdescwidth}}%
{\end{longtable}}%