[PATCH inputproto XI 2.2] Set a flag on the pointer-emulating touch event

[Chase Douglas]

On 01/02/2012 06:00 PM, Peter Hutterer wrote:
> On Mon, Jan 02, 2012 at 05:55:47PM -0800, Chase Douglas wrote:
>> On 01/02/2012 03:29 PM, Peter Hutterer wrote:
>>> Toolkits need to know which touch event emulated a pointer event and which
>>> ones do not. To quote Carlos Garnacho:
>>>
>>>     GTK+ does client-side windows by default (GdkWindows without a backing X
>>>     window), for this to work the toplevel window in the client needs to
>>>     select for more events that it wouldn't normally select for in order to
>>>     cater for the event masks in such child "windows". This means that
>>>     ideally GTK+ should set the touch events mask in the toplevel, and then
>>>     find out whether the "window" would receive pointer or touch events for
>>>     the sequence emulating the pointer, and perform the emulation itself.
>>>
>>> Reported-by: Carlos Garnacho <carlosg at gnome.org>
>>> Signed-off-by: Peter Hutterer <peter.hutterer at who-t.net>
>>> ---
>>> IIRC we did discuss this months ago and decided not to set the flag but the
>>> above use-case cannot easily be solved right now. Adding this flag in the
>>> server is simple enough.
>>>
>>>  XI2.h              |    1 +
>>>  specs/XI2proto.txt |    8 ++++++--
>>>  2 files changed, 7 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/XI2.h b/XI2.h
>>> index 4368006..e864b06 100644
>>> --- a/XI2.h
>>> +++ b/XI2.h
>>> @@ -158,6 +158,7 @@
>>>  #define XIPointerEmulated                       (1 << 16)
>>>  /* Device event flags (touch events only) */
>>>  #define XITouchPendingEnd                       (1 << 16)
>>> +#define XITouchEmulatingPointer                 (1 << 17)
>>
>> Is this easier than having a dual-purpose XIPointerEmulated flag? We
>> would have to push XITouchPendingEnd to the 17th bit, but an ABI break
>> right now isn't too bad.
>>
>> Or, do you have a specific reason why we shouldn't reuse the flag?
> 
> yeah, to avoid confusion. XIPointerEmulated and XITouchEmulatingPointer have
> exactly the opposite meaning, so I'd rather have the two with different
> names.
> 
> Plus, we get semi-namespacing this way too for the flags.

Fair enough.

Reviewed-by: Chase Douglas <chase.douglas at canonical.com>

Let me know if you'd like me to apply and release a new version of the
proto, though I won't get to it till tomorrow.