The ending x (horizontal) position of the Draggable instance.
endX gets populated immediately when the mouse (or touch) is released after dragging, even before tweening has completed. This makes it easy to predict exactly where the element will land (useful for
throwProps:true Draggables where momentum gets applied). For a Draggable of
endX would pertain to the
x transform translation, as in the css
type:"top,left", the Draggable's
x would refer to the css
"left" value that's applied. This is not the global coordinate - it is the inline css-related value applied to the element.