virtual_touchscreen
Simple virtual input device for testing things in Linux. Creates a character device and an input device.
.
Building
module
Building for current kernel:
make
Building for custom kernel (from a configured kernel directory):
make modules M=/path/to/virtual_touchscreen/
application
Use run virtual_touchscreen.clj or just use pre-built virtual_touchscreen.jar from Github releases
Using
Some testing
# insmod virtual_touchscreen.ko
# dmesg | grep virtual_touchscreen
virtual_touchscreen: Major=250
# cat /dev/virtual_touchscreen
Usage: write the following commands to /dev/virtual_touchscreen:
x num - move to (x, ...)
y num - move to (..., y)
d 0 - touch down
u 0 - touch up
s slot - select multitouch slot (0 to 9)
a flag - report if the selected slot is being touched
e 0 - trigger input_mt_report_pointer_emulation
X num - report x for the given slot
Y num - report y for the given slot
S 0 - sync (should be after every block of commands)
M 0 - multitouch sync
T num - tracking ID
also 0123456789:; - arbitrary ABS_MT_ command (see linux/input.h)
each command is char and int: sscanf("%c%d",...)
<s>x and y are from 0 to 1023</s> Probe yourself range of x and y
Each command is terminated with '\n'. Short writes == dropped commands.
Read linux Documentation/input/multi-touch-protocol.txt to read about events
1# printf 'x 200\ny 300\nS 0\n' > /dev/virtual_touchscreen
1# printf 'd 0\nS 0\n' > /dev/virtual_touchscreen
1# printf 'u 0\nS 0\n' > /dev/virtual_touchscreen
2# hd /dev/input/event11 # or whatever udev assigns
# printf 'x 200\ny 300\nS 0\n' > /dev/virtual_touchscreen
# printf 'd 0\nS 0\n' > /dev/virtual_touchscreen
# printf 'u 0\nS 0\n' > /dev/virtual_touchscreen
And events should flow from the newly created input device:
# hd /dev/input/event11 # or whatever udev assigns
00000000 df 32 48 4f a6 10 02 00 03 00 00 00 c8 00 00 00 |.2HO............|
00000010 df 32 48 4f ab 10 02 00 03 00 01 00 2c 01 00 00 |.2HO........,...|
00000020 df 32 48 4f bf 10 02 00 00 00 00 00 00 00 00 00 |.2HO............|
00000030 e3 32 48 4f af af 09 00 01 00 4a 01 01 00 00 00 |.2HO......J.....|
00000040 e3 32 48 4f bc af 09 00 00 00 00 00 00 00 00 00 |.2HO............|
00000050 e7 32 48 4f 3d bb 05 00 01 00 4a 01 00 00 00 00 |.2HO=.....J.....|
00000060 e7 32 48 4f 50 bb 05 00 00 00 00 00 00 00 00 00 |.2HOP...........|
GUI
There is a GUI application that can also provide data for virtual touchscreen: virtual_touchscreen.clj. (pre-built bundled version; SHA256=917698e287e1b707e09c3040d6347f5f041d7a60fef0a6f5e51c2b93ccd39f3c, also available on Github Releases)
It listens port 9494 and provides virtual_touchscreen input for connected clients.
Example (checked with Clojure 1.3, may need updating):
hostA$ java -cp clojure.jar clojure.main virtual_touchscreen.clj
hostB# nc hostA 9494 > /dev/virtual_touchscreen
Misc
There is also experimental script to read /dev/input/eventX of some real device and output data for virtual_touchscreen. It is long unmaintained although. Maybe see forks for alternative script.
Licence
Kernel module's licence is GPL. GUI app's license is MIT or Apache 2.0.