Application Launch Detection

[Mary Dwyer <Mary Dwyer ireland sun com>]

hi

I haven't fallen off the email thread - I've been keeping track of the ideas put 
forward and trying to get a picture of what is wanted and how it could be 
implemented.

The current thread seems to be:

1. avoid use of LD_PRELOAD
2. do not patch Xlib
3. concentrate on establishing a common protocol that will work for both gnome 		
   apps and KDE apps (ie KDE apps running under gnome will use gnome visual
   feedback, and vice versa)
   
 - To achieve this ensure that gnome apps set the value of the _NET_WM_PID atom
   on the first window they map (as do KDE apps).
      
 - Then a Gnome Launcher process can monitors the _NET_CLIENT_LIST property
   on the root window. It checks the _NET_WM_PID property of each window and 		
   stops the matching visual feedback.
   
   Essential to this is starting a feedback instance identifiable by the PID
   of the app being launched.
   But I cannot figure out how/where to start the feedback display instance
   for the app., i.e. how does the Launcher know the PID of the app being 
   started? If you launch the feedback display from within the gnome application
   (eg from gnome_init()) then you lose interoperability with KDE apps.
   
   I guess I don't fully understand how the KDE app-launcher starts the         
   feedback.  Rik's mail to wm-spec-list outlining how it works 
   (http://mail.gnome.org/archives/wm-spec-list/2000-September/msg00000.html)    
   specifies that 
   "the executable is started and the pid of the running process is noted ....
   .... then a signal is sent to the panel's taskbar object, informing it of the 
   name of the application and the pid".  
   
   Could you give some more detail on how this is done? (bearing in mind I know
   very little about KDE :-( )
   
   But, am I right in assuming from the various emails that this is the way      
   forward on this? ie
   - in coming up with a solution going forward, ignore legacy apps as well as 
     non-gnome and non-KDE apps (and possibly do a hack for these sort of apps)
   - ensure that gnome apps set the _NET_WM_PID property 
   - have a Launcher process separated totally from the apps, that
     starts an instance of feedback identified by the PID of the app
     being launched (how to do this?).  
   - The Launcher then monitors the _NET_CLIENT_LIST property on the root 
     window in order to stop the feedback instance when the app is mapped. 
     
If I have picked things up wrong from the emails on this please set me 
right :-)
I am far from being an expert in Xlib or window manager work, but I would very 
much like to be involved in working on a mechanism for Application Launch 
Feedback in gnome.


thanks
Mary
   
~ I speak for myself, not for my employer ~
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Mary Dwyer
Desktop Applications & Middleware Grp
Sun Microsystems Ireland
Tel: +353-1-8199222 (xt 19222)
email: mary dwyer ireland sun com
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