CGEventField.scrollWheelEventFixedPtDeltaAxis1

Key to access a field that contains scrolling data. The scrolling data represents a line-based or pixel-based change in vertical position since the last scrolling event from a Mighty Mouse scroller or a single-wheel mouse scroller. The scrolling data uses a fixed-point 16.16 signed integer format. For example, if the field contains a value of 1.0, the integer 0x00010000 is returned by CGEventGetIntegerValueField. If this key is passed to CGEventGetDoubleValueField, the fixed-point value is converted to a double value.

case scrollWheelEventFixedPtDeltaAxis1