We Keep Coding

Let HTML5 Notification disappear after a delay?

I want to use HTML5 notifications which work great.
The problem is that they never disappear.
How can I set a delay after which the HTML5 notification disappear?

You can just call the .close() method:
var n = new Notification("Hello");
setTimeout(n.close.bind(n), 2000);
See here on MDN for details.

The notification should have a built in close button, no?
HTML
Notify me!
JS
<script>
var Notification = window.Notification || window.mozNotification || window.webkitNotification;
Notification.requestPermission(function (permission) {
// console.log(permission);
});
function show() {
var instance = new Notification(
"Hey", {
body: "this is a message"
}
);
instance.onclick = function () {
// Something to do
};
instance.onerror = function () {
// Something to do
};
instance.onshow = function () {
// Something to do
};
instance.onclose = function () {
// Something to do
};
return false;
}
</script>

clearTimeout/setTimeout on mobile devices

I have to make a button that has the following functions:
If you click on it, it should show some lines and hide them after 3 seconds, but if you click on the button before the 3 seconds are over the lines should hide as well.
I have written some code that is working perfectly on desktop browsers, but on mobile browsers it is not. Android devices seem to ignore my clearTimeout and on iphones it seems more like a "buttonPressed" event.
I have created a jsfiddle so that you can see what i have written.
var timeout = null;
var buttonCallback = function() {
if( timeout === null ) {
log('show lines');
timeout = setTimeout(buttonCallback, 3000);
}
else {
clearTimeout(timeout);
timeout = null;
log('hide lines');
}
}
var hammerElement = Hammer(document.getElementById('showLines'));
hammerElement.on("touch", function(e) {
e.preventDefault()
buttonCallback();
});
Any idea how i can make this behaviour work for mobile browsers?

As #wumm mentioned, it works in my iPhone5 iOS7 as well.
Another way you could try is this fiddle I setup for you: http://jsfiddle.net/thePav/jC32X/5
HTML
<button id="showLines">Show Lines</button>
JS
var timeout;
var flag = false;
function buttonCallback() {
$('#showLines').click(function(){
if(flag == false){
flag = true;
//show lines here
timeout = setTimeout(function(){
flag = false;
//hide lines here
}, 3000);
}else{
flag = false;
clearTimeout(timeout);
//hide lines here
}
});
}
$(document).ready(function(){
buttonCallback();
});
Not sure what the issue with your code was but this is just another way to implement it.

The error was that on some mobile devices that I was testing (not all!) has sometimes send 2 tab events (double tab).
To fix that I have been added a delayTime and checked when the function got called last time.
var buttonCallback = function() {
if( timeout === null ) {
//for old slow andoid devices
if ((new Date().getTime() - delayTime) < 2200)
return;
delayTime = new Date().getTime();
log('show lines');
timeout = setTimeout(buttonCallback, 3000);
}
// for fast devices to prevent the double tab error
else if ( (new Date().getTime() - delayTime) > 1200 ) {
clearTimeout(timeout);
timeout = null;
log('hide lines');
}
}

Check if my website is open in another tab

I want to check with JavaScript if the user has already opened my website in another tab in their browser.
It seems I cannot do that with pagevisibility...
The only way I see is to use WebSocket based on a session cookie, and check if the client has more than one socket. But by this way, from current tab, I have to ask my server if this user has a tab opened right next to their current browser tab. It is a little far-fetched!
Maybe with localstorage?

The shorter version with localStorage and Storage listener
<script type="text/javascript">
// Broadcast that you're opening a page.
localStorage.openpages = Date.now();
var onLocalStorageEvent = function(e){
if(e.key == "openpages"){
// Listen if anybody else is opening the same page!
localStorage.page_available = Date.now();
}
if(e.key == "page_available"){
alert("One more page already open");
}
};
window.addEventListener('storage', onLocalStorageEvent, false);
</script>
Update:
Works on page crash as well.
Stimulate page crash in chrome: chrome://inducebrowsercrashforrealz
Live demo

Using local storage I created a simple demo that should accomplish what your looking to do. Basically, it simply maintains a count of currently opened windows. When the window is closed the unload events fire and remove it from the total window count.
When you first look at it, you may think there's more going on than there really is. Most of it was a shotty attempt to add logic into who was the "main" window, and who should take over as the "main" window as you closed children. (Hence the setTimeout calls to recheck if it should be promoted to a main window) After some head scratching, I decided it would take too much time to implement and was outside the scope of this question. However, if you have two windows open (Main, and Child) and you close the Main, the child will be promoted to a main.
For the most part you should be able to get the general idea of whats going on and use it for your own implementation.
See it all in action here:
http://jsbin.com/mipanuro/1/edit
Oh yeah, to actually see it in action... Open the link in multiple windows. :)
Update:
I've made the necessary changes to have the the local storage maintain the "main" window. As you close tabs child windows can then become promoted to a main window. There are two ways to control the "main" window state through a parameter passed to the constructor of WindowStateManager. This implementation is much nicer than my previous attempt.
JavaScript:
// noprotect
var statusWindow = document.getElementById('status');
(function (win)
{
//Private variables
var _LOCALSTORAGE_KEY = 'WINDOW_VALIDATION';
var RECHECK_WINDOW_DELAY_MS = 100;
var _initialized = false;
var _isMainWindow = false;
var _unloaded = false;
var _windowArray;
var _windowId;
var _isNewWindowPromotedToMain = false;
var _onWindowUpdated;
function WindowStateManager(isNewWindowPromotedToMain, onWindowUpdated)
{
//this.resetWindows();
_onWindowUpdated = onWindowUpdated;
_isNewWindowPromotedToMain = isNewWindowPromotedToMain;
_windowId = Date.now().toString();
bindUnload();
determineWindowState.call(this);
_initialized = true;
_onWindowUpdated.call(this);
}
//Determine the state of the window
//If its a main or child window
function determineWindowState()
{
var self = this;
var _previousState = _isMainWindow;
_windowArray = localStorage.getItem(_LOCALSTORAGE_KEY);
if (_windowArray === null || _windowArray === "NaN")
{
_windowArray = [];
}
else
{
_windowArray = JSON.parse(_windowArray);
}
if (_initialized)
{
//Determine if this window should be promoted
if (_windowArray.length <= 1 ||
(_isNewWindowPromotedToMain ? _windowArray[_windowArray.length - 1] : _windowArray[0]) === _windowId)
{
_isMainWindow = true;
}
else
{
_isMainWindow = false;
}
}
else
{
if (_windowArray.length === 0)
{
_isMainWindow = true;
_windowArray[0] = _windowId;
localStorage.setItem(_LOCALSTORAGE_KEY, JSON.stringify(_windowArray));
}
else
{
_isMainWindow = false;
_windowArray.push(_windowId);
localStorage.setItem(_LOCALSTORAGE_KEY, JSON.stringify(_windowArray));
}
}
//If the window state has been updated invoke callback
if (_previousState !== _isMainWindow)
{
_onWindowUpdated.call(this);
}
//Perform a recheck of the window on a delay
setTimeout(function()
{
determineWindowState.call(self);
}, RECHECK_WINDOW_DELAY_MS);
}
//Remove the window from the global count
function removeWindow()
{
var __windowArray = JSON.parse(localStorage.getItem(_LOCALSTORAGE_KEY));
for (var i = 0, length = __windowArray.length; i < length; i++)
{
if (__windowArray[i] === _windowId)
{
__windowArray.splice(i, 1);
break;
}
}
//Update the local storage with the new array
localStorage.setItem(_LOCALSTORAGE_KEY, JSON.stringify(__windowArray));
}
//Bind unloading events
function bindUnload()
{
win.addEventListener('beforeunload', function ()
{
if (!_unloaded)
{
removeWindow();
}
});
win.addEventListener('unload', function ()
{
if (!_unloaded)
{
removeWindow();
}
});
}
WindowStateManager.prototype.isMainWindow = function ()
{
return _isMainWindow;
};
WindowStateManager.prototype.resetWindows = function ()
{
localStorage.removeItem(_LOCALSTORAGE_KEY);
};
win.WindowStateManager = WindowStateManager;
})(window);
var WindowStateManager = new WindowStateManager(false, windowUpdated);
function windowUpdated()
{
//"this" is a reference to the WindowStateManager
statusWindow.className = (this.isMainWindow() ? 'main' : 'child');
}
//Resets the count in case something goes wrong in code
//WindowStateManager.resetWindows()
HTML:
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>JS Bin</title>
</head>
<body>
<div id='status'>
<span class='mainWindow'>Main Window</span>
<span class='childWindow'>Child Window</span>
</div>
</body>
</html>
CSS:
#status
{
display:table;
width:100%;
height:500px;
border:1px solid black;
}
span
{
vertical-align:middle;
text-align:center;
margin:0 auto;
font-size:50px;
font-family:arial;
color:#ba3fa3;
display:none;
}
#status.main .mainWindow,
#status.child .childWindow
{
display:table-cell;
}
.mainWindow
{
background-color:#22d86e;
}
.childWindow
{
background-color:#70aeff;
}

(2021) You can use BroadcastChannel to communicate between tabs of the same origin.
For example, put the following at the top level of your js code, then test by opening 2 tabs:
const bc = new BroadcastChannel("my-awesome-site");
bc.onmessage = (event) => {
if (event.data === `Am I the first?`) {
bc.postMessage(`No you're not.`);
alert(`Another tab of this site just got opened`);
}
if (event.data === `No you're not.`) {
alert(`An instance of this site is already running`);
}
};
bc.postMessage(`Am I the first?`);

I know it is late, but maybe help someone
This snippet of code, will detect how many tabs are open and how many are active (visible) and if none of tabs is active, it will choose last opened tab, as active one.
This code will handle windows/tab crash too and it will refresh the count at crash.
Because localStorage is not supported on Stack Overflow currently, please test here.
<html>
<body>
Open in several tabs or windows
<div id="holder_element"></div>
<script type="text/javascript">
//localStorage.clear();
manage_crash();
//Create a windows ID for each windows that is oppened
var current_window_id = Date.now() + "";//convert to string
var time_period = 3000;//ms
//Check to see if PageVisibility API is supported or not
var PV_API = page_visibility_API_check();
/************************
** PAGE VISIBILITY API **
*************************/
function page_visibility_API_check ()
{
var page_visibility_API = false;
var visibility_change_handler = false;
if ('hidden' in document)
{
page_visibility_API = 'hidden';
visibility_change_handler = 'visibilitychange';
}
else
{
var prefixes = ['webkit','moz','ms','o'];
//loop over all the known prefixes
for (var i = 0; i < prefixes.length; i++){
if ((prefixes[i] + 'Hidden') in document)
{
page_visibility_API = prefixes[i] + 'Hidden';
visibility_change_handler = prefixes[i] + 'visibilitychange';
}
}
}
if (!page_visibility_API)
{
//PageVisibility API is not supported in this device
return page_visibility_API;
}
return {"hidden": page_visibility_API, "handler": visibility_change_handler};
}
if (PV_API)
{
document.addEventListener(PV_API.handler, function(){
//console.log("current_window_id", current_window_id, "document[PV_API.hidden]", document[PV_API.hidden]);
if (document[PV_API.hidden])
{
//windows is hidden now
remove_from_active_windows(current_window_id);
//skip_once = true;
}
else
{
//windows is visible now
//add_to_active_windows(current_window_id);
//skip_once = false;
check_current_window_status ();
}
}, false);
}
/********************************************
** ADD CURRENT WINDOW TO main_windows LIST **
*********************************************/
add_to_main_windows_list(current_window_id);
//update active_window to current window
localStorage.active_window = current_window_id;
/**************************************************************************
** REMOVE CURRENT WINDOWS FROM THE main_windows LIST ON CLOSE OR REFRESH **
***************************************************************************/
window.addEventListener('beforeunload', function ()
{
remove_from_main_windows_list(current_window_id);
});
/*****************************
** ADD TO main_windows LIST **
******************************/
function add_to_main_windows_list(window_id)
{
var temp_main_windows_list = get_main_windows_list();
var index = temp_main_windows_list.indexOf(window_id);
if (index < 0)
{
//this windows is not in the list currently
temp_main_windows_list.push(window_id);
}
localStorage.main_windows = temp_main_windows_list.join(",");
return temp_main_windows_list;
}
/**************************
** GET main_windows LIST **
***************************/
function get_main_windows_list()
{
var temp_main_windows_list = [];
if (localStorage.main_windows)
{
temp_main_windows_list = (localStorage.main_windows).split(",");
}
return temp_main_windows_list;
}
/**********************************************
** REMOVE WINDOWS FROM THE main_windows LIST **
***********************************************/
function remove_from_main_windows_list(window_id)
{
var temp_main_windows_list = [];
if (localStorage.main_windows)
{
temp_main_windows_list = (localStorage.main_windows).split(",");
}
var index = temp_main_windows_list.indexOf(window_id);
if (index > -1) {
temp_main_windows_list.splice(index, 1);
}
localStorage.main_windows = temp_main_windows_list.join(",");
//remove from active windows too
remove_from_active_windows(window_id);
return temp_main_windows_list;
}
/**************************
** GET active_windows LIST **
***************************/
function get_active_windows_list()
{
var temp_active_windows_list = [];
if (localStorage.actived_windows)
{
temp_active_windows_list = (localStorage.actived_windows).split(",");
}
return temp_active_windows_list;
}
/*************************************
** REMOVE FROM actived_windows LIST **
**************************************/
function remove_from_active_windows(window_id)
{
var temp_active_windows_list = get_active_windows_list();
var index = temp_active_windows_list.indexOf(window_id);
if (index > -1) {
temp_active_windows_list.splice(index, 1);
}
localStorage.actived_windows = temp_active_windows_list.join(",");
return temp_active_windows_list;
}
/********************************
** ADD TO actived_windows LIST **
*********************************/
function add_to_active_windows(window_id)
{
var temp_active_windows_list = get_active_windows_list();
var index = temp_active_windows_list.indexOf(window_id);
if (index < 0)
{
//this windows is not in active list currently
temp_active_windows_list.push(window_id);
}
localStorage.actived_windows = temp_active_windows_list.join(",");
return temp_active_windows_list;
}
/*****************
** MANAGE CRASH **
******************/
//If the last update didn't happened recently (more than time_period*2)
//we will clear saved localStorage's data and reload the page
function manage_crash()
{
if (localStorage.last_update)
{
if (parseInt(localStorage.last_update) + (time_period * 2) < Date.now())
{
//seems a crash came! who knows!?
//localStorage.clear();
localStorage.removeItem('main_windows');
localStorage.removeItem('actived_windows');
localStorage.removeItem('active_window');
localStorage.removeItem('last_update');
location.reload();
}
}
}
/********************************
** CHECK CURRENT WINDOW STATUS **
*********************************/
function check_current_window_status(test)
{
manage_crash();
if (PV_API)
{
var active_status = "Inactive";
var windows_list = get_main_windows_list();
var active_windows_list = get_active_windows_list();
if (windows_list.indexOf(localStorage.active_window) < 0)
{
//last actived windows is not alive anymore!
//remove_from_main_windows_list(localStorage.active_window);
//set the last added window, as active_window
localStorage.active_window = windows_list[windows_list.length - 1];
}
if (! document[PV_API.hidden])
{
//Window's page is visible
localStorage.active_window = current_window_id;
}
if (localStorage.active_window == current_window_id)
{
active_status = "Active";
}
if (active_status == "Active")
{
active_windows_list = add_to_active_windows(current_window_id);
}
else
{
active_windows_list = remove_from_active_windows(current_window_id);
}
console.log(test, active_windows_list);
var element_holder = document.getElementById("holder_element");
element_holder.insertAdjacentHTML("afterbegin", "<div>"+element_holder.childElementCount+") Current Windows is "+ active_status +" "+active_windows_list.length+" window(s) is visible and active of "+ windows_list.length +" windows</div>");
}
else
{
console.log("PageVisibility API is not supported :(");
//our INACTIVE pages, will remain INACTIVE forever, you need to make some action in this case!
}
localStorage.last_update = Date.now();
}
//check storage continuously
setInterval(function(){
check_current_window_status ();
}, time_period);
//initial check
check_current_window_status ();
</script>
</body>
</html>

What is the better way to get mouse hold time?

I'm trying to count the time that player is holding the mouse button down. I tried this but it didn't works:
var Game = cc.Layer.extend({
count: false,
countTimer: null,
init: function () {
var selfPointer = this;
this.canvas.addEventListener('mousedown', function(evt) {
selfPointer.count = true;
selfPointer.countTimer = window.setTimeout(selfPointer.Count(), 1);
});
this.canvas.addEventListener('mouseup', function(evt) {
selfPointer.count= false;
window.clearTimeout(selfPointer.countTimer);
});
},
Count: function() {
if (this.count)
{
window.setTimeout(this.Count(), 1);
}
}
This is a part of my code(for brevity) that I want to do an action any 1 milisecond if player is holding the button.
This isn't working besides, I presume that is a better way to do this than mine way. Any ideas?

Why do you use timeouts for this simple task? You can just get time of mousedown, time of mouseup and calculate difference of them. Anyway, timer resolution in browsers is less than 1ms. Read this article of Nickolas Zakas to get more info about time resolution.
Code is:
var Game = cc.Layer.extend({
init: function () {
var holdStart = null,
holdTime = null;
this.canvas.addEventListener('mousedown', function(evt) {
holdStart = Date.now()
});
this.canvas.addEventListener('mouseup', function(evt) {
holdTime = Date.now() - holdStart;
// now in holdTime you have time in milliseconds
});
}

Well if you are targeting newer browsers that are HTML5 compatible you can use web workers for this kind of task. Simply post a message to the web worker on mouse press to start the timer. The web worker can post a message back every 1 ms ish to trigger your in game action and then on mouse release, post another message to the web worker telling it to stop.
Here is just a quick example of how that would work. You would need to run from a local server to have web workers working.
Game.js
function start() {
var worker = new Worker("ActionTrigger.js");
worker.addEventListener('message', function(objEvent) {
console.log("Holding");
});
worker.postMessage("start");
window.onmousedown = function() {
console.log("Mouse press");
worker.postMessage("startTrigger");
}
window.onmouseup = function() {
console.log("Mouse release");
worker.postMessage("endTrigger");
}
}
ActionTrigger.js
var trigger = false;
var interval = 1;
self.addEventListener('message', function(objEvent) {
if(objEvent.data == 'startTrigger')
trigger = true;
else if(objEvent.data == 'endTrigger')
trigger = false;
else if(objEvent.data == 'start')
timerCountdown();
});
function timerCountdown() {
if(trigger)
postMessage("");
setTimeout(timerCountdown,interval);
}

You could use something like this:
http://jsfiddle.net/yE8sh/
//Register interval handle
var timer;
$(document).mousedown(function(){
//Starts interval. Run once every 1 millisecond
timer=self.setInterval(add,1);
});
$(document).mouseup(function(){
//Clears interval on mouseup
timer=window.clearInterval(timer);
});
function add(){
//The function to run
$("body").append("a");
}

Detect Mousemovent inside of blur function Jquery

I am trying to create a neat way to stop an AJAX called based upon if the browser is in focus, and if the mouse moves.. So here's what I want it to do:
If the user goes to a different tab in their browser, minimized the window, or goes somewhere else other than the web app, I want it to kill the AJAX calls in 1 minute. If the user moves the mouse anywhere in the web app, it should consider the user "focused" on the app, and thus continue the ajax calls. I put a timeout called "st" in there to take care of the "timeout" portion, but adding in a mouse detector is a little more advanced. Here's what I have:
var window_focus = true;
$(document).ready(function () {
$('#alertbox').click(function () {
$('#alertbox').slideUp("slow");
});
// Check focal point
$(window).focus(function () {
if (window_focus) {
return
}
window_focus = true;
waitForMsg();
}).blur(function () {
if (!window_focus) {
return
}
console.log('Init Suspension...');
// Set Timeout
$(function () {
st = setTimeout(function () {
clearTimeout(setTimeoutConst);
window_focus = false;
document.title = 'Timed Out | WEBSITE';
console.log('Suspended');
}, 60000);
});
});
waitForMsg();
});
I was going to try adding in something like this:
$(function () {
$().mousemove(function () {
console.log('Reinitialize');
clearTimeout(st);
waitForMsg();
});
});
But it didn't work. Thanks for your help.

http://jsfiddle.net/popnoodles/5mqMm/
You probably want this using .one(). This will see the mouse move, run your procedure and not run it again, until the window is reloaded or it's on another page.
Putting it inside of blur means blurring sets it up again.
}).blur(function () {
$(document).one('mousemove', function(){
// i react ONCE to the mouse being moved
console.log('Reinitialize');
clearTimeout(st);
waitForMsg();
// focus the window again as desired
$(window).trigger('focus');
});
if (!window_focus) {
return
}
console.log('Init Suspension...');
// Set Timeout
$(function () {
st = setTimeout(function () {
clearTimeout(setTimeoutConst);
window_focus = false;
document.title = 'Timed Out | WEBSITE';
console.log('Suspended');
}, 60000);
});
});

Try this jsfiddle
var window_focus = true, lastMouseMoveTime;
$(document).ready(function () {
lastMouseMoveTime = new Date().getTime();
$('#alertbox').click(function () {
$('#alertbox').slideUp("slow");
});
// Check focal point
$(window).focus(function () {
if (window_focus) {
return
}
window_focus = true;
waitForMsg();
}).blur(function () {
if (!window_focus) {
return
}
window_focus = false;
console.log('Init Suspension...');
// Set Timeout
});
waitForMsg();
$(document).mousemove(function(){
lastMouseMoveTime = new Date().getTime();
if(!window_focus ){
waitForMsg(); // restarting ajax if it stopped because of mousemove.
}
});
});
in your ajax call method
if( !window_focus){
if( new Date().getTime() - lastMouseMoveTime > 60*1000 ){
return;
}
}