Javascript event when page is actually shown in a web browser_问答_开发者

Javascript event when page is actually shown in a web browser

开发者 https://www.devze.com 2022-12-10 10:00 出处：网络

I\'m developing a web site which shows different images in a loop using cross fading. Now, I want this loop to start no earlier than the page is actually shown by the user. The typical scenario is whe

I'm developing a web site which shows different images in a loop using cross fading. Now, I want this loop to start no earlier than the page is actually shown by the user. The typical scenario is when the user fires up a new tab entering the url of my site, goes back to an old tab (or opens a new tab), waiting for my site to load. As soon as the site has been loaded, he goes back to the tab where my site has been loaded: I want the loop to start only when the tab contain开发者_JAVA百科ing the loaded page gets the focus.

How can I do that? I'm using the jQuery lib but plain vanilla javascript would be as great.

Thanks.

<html><head>

<script type="text/javascript">
window.__hasfocus = true;
window.onload = function() {
    window.__loaded = true;
    if(window.__hasfocus && !window.__startFlag) start();
}
window.onblur = function() { window.__hasfocus = false; }
window.onfocus = function() {
    if(window.__loaded && !window.__startFlag) start();
}
function start() {
    window.__startFlag = true;
    alert('starting');
}
</script>
</head>

<body>
<img title="" src="http://stereo.gsfc.nasa.gov/img/spaceweather/preview/tricompSW.jpg">
</body>
</html>