Voir la source de Extensions de fichiers sous GNOME

(Tested with GNOME 2.14)

2 steps:
* Map your extension with a MIME type
* Map this MIME type to an application

The goal is to map <code>.eml</code> with a locally installed Thunderbird (<code>~/software/thunderbird/thunderbird</code>).

== Map your extension with a MIME type ==

* (needed?) Declare the MIME type in /etc/mime.types
ex:
<pre>
application/local.mozilla.thunderbird		eml
</pre>

* Declare the MIME type in /usr/share/mime/packages/
ex: /usr/share/mime/packages/thunderbird.xml :
<pre>
<?xml version="1.0" encoding="UTF-8"?>
<mime-info xmlns='http://www.freedesktop.org/standards/shared-mime-info'>
	<mime-type type="application/local.mozilla.thunderbird">
		<comment>Saved mail</comment>
		<comment xml:lang="fr">Courriel enregistré</comment>
		<glob pattern="*.eml"/>
	</mime-type>
</mime-info>
</pre>

* Refresh the mime cache:
 update-mime-cache /usr/share/mime/


== Map your MIME type to an application ==

* You can right-click on a file with your extension, and select "Open with".
 ~/.local/share/applications/*.desktop
 ~/.local/share/applications/mimeinfo.cache

* You can create a site-wide .desktop with 'NoDisplay=true' so it doesn't show in the Applications menu
 /usr/local/share/applications/*.desktop
 /usr/local/share/applications/mimeinfo.cache
or
 /usr/share/applications/*.desktop
 /usr/share/applications/mimeinfo.cache
Then update the cache with:
 update-desktop-database

More: create a 'file'-like file detection. Currently the added MIME type conflicts with 'plain text'.


== Files ==

<pre>
/etc/mime.types                           # MIME declaration
/usr/share/mime/packages/*.xml            # glob
/usr/share/mime/application/*.xml         # cache?
/usr/share/mime/mime.cache                # cache
/usr/share/mime-info/*.mime               # ?
/usr/share/mime-info/*.keys               # ?
/usr/share/application-registry/*.applications # priority?
/usr/share/applications/*.desktop         # menu entry and App->MIMEs association
/usr/share/applications/mimeinfo.cache    # MIME->Apps association cache
/usr/share/applications/defaults.list     # priority override
</pre>

<pre>
/usr/local/share/applications/ # alternate hierarchy
~/.local/share/applications/   # alternate hierarchy
</pre>

Priority precedence:
<pre>
~/.local/share/applications/defaults.list
[Gnome hard-coded priorities, e.g. abiword.desktop - ugh >p]
/usr/local/share/applications/defaults.list
/usr/share/applications/defaults.list
</pre>

Sample defaults.list:
<pre>
[Default Applications]
application/msword=openoffice.org2.4-writer.desktop
</pre>

Icons:
 /usr/share/icons/*/*/mimetypes
 ex: 
 /usr/share/icons/hicolor/48x48/mimetypes/openofficeorg23-text.png

== TODO ==

* /usr/share/application-registry/*.applications
(for priority/precedence?)

* Do we need to use these:
 /usr/share/mime-info/*.mime
 /usr/share/mime-info/*.keys


== Avoid Abiword hard-coded high priorioty ==

 dpkg-divert --rename \
  --divert /usr/share/applications/abiword-nothardcoded.desktop\
  /usr/share/applications/abiword.desktop
 update-desktop-database

== Links ==

* http://kapo-cpp.blogspot.com/2008/02/register-your-own-mime-type-on-free.html
** Un bon résumé
** Mention des xdg-utils qui font le travail plus proprement

* http://docs.sun.com/app/docs/doc/806-6878/6jfpqt2tp?a=view
** /usr/share/gnome/application-registry
** /usr/share/application-registry/ (Debian)

* [http://standards.freedesktop.org/desktop-entry-spec/desktop-entry-spec-0.9.4.html#mime-types .desktop reference]
* [http://www.gnome.org/~shaunm/admin-guide/mimetypes-9.html Gnome reference]

* http://ubuntuforums.org/showthread.php?t=726230
** update-desktop-database (man -> undocumented)
** /usr/share/applications/mimeinfo.cache

* http://forum.ubuntu-fr.org/viewtopic.php?id=160531
** update-mime-database /usr/share/mime/

* [http://lists.rpath.com/pipermail/distro-list/2005-January/000192.html Gnome/KDE file associations]
** /usr/share/applications/defaults.list

* [http://live.gnome.org/GnomeLiveCd_2fHowTo Local overrides]
** /usr/share/applications/defaults.list
** (?) /etc/gnome/defaults.list
** ~/.local/share/applications/defaults.list