javascript 如何检查 dom 元素是否可聚焦？
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How to check if a dom element is focusable?
提问by Konstantin Solomatov
Many DOM elements are focusable: divs with tabIndex, input elements, etc. Is there any simple way to check whether an element is focusable than checking a zillion of different cases? Is there a jQuery method for this?
许多 DOM 元素是可聚焦的：带有 tabIndex、输入元素等的 div。有没有比检查无数种不同情况更简单的方法来检查元素是否可聚焦？是否有一个 jQuery 方法？
采纳答案by gustavohenke
Answer "translated" from here: Which HTML elements can receive focus?
从这里回答“翻译”：哪些 HTML 元素可以接收焦点？
<a>or<area>withhref- Any form elements which aren't disabled
- iframes
- Any element with
tabindex
<a>或<area>与href- 任何未禁用的表单元素
- 内嵌框架
- 任何元素
tabindex
Additionaly, I believe that hidden elements can't get focus also.
另外，我相信隐藏元素也无法获得焦点。
Assuming that conditions, the following function may help you (assuming it'll always receive an jQuery element):
假设条件，以下函数可能会帮助你（假设它总是会收到一个 jQuery 元素）：
function canFocus( $el ) {
if ( $el.is( ":hidden" ) || $el.is( ":disabled" ) ) {
return false;
}
var tabIndex = +$el.attr( "tabindex" );
tabIndex = isNaN( tabIndex ) ? -1 : tabIndex;
return $el.is( ":input, a[href], area[href], iframe" ) || tabIndex > -1;
}
