On Thu, Jan 20, 2011 at 12:12 PM, Ping Cheng <pingli...@gmail.com> wrote:
> On Wed, Jan 19, 2011 at 12:46 PM, Chris Bagwell <ch...@cnpbagwell.com> wrote:
>> On Wed, Jan 19, 2011 at 12:41 PM, Ping Cheng <pingli...@gmail.com> wrote:
>>> On Tue, Jan 18, 2011 at 6:19 PM, Chris Bagwell <ch...@cnpbagwell.com> wrote:
>>>>
>>>>>> Is there driver your interested in? Its difficult to talk in abstract.
>>>>>
>>>>> I'm moving the existing _TAP_ based USB TPC to _MT_ based format.
>>>>> That's why I don't want to reuse _TAP_ again.
>>>>
>>>> OK. Thanks. That clears up some things. So this will be 2 input
>>>> devices: 1) pen+eraser and 2) touchscreen (no pad buttons).
>>>>
>>>> For touchscreen device, it would be very much to your advantage to
>>>> look just like pre-existing touchscreens. So I agree that means no
>>>> DOUBLETAP and for that matter no BTN_TOOL_FINGER from kernel side.
>>>> The goal would be for xf86-input-evdev and xf86-input-wacom to both
>>>> support equally.
>>>
>>> I had to sleep on this email to "dream" through :).
>>>
>>> I think we need BTN_TOOL_FINGER to report single touch events. That's
>>> what we have discussed at LKML earlier for wacom_w8001. Dimitry told
>>> us to use BTN_TOOL_FINGER for ST. And you agreed.
>>
>> The agreement wasn't in isolation. It was to use BTN_TOOL_FINGER and
>> a new ioctl() so user land can query to see the FINGER device is a
>> touchscreen. Are you adding support for that ioctl?
>>
>> If not then I recommend sticking with pre-existing standard and not
>> sending BTN_TOOL_FINGER in TPC kernel driver so that xf86-input-wacom
>> has enough info to know its an Absolute touchscreen and not relative
>> touchpad like it assumes for Bamboo today.
>>
>> Please see hid_ntrig.c. It and Wacom Tablet PC both present 2 input
>> devices with same feature set on both.
>>
>> What it does on its touchscreen input is NOT declare BTN_TOOL_FINGER
>> so applications can tell its an absolute mode touchscreen. It does
>> declare BTN_TOOL_DOUBLETAP though and sends it during 2-finger touch
>> time periods (no affect on reported ABS_X/ABS_Y values which always
>> track first touch). It also sends MT events.
>>
>> This plays very nice with xf86-input-evdev and also should play very,
>> very nice with current git xf86-input-wacom (correctly hotplugs,
>> correctly sets WCM_2FGT, etc).
>
> I removed BTN_TOOL_FINGER from the kernel dirver. But I am facing an
> issue for ST device. Without BTN_TOOL_FINGER, xf86-input-wacom does
> think we have a touch device. So, the solution works for 2FGT devices.
> But not for 1FGT devices. At least not without code change. I gathered
> the following options:
>
> 1. set BTN_TOOL_DOUBLETAP for 1FGT as well. That's not a solution I
> like since the device only supports one finger;
>
> 2. set BTN_TOOL_FINGER for 1FGT. It confuses xf86-input-evdev, which
> you don't like;
>
> 3. update the code. The code would be ugly.
>
> Do you have other suggestions? Thank you.
>
> Ping
>
Lets try to solve the ABSOLUTE mode problem and then I think it helps
solves 1FGT as well. In wcmDeviceTypeKeys(), I was thinking we should
add something like this:
/* Detect older convention for touchscreen inputs that do not support
stylus on same input device */
if (BTN_TOUCH && !BTN_TOOL_FINGER && !BTN_TOOL_PEN)
{
/* This will result in absolute mode for touchscreens */
priv->common->tablet_type |= WCM_LCD;
/* Detect touchscreen with 1 touch since it wasn't able to use
BTN_TOOL_FINGER */
if (!BTN_TOOL_DOUBLETAP)
priv->common->tablet_type |= WCM_1FGT;
}
What do you think?
Its a little ugly but I guess thats kernel's fault since its their
convention. When that new ioctl comes around, we can technically add
BTN_TOOL_FINGER back in on kernel side and base WCM_LCD on ioctl()
value somehow. We can do it both above "old" way and new ioctl() way
to be backwards compatible.
wacom_w8001.c should work in this way as well. With its interface, 1
touch devices will correctly set 1FGT because it sets BTN_TOOL_FINGER
but not BTN_TOOL_DOUBELTAP. It will incorrectly default to relative
mode until we support that new ioctl() in xf86-input-wacom.
Your call if you want to skip straight to new BTN_TOOL_FINGER+ioctl()
approach but I think it would be nice to be able to route hid_ntrig's
touchscreen device to xf86-input-wacom (so need something like above
for its sake).
Chris
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