What could be the reason of twice tap (touch) to press onscreen button, that presses from single mouse click?

Question

I must say first - I AM NOT THE PROG OWNER, I don't know how it works and etc, I just need an advice that I could give them.

The program is running on windows based tablet PC with windows 8.

There is some prog that uses OpenGL ES 2.0. It renders some buttons and displays those. Those buttons can be pressed by mouse left button, but if you use sensor screen, you must tap that button twice for single press.

Shortly - some button displayed.
Mouse left button single click -> button pressed
Single finger tap -> button not pressed
Double finger tap -> button pressed.

I don't understand why that happens. Single tap should imitate single click... Weird.

Anyone have any ideas?

Answer 1

I am not sure about this, but I think this may have something to do with how the program checks if the button is pressed. (long long time ago in my C++ days) If it checks the coordinates on click event then there is a possibility that when you touch the button, it only registers the location of the press, and not the press itself. On the second touch the location is already on the button so the click event is true on that button.

Anyone with more insight please feel free to edit ;-)