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IntersectionObserverEntry.intersectionRect

This is an experimental technology
Check the Browser compatibility table carefully before using this in production.

The IntersectionObserverEntry interface's read-only intersectionRect property is a DOMRectReadOnly object which describes the smallest rectangle that contains the entire portion of the target element which is currently visible within the intersection root.

Syntax

var intersectionRect = IntersectionObserverEntry.intersectionRect;

Value

A DOMRectReadOnly which describes the part of the target element that's currently visible within the root's intersection rectangle.

This rectangle is computed by taking the intersection of boundingClientRect with each of the target's ancestors' clip rectangles, with the exception of the intersection root itself.

Example

In this simple example, an intersection callback stores the intersection rectangle for later use by the code that draws the target elements' contents, so that only the visible area is redrawn.

function intersectionCallback(entries) {
  entries.forEach(function(entry) {
    refreshZones.push({
      element: entry.target,
      rect: entry.intersectionRect
    });
  });
}

Specifications

Browser compatibility

Feature Chrome Edge Firefox Internet Explorer Opera Safari
Basic support 51 15

53 — 551

55

No ? ?
Feature Android webview Chrome for Android Edge mobile Firefox for Android IE mobile Opera Android iOS Safari
Basic support 51 51 Yes ? No ? ?

1. From version 53 until version 55 (exclusive): this feature is behind the dom.IntersectionObserver.enabled preference (needs to be set to true). To change preferences in Firefox, visit about:config.

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https://developer.mozilla.org/en-US/docs/Web/API/IntersectionObserverEntry/intersectionRect