/mdn-git/developer.mozilla.org/en-US/docs/Web/API/MouseEventMouseEvent
altKey button buttons clientX clientY ctrlKey getModifierState initMouseEvent layerX layerY metaKey MouseEvent movementX movementY mozInputSource offsetX offsetY pageX pageY relatedTarget screenX screenY shiftKey WEBKIT_FORCE_AT_FORCE_MOUSE_DOWN_static WEBKIT_FORCE_AT_MOUSE_DOWN_static webkitForce x y