@emph{''CentOS like trees, has roots, trunk, branches, leaves and

flowers.  Day by day they work together in freedom, ruled by the laws

of nature and open standards, to show the beauty of its existence.''}

This section describes the organization of files and directories

inside the CentOS Artwork Repository, the names convenctions, how to

extend the current layout and the way content is produced, as well. 

The repository layout is used as standard backend for automation

scripts to work correctly. If repository layout changes unexpectedly,

automation scripts may get confuse themselves and stop doing what you

may expect from them to do.

As convenction, inside CentOS Artwork Repository, files and

directories related to CentOS corporate visual identity are organized

under three top level directories named: @file{trunk/},

@file{branches/}, and @file{tags/}. 

The @file{trunk/} directory (@pxref{Directories trunk}) organizes the main

development line of CentOS corporate visual identity. Inside

@file{trunk/} directory structure, the CentOS corporate visual

identity concepts are implemented using directories.  There is one

directory level for each relevant concept inside the repository. The

@file{trunk/} directory structure is mainly used to perform

development tasks related to CentOS corporate visual identity.

The @file{branches/} directory (@pxref{Directories branches}) oranizes

parallel development lines to @file{trunk/} directory. The

@file{branches/} directory is used to set points in time where

develpment lines are devided one from another taking separte and

idependent lives that share a common past from the point they were

devided on. The @file{branches/} directory is mainly used to perform

quality assurance tasks related to CentOS corporate visual identity.

The @file{tags/} directory (@pxref{Directories tags}) organizes parallel frozen

lines to @file{branches/} directory.  The parallel frozen lines are

immutable, nothing change inside them once they has been created.  The

@file{tags/} directory is mainly used to publish final releases of

CentOS corporate visual identity.

The CentOS Artwork Repository layout is firmly grounded on a

Subversion base.  Subversion (@url{http://subversion.tigris.org}) is 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.  Subversion keeps a

single copy of the master sources.  This copy  is called the source

``repository''; it contains all the information to permit extracting

previous versions of those files at any time.

@subsection Repository file names

Repository name convenctions are applied to files and directories

inside the repository layout. As convenction, file names are all

written in lowercase (@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.).

Repository name convenctions are implemented inside the

@code{cli_getRepoName} function of @file{centos-art.sh} script. With

@code{cli_getRepoName} function the amount of commands and

convenctions to remember are reduced and concentrated in just one

single place to look for fixes and improvements.

@subsection Repository work flow

As repository work flow we understand a serie of normalized steps used

to produce contents inside CentOS Artwork Repository. There are three

remarkable actions inside the repository that we need to provide a

normalized work flow for, they are: @emph{Rendition},

@emph{Localization} and @emph{Programming}.

@subsubsection Rendition

Rendition is the action through which The CentOS Project Corporate

Identity is produced inside the repository. The CentOS Project

Corporate Identityis is made, in part, of several visual

manifestations.  These visual manifestations implement the Corporate

Identity by mean of images placed in key areas of their visual space. 

As work flow to produce these images, we decompose them in design

models and artistic motifs. Design models provide the image structure

(i.e., dimension, translation markers, common designs, etc.) and

artistic motifs the visual style (i.e., the background information

provide the look and feel). 

Design models are created for each visual manifestation the CentOS

Project is made of. This way we describe the visual manifestation and

provide a template system for it where several artistic motifs can be

applied. Artistic motifs are created with design models in mind, not

the visual manifestation such design models is built for.

The combination of one design models with one artistic motifs is what

we know as one @emph{theme}. Inside themes directory structure, you

can find several design models and several artistic motifs, apart one

another, that can be albitrarily combined one another through

@emph{theme rendition}, a flexible way to produce images for different

visual manifestations inside CentOS Artwork Repository. Theme

rendition takes place in @file{trunk/Identity/Themes/Models} and

@file{trunk/Identity/Themes/Motifs} directory structures.

In addition to theme rendition, you can find another way of image

production, a more direct way of image production where there is no

artistic motif at all, but design models only. Such configuration is

named @emph{direct rendition} and is very useful to produce simple

content that doesn't need specific background information like icons

and illustrations used in documentation. Direct rendition takes place

in @file{trunk/Identity/Models} and @file{trunk/Identity/Images}

directory structures.

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

@subsubsection Localization

Whatever content rendition you perform, sometimes you need to produce

content in different languages. Production of content in different

languages is known as localization or l10n for short.  Inside CentOS

Artwork Repository, content localization is performed using the

processed provided by @command{gettext} internationalization standard.

Basically, the @command{gettext} internationalization standard

consists on retriving translatable strings from source files and

creating Portable Objects and Machine Objects. Portable Objects

contain the information used by translators to do their work, they are

files that can be edited by any convenctional text editor like Vim,

Emacs or Nano. On the other hand, Machine Objects are produced to be

machine-redable 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, the types

of source files we use inside the repository are limitted to the file

types supported by @command{gettext} program. Most of source files

supported by @command{gettext} are those from programming languages

like C, C++, Bash, Python and Perl just to mention a few ones from the

long list of supported formats. However, formats like SVG, XHTML and

Docbook don't figure as supported in the long list of

@command{gettext} supported source files. For these formats we use the

@command{xml2po} program that come in the @file{gnome-doc-utils}

package instead.  The @command{xml2po} program reads one XML based

file and extracts translatable strings from it and creates one

Portable Object that is use to create a translated XML based file 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 file is used just temporally to

produce the final translated XML based file.

@quotation

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

Artwork Repository be sure to use source files supported by

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

@end quotation

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

@subsubsection Programming

So far, we've seen a conceptual view of how image production inside

CentOS Artwork Repository is performed, but how all this is

implemented, what is the practical view?

The practical view can be found through @command{centos-art.sh}

script, a bash script specially designed to automate most frequent

tasks inside CentOS Artwork Repository. The @command{centos-art.sh}

script is stored in @file{trunk/Scripts} directory structure and is

there where the main development for @command{centos-art.sh} script

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

in several functionalities that perform specific tasks inside the

repository. Such functionalities relay on repository organization to

work as expected. 

Maiking the @command{centos-art.sh} script to automate tasks is the

only possible work flow that I can think about right now. If you are a

programmer, take a functionality from @command{centos-art.sh} script,

study it, look how to improve it and share your ideas at

@email{centos-devel@@centos.org} mailing list. 

@quotation 

@strong{Note} As default configuration, everyone is denied from

committing changes up to CentOS Artwork Repository. In order to gain

commit rights, you need to prove your interest in contributing and

maintaining that contribution.  Otherwise, if you only want to comment

your ideas, the @email{centos-devel@@centos.org} mailing list exists

for you to manifest yourself. This restrictions are necessary to

protect our work from spammers.

@end quotation

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

@subsection Work lines

The CentOS Artwork Repository is organized using the Rendition,

Localization and Programming concepts described above.  These concepts

suggest three different work lines to get focused in: 

@table @strong

@item Graphic design 

This work line exists to cover the corporate design (e.g., brand

design, typography design and theme design). Other areas that could be

included here are icon design and illustration design for

documentation.

@item Documentation

This work line exists to describe what each directory structure inside

the CentOS Artwork Repository is for and how to produce content inside

it.

@item Translation

This work line exists to localize corporate design and documentation

source files, so they can be produced in different languages.

@item Automation

This work line exists to standardize corporate design, documentation

and localization processes and automate their production. There is no

need to repeat several tasks time after time if they can be programmed

in just one for you to execute. If you need to improve the way content

is produced, look inside automation scripts and make your improvement

there for every one to benefit.

@end table

@subsection Parallel directories

Inside CentOS Artwork Repository, parallel directories are simple

directory entries built from a common parent directory and placed in a

location different to that, the common parent directory is placed on.

Parallel directories are useful to create branches, tags,

translations, documentation, pre-rendering configuration script, and

similar directory structures.

Parallel directories take their structure from one unique parent

directory. Inside CentOS Artwork Repository, this unique parent

directory is under @file{trunk/Identity} location.  The

@file{trunk/Identity} location must be considered the reference for

whatever information you plan to create inside the repository.

In some circumstances, parallel directories may be created removing

uncommon information from their paths. Uncommon path information

refers to those directory levels in the path which are not common for

other parallel directories.  For example, when rendering

@file{trunk/Identity/Themes/Motifs/TreeFlower/Distro} directory

structure, the @file{centos-art.sh} script removes the

@file{Motifs/TreeFlower/} directory levels from path, in order to

build the parallel directory used to retrived translations, and

pre-rendering configuration scripts required by @code{render}

functionality.

Another example of parallel directory is the documentation structure

created by @code{manual} functionality. This time,

@file{centos-art.sh} script uses parallel directory information with

uncommon directory levels to build the documentation entry required by

Texinfo documentation system, inside the repository.

Othertimes, parallel directories may add uncommon information to their

paths. This is the case we use to create branches and tags. When we

create branches and tags, a numerical identifier is added to parallel

directory structure path. The place where the numerical identifier is

set on is relevant to corporate visual identity structure and should

be carefully considered where it will be.

When one parent directory changes, all their related parallel

directories need to be changed too. This is required in order for

parallel directories to retain their relation with the parent

directory structure.  In the other hand, parallel directories should

never be modified under no reason but to satisfy the relation to their

parent directory structure.  Liberal change of parallel directories

may suppresses the conceptual idea they were initially created for;

and certainly, things may stop working the way they should do.

@subsection Syncronizing path information

Parallel directories are very useful to keep repository organized but

introduce some complications.  For instance, consider what would

happen to functionalities like @code{manual} (@samp{trunk Scripts Bash

Functions Manual}) that rely on parent directory structures to create

documentation entries (using parallel directory structures) if one of

those parent directory structures suddenly changes after the

documentation entry has been already created for it? 

In such cases, functionalities like @code{manual} may confuse

themselves if path information is not updated to reflect the relation

with its parent directory.  Such functionalities work with parent

directory structure as reference; if a parent directory changes, the

functionalities dont't even note it because they work with the last

parent directory structure available in the repository, no matter what

it is. 

In the specific case of documentation (the @code{manual}

functionality), the problem mentioned above provokes that older parent

directories, already documented, remain inside documentation directory

structures as long as you get your hands into the documentation

directory structure (@file{trunk/Manuals}) and change what must be

changed to match the new parent directory structure.

There is no immediate way for @code{manual}, and similar

functionalities that use parent directories as reference, to know when

and how directory movements take place inside the repository. Such

information is available only when the file movement itself takes

place inside the repository. So, is there, at the moment of moving

files, when we need to syncronize parallel directories with their

unique parent directory structure.

@quotation

@strong{Warning} There is not support for URL reference inside

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

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

@end quotation

As CentOS Artwork Repository is built over a version control system,

file movements inside the repository are considered repository

changes. In order for these repository changes to be versioned, we

need to, firstly, add changes into the version control system, commit

them, and later, perform movement actions using version control system

commands. This configuration makes possible for everyone to know about

changes details inside the repository; and if needed, revert or update

them back to a previous revision.

Finally, once all path information has been corrected, it is time to

take care of information inside the files. For instance, considere

what would happen if you make a reference to a documentation node, and

later the documentation node you refere to is deleted. That would make

Texinfo to produce error messages at export time. So, the

@file{centos-art.sh} script needs to know when such changes happen, in

a way they could be noted and handled without producing errors.

@subsection What is the right place to store it?

Occasionly, you may find that new corporate visual identity components

need to be added to the repository. If that is your case, the first

question you need to ask yourself, before start to create directories

blindly all over, is: What is the right place to store it?

The CentOS Community different free support vains (see:

@url{http://wiki.centos.org/GettingHelp}) are the best place to find

answers to your question, 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 and

so, make your propositions based on it.

When we are looking for the correct place to store new files, to bear

in mind the corporate visual identity structure used inside the CentOS

Artwork Repository (@pxref{Directories trunk Identity}) would be probaly the best

advice we could offer, the rest is just matter of choosing appropriate

names.  To illustrate this desition process let's consider the

@file{trunk/Identity/Themes/Motifs/TreeFlower} directory as example.

It is the trunk development line of @emph{TreeFlower} artistic motif.

Artistic motifs are considered part of themes, which in turn are

considered part of CentOS corporate visual identity.

When building parent directory structures, you may find that reaching

an acceptable location may take some time, and as it uses to happen

most of time; once you've find it, that may be not a definite

solution.  There are many concepts that you need to play with, in

order to find a result that match the conceptual idea you try to

implement in the new directory location. To know which these concepts

are, split the location in words and read its documentation entry from

less specific to more specific.

For example, the @file{trunk/Identity/Themes/Motifs/TreeFlower}

location evolved through several months of contant work and there is

no certain it won't change in the future, even it fixes quite well the

concept we are trying to implement.  The concepts used in

@file{trunk/Identity/Themes/Distro/Motifs/TreeFlower} location are

described in the following commands, respectively:

@verbatim

centos-art manual --read=turnk/

centos-art manual --read=turnk/Identity/

centos-art manual --read=turnk/Identity/Themes/

centos-art manual --read=turnk/Identity/Themes/Motifs/

centos-art manual --read=turnk/Identity/Themes/Motifs/TreeFlower/

@end verbatim

Other location concepts can be found similary as we did above, just

change the location we used above by the one you are trying to know

concepts for.