WheelEvent

The DOM WheelEvent represents events that occur due to the user moving a mouse wheel or similar input device.

This is really different event object from MouseWheelEvent.

Attributes

Attribute	Type	Description
`deltaX`	`double`	Horizontal scroll amount. Read only.
`deltaY`	`double`	Vertical scroll amount. Read only.
`deltaZ`	`double`	Scroll amount for the z-axis. Read only.
`deltaMode`	`unsigned long`	Unit of delta values. See Delta modes for a list of permitted values. Read only.

deltaX, deltaY and deltaZ was defined as long at first. Next, they were defined as float. Finally, they are defined as double. The type in IE9 is long.

Constants

Delta modes

Constant	Value	Description
`DOM_DELTA_PIXEL`	`0x00`	The delta values are specified in pixels.
`DOM_DELTA_LINE`	`0x01`	The delta values are specified in lines.
`DOM_DELTA_PAGE`	`0x02`	The delta values are specified in pages.

Feature	Chrome	Firefox (Gecko)	Internet Explorer	Opera	Safari (WebKit)
Basic support	31	17.0 (17.0)	9.0	18	Not supported
`window.WheelEvent`	(Yes) (*1)	17.0 (17.0)	9.0	Not supported	(Yes) (*1)

Feature	Android	Firefox Mobile (Gecko)	IE Phone	Opera Mobile	Safari Mobile
Basic support	?	17.0 (17.0)	?	?	?
`window.WheelEvent`	?	17.0 (17.0)	?	?	?

Note that Chrome and Safari don't support D3E's WheelEvent actually; nevertheless they return object for window.WheelEvent.