javascript - Check if window has focus

Question

I need to check if the user has windows on focus, I'm currently doing this:

var isonfocus=true;  
window.onblur = function(){  
  isonfocus=false;  
}  
window.onfocus = function(){  
  isonfocus=true;  
}

And whenever I need to check if the user has the windows on focus I just do if(isonfocus==true).

Problem: if the user loses focus before the page loads, even if I do if(isonfocus==true) it will return true, even though the window is not on focus, and defining the var to false var isonfocus=false; will do the reverse.

Can someone help me? Thanks.

UPDATE
Imagine a PTC (Paid-To-Click) site, when you go and click an ad to view, most sites verify if the user is actually seeing the advertiser site (has focus) or not (lost focus).
This is similar with what I need, I need a way to verify if the user has the window (which contains an iframe) on focus.
And to gain focus, the user could click the iframe, document or on the tab.
And please note that this needs to work on all major browsers.

score 82 · Accepted Answer

为什么不使用hasFocus方法，例如

if (document.hasFocus()) {
    ...
}

如果您也需要处理iframe's ，那么您的支票就变成了或者，例如

function isFocused() {
    return document.hasFocus() || document.getElementById('iframe').contentWindow.document.hasFocus();
}

score 18 · Accepted Answer

18

您可以使用document.visibilityState来了解页面是否处于焦点。

于 2018-05-25T14:49:17.260 回答

score 5 · Accepted Answer

var has_focus = true;

function loading_time() {
    $(":focus").each(function() {
      if($(this).attr("id")=="iframeID") has_focus = true;
    });

    if(has_focus==true) alert('page has focus');
    else alert('page has not focus');

    setTimeout("loading_time()", 2000);
}

window.onblur = function(){  
    has_focus=false;  
}  
window.onfocus = function(){  
    has_focus=true;  
}

$(window).load(function(){
    setTimeout("loading_time()", 2000);
});

为了提高效率，您需要var has_focus = false;让用户点击页面上的某个位置。

score 2 · Accepted Answer

跨浏览器 jQuery 解决方案！ 以下插件将通过您对各种版本的 IE、Chrome、Firefox、Safari 等的标准测试。并相应地建立您声明的方法。它还处理以下问题：

计时器！哇！
onblur|.blur/onfocus|.focus “重复”调用
窗口通过选择备用应用程序失去焦点，如 word
- 这往往是不可取的，因为如果您打开了一个银行页面，并且它的onblur事件告诉它屏蔽该页面，那么如果您打开计算器，您将无法再看到该页面！
不触发页面加载

使用很简单：

$.winFocus(function(event, isVisible) {
    console.log("Combo\t\t", event, isVisible);
});

//  OR Pass False boolean, and it will not trigger on load,
//  Instead, it will first trigger on first blur of current tab_window
$.winFocus(function(event, isVisible) {
    console.log("Combo\t\t", event, isVisible);
}, false);

//  OR Establish an object having methods "blur" & "focus", and/or "blurFocus"
//  (yes, you can set all 3, tho blurFocus is the only one with an 'isVisible' param)
$.winFocus({
    blur: function(event) {
        console.log("Blur\t\t", event);
    },
    focus: function(event) {
        console.log("Focus\t\t", event);
    }
});

//  OR First method becoms a "blur", second method becoms "focus"!
$.winFocus(function(event) {
    console.log("Blur\t\t", event);
},
function(event) {
    console.log("Focus\t\t", event);
});

New&improvedversion,madeforbothvanillaandjQueryfoundhere!

/*    Begin Plugin    */
;;(function($){$.winFocus||($.extend({winFocus:function(){var a=!0,b=[];$(document).data("winFocus")||$(document).data("winFocus",$.winFocus.init());for(x in arguments)"object"==typeof arguments[x]?(arguments[x].blur&&$.winFocus.methods.blur.push(arguments[x].blur),arguments[x].focus&&$.winFocus.methods.focus.push(arguments[x].focus),arguments[x].blurFocus&&$.winFocus.methods.blurFocus.push(arguments[x].blurFocus),arguments[x].initRun&&(a=arguments[x].initRun)):"function"==typeof arguments[x]?b.push(arguments[x]):
"boolean"==typeof arguments[x]&&(a=arguments[x]);b&&(1==b.length?$.winFocus.methods.blurFocus.push(b[0]):($.winFocus.methods.blur.push(b[0]),$.winFocus.methods.focus.push(b[1])));if(a)$.winFocus.methods.onChange()}}),$.winFocus.init=function(){$.winFocus.props.hidden in document?document.addEventListener("visibilitychange",$.winFocus.methods.onChange):($.winFocus.props.hidden="mozHidden")in document?document.addEventListener("mozvisibilitychange",$.winFocus.methods.onChange):($.winFocus.props.hidden=
"webkitHidden")in document?document.addEventListener("webkitvisibilitychange",$.winFocus.methods.onChange):($.winFocus.props.hidden="msHidden")in document?document.addEventListener("msvisibilitychange",$.winFocus.methods.onChange):($.winFocus.props.hidden="onfocusin")in document?document.onfocusin=document.onfocusout=$.winFocus.methods.onChange:window.onpageshow=window.onpagehide=window.onfocus=window.onblur=$.winFocus.methods.onChange;return $.winFocus},$.winFocus.methods={blurFocus:[],blur:[],focus:[],
exeCB:function(a){$.winFocus.methods.blurFocus&&$.each($.winFocus.methods.blurFocus,function(b,c){this.apply($.winFocus,[a,!a.hidden])});a.hidden&&$.winFocus.methods.blur&&$.each($.winFocus.methods.blur,function(b,c){this.apply($.winFocus,[a])});!a.hidden&&$.winFocus.methods.focus&&$.each($.winFocus.methods.focus,function(b,c){this.apply($.winFocus,[a])})},onChange:function(a){var b={focus:!1,focusin:!1,pageshow:!1,blur:!0,focusout:!0,pagehide:!0};if(a=a||window.event)a.hidden=a.type in b?b[a.type]:
document[$.winFocus.props.hidden],$(window).data("visible",!a.hidden),$.winFocus.methods.exeCB(a);else try{$.winFocus.methods.onChange.call(document,new Event("visibilitychange"))}catch(c){}}},$.winFocus.props={hidden:"hidden"})})(jQuery);
/*    End Plugin      */

// Simple example
$(function() {
	$.winFocus(function(event, isVisible) {
		$('td tbody').empty();
		$.each(event, function(i) {
			$('td tbody').append(
				$('<tr />').append(
					$('<th />', { text: i }),
					$('<td />', { text: this.toString() })
				)
			)
		});
		if (isVisible) 
			$("#isVisible").stop().delay(100).fadeOut('fast', function(e) {
				$('body').addClass('visible');
				$(this).stop().text('TRUE').fadeIn('slow');
			});
		else {
			$('body').removeClass('visible');
			$("#isVisible").text('FALSE');
		}
	});
})

body { background: #AAF; }
table { width: 100%; }
table table { border-collapse: collapse; margin: 0 auto; width: auto; }
tbody > tr > th { text-align: right; }
td { width: 50%; }
th, td { padding: .1em .5em; }
td th, td td { border: 1px solid; }
.visible { background: #FFA; }

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js"></script>
<h3>See Console for Event Object Returned</h3>
<table>
    <tr>
        <th><p>Is Visible?</p></th>
        <td><p id="isVisible">TRUE</p></td>
    </tr>
    <tr>
        <td colspan="2">
            <table>
                <thead>
                    <tr>
                        <th colspan="2">Event Data <span style="font-size: .8em;">{ See Console for More Details }</span></th>
                    </tr>
                </thead>
                <tbody></tbody>
            </table>
        </td>
    </tr>
</table>

score 1 · Accepted Answer

如果您不关心 Opera 支持，则使用该document.hasFocus()方法可能会获得更好的结果。有关详细信息，请参见此处。

score 0 · Accepted Answer

此主题中的信息太旧。继续使用 : document.hasFocus()。现在它将适用于您需要的每个浏览器。

浏览器兼容性：https ://developer.mozilla.org/en-US/docs/Web/API/Document/hasFocus#browser_compatibility

score -2 · Accepted Answer

如果用户的浏览器窗口聚焦/处于活动状态，但刚刚单击了刷新按钮（或 url 栏等），document.hasFocus()则会告诉您该窗口未处于活动状态。

但是，您可以调用window.focus()并查看该focus事件是否实际被触发。如果是，则浏览器仍处于焦点/活动状态。

const windowHasFocus = function () {
  if (document.hasFocus()) return true
  let hasFocus = false

  window.addEventListener('focus', function () {
    hasFocus = true
  })
  window.focus()

  return hasFocus
}

javascript - Check if window has focus

7 回答 7

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