Bug 328687

In current  KTP it's way to easy to miss  incoming message in inactive  chat window. 
Case:
 There's inactive chat window open on another desktop or hidden under other windows. Contact list window is also invisible . New message was received.

Unread message is indicated by 
   - Contact avatar changes to "new message" icon
   -  KDE notifications (sound/pop-up window, app highlight on task manager/number on notification systray applet)

Number on notifications applet is not good indication as it changes quite often. And played sound, pop-up window,  icon in contact list are easy to miss due user to not being at the computer when message arrives, notification window displayed on second screen,  muted sound/headphones plugged, contacts not being visible etc...

The most reliable clue  is  highlighted app in task manager. But if user uses different applet for managing tasks (ie daisy, other dock applet) or sets up task manager to show apps from current desktop/minimized only there's no easy to discover/persistent clue that there's new  message. 

Most common solution to this problem  I'd really love to see is to display "new message" icon in systray. 
Pros:
  - it's persistent (user has to take an action to remove it)
  - it's placed in most visible element on the desktop.

Cons:
  - it's not implemented yet ;)
  - we can't take for granted  there's systray at all (dark side of KDE famous flexibility)