MouseEvent: WEBKIT_FORCE_AT_MOUSE_DOWN static property
Non-standard: This feature is not standardized. We do not recommend using non-standard features in production, as they have limited browser support, and may change or be removed. However, they can be a suitable alternative in specific cases where no standard option exists.
MouseEvent.WEBKIT_FORCE_AT_MOUSE_DOWN is a proprietary, WebKit-specific, static numeric property whose value is the minimum force necessary for a normal click.
BecauseWEBKIT_FORCE_AT_MOUSE_DOWN is a static property ofMouseEvent, you always use it asMouseEvent.WEBKIT_FORCE_AT_MOUSE_DOWN, rather than as a property of aMouseEvent instance.
Specifications
Not part of any specification. Apple hasa description at the Mac Developer Library.