Re: [PATCH 2/2 v3] Add keyboard shortcuts inhibitor

[Olivier Fourdan]

Hi Jonas,

> > [...]
> > +   A keyboard shortcuts inhibitor instructs the compositor to ignore
> > +   its own keyboard shortcuts when the associated surface has keyboard
> > +   focus. As a result, when the surface is focused, it will receive all
> > +   keyboard events, even those which would normally be caught by the
> > +   compositor for its own shortcuts.
> > +
> > +   The Wayland compositor is however under no obligation to disable
> > +   all of its shortcuts, and may keep some special key combo for its own
> > +   use, including but not limited to one allowing the user to forcibly
> > +   restore normal keyboard events routing in the case of an unwilling
> > +   client.
> > +
> > +   If the surface is destroyed, unmapped, or loses keyboard focus, the
> > +   the compositor will restore its own keyboard shortcuts.
> > +
> > +   When the compositor restores its own keyboard shortcuts, an
> > +   "inactive" event is emitted to notify the client that the keyboard
> > +   shortcuts inhibitor is not effectively active for the surface any
> > +   more, and the client should not expect to receive all keyboard events.
> > +
> > +   When the keyboard shortcuts inhibitor is inactive, either because
> > +   the user has requested it using any mechanism the compositor may offer
> > +   or because the surface doesn't have keyboard focus, the client has
> > +   no way to forcibly reactivate the keyboard shortcuts inhibitor.
> > +
> > +   When the surface regains keyboard focus, the inhibitor will take effect
> > +   again and an "active" event emitted to notify the client.
> 
> I think we should loosen up the details for when an "active" event may
> be sent again. For example, if a user presses the magic combination
> deactivating the inhibitation, but never leaves the surface in question,
> it might want to do that without switching focus back and forth.

Right, I don't have strong opinions about that myself, do we really need to 
send a "deactivate" on focus lost and an "activate" event when focus is 
regained? 

The client itself should not expect any key event delivery from the compositor 
when the surface doesn't have keyboard focus, even less the compositor own 
shortcuts.

That would leave the activate/deactivate events to what they really mean, i.e. 
activate or deactivate an existing shortcut-inhibitor requested by the client, 
like for example when using a compositor specific key combo.
 
> Also, what happens if there multiple seats active? Do we need to make
> this protocol seat aware or do we assume that all seats want their
> shortcuts inhibited, and if so, what seats keyboard focus takes
> precedence, or is it any seats keyboard focus?

Well, initially, I reckoned it would be easier to apply the shortcut inhibitor 
to all seats, but on a second thought, making the protocol seat aware makes 
sense.

That raises another question then, do we need to pass the seat serial as well 
there? I guess we ought to, don't we?

> A third thing, is, do we care about letting the client know about the
> magic combination? The client could help with displaying how to
> uninhibit, and we could possibly avoid ending up with multiple ways to
> uninhibit, as the client will most likely have one way, and the
> compositor another.
> 
> The client and compositor "sharing" the magic combination would also
> enable more predictable enabling/disabling interaction. For example, if
> a client destroys the inhibitation on deactivation, in order to update
> the user interface to explicitly require re-enabling, one can only use
> the compositor side magic combo to *disable* the inhibitation, but never
> enable. This is a bit awkward, as it's AFAIK often the same combination
> that is used for both enabling and disabling. Without this, we'd end up
> with the application side magic combo used most often, and the
> compositor side magic combo, mostly unused due to inconvenience thus
> forgotten.

If the compositor has to "tell" the client what key combo is used to 
enable/disable an existing shortcut inhibitor, we also need to add an event to 
notify if the key combo is modified as the compositor may even have that 
configurable (i.e. a client requests shortcuts to be inhibited, the user 
disable the shortcut inhibitor, then changes the compositor settings to use 
another key combo, the compositor needs to send an event telling the new key 
combo so the client can update its own shortcut).

> > +
> > +
> > +
> > +  
> > +   Remove the keyboard shortcuts inhibitor from the associated wl_surface.
> > +  
> > +
> > +
> > +
> > +  
> > +   This event indicates that the shortcut inhibitor is active.
> > +
> > +   The compositor will send this event every time it deactivates its
> > +   shortcuts for the given surface, this occurs typically when the
> > +   surface which requested keyboard shortcuts inhibit regains focus
> > +   or when the initial request "inhibit_shortcuts" becomes active.
> > +  
> > +   

Re: [PATCH 2/2 v3] Add keyboard shortcuts inhibitor

[Jonas Ådahl]

On Wed, Apr 05, 2017 at 02:30:15PM +0200, Olivier Fourdan wrote:
> This adds a new protocol to let Wayland clients specify that they want
> all keyboard events to be send to the client, regardless of the
> compositor own shortcuts.
> 
> This is for use by virtual machine and remote connections viewers.

Look out for style nits (especially now that Yong has cleaned up
inconsistencies in the other protocol XML files!), but there are some
other comments below too.

> 
> Signed-off-by: Olivier Fourdan 
> ---
>  v2: Clarify that that the compositor is under no obligation to ignore
>  every shortcut (ajax)
>  Add "inhibit_active" and "inhibit_inactive" events to notify clients
>  Add "already_inhibited" error
>  v3: Rename "inhibit_active" and "inhibit_inactive" events to simply
>  "active" and "inactive" and fix some Tab in the middle of the text.
> 
>  Makefile.am|   1 +
>  unstable/keyboard-shortcuts-inhibit/README |   4 +
>  .../keyboard-shortcuts-inhibit-unstable-v1.xml | 132 
> +
>  3 files changed, 137 insertions(+)
>  create mode 100644 unstable/keyboard-shortcuts-inhibit/README
>  create mode 100644 
> unstable/keyboard-shortcuts-inhibit/keyboard-shortcuts-inhibit-unstable-v1.xml
> 
> diff --git a/Makefile.am b/Makefile.am
> index 12465e6..d100c13 100644
> --- a/Makefile.am
> +++ b/Makefile.am
> @@ -13,6 +13,7 @@ unstable_protocols =
> \
>   unstable/xdg-foreign/xdg-foreign-unstable-v1.xml
> \
>   unstable/idle-inhibit/idle-inhibit-unstable-v1.xml  
> \
>   unstable/xwayland-keyboard-grab/xwayland-keyboard-grab-unstable-v1.xml  
> \
> + 
> unstable/keyboard-shortcuts-inhibit/keyboard-shortcuts-inhibit-unstable-v1.xml
>  \
>   $(NULL)
>  
>  stable_protocols =   
> \
> diff --git a/unstable/keyboard-shortcuts-inhibit/README 
> b/unstable/keyboard-shortcuts-inhibit/README
> new file mode 100644
> index 000..63ff335
> --- /dev/null
> +++ b/unstable/keyboard-shortcuts-inhibit/README
> @@ -0,0 +1,4 @@
> +Compositor shortcuts inhibit protocol
> +
> +Maintainers:
> +Olivier Fourdan 
> diff --git 
> a/unstable/keyboard-shortcuts-inhibit/keyboard-shortcuts-inhibit-unstable-v1.xml
>  
> b/unstable/keyboard-shortcuts-inhibit/keyboard-shortcuts-inhibit-unstable-v1.xml
> new file mode 100644
> index 000..bb35de1
> --- /dev/null
> +++ 
> b/unstable/keyboard-shortcuts-inhibit/keyboard-shortcuts-inhibit-unstable-v1.xml
> @@ -0,0 +1,132 @@
> +
> +
> +
> +  
> + Copyright © 2017 Red Hat Inc.
> +
> + Permission is hereby granted, free of charge, to any person obtaining a
> + copy of this software and associated documentation files (the 
> "Software"),
> + to deal in the Software without restriction, including without 
> limitation
> + the rights to use, copy, modify, merge, publish, distribute, sublicense,
> + and/or sell copies of the Software, and to permit persons to whom the
> + Software is furnished to do so, subject to the following conditions:
> +
> + The above copyright notice and this permission notice (including the 
> next
> + paragraph) shall be included in all copies or substantial portions of 
> the
> + Software.
> +
> + THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS 
> OR
> + IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
> + FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
> + THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR 
> OTHER
> + LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
> + FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
> + DEALINGS IN THE SOFTWARE.

Indentation issue.

> +  
> +
> +  
> + This protocol specifies a way for a client to request the compositor
> + to ignore its own keyboard shortcuts, so that all keyboard events
> + get forwarded to a surface.
> +
> + Warning! The protocol described in this file is experimental and
> + backward incompatible changes may be made. Backward compatible
> + changes may be added together with the corresponding interface
> + version bump.
> + Backward incompatible changes are done by bumping the version
> + number in the protocol and interface names and resetting the
> + interface version. Once the protocol is to be declared stable,
> + the 'z' prefix and the version number in the protocol and
> + interface names are removed and the interface version number is
> + reset.

Indentation issue

> +  
> +
> +  
> +

Stray newline, and missing .

> +
> +  
> + Destroy the keyboard shortcuts inhibitor manager.
> +  
> +
> +
> +
> +  
> + Create a new