How to Determine if an Input Element is Focused in jQuery?-JS Tutorial-php.cn

How to Determine if an Input Element is Focused in jQuery?

Barbara Streisand

Release： 2024-11-21 09:47:14

Original

919 people have browsed it

How to Determine if an Input Element is Focused in jQuery?

How to Use jQuery to Determine if an Input is Focused

In a website's front page, multiple

elements use the CSS :hover pseudo-class to display a border when the mouse hovers over them. One of these

elements contains a

that, with jQuery's help, maintains the border when any of its input elements have focus.

This setup works flawlessly, except in IE6, which does not support :hover on elements other than tags. To address this issue, jQuery is utilized to mimic CSS :hover using the $(#element).hover() method.

However, a problem arises when jQuery handles both the form's focus() and hover(). When an input element gains focus and the user moves the mouse in and out, the border disappears.

To resolve this behavior, consider using a conditional statement. For example, by checking if any inputs have focus on mouse out events, it is possible to prevent the border from fading away. Since jQuery lacks a :focus selector, alternative approaches need to be explored.

jQuery 1.6

jQuery 1.6 introduced a :focus selector, eliminating the need for custom implementations. Simply use:

$("..").is(":focus")

Copy after login

jQuery 1.5 and Below

Newer methods have emerged for testing focus, including Ben Alman's implementation:

jQuery.expr[':'].focus = function( elem ) {
  return elem === document.activeElement &amp;&amp; ( elem.type || elem.href );
};

Copy after login

This defines a custom selector, allowing usage like:

if ($("...").is(":focus")) {
  ...
}

Copy after login

Any jQuery Version

For retrieving the currently focused element:

$(document.activeElement)

Copy after login

To ensure compatibility with both jQuery versions 1.6 and lower:

(function ( $ ) {
    var filters = $.expr[":"];
    if ( !filters.focus ) { 
        filters.focus = function( elem ) {
           return elem === document.activeElement &amp;&amp; ( elem.type || elem.href );
        };
    }
})( jQuery );

Copy after login

The above is the detailed content of How to Determine if an Input Element is Focused in jQuery?. For more information, please follow other related articles on the PHP Chinese website!

source：php.cn

Previous article：How Can I Retrieve Variables Within a JavaScript Function\'s Scope? Next article：Simplify TailwindCSS with TailwindBox

Statement of this Website

The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn