RE: [PATCH] Input: Change BTN_TOOL_FINGER flag when hover event trigger

[廖崇榮 <kt.liao@emc.com.tw>]

Hi Dmitry,

I want to confirm my thought for your idea to avoid misunderstanding.
I think you want to encapsulate " BTN_TOOL_FINGER" in the [input_mt_report_pointer_emulation] if hover happen.
Vendor driver only report "ABS_DISTANCE" and let [input_mt_report_pointer_emulation] emit BTN_TOOL_FINGER report without change function parameter.

Please let me know if my misunderstand about your idea.

Thanks  KT

-----Original Message-----
From: Dmitry Torokhov [mailto:dmitry.torokhov@gmail.com] 
Sent: Tuesday, May 17, 2016 1:54 AM
To: 廖崇榮
Cc: linux-input@vger.kernel.org; linux-kernel@vger.kernel.org; zac.hsieh@emc.com.tw; 黃世鵬 經理; 'Charles Mooney'; 'Agnes Cheng'
Subject: Re: [PATCH] Input: Change BTN_TOOL_FINGER flag when hover event trigger

Hi Kt,

On Mon, May 16, 2016 at 07:27:25PM +0800, 廖崇榮 wrote:
> 
> Only ABS_DISTANCE is not enough for upper OS to distingiush hover 
> event be triggered from object from faraway to and close touchpad 
> surface or from object prepare to leave the touchpad surface. Add 
> BTN_TOOL_FINGER flag to help it.
> 
>                  object_from_faraway    object_inside_hover_area
> object_touch_surface
> BTN_TOUCH                 0                          0             1
> BTN_TOOL_FINGER           0                          1              1
> ABS_DISTANCE               0                           1             0
> 
> Signed-off by: Duson Lin <dusonlin@emc.com.tw>

I was wondering if we could do without modifying all the drivers that are using input_mt_report_pointer_emulation(), by figuring out if we should be emitting BTN_TOOL_FINGER right there:

"If device supports ABS_DISTANCE and does not support ABS_MT_DISTANCE and ABS_DISTANCE != 0 is reported in current frame and there are no other contacts then report BTN_TOOL_FINGER."

Thanks.

--
Dmitry