mouseDown(opt_elementOrButton, opt_button)code »
Presses a mouse button. The mouse button will not be released until
#mouseUp
is called, regardless of whether that call is made in this
sequence or another. The behavior for out-of-order events (e.g. mouseDown,
click) is undefined.
If an element is provided, the mouse will first be moved to the center
of that element. This is equivalent to:
sequence.mouseMove(element).mouseDown()
Warning: this method currently only supports the left mouse button. See
issue 4047.