[PATCH synaptics] Prevent button mashing on clickpads

[Daniel Colascione]

On 10/29/2013 05:04 PM, Peter Hutterer wrote:
> On Sun, Oct 27, 2013 at 04:24:47PM -0700, Daniel Colascione wrote:
>> The tiny patch below disables the clickpad hardware "button" when
>> syndaemon has asked us to disable tapping.  Without this patch, I
>> frequently find myself accidentally clicking while typing.
>
> isn't this a physical button? if so, it'd be better to just disable the
> touchpad fully instead of just disabling tapping.

It's a physical button, but it's unlike other physical buttons in that 
it takes up the _entire trackpad_. It's a lot easier to trigger this 
button than it is to trigger a traditional button, so it really should 
be treated as a tap for disablement purposes.

The idea behind using TOUCHPAD_TAP_OFF instead of TOUCHPAD_OFF is to 
allow the user to move the cursor as soon as possible after typing. By 
the time the user gets around to actually clicking something, the 
type-inhibit delay will have expired and we'll have turned off 
TOUCHPAD_TAP_OFF. This way, the user never notices the delay --- users 
will take a few hundred ms to click anyway. If we used TOUCHPAD_OFF 
instead, you'd either have to shorten the delay or cause users more 
annoyance.