offsetWidth property
The HTMLElement.offsetWidth read-only property returns
the layout width of an element as an integer.
Typically, offsetWidth is a measurement in pixels of the element's CSS
width, including any borders, padding, and vertical scrollbars (if
rendered). It does
not include the width of pseudo-elements such as ::before or
::after.
If the element is hidden (for example, by setting style.display on the
element or one of its ancestors to "none"), then 0 is
returned.
Implementation
external int get offsetWidth;