Re: [PATCH RESEND] USB HID: Add ID for eGalax Multitouch used in JooJoo tablet

[Chase Douglas <chase.douglas@canonical.com>]

On Tue, 2010-08-17 at 13:33 +0200, Stéphane Chatty wrote:
> Yes, the debate is what to do when the 'actual oldest' finger is  
> released: should the 'second oldest' take its place or should this be  
> a release or should somthing else occur.
> 
> Some arguments in favour of the first option:
> - My experience is that 'accidental' touches are transient.  
> Therefore, the conjunction of having an accidental touch and a  
> release is not very frequent.
>   - At the opposite, on very large screens, it may sometimes be  
> comfortable to "replace one finger with another", thus 'moving' the  
> dragged object from one hand to the other.
> 
> More or less, the debate is about statistics and user experience  
> design...

Thanks for the explanation! Since this comes down to what the user
intends with multiple touches on the screen, I'll trust your experience
over mine :).

However, while your 'eldest' method may be good for touchscreens, I
think it's a moot point for touchpads since they are relative devices
(even if they are really absolute in the driver). The user won't be able
to continuously drag across the screen by using multiple fingers because
each switch of coordinates from the eldest to the next eldest will
generate a relative motion that will just shift the object back where we
started a drag.

I'll probably leave my current implementation for the trackpad as is,
since it's easier than the 'eldest' method and provides just as much
functionality.

-- Chase

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