Re: Add function to make frame topmost?

[David De La Harpe Golden]

Stefan:
>
> I see, thanks.  I don't know if there's a word for such things
> under X11 (I guess we should ask the freedesktop guys).

Not affiliated with freedesktop as such, just familiar with specs:

ITYM "Always on top" or "above other windows", or technically asking 
that _NET_WM_STATE include _NET_WM_STATE_ABOVE

N.B. For "normal" windows (such as ordinary emacs frames), this is 
something  usually configured by the user via the window manager's menu, 
setting it within emacs for normal frames would not be something I would 
particularly want or need to do, though possible (*** below), and 
setting it for special framey things is not AFAIK a good idea (following):

http://standards.freedesktop.org/wm-spec/wm-spec-latest.html#STACKINGORDER

[lennart]
> My use case for something like this is reminders that pops up at a
> certain times.

Note that X11 apps (or more usually the gui toolkit the app uses) 
specify the purpose of the window in higher-level terms 
_NET_WM_WINDOW_TYPE, like "this is a tooltip", "this is a notification" 
_NET_WM_WINDOW_TYPE_TOOLTIP, _NET_WM_WINDOW_TYPE_NOTIFICATION
etc.

The window manager then places it in the appropriate stacking group, 
among other things:

"""
This property SHOULD be used by the window manager in determining the 
decoration, stacking position and other behavior of the window.
"""

The greater diversity in window management on X11 than windoze
makes observing such things pretty important -  "this is a notification" 
may make a whole lot more sense to a tiling wm than "above plz k thx".

Please note that abusing _NET_WM_STATE for attention purposes is 
specifically highlighted as a What Not To Do in the spec:

"""
_NET_WM_STATE_ABOVE and _NET_WM_STATE_BELOW are mainly meant for user 
preferences and should not be used by applications e.g. for drawing 
attention to their dialogs (the Urgency hint should be used in that 
case, see the section called “Urgency”).'
"""


***
One can certainly do this from within emacs as per the spec (note you
do this for mapped windows by sending a client message to the root 
window).  Note however, that window managers may refuse an app's request 
to be always on top.

(defun x-toggle-frame-always-on-top (&optional frame)
    (x-send-client-message
     frame 0 frame "_NET_WM_STATE" 32
     ;; _NET_WM_STATE_REMOVE = 0
     ;; _NET_WM_STATE_ADD = 1
     ;; _NET_WM_STATE_TOGGLE = 2
     '(2 "_NET_WM_STATE_ABOVE" 0 1)))