Function getStackingContext

getStackingContext(node, activeWindow?): StackingContext | undefined
Recursive function that finds the closest parent stacking context. See also https://developer.mozilla.org/en-US/docs/Web/CSS/CSS_Positioning/Understanding_z_index/The_stacking_context

Original author: Kerry Liu / https://github.com/gwwar
Parameters
- node: Element
- OptionalactiveWindow: Window
  The target active window as applicable.
Returns StackingContext | undefined
The closest parent stacking context or undefined if none.
See
- https://github.com/gwwar/z-context/blob/master/content-script.js
- https://github.com/gwwar/z-context/blob/master/LICENSE