Changes between Version 7 and Version 8 of qt

Timestamp:

10/13/2021 08:54:07 PM (3 years ago)

Author:

Tim Harvey

Comment:

added details about configuring Qt input

qt

@@ -191 +191 @@
 }}}
 
+Qt's input systems:
+
+Qt can use Linux evdev directly for input or it can use helper libraries such as libinput or tslib:
+ * By default Qt5 on Ubuntu is using libinput and there is no tslib support
+ * To troublshoot input you can set 'QT_LOGGING_RULES=qt.qpa.input=true'.
+ * If you wish to disable libinput you can set 'QT_QPA_EGLFS_NO_LIBINPUT=1' for eglfs backend or 'QT_QPA_FB_NO_LIBINPUT=1' for linuxfb backend and input will default to evdev.
+
+evdev:
+
+When using evdev you can parameters via QT_QPA_EVDEV_TOUCHSCREEN_PARAMETERS with colon separated parameters, for example:
+ - Run fingerpaint using evdev and linuxfb backend and specify /dev/input/event1 for input, rotate input 90 degrees, and invert both x and y: 
+{{{#!bash
+QT_LOGGING_RULES=qt.qpa.input=true QT_QPA_FB_NO_LIBINPUT=1 QT_QPA_EVDEV_TOUCHSCREEN_PARAMETERS=/dev/input/event1:rotate=90:invertx:inverty ./fingerpaint -platform linuxfb
+}}}
+
 For more details Qt Input see:
  - https://doc.qt.io/qt-5.12/embedded-linux.html