The current version of Kronolith (2.2-cvs, already in alpha, soon to 
be released) makes it very clear which calendars you are viewing, and 
how to turn each one off. I don't think that making this configurable 
would be an overall help to the software or the users.

I am not sure if Kronolith already does this and if so, I apologize 
for this entry. I have a clinical information management system that I 
built out of the horde framework by adding custom modules for various 
clinical functions such as electronic data capture, pharmacovigilance, 
etc.



I also make use of existing horde modules such as Kronolith for 
calendaring applications. One of the primary issues that 
not-so-computer-savvy folks get back to me on is that they often get 
confused with the idea that when they view the calendar events, they 
might actually be viewing events belonging to multiple calendars 
(assuming multiple of them are selected on the calendar selection 
menu) at the same time. I was soon forced to modify the codebase to 
allow for single calendar event viewing instead of the ability to 
select multiple calendars at the same time (based on orders from above).



I was wondering if it is worth adding a feature that allows through a 
preference to switch from the ability to view multiple calendar events 
at the same time to a single calendar at the same time. I guess this 
could be done somewhat as follows:





======================================================

In prefs.php, add a preference value.

$prefGroups['view']['members'][] =  'caldisplaymode';

$_prefs['caldisplaymode'] = array(

     'value' => 'single',

     'locked' => false,

     'shared' => false,

     'type' => 'enum',

     'enum' => array('single'=>'Single Calendar','multiple'=>'Multiple 
Calendars'),

     'desc' => _("Select if you want to view multiple calendar events 
at the same time or only a single calendar events at the same time."),

);



And in /lib/base.php:

if ($GLOBALS['prefs']->getValue('caldisplaymode')=='single') {

     $GLOBALS['display_calendars'] = array($d_cal);

} else if (in_array($d_cal, $GLOBALS['display_calendars'])) {

     $key = array_search($d_cal, $GLOBALS['display_calendars']);

     unset($GLOBALS['display_calendars'][$key]);

} else

     $GLOBALS['display_calendars'][] = $d_cal;



==================================================



Just a thought.