Java, touch screen support

[Pekka Paalanen]

On Tue, 7 Aug 2012 09:42:25 +0200
Hársszegi Tibor <Tibor.Harsszegi at scientificgames.hu> wrote:

> Hello,
> 
> I know that this is a complete noob question, but is there any way to do graphics
> on Wayland (via Cairo? maybe) on Java?

I don't really know Java in that respect.

> Also I assume if the Linux kernel supports a given touch screen by its kernel,
> then Wayland can use this as an input device, right?

Yes, as long as the device shows up as an evdev device. It can come
directly from a kernel driver, or a user space driver that creates a
new evdev device using uinput.

As an example,
http://who-t.blogspot.fi/2012/07/elographics-touchscreen-setup.html
talks about setting an Elographics touchscreen for X, but while doing
it they create an evdev device that also Weston could use. I haven't
tried that, but I can't think of any reason why it wouldn't work.

The touchscreen of Samsung Galaxy Nexus works.

Mind you, that we have no pointer emulation from a touch device. An
input device can never be both a pointer and a touch device, and we
haven't implemented any pointer emulation. Given that touch device
support is practically non-existant in the Weston demo clients, apart
from one special demo, you can't do much without writing your own
application or improving the demos. However, the protocol and server
bits are there and ready for use.

Oh and note that we talking about Weston. Wayland says nothing about
how you get input to the server. Weston's DRM backend uses evdev
devices.


Thanks,
pq