Range.getBoundingClientRect() - Web APIs 编辑

Experimental

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

The Range.getBoundingClientRect() method returns a DOMRect object that bounds the contents of the range; this is a rectangle enclosing the union of the bounding rectangles for all the elements in the range.

This method is useful for determining the viewport coordinates of the cursor or selection inside a text box. See Element.getBoundingClientRect() for details on the returned value.

Syntax

boundingRect = range.getBoundingClientRect()

Example

HTML

<div id="highlight"></div>
<p>This example positions a "highlight" rectangle behind the contents of a range. The range's content <b>starts here</b> and continues on until it <b>ends here</b>. The bounding client rectangle contains everything selected in the range.</p>

CSS

#highlight {
  background: yellow;
  position: absolute;
  z-index: -1;
}

p {
  width: 200px;
}

JavaScript

const range = document.createRange();
range.setStartBefore(document.getElementsByTagName('b').item(0), 0);
range.setEndAfter(document.getElementsByTagName('b').item(1), 0);

const clientRect = range.getBoundingClientRect();
const highlight = document.getElementById('highlight');
highlight.style.left = `${clientRect.x}px`;
highlight.style.top = `${clientRect.y}px`;
highlight.style.width = `${clientRect.width}px`;
highlight.style.height = `${clientRect.height}px`;

Result

Specifications

Browser compatibility

BCD tables only load in the browser

See also

• Range.getClientRects() - finer-grained result for non-rectangular ranges (e.g., when the selection wraps onto the next line);
• Element.getBoundingClientRect()
• Document.caretPositionFromPoint() - to get the (node, offset) from viewport coordinates.