Different operating systems get highly different keypress/keyrelease events from bluetooth barcode scanner that is connected to the device as a bluetooth HID keyboard.

Events are filtered:
qApp->installEventFilter(this);

And printed:

bool HandyBarcode::eventFilter(QObject *obj, QEvent *e)
{
Q_UNUSED(obj);
if (e->type() == QEvent::KeyRelease || e->type() == QEvent::KeyPress)

Differencies between operating system:

iOS: Gets both KeyPress and KeyRelease events, but only when input focus is in an input text field. (I would want to get them always, regardless of the focus).

Android: Gets only KeyRelease events for characters, Keypress and Keyrelease events are got for shift key.

In desktop operating systems (Windows) pressing X (or reading with barcode reader) results to these events:
QKeyEvent(KeyPress, 1000020, 2000000, """", false, 1)
QKeyEvent(KeyPress, 58, 2000000, ""X"", false, 1)
QKeyEvent(KeyRelease, 58, 2000000, ""X"", false, 1)
QKeyEvent(KeyRelease, 1000020, 0, """", false, 1)

In iOS result is (nearly the same, except keyrelease is without shif modifier and text is small x):
QKeyEvent(KeyPress, 1000020, 2000000, """", false, 1)
QKeyEvent(KeyPress, 58, 2000000, ""X"", false, 1)
QKeyEvent(KeyRelease, 58, 0, ""x"", false, 1)
QKeyEvent(KeyRelease, 1000020, 0, """", false, 1)

In Android result is - no keyPress for X + in keyrelease x is with small letters:
D/Qt ( 4012): ..\..\client\src\core\handybarcode.cpp:68 (virtual bool HandyBarcode::eventFilter(QObject*, QEvent*)): QKeyEvent(KeyPress, 1000020, 0, ""
D/Qt ( 4012): ..\..\client\src\core\handybarcode.cpp:68 (virtual bool HandyBarcode::eventFilter(QObject*, QEvent*)): QKeyEvent(KeyRelease, 1000020, 2000000, ""
D/Qt ( 4012): ..\..\client\src\core\handybarcode.cpp:68 (virtual bool HandyBarcode::eventFilter(QObject*, QEvent*)): QKeyEvent(KeyRelease, 58, 0, ""x"", false, 1)