IntersectionObserver: root property
The IntersectionObserver
interface's read-only
root
property identifies the Element
or
Document
whose bounds are treated as the bounding box
of the viewport for the element which is the observer's target.
If the root
is null
, then the bounds of the actual document
viewport are used.
Value
A Element
or Document
object whose bounding box is used
as the bounds of the viewport for the purposes of determining how much of the target
element is visible. The intersection of this bounding rectangle, offset by any margins
specified in the options passed to the
IntersectionObserver()
constructor, the target element's bounds, minus the bounds of every element or other
object which overlaps the target element, is considered to be the visible area of the
target element.
If root
is null
, then the owning document is used as the
root, and the bounds its viewport (that is, the visible area of the document) are used
as the root bounds.
Examples
This example sets the border
of the intersection observer's root element
to be a 2-pixel medium green line.
js
observer.root.style.border = "2px solid #44aa44";
Specifications
Specification |
---|
Intersection Observer # dom-intersectionobserver-root |
Browser compatibility
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