onTapDown property

A pointer has contacted the screen at a particular location with a primary button, which might be the start of a tap.

This triggers after the down event, once a short timeout (kPressTimeout) has elapsed, or once the gestures has won the arena, whichever comes first.

The position of the pointer is provided in the callback's details argument, which is a TapDragDownDetails object.

The number of consecutive taps, and the keys that were pressed on tap down are also provided in the callback's details argument.

See also:

• kPrimaryButton, the button this callback responds to.
• TapDragDownDetails, which is passed as an argument to this callback.