Concept of program running on Touch Screen

Today, I talked to my colleagues about how to run on the touch screen.ProgramBecause I have never done it before, I just analyzed it theoretically,

At the beginning, I thought that I should call the hardware driver to see if the machine does not support touch screens. But I thought it was wrong. Isn't that equivalent to the input/output function, if you think about it again, there is no direct relationship between the touch screen program and the touch screen program. The touch screen operation is to simulate the mouse operation, and the hardware and software operations have been completed, no program is required to do anything,

The final conclusion is that the normal development program is that when the touch screen does not exist, it is the mouse