\documentclass{article}

\usepackage{longtable}

\usepackage[pdftex]{graphicx}

\usepackage{hyperref}

\hypersetup{pdfauthor={CentOS Documentation SIG},%

            pdftitle={KDE Display Manager (KDM)},%

            pdfsubject={CentOS Corporate Visual Identity}%

            }

\title{KDE Display Manager (KDM)}

\author{CentOS Documentation SIG}

\begin{document}

\maketitle

\begin{abstract} 

This article describes the KDM Visual Style for CentOS Distribution.

KDE Display Manager (KDM) is the second choice defined as CentOS

Display Manager. If users leave their computers on all the time and

don't share their system, they won't see this as often as users who

share a desktop system with other users on the system or laptop users

who reboot and login more frequently.

Copyright \copyright\ 2010\ The CentOS Project. Permission is

granted to copy, distribute and/or modify this document under the

terms of the GNU Free Documentation License, Version 1.2 or any later

version published by the Free Software Foundation; with no Invariant

Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the

license is included in the section entitled ``GNU Free Documentation

License''.  

\end{abstract}

\tableofcontents

\section{Workplace}

\begin{itemize}

\item SVN:trunk/Identity/Themes/\$THEME/Distro/BootUp/KDM/

\item SVN:trunk/Translations/Identity/Themes/Distro/BootUp/KDM/

\item SVN:trunk/Scripts/Identity/Themes/Distro/BootUp/KDM/

\end{itemize}

\section{Theme}

\input{table-theme.tex}

\section{Design}

The centos-release.png and screenshot.png images are rendered for each

major release of CentOS. This task is done using the script render.sh

available in the workplace.  This script creates the appropriate PNG

images under img/\$VERSION/ directory.

The background.png image is taken from Backgrounds section. This task

is done using the script build.sh available in the workplace. This

script collects all information needed, groups it and stores it under

tgz/\$VERSION/\$RESOLUTION/ with the form \$THEME.tar.gz.

Whith the build.sh script you can create KDM themes for specific

CentOS major releases, and inside each major release for specific

screen resolutions.

KDM theme uses the same standard that GDM theme does. More information

about GDM theming is available in the \textit{GNOME Display Manager

Reference Manual}. This guide is available online and inside your

system's help. As shortcut to get that help, you can run the following

command:

\begin{itemize}

\item gnome-help file:///usr/share/gnome/help/gdm/C/gdm.xml\#thememanual

\end{itemize}

\section{Configuration}

\input{table-config.tex}

\begin{description}

\item[Theme]: In the file \emph{kdmrc}, \texttt{Theme} defines which

is the KDM theme used by default.

\texttt{Theme=/usr/share/apps/kdm/themes/Modern/}

\item[UseTheme]: In the file \emph{kdmrc}, \texttt{UseTheme} defines

the precedence of background. If true KDM theme background image takes

precedence against KDM background.

\texttt{UseTheme=true}

\item[Wallpaper]: In the file \emph{backgroundrc}, \texttt{Wallpaper}

defines the default configuration for KDM background.

\texttt{Wallpaper=/usr/share/backgrounds/images/default.png}

\end{description}

The background image used on KDM is one file, and the background image

used on KDM theme is another file. Even they are independent files,

the monolithic visual structure requires the same visual information

in these images.

More information about KDE login screen, KDM and its configuration can

be found in KDE help. As shortcut to get that help, you can run the

following commands:

\begin{itemize}

\item khelpcenter help:/kdm/login.html

\item khelpcenter help:/kdm/configuring-kdm.html

\item khelpcenter help:/kdm/kdm-files.html

\end{itemize}

\section{Rendering}

\section{Testing}

\section{Issues}

\begin{description}

\item[Transition from Greeter to Desktop]: If KDE desktop background

and KDM background are the same (and they should because the

monolithic visual structure) the transition from login screen to

desktop is ``smooth'' because the background image is always visible

on the screen.

\item[Differences between KDM and GDM themes]: KDM and GDM

themes\footnote{It refers to the \emph{.xml} files and its related

files.} are basically the same except for the following differences:

\begin{enumerate}

\item KDM theme requires the ``user-entry'' and ``pw-entry'' stocks.

This forces the using of two boxes, one for username and one for

password. This boxes are visibly appart one from another. In GDM we

use just one box (the ``user-pw-entry'' stock), both for

username and password.

\item In KDM theme, messages were centered on the screen to fit the

KDM two-boxes design. In GDM they are centered to the

``user-pw-entry'' stock width.

\item In KDM theme, the ``language'' stock shows nothing. It creates

an empty space in the screen. The language block was commented to save

space on the screen. In GDM laguage buttom is present and when clicked

a box pops up with a list of languages to choose.

\item Both KDM and GDM themes use the same font defintion in the

\emph{.xml} file, but in presentation they look quiet different. For

example the KDM clock's \emph{Sans 10 Bold} theme definition does not

take effect. Probably font definition in \emph{kdmrc} file takes

precedence against theme's one.

\end{enumerate}

\item[Different resolutions]: Designing of KDM theme needs to be

expandable through different screen resolutions. By default, KDM theme

uses a background image of 2048x1536 pixels. When screen resolution

changes the predifined behaviour is to scale this image to fit the

current display resolution. If the screen resolution is higher, or

differs in ratio (for example when it is a wide screens) the design of

KDM theme could loose quality or look different from the original one.

As a workaround, if KDM theme looks narrow or deformed to you, use the

build.sh script to create the KDM theme in your specific screen

resolution.

\item[KDM theme installation]: To install a KDM theme you need to copy

its files from the workplace to its location in the filesytem. If you

want to make that KDM theme your default one, then you also need to

update the KDM configuration files to match your theme location. Both

of these actions require you to have \emph{root} privileges.

\item[Default Display Manager]: By default KDM is the second display

manager choice\footnote{See the file \emph{/etc/X11/prefdm}.}. To use

KDM as first choise, run the following command (as \emph{root}) and

reboot:

\texttt{echo "DISPLAYMANAGER=KDE" > /etc/sysconfig/desktop}

\item[Package content]: CentOS Default KDM Theme seems to be inside

the package redhat-artwork. In contrast with GDM which has some files in

redhat-logos and others in redhat-artwork. Could we standardize this ?

All files in just one package (redhat-artwork) or files divided in two

packages (redhat-artwork, and redhat-logos).

\end{description}

% License section

\input{../../../../../Licenses/GFDL.tex}

\end{document}