visibilitychange

Summary

Set the visibility state of an element

Property of dom/Documentdom/Document

Syntax

var result = element.visibilitychange;
element.visibilitychange = value;

Examples

var timer = 0;
var PERIOD_VISIBLE = 1000;
var PERIOD_NOT_VISIBLE = 60000;

function onLoad() {
   timer = setInterval(checkEmail, (document.hidden) ? PERIOD_NOT_VISIBLE : PERIOD_VISIBLE);
   if(document.addEventListener) document.addEventListener("visibilitychange", visibilityChanged);
}

function visibilityChanged() {
   clearTimeout(timer);
   timer = setInterval(checkEmail, (document.hidden) ? PERIOD_NOT_VISIBLE : PERIOD_VISIBLE);
}

function checkEmail() {
   // Check server for new messages
}

window.onload = onLoad;

Notes

Remarks

This event is not triggered when it is registered.

Syntax

Event handler parameters

This method has no parameters.

Related specifications

Page Visibility

Recommendation

See also

Related articles

Performance

• navigation timing

• resource timing

• user timing

• hidden

• visibilityState

• visibilitychange

• HTML5 Techniques for Optimizing Mobile Performance

Attributions

• Microsoft Developer Network: [Windows Internet Explorer API reference Article]