Document.hasFocus()
The
Document.hasFocus()
method returns a Boolean
value indicating whether the document or any element inside the document has focus. This method can be used to determine whether the active element in a document has focus.When viewing a document, an element with focus is always the active element in the document, but an active element does not necessarily have focus. For example, an active element within a popup window that is not the foreground does not have focus.
Syntax
JavaScript
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focused = document.hasFocus();
Return value
false
if the active element in the document has no focus; true
if the active element in the document has focus.
Example
html;highlight:[17]
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<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8" /> <title>TEST</title> <style> #message { font-weight: bold; } </style> <script> setInterval( checkPageFocus, 200 ); function checkPageFocus() { var info = document.getElementById("message"); if ( document.hasFocus() ) { info.innerHTML = "The document has the focus."; } else { info.innerHTML = "The document doesn't have the focus."; } } function openWindow() { window.open ( "http://developer.mozilla.org/", "mozdev", "width=640, height=300, left=150, top=260" ); } </script> </head> <body> <h1>JavaScript hasFocus example</h1> <div id="message">Waiting for user action</div> <div><button onclick="openWindow()">Open a new window</button></div> </body> </html>
Specification
Specification | Status | Comment |
---|---|---|
WHATWG HTML Living Standard The definition of 'Document.hasFocus()' in that specification. |
Living Standard | Initial definition |
Browser compatibility
Feature | Chrome | Firefox (Gecko) | Internet Explorer | Opera | Safari |
---|---|---|---|---|---|
Basic support | 30 | 3.0 (1.9) | 6.0 | 12.10 | (Yes) |
Feature | Android | Firefox Mobile (Gecko) | IE Mobile | Opera Mobile | Safari Mobile |
---|---|---|---|---|---|
Basic support | ? | 1.0 (1.9) | ? | No support | ? |
See also
License
© 2016 Mozilla Contributors
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-us/docs/web/api/document/hasfocus