The amount that is expected to scroll vertically, in units determined by deltaMode.
See also:
WheelEvent.deltaY from the W3C.
num get deltaY { if (JS('bool', '#.deltaY !== undefined', this)) { // W3C WheelEvent return this._deltaY; } throw new UnsupportedError('deltaY is not supported'); }
© 2012 the Dart project authors
Licensed under the Creative Commons Attribution-ShareAlike License v4.0.
https://api.dartlang.org/stable/2.0.0/dart-html/WheelEvent/deltaY.html