Input (BS5) with inoutmode Text, without keybord

I receive text from an integrated scanner or my custom-programmed keyboard. Unfortunately, I only receive text from the scanner in ‘text’ input mode – but then the keyboard on the device (Android) also opens. If I set the input mode to ‘none,’ ‘my keyboard’ also works, but the scanner text disappears into nowhere.

Also I miss a event like Change for that.

Does anyone have any ideas?