The CentOS Artwork Repository is supported by Subversion

(@url{http://subversion.tigris.org/}), a version control system which

allows you to keep old versions of files and directories (usually

source code), keep a log of who, when, and why changes occurred, etc.,

like CVS, RCS or SCCS.  

When using Subversion there is one @emph{source repository} and many

@emph{working copies} of that source repository. The working copies

are independent one another, can be distributed all around the world

and provide a local place for designers, documentors, translators and

programmers to perform their works in a descentralized way.  The

source repository, on the other hand, provides a central place for all

independent working copies to interchange data and provides the

information required to permit extracting previous versions of files

at any time.

@subsection Repository policy

@cindex Repository policy

The CentOS Artwork Repository is a collaborative tool that anyone can

have access to. However, changing that tool in any form is something

that should be requested in @email{centos-devel@@centos.org} mailing

list.  Generally, people download working copies from CentOS Artwork

Repository, study the repository organization, make some changes in

their working copies, make some tests to verify such changes do work

the way expected and finally request access to commit them up to the

CentOS Artwork Repository (i.e., the source repository) for others to

benefit from them.

Once you've received access to commit your changes, there is no need

for you to request permission again to commit other changes from your

working copy to CentOS Artwork Repository as long as you behave as a

@emph{good community citizen}.

As a good community citizen one understand of a person who respects

the work already done for others and share ideas with authors before

changing relevant parts of their work, specially in situations when

the access required to realize the changes has been granted already.

Of course, there is a time when conversation has taken place, the

paths has been traced and changing the work is so obvious that there

is no need for you to talk about it; that's because you already did,

you already built the trust to keep going. Anyway, the mailing list

mentioned above is available for sharing ideas in a way that good

relationship between community citizens could be constantly balanced.

The relationship between community citizens is monitored by repository

administrators. Repository administrators are responsible of granting

everything goes the way it needs to go in order for the CentOS Artwork

Repository to comply its mission which is: to provide a colaborative

tool for The CentOS Community where The CentOS Project Corporate

Identity is built and maintained from The CentOS Community itself.

It is also important to remember that all source files inside CentOS

Artwork Repository should comply the terms of GNU General Public

License (@pxref{GNU General Public License}) in order for them to

remain inside the repository.

@subsection Repository organization 

@cindex Repository organization

The CentOS Artwork Repository uses a @file{trunk}, @file{branches},

and @file{tags} organization.  

@table @file

@item trunk

The @file{trunk} directory organizes the main development line of

CentOS Artwork Repository. @xref{Directories trunk}, for more

information.

@item branches

The @file{branches} directory oranizes intermediate development lines

taken from the main development line.  @xref{Directories branches},

for more information.

@item tags

The @file{tags} directory organizes frozen development lines taken

either from the main or the intermediate lines of development.

@xref{Directories tags}, for more information.

@end table

@subsection Repository file names

@cindex Repository file names

Inside the CentOS Artwork Repository, file names are all written in

lowercase (e.g., @samp{01-welcome.png}, @samp{splash.png},

@samp{anaconda_header.png}, etc.) and directory names are all written

capitalized (e.g., @samp{Identity}, @samp{Themes}, @samp{Motifs},

@samp{TreeFlower}, etc.).

@subsection Repository work lines

Inside CentOS Artwork Repository there are four major work lines of

production which are: @emph{graphic design}, @emph{documentation},

@emph{localization} and @emph{automation}.  These work lines describe

different areas of content production. Content production inside these

specific areas may vary as much as persons be working on them.

Producing content in too many different ways may result innapropriate

in a collaborative environment like CentOS Artwork Repository where

content produced in one area depends somehow from content produced in

another different area. So, a @emph{content production standard} is

required for each available work line.

@subsubsection Graphic design

@cindex Graphic design work line

@xref{Directories trunk Identity}, for more information about The

CentOS Corporate Identity and how graphic design fits on it.

@subsubsection Documentation

@cindex Documentation work line

@xref{Directories trunk Manuals}, for more information on

documentation.

@subsubsection Localization

@cindex Localization work line

The localization work line exists to provide the translation messages

required to produce content in different languages. Translation

messages inside the repository are stored as portable objects (e.g.,

.po, .pot) and machine objects (.mo) under @file{trunk/Locales}

directory structure.

The procedure used to localize content is taken from @command{gettext}

standard specification.  Basically, translatable strings are retrived

from source files in order to create portable objects and machine

objects for them.  These portable objects are editable files that

contain the information used by translators to localize the

translatable strings retrived from source files. On the other hand,

machine objects are produced to be machine-redable only, as its name

implies, and are produced from portable objects.

Since @command{gettext} needs to extract translatable strings form

source files in order to let translators to localize them, we are

limitted to use source files supported by @command{gettext} program.

This is not a limitation at all since @command{gettext} supports most

popular programming laguages (e.g., C, C++, Java, Bash, Python, Perl,

PHP and GNU Awk just to mention a few ones). Nevertheless, formats

like SVG, XHTML and Docbook don't figure as supported formats in the

list of @command{gettext} supported source files.

To translate XML based source files like SVG, XHTML and Docbook we use

the @command{xml2po} program instead. The @command{xml2po} comes with

the @file{gnome-doc-utils} package and retrives translatable strings

from one XML file to produce portable objects for them. 

@quotation

@strong{Note}

Portable objects produced by @command{xml2po} have the same format

that portable objects produced by @command{gettext}. This make the

localization process quite consistent from translators' point of view.

No matter what the source file be, the translator will always face the

same translation file format (i.e., the portable object format).

@end quotation

With the portable object in place, the @command{xml2po} program is

used again to create the final translated XML, just with the same

definition of the source file where translatable strings were taken

from (e.g., if we extract translatable strings from a SVG file, as

result we get the same SVG file but with translatable strings already

localized ---obviously, for this to happen translators need to

localize translatable strings inside the portable object first,

localization won't appear as art of magic---).  When using

@command{xml2po}, the machine object is used as temporal file to

produce the final translated XML file.

@quotation

@strong{Tip} If you want to have your content localized inside CentOS

Artwork Repository be sure to use source files supported either by

@command{gettext} or @command{xml2po} programs.

@end quotation

@xref{Directories trunk Locales}, for more information.

@subsubsection Automation

@cindex Automation work line

The automation work line exists to standardize content production in

CentOS Artwork Repository. There is no need to type several tasks,

time after time, if they can be programmed into just one executable

script.

The automation work line takes place under @file{trunk/Scripts}

directory structure. Here is developed the @command{centos-art.sh}

script, a bash script specially designed to automate most frequent

tasks (e.g., rendition, documentation and localization) inside the

repository.  Basically, the @command{centos-art.sh} script is divided

in several functionalities independent one another that perform

specific tasks and relay on repository organization to work as

expected.

@quotation

@strong{Tip} If you need to improve the way content is produced, look

inside automation scripts and make your improvement there for everyone

to benefit.

@end quotation

@xref{Directories trunk Scripts}, for more information on automation.

@subsection Connection between directories

@cindex Connection between directories

@cindex Master paths

@cindex Auxiliar paths

In order to produce content in CentOS Artwork Repository, it is

required that all work lines be connected somehow.  This is the way

automation scripts can know where to retrive the information they need

to work with (e.g., design model, translation messages, output

location, etc.).  We build this kind of connection using two path

constructions named @emph{master paths} and @emph{auxiliar paths}.

The master path points only to directories that contain the source

files (e.g., SVG files) required to produce base content (e.g., PNG

files) through automation scripts.  Each master path inside the

repository may have several auxiliar paths associated, but auxiliar

paths can only have one master path associated.

The auxiliar paths can point either to directories or files. When an

auxiliar path points to a directory, that directory contains

information that modifies somehow the content produced from master

paths (e.g., translation messages) or provides the output information

required to know where to store the content produced from master path.

When an auxiliar path points to a file, that file has no other purpose

but to document the master path it refers to.

The relation between auxiliar paths and master paths is realized

combining two path informations which are: the master path itself and

one second level directory structure from the repository.  Generally,

the master path is considered the path identifier and the second level

directory structure taken from the repository is considered the common

part of the path where the identifier is appended. 

@float Figure, Path construction

@verbatim

-----+---------------+----------------------------+------+-----------

Path | Suffix        | Identifier                 |Prefix| Type 

-----+---------------+----------------------------+------+-----------

  A  |               |trunk/Identity/Models/Brands|      | Directory 

-----+---------------+----------------------------+------+-----------

  B  |  trunk/Manual/|trunk/Identity/Models/Brands|.texinfo | File      

-----+---------------+----------------------------+------+-----------

  C  | trunk/Locales/|trunk/Identity/Models/Brands|      | Directory 

-----+---------------+----------------------------+------+-----------

  D  |               |trunk/Identity/Images/Brands|      | Directory 

-----+---------------+----------------------------+------+-----------

  E  | trunk/Locales/|trunk/Identity/Images/Brands|.texinfo | File      

-----+---------------+----------------------------+------+-----------

  A = Master path.

  B = Auxiliar path to documentation entry.

  C = Auxiliar path to translation messages.

  D = Auxiliar path to final content output.

  E = Auxiliar path to documentation entry.

@end verbatim

@caption{Path construction.}

@end float

The path information described above (@pxref{Path construction}) is

used by direct rendition and can be taken as reference to add other

components that are equally produced in the repository.  To add new

components that make use of direct rendition inside the repository,

change just the component name used above (e.g., @file{Brands}) to

that one you want to add, without changing the path structure around

it.

The file organization used by theme rendition extends direct rendition

by separating design models information from backgrounds information.

To better understand this configuration, you can consider it as two

independent lists, one of design models and one of artistic motifs,

which are arbitrary combined between themselves in order to render

images in specific ways. The possibilities of this configuration are

endless and let us describe visual manifestations very well.  For

example, consider the organization used to produce @file{Anaconda}

images; for CentOS distribution major release 5; using @file{Default}

design models and version @file{3} of @file{Flame} artistic motif:

@float Figure, Path construction extended

@verbatim

-----+---------------+------------------------------------------------------+------+-----------

Path | Suffix        | Identifier                                           |Prefix| Type 

-----+---------------+------------------------------------------------------+------+-----------

  A  |               |trunk/Identity/Models/Themes/Default/Distro/5/Anaconda|      | Directory 

-----+---------------+------------------------------------------------------+------+-----------

  B  |  trunk/Manual/|trunk/Identity/Models/Themes/Default/Distro/5/Anaconda|.texinfo | File      

-----+---------------+------------------------------------------------------+------+-----------

  C  | trunk/Locales/|trunk/Identity/Models/Themes/Default/Distro/5/Anaconda|      | Directory 

-----+---------------+------------------------------------------------------+------+-----------

  D  |               |trunk/Identity/Images/Themes/Flame/3/Distro/5/Anaconda|      | Directory 

-----+---------------+------------------------------------------------------+------+-----------

  E  | trunk/Locales/|trunk/Identity/Images/Themes/Flame/3/Distro/5/Anaconda|.texinfo | File      

-----+---------------+------------------------------------------------------+------+-----------

  A = Master path.

  B = Auxiliar path to documentation entry.

  C = Auxiliar path to translation messages.

  D = Auxiliar path to final content output.

  E = Auxiliar path to documentation entry.

@end verbatim

@caption{Path construction extended.}

@end float

The path information described above (@pxref{Path construction

extended}) is used by theme rendition and can be taken as reference to

add other components that are equally produced in the repository.

In this configuration we can change both design model name (e.g.,

@file{Default}) and artistic motif name (e.g., @file{Flame/3}) to

something else in order to achieve a different result. The only

limitations impossed are the storage space provided in the server

machine and your own creativeness as graphic designer.

@quotation

@strong{Note}

A theme ready for implementation may consume from 100 MB to 400 MB of

storage space. The exact space consumed by a theme depends on the

amount of screen resolutions the theme supports. The more screen

resolutions the theme supports, the more storage space demanded for

it.

@end quotation

In this configuration we saw how to build the path information for

@file{Anaconda} component as part of CentOS Distribution visual

manifestation, but that is not the only component we have inside

CentOS Distribution visual manifestation.  There are other components

like Syslinux, Grub, Rhgb, Gdm, Kdm, Gsplash and Ksplash that share a

similar file organization to that described above for @file{Anaconda}

component.

@subsection Syncronizing path information

@cindex Syncronizing path information

Syncronizing path information is the action that keeps all path

information up to date in the repository. This action implies both

@emph{file movement} and @emph{file content replacement} in this very

specific order. File movement is related to duplicate, delete and

rename files and directories in the repository.  File content

replacement is related to replace information, path information in

this case, inside files in the repository.

The order followed to syncronize path information is relevant because

the versioned nature of the files we are working with. We don't

perform file content replacement first because that would imply a

repository change which will immediatly demmand a commit in order for

actions like duplicate, delete or rename to take place. However, if we

perform file movement first, it is possible to commit both file moved

and file content replacements as if they were just one change. In this

case the file content replacement takes palce in the target location

that have been duplicated or renamed, not the one use as source

location. This configuration is specially useful when files are

renamed (i.e., one file is copied from a source location to a target

location and then the source location of it is removed from

repository).

@quotation

@strong{Warning} There is no support for URLs actions inside

@command{centos-art.sh} script.  The @command{centos-art.sh} script is

designed to work with local files inside the working copy only. If you

need to perform URL actions directly, use Subversion commands instead.

@end quotation

When one master path is changed it is required that all related

auxiliar paths be changed, too. This is required in order for master

paths to retain their relation with auxiliar paths.  This way,

automation scripts are able to know where to retrive translation

messages from, where to store final output images to and where to look

for documentation. If relation between master paths and auxiliar paths

is lost, there is no way for automation scripts to know where to

retrive the information they need.

The auxiliar paths should never be modified under any reason but to

satisfy the relationship with the master path.  Liberal change of

auxiliar paths may suppress the conceptual idea they were initially

created for; and certainly, automation scripts may stop working as

expected. The update direction to rename path information must be from

master path to auxiliar path and never the opposite.

The relation between master and auxiliar paths is useful to keep

repository organized but introduce some complications when we work

with files that use master path information as reference to build

structural information.  This is the case of repository documentation

manual source files where inclusions, menus, nodes and cross

references are built using master path information as reference.  Now,

to see what kind of complication we are talking about, consider what

would happen to a structural definitions (i.e., inlusions, menus,

nodes and cross refereces) already set in the manual from one master

path that is suddenly renamed to something different.  If the path

information is not syncronized, at this point, we lose connection

between the master path and the auxiliar path created to store the

related documentation entry, as well as the related structural

definitions that end up pointing to a master path that no longer

exist.

The syncronization of path information is aimed to solve these kind of

issues.

@subsection Extending repository organization

@cindex Extending repository organization

Occasionly, you may find that new components of The CentOS Project

Corporate Identity need to be added to the repository in order to work

them out. If that is the case, the first question we need to ask

ourselves, before start to create directories blindly all over, is:

@emph{What is the right place to store it?}

The best place to find answers is in The CentOS Community (see page

@url{http://wiki.centos.org/GettingHelp}), but going there with hands

empty is not good idea. It may give the impression you don't really

care about. Instead, consider the following suggestions to find your

own comprehension in order to make your own propositions based on it.

When extending respository structure it is very useful to bear in mind

The CentOS Project Corporate Identity Structure (@pxref{Directories

trunk Identity}) The CentOS Mission and The CentOS Release Schema. The

rest is just matter of choosing appropriate names. It is also worth to

know that each directory in the repository responds to a conceptual

idea that justifies its existence.

To build a directory structure, you need to define the conceptual idea

first and later create the directory. There are some locations inside

the repository that already define some concepts you probably want to

reuse. For example, @file{trunk/Identity/Images/Themes} to store theme

artistic motifs, @file{trunk/Identity/Models/Themes} to store theme

design models, @file{trunk/Manual} to store documentation files,

@file{trunk/Locales} to store translation messages,

@file{trunk/Scripts} to store automation scripts and so on.

To illustrate this desition process let's consider the

@file{trunk/Identity/Images/Themes/TreeFlower/3} directory structure

as example.  This directory can be read as: the theme development line

of version @file{3} of @file{TreeFlower} artistic motif. Additional,

we can identify that artistic motifs are part of themes as well as

themes are part of The CentOS Project Corporate Identity. These

concepts are better described independently in each documentation

entry related to the directory structure as it is respectively shown

in the list of commands bellow.

@verbatim

centos-art help --read turnk

centos-art help --read turnk/Identity

centos-art help --read turnk/Identity/Themes

centos-art help --read turnk/Identity/Images/Themes

centos-art help --read turnk/Identity/Images/Themes/TreeFlower

centos-art help --read turnk/Identity/Images/Themes/TreeFlower/3

@end verbatim

The concepts behind other location can be found in the same way

described above, just change the path information used above to the

one you are trying to know concepts for.