:wc: relfile 00-WikiIndex

---3 Handling Input from Touchscreens

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I wasn't going to write this (I didn't even consider this) when started this.
The target environment for ''FatdogArm'' is desktop, not tablet. 
But I chanced to get my hands on an A10 tablet which worked nicely with what
I've built so far, so it was a waste not trying to exploit what it can do,
and in this case, its touch input.
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To get touchscreen input to work, there are a few components which needs to
be available and work together.
   # Kernel driver for the touch input hardware.
   
   # The Xorg input driver for touchscreen. ::
     Note: Using standard mouse modules will not work, as touch input
     hardware usually provides its input in absolute coordinates (instead of
     relative coordinates like mice). 
     
   # Toolkit which supports touch gestures (e.g. GTK3? QT5?)
   
   # A virtual keyboard.
   . 
   
For the A10 tablet that I have, its input is supported by ft5x_ts module, so
that part is easily sorted (other tablets may not be so lucky - some use
touchscreens whose drivers are unavailable).

The Xorg input driver module is kindly donated by Pengutronix, here:
http://www.pengutronix.com/software/xf86-input-tslib/index_en.html . 
This Xorg modules requires [[http://tslib.berlios.de/] tslib] to build; and
it provides mouse-like input. As far as I know it is not multi-touch capable.

Next, one needs a touch-aware toolkit so that the applications can use the
(by now) familiar idioms like tap-drag to scroll, pinch in/out to zoom, etc.
Unfortunately the toolkit I'm using is GTK2 and GTK2 isn't touch-aware, so
all interactions needs to be done using mouse idioms (scrollbars, etc).
This is difficult, especially on smaller tablets (mine has 7 inch screen). 
Sure, one can enlarge the scrollbars but then precious screen space is wasted.

Lastly, one needs a virtual keyboard (otherwise, how do you do data entry?).
Here, one can use [[http://homepage3.nifty.com/tsato/xvkbd/] xvkbd] or
[[http://packages.debian.org/source/sid/matchbox-keyboard] matchbox-keyboard],
among others.

----

I haven't tested GTK3 or any other touch-aware toolkits that is designed with
touchscreens in mind, so I can't vouch for their effectiveness. But for the
setup I outlined above, __although it works__, it is painful to use. 

Thus I am still in the opinion that the best way to do real work on tablets
is still to attach a physical keyboard and mouse (a large enough monitor
is a bonus). Touch is fun for browsing and consuming content, but rather 
clumsy for "real work".