Whenever i start an app, its icon appears in the launcher. Is there any way to disable this behaviour for certain specific apps(like guake, rhythmbox, etc). I just want them to start without their icon appearing on the launcher. Any ideas. Help would be highly appreciated.
Normally this can be done using window manager hint (
_NET_WM_STATE_SKIP_TASKBAR), which can be triggered in Compiz using Window Rules plugin (manageable using
compizconfig-settings-manager) or using
wmctrl, for example:
wmctrl -r Rhythmbox -b add,skip_taskbar
This would normally hide icon from taskbar in most desktop environments. Unfortunately, Unity currently doesn't support these states for already opened window, there's even a failing test (
test_invisible_windows.py) for Unity 5 with an eloquent comment: "We don't support changing window states after they've been mapped."
So unless there's some way to launch target applications with a required window state, this, otherwise standard solution, is a dead end.
There might be some Unity-specific solution specific (e.g. a key for a launcher/.desktop file).
Unfortunately, there doesn't seem to be any easy solution, so the best chance might be to revive bug #750728 or open the new one.
The aforementioned test was removed for Unity 6, so it seems that Unity developers aren't interested in fixing this bug (or it's a very low priority).