Multi-touch Screen does not support

After my research I have discover that Qt 5.4 does not support the multi-touchscren. According to this;

"export QT_XCB_DEBUG_XINPUT_DEVICES=1

and try your Qt application again. At startup, Qt will enumerate the input devices available, like this

XInput version 2.2 is available and Qt supports 2.2 or greater
input device ... (keyboard, mouse etc.) ...
input device Advanced Silicon S.A CoolTouch(TM) System
has valuator "Abs MT Position X" recognized? true
has valuator "Abs MT Position Y" recognized? true
has touch class with mode 1
it's a touchscreen with type 0 capabilities 0x21 max touch points 10
If it does not say Qt supports 2.2 or greater, it means the headers weren’t available when Qt was built, so the support for touch was not included. If you do have 2.2 or greater but it doesn’t say it’s a touchscreen at the end, there may be some other problem such that the touchscreen is not recognized, and you may want to write up a bug, after verifying that touch works in other X11 applications.
"

my result :

celal@cs1323:~/workspace/build-fingerpaint-Desktop_Qt_5_4_0_GCC_64bit-Debug$ ./fingerpaint
qt.qpa.input.devices: XInput version 2.2 is available and Qt supports 2.0
qt.qpa.input.devices: input device Virtual core XTEST pointer
qt.qpa.input.devices: has class 1
qt.qpa.input.devices: has valuator "Rel X" recognized? true
qt.qpa.input.devices: has valuator "Rel Y" recognized? true
qt.qpa.input.devices: input device SynPS/2 Synaptics TouchPad
qt.qpa.input.devices: has class 1
qt.qpa.input.devices: has valuator "Rel X" recognized? true
qt.qpa.input.devices: has valuator "Rel Y" recognized? true
qt.qpa.input.devices: has valuator "Rel Horiz Scroll" recognized? true
qt.qpa.input.devices: has valuator "Rel Vert Scroll" recognized? true
qt.qpa.input.devices: has valuator "Abs MT Pressure" recognized? true
qt.qpa.input.devices: has class 3
qt.qpa.input.devices: has class 3
qt.qpa.input.devices: it's a touchpad with type 1 capabilities 0x4 max touch points 1 size 91.434783 x 64.156863
qt.qpa.input.devices: input device Logitech Unifying Device. Wireless PID:400a
qt.qpa.input.devices: has class 1
qt.qpa.input.devices: has valuator "Rel X" recognized? true
qt.qpa.input.devices: has valuator "Rel Y" recognized? true
qt.qpa.input.devices: has valuator "Rel Horiz Wheel" recognized? true
qt.qpa.input.devices: has valuator "Rel Vert Wheel" recognized? true
qt.qpa.input.devices: has class 3
qt.qpa.input.devices: has class 3
qt.qpa.input.devices: input device Focaltech Systems FT5926 MultiTouch
qt.qpa.input.devices: has class 1
qt.qpa.input.devices: has valuator "Abs MT Position X" recognized? true
qt.qpa.input.devices: has valuator "Abs MT Position Y" recognized? true
qt.qpa.input.devices: has valuator "Abs MT Touch Major" recognized? true
qt.qpa.input.devices: has valuator "Abs MT Touch Minor" recognized? true
qt.qpa.input.devices: has valuator "Abs MT Orientation" recognized? false
qt.qpa.input.devices: has valuator "Abs MT Tool X" recognized? false
qt.qpa.input.devices: has valuator "Abs MT Tool Y" recognized? false