Re: Review: FULLSCREEN_MONITORS Hint

[Havoc Pennington <hp redhat com>]

Hi,

Thanks for the patch! I dug out some past threads, for reference:

http://mail.gnome.org/archives/wm-spec-list/2007-March/msg00002.html
http://mail.gnome.org/archives/wm-spec-list/2007-April/msg00001.html

Grant Patterson wrote:
>       <para>
> When placing children of the window (i.e. popup dialogs), the Window 
> Manager
> centers them on the monitor containing the mouse cursor, provided
> this is a monitor listed in _NET_WM_FULLSCREEN_MONITORS. If not, children
> are placed on the first monitor indicated in the list.
>       </para>

Probably this should be a suggestion not a requirement - the important 
thing to have in the spec is something like "windows transient for the 
window with _NET_WM_FULLSCREEN_MONITORS set, such as those with type 
_NET_WM_WINDOW_TYPE_DIALOG, are generally expected to be positioned 
(e.g. centered) with respect to only one of the monitors." You could 
continue to say something like "An example window manager policy might 
center the dialog on the fullscreen monitor containing the mouse 
pointer, or just choose the first fullscreen monitor if none of them 
contain the mouse pointer."

It might be useful to explain some example applications that could use 
the hint.

"Virtual machine software may use this hint to have a virtual operating 
system instance that will see multiple monitors. The multiple physical 
monitors are mapped to multiple virtual monitors controlled by the 
virtual machine software."

"This hint might also be used by a movie or presentation application 
that could allow the user to set up a movie or presentation such that it 
spans multiple monitors."

"In both cases, the application would have some user interface allowing 
the user to configure which monitors the application fullscreens to. The 
window manager need not provide such an interface, though it could."

I guess some of this could go in the "Implementation Notes" rather than 
in the main part of the spec.

> <programlisting><![CDATA[
>   window  = the respective client window
>   message_type = _NET_WM_FULLSCREEN_MONITORS
>   format = 32
>   data.b[0] = number of monitors (n) in the list
>   data.b[1] = first monitor in the list
>   data.b[2] = second monitor in the list
>   ...

It might be nice to say explicitly what these indexes correspond to. 
(Are they the indexes returned by the Xinerama extension?)

Another thing to address, I believe the Xinerama config can now change 
dynamically... what happens then? (I'm not sure, to be honest, what the 
plans are in this area from X.org)

Havoc