On 4/2/17 2:57 AM, Peter Hutterer wrote:
woohoo, grabs. My favourite topic! ;)
On Wed, Mar 22, 2017 at 05:27:22PM +0100, Olivier Fourdan wrote:
>> [snip]
+ <description summary="Protocol for grabbing the keyboard from Xwayland">
+ This protocol specifies a way for Xwayland to request all keyboard
+ events to be forwarded to a surface even when the surface does not
+ have keyboard focus.
+
+ Unlike the X11 protocol, Wayland doesn't have the notion of
+ active grab on the keyboard.
+
+ When an X11 client acquires an active grab on the keyboard, all
+ key events are reported only to the grabbing X11 client.
+ When running in Xwayland, X11 applications may acquire an active
+ grab but that cannot be translated to the Wayland compositor who
+ may set the input focus to some other surface, thus breaking the
+ X11 client assumption that all key events are reported.
+
+ When an X11 client requests a keyboard grab, the Wayland compositor
+ may either inform or ask the user for the right to forward all key
+ events to the given client surface.
this is confusing :) paragraph 3 talks aobut what's not working and
paragraph 4 about what this protocol should fix. How about something like:
This protocol is application-specific to meet the needs of the X11
protocol through Xwayland. It provides a way for XWayland to request
all keyboard events to be forwarded to a surface even when the
surface does not have keyboard focus.
In the X11 protocol, a client may request an "active grab" on the
keyboard. On success, all key events are reported only to the
grabbing X11 client. For details, see XGrabKeyboard(3).
The core Wayland protocol does not have a notion of an active
keyboard grab. When running in Xwayland, X11 applications may
acquire an active grab inside XWayland but that cannot be translated
to the Wayland compositor who may set the input focus to some other
surface. In doing so, it breaks the X11 client assumption that all
key events are reported to the grabbing client.
This protocol specifies a way for Xwayland to request all keyboard
be directed to the given surface. The protocol does not guarantee
that the compositor will honor this request and it does not
prescribe user interfaces on how to handle the respond. For example,
a compositor may inform the user that all key events are now
forwarded to the given client surface, or it may ask the user for
permission to do so.
Warning! Things may go boom... etc. etc.
I think it may be worth it to add a little safety net:
“Compositors are required to restrict this interface to Xwayland alone,
and raise a protocol error for native Wayland clients.”
Cheers,
--
Quentin “Sardem FF7” Glidic
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