Hi Pascal,
I've had the same issue. Here is how I solved it with JS:
<code>
function collapse( panel ){
  panel.addClassName('collapsed').removeClassName('expanded');
}
function collapsePanels() {
  $$('.PanelIndex').each( collapse );
  $$('.PanelAbkuerzungenLink').each( collapse );
  $$('.PanelDifferentialDiagnosen').each( collapse );
  $$('.PanelEintraege').each( collapse );
};
</code>
Just insert the ids of the panels you wank to be collapsed during page
loading.
You would need to add this to a page as XWiki.JavaScriptExtension object,
and make sure it is loaded for instance in the sheet.
BTW, I would really like to see a version of this using a session cookie. :)
Best regards,
Michael
(XWiki && XWiki.domIsLoaded && collapsePanels()) ||
document.observe("xwiki:dom:loaded", collapsePanels);
2014-09-17 21:40 GMT+02:00 Pascal BASTIEN <pbasnews-xwiki(a)yahoo.fr>fr>:
  Thxs you (again :-) )
 You have just confirmed what I was afraid of, I mean js + cookie.
 I will probably look into this collapsed menu , this week. but, I am not
 sure if this replies to your issue...
 If you like, I will show you the result... if I manage :-/
 ________________________________
  De : Ecaterina Moraru (Valica) <valicac(a)gmail.com>
 À : Pascal BASTIEN <pbasnews-xwiki(a)yahoo.fr>fr>; XWiki Users <users(a)xwiki.org
  
 Envoyé le : Mercredi 17 septembre 2014
19h01
 Objet : Re: [xwiki-users] need advice about an extension developpment
 Hi Pascal,
 If you look at
 
http://www.cssportal.com/css3-preview/showing-and-hiding-content-with-pure-…
 the CSS code for making this work is using the :focus pseudo-class, which
 is triggered when the link is selected using the mouse pointer or keyboard.
 It's normal that if you navigate the focus of that element to be lost.
 If you want something persistent you must implement it with JS and
 cookies. CSS is not the tool to achieve these things.
 On this topic there is also this issue
 
http://jira.xwiki.org/browse/XWIKI-10498 but this is not a priority and
 not sure when/who will try to fix it (maybe even you :) )
 Thanks,
 Caty
 On Wed, Sep 17, 2014 at 4:48 PM, Pascal BASTIEN <pbasnews-xwiki(a)yahoo.fr>
 wrote:
 Hello,
  
 >I try to writing an extension to add
the right panel collapsible (with
 CSS only). Something like this:
 seek panel)
 explained here 
http://www.cssportal.com/css3-preview/showing-and-hiding-content-with-pure-…
 I inserted code in rightpanels.vm and CSS but the
limitation is when I 
 navigate on another xwiki page/space the right panel is reset.
My right
 panel is  not persistent.
 Do you have an advice to make my right panel
persistent:
- if user show panel and change current page, right panel  must be still 
 open
 - if user hide panel and change current page right
panel must be  still 
 hide
  
 >javascript (and cookie) are mandatory
in my case?
 >Do you have an elegant tip: an secret xwiki API ?
  
 >Thxs
  
 >Pascal B
 >_______________________________________________
 >users mailing list
 >users(a)xwiki.org
 >http://lists.xwiki.org/mailman/listinfo/users
  
_______________________________________________
 users mailing list
 users(a)xwiki.org
 
http://lists.xwiki.org/mailman/listinfo/users