Use a touchscreen with Raspberrypi and QML

davidino

Goodmorning,
I write you since I'm trying to use a tft display waveshare 3.5a together with a RaspberryPi0 and use its touchscreen.

The program controls the HDMI screen and then it's copy to the tft display with https://github.com/tasanakorn/rpi-fbcp.
I developed an application with QML and C++ languages, the MouseArea object works with mouse but it doesn't with touchscreen. Trying to substitute it with MultiPointTouchArea, it's the same.
The touch screen works correctly since I could calibrate it with the program ts_calibrate. If I use the "cat /dev/input/touchscreen0" on the command prompt, clicking on the touchscreen I got response.
The raspberry pi image was generated with Boot2Qt and the Qt version is 5.12.0.
Before launching the application, I launch the following bash script to configure some variables. I tried several configurations commenting/uncommenting some of them but unsuccessfully.

#!/bin/sh

export PATH=${PATH}:/usr/bin/qt5

# the other option is linuxfb if just using qt widgets
export QT_QPA_PLATFORM=eglfs

# physical width and height units are mm

# for the official Pi 7" touchscreen
#export QT_QPA_EGLFS_PHYSICAL_WIDTH=155
#export QT_QPA_EGLFS_PHYSICAL_HEIGHT=86

# for the pitft35r 480x320 touchscreen
#export QT_QPA_EGLFS_WIDTH=480
#export QT_QPA_EGLFS_HEIGHT=320
#export QT_QPA_EGLFS_PHYSICAL_WIDTH=85
#export QT_QPA_EGLFS_PHYSICAL_HEIGHT=50
# set a rotate value appropriate with the one used in the overlay 
#export QT_QPA_EVDEV_TOUCHSCREEN_PARAMETERS=/dev/input/touchscreen0:rotate=90

# for the pitft28r 320x240 touchscreen
#export QT_QPA_EGLFS_WIDTH=320
#export QT_QPA_EGLFS_HEIGHT=240
#export QT_QPA_EGLFS_PHYSICAL_WIDTH=78
#export QT_QPA_EGLFS_PHYSICAL_HEIGHT=50
# set a rotate value appropriate with the one used in the overlay 
#export QT_QPA_EVDEV_TOUCHSCREEN_PARAMETERS=/dev/input/touchscreen0:rotate=90

#export TSLIB_CONFFILE=/etc/ts.conf
#export TSLIB_CALIBFILE=/etc/pointercal
#export TSLIB_CONSOLEDEVICE=none
export TSLIB_FBDEVICE=/dev/fb1
export TSLIB_TSDEVICE=/dev/input/touchscreen0
#export TSLIB_PLUGINDIR=/usr/lib/ts
#export QWS_MOUSE_PROTO='Tslib:/dev/input/event0'

#export QT_QPA_EGLFS_DISABLE_INPUT=1
export QT_QPA_FB_TSLIB=1
#export QT_QPA_EGLFS_HIDECURSOR=1
#export QT_QPA_EVDEV_MOUSE_PARAMETERS=abs
export QT_QPA_EVDEV_TOUCHSCREEN_PARAMETERS=/dev/input/touchscreen0:rotate=90

if [ -z "${XDG_RUNTIME_DIR}" ]; then
    export XDG_RUNTIME_DIR=/tmp/user/${UID}

    if [ ! -d ${XDG_RUNTIME_DIR} ]; then
        mkdir -p ${XDG_RUNTIME_DIR}
    fi
fi

Apparently there is a problem for the QML to intercept the touchscreen events.
Can you advise me?

Thank you in advanced.
Davidino

davidino

Solution here:
https://forum.qt.io/topic/115562/how-to-make-widgets-react-to-touches-instead-of-mouse-clicks/7

Thank you.