onLongPressDown property

Called when a pointer has contacted the screen at a particular location with a primary button, which might be the start of a long-press.

This triggers after the pointer down event.

If this recognizer doesn't win the arena, onLongPressCancel is called next. Otherwise, onLongPressStart is called next.

See also:

• kPrimaryButton, the button this callback responds to.
• onSecondaryLongPressDown, a similar callback but for a secondary button.
• onTertiaryLongPressDown, a similar callback but for a tertiary button.
• LongPressDownDetails, which is passed as an argument to this callback.
• GestureDetector.onLongPressDown, which exposes this callback in a widget.