Detect moving to a new tab in Mobile Safari

Question

I have a series of pages that open popups (new tabs in Mobile Safari.) Each of these popups needs to know when they are the focused or not. On desktops, we use window.

Answer 1

I don't think that onblur can be detected, but this is a code to detect onfocus:

var timestamp=new Date().getTime();
function checkResume()
{
    var current=new Date().getTime();
    if(current-timestamp>5000)
    {
        var event=document.createEvent("Events");
        event.initEvent("focus",true,true);
        document.dispatchEvent(event);
    }
    timestamp=current;
}
window.setInterval(checkResume,50);

Then you just write:

document.addEventListener("focus",function()
{
    alert("Focus detected");
},false);