kPrimaryButton top-level constant
The bit of PointerEvent.buttons that corresponds to a cross-device behavior of "primary operation".
More specifially, it includes:
- kTouchContact: The pointer contacts the touch screen.
- kStylusContact: The stylus contacts the screen.
- kPrimaryMouseButton: The primary mouse button.
- kSecondaryButton, which describes a cross-device behavior of "secondary operation".
const int kPrimaryButton = 0x01