I am trying to build an on screen keyboard, for a simple counter application, that adds some points for 2 diffeent teams in 2 columns.

The design thing is pretty simple, but it seems hard for me to programm the buttons, in order to insert numbers properly.
I have added all the necesery OnClickListeners and used for example this code for number 1
editText1.setText("1");
But, when i try to press the 1 button multiple times, it doesn't type 111 etc. It keeps replacing the last number that was inputed. So if i press 1 and then 2, it just replaces 1 with 2.
Any idea on how this can work please? :D