I have different controls on screen and hide and show them asynchronously. Is there any way to track when an element becomes actually visible on the screen? I actually want to get a callback when that happens and move the focus on that element!
try this
var trk = new Array("element1","element2","element3"); // add elements IDS whom you want to track
window.onload = function(){
track();
}
function track()
{
var ele;
for(var i=0;i<trk.length;i++)
{
ele= document.getElementById(trk[i]);
if(ele)
{
if(ele.style.display!="none")
{
// do something
}
}
}
setTimeout(function(){track();},1);
}
The only way that I can think of is to have a setInterval method which checks of the element.style.display!=="none", or whatever other method you used to hide and show the element.
Something like:
var myInterval = setInterval(function()
{
var element = document.getElementByID("SomeElement");
if( element.style.display!=="none" || element.style.visibility!=="hidden")
{
//exit the interval
clearInterval(myInterval);
doSomeFunction();
}
}, 20);
Related
I have a setInterval on a function X that runs every 500ms. In this function X, I call another function Y that essentially binds an event on some divs. However, I would like to unbind these events the next time the function X is called (to start "fresh"). My code doesn't seem to work:
setInterval(this.board.updateBoard, 500); //called from another constructor
This then initiates the functions below:
Board.prototype.updateBoard = function() {
//I attempt to unbind ALL my divs
var divs = this.$el.find("div");
for(var i = 0; i < divs.length; i++) {
$(divs[i]).unbind(); //Apparently this doesn't work?
}
//...some code here...
//find appropriate $div's (multiple of them), and then calls this.beginWalking() below on each of those
//loop here
this.beginWalking($div, direction + "0", direction + "1");
//end of loop
}
//alternate between classes to give appearance of walking
Board.prototype.beginWalking = function ($div, dir0, dir1) {
return setInterval(function () {
if ($div.hasClass(dir0)) {
$div.removeClass(dir0);
$div.addClass(dir1);
} else {
$div.removeClass(dir1);
$div.addClass(dir0);
}
}.bind(this), 80);
};
Basically, updateBoard is called every 500ms. Each time it's called, beginWalking is called to set another interval on a div. The purpose of this other interval, which functions correctly, is to add and remove a class every 80ms. I just can't seem to unbind everything before the next updateBoard is called.
Any suggestions appreciated!
use clearInterval()
edit: $(selector).toggleClass(dir0) might also be helpful
// In other file, use a global (no var) if you need to read it from another file:
updaterGlobal = setInterval(this.board.updateBoard, 500);
// store interval references for clearing:
var updaterLocals = [];
Board.prototype.updateBoard = function() {
//I attempt to unbind ALL my divs
var divs = this.$el.find("div");
// Stop existing div timers:
while(updaterLocals.length > 0){
clearInterval(updaterLocals[0]);
updaterLocals.shift(); // remove the first timer
}
//...some code here...
//loop here to call the below on several $div's
this.beginWalking($div, direction + "0", direction + "1");
//end of loop
}
//alternate between classes to give appearance of walking
Board.prototype.beginWalking = function ($div, dir0, dir1) {
var interval = setInterval(function () {
if ($div.hasClass(dir0)) {
$div.removeClass(dir0);
$div.addClass(dir1);
} else {
$div.removeClass(dir1);
$div.addClass(dir0);
}
}.bind(this), 80);
// Save the timer:
updaterLocals.push(interval);
return;
};
OK so I am making a reaction tester, and I have a function that makes shapes appear on screen, So what I want is some sort of function were after 5 clicks on a certain element it will end a function. Is there a way of doing that? sorry if its a dumb question, its because I am new to the whole coding...
Here you go
var clickHandler = (function (e) {
var count = 0;
return function () {
count += 1;
if (count > 5) {
return;
}
// do other stuff here
}
}());
aDiv.addEventListener('click', clickHandler, false);
You Can use static variable to count how many times the object has been clicked.
and here is how you can create static variable in javascript.
You can unbind the click event once the counter reaches 5. See the example below
function test(sender) {
sender.dataset.clicked++;
console.log("I've been clicked", sender.dataset.clicked);
if (+sender.dataset.clicked === 5) {
// unbind the event
sender.onclick = null;
}
return;
}
<div onclick="test(this);" data-clicked="0">click me</div>
You may use global variable which may remain counting on click function
<script>
var globalvar = 0;
onclickfunct()
{
globalvar += 1;
if(globalvar == 5)
{
//do my work
}
else
{
//give alert
}
}
</script>
I have a piece of code that hides an element on mouseout.
The code looks like this:
var myMouseOutFunction = function (event) {
setTimeout(function () {
$(".classToHide").hide();
$(".classToShow").show();
}, 200);
};
This produces a result very close to what I want to do. However, I want to wait the time on the timeout (in this case 200 ms) then check to see if my mouse is still "out" of the element. If it is, I want to do .hide() and .show() on the desired elements.
I want to do this because if a user slightly mouses out then quickly mouses back in, I don't want the elements to flicker (meaning: hide then show real quick) when the user just wants to see the element.
Assign the timeout's return value to a variable, then use clearTimeout in the onmouseover event.
Detailing Kolink answer
DEMO: http://jsfiddle.net/EpMQ2/1/
var timer = null;
element.onmouseout = function () {
timer = setTimeout(function () {
$(".classToHide").hide();
$(".classToShow").show();
}, 200);
}
element.onmouseover = function () {
clearTimeout(timer);
}
You should use mouseenter and mouseleave of jquery. mouseenter and mouseleave will get called only once.and use a flag if to check if mouseenter again called.
var isMouseEnter ;
var mouseLeaveFunction = function (event) {
isMouseEnter = false;
setTimeout(function () {
if(isMouseEnter ){ return;}
$(".classToHide").hide();
$(".classToShow").show();
}, 200);
};
var mouseEnterFunction = function(){
isMouseEnter = true;
}
Use a boolean flag:
var mustWait = true;
var myMouseOutFunction = function (event) {
setTimeout(function () {
if(mustWait){
mustWait = false;
}
else{
$(".classToHide").hide();
$(".classToShow").show();
mustWait = true;
}
}, 200);
};
I'm using JS to animate two images by having them toggle on and off. I have an initial image which, when the animation is turned on, appears on the screen and stays on. The second image, which has a higher z value, is then set to toggle on and off every 1 second in the same location as the first image, so it appears as if the two are alternating.
I'm using window.setInterval to make the second image blink, but when I need to turn the animation off (and I'm removing both images from the screen), my window.clearInterval is not "working" The first image will be gone, but the second one keeps blinking on and off every second.
Code:
function notebookNotification(setting)
{
$("#lightNotificationContainer").show();
var notificationAnimation = window.setInterval('$("#darkNotificationContainer").toggle()', 1000);
if(setting == 0)
{
window.clearInterval(notificationAnimation);
$("#lightNotificationContainer").hide();
$("#darkNotificationContainer").hide();
}
}
Anyone see why it isn't working?
Reading between the lines, I think what you're saying is this:
You execute notebookNotification(1); and the animation starts
You execute notebookNotification(0); and the animation does not stop.
My guess is that you want notebookNotification(0) to disable the flashing.
In order to do that, you need to rework this function considerably. You need to store the intervalID that comes from setInterval in a variable that survives outside of the scope of this function and can be used for clearInterval on subsequent calls to this function.
For example:
var intervalID;
function notebookNotification(setting)
{
if(setting == 0)
{
if(intervalID) {
window.clearInterval(intervalID);
intervalID = null;
}
$("#lightNotificationContainer").hide();
$("#darkNotificationContainer").hide();
}
else
{
$("#lightNotificationContainer").show();
if(!intervalID) {
intervalID = window.setInterval('$("#darkNotificationContainer").toggle()', 1000);
}
}
}
Here, try this:
http://jsfiddle.net/WGxmy/
Saving the interval to a global variable -- not one inside a function -- lets you clear it later.
var keepflashing = true;
var isShowing = true;
function notebookNotification()
{
if(!isShowing)
$("#lightNotificationContainer").show();
else
$("#lightNotificationContainer").show();
isShowing = !isShowing;
if(keepflashing)
setTimeout( function(){ notebookNotification(setting); },100);
else
{
$("#lightNotificationContainer").hide();
$("#darkNotificationContainer").hide();
}
}
Maybe you can avoid calling clearInterval() generally?
function notebookNotification(setting)
{
if(setting == 0)
{
$("#lightNotificationContainer").hide();
$("#darkNotificationContainer").hide();
}
else
{
$("#lightNotificationContainer").show();
window.setInterval('$("#darkNotificationContainer").toggle()', 1000);
}
}
what I got now is:
function()
{
setInterval("getSearch()",10000);
getSearch();
}
);
But I want this interval to pause if the mouse cursor is placed inside a div on my website. How do I attack this problem? Surely I need to give the div an ID.. But some input on how to make the javascript/jquery part is much appreciated.
EDIT: More of my code.. I'm not quite sure where to insert the code in the answers inside this:
$(
function()
{
setInterval("getSearch()",10000);
getSearch();
}
);
TwitterCache = {};
function getSearch()
{
var url = "http://search.twitter.com/search.json?q=test&refresh=6000&callback=?"; // Change your query here
$.getJSON
(
url,
function(data)
{
if( data.results ) // Checks to see if you have any new tweets
{
var i = -1, result, HTML='', HTML2='';
while( (result = data.results[++i]) && !TwitterCache[result.id] )
{
insert html.. blabla}
setInterval returns a "reference" to that interval you set up, allowing you to stop it with window.clearInterval(), and that's what you have to do:
var myInterval;
function startMyInterval() {
if (!myInterval) {
// It's better to call setInterval width a function reference, than a string,
// also always use "window", in case you are not in its scope.
myInterval = window.setInterval(getSearch, 10000);
}
}
function stopMyInterval() {
if (myInterval) {
window.clearInterval(myInterval);
}
}
startMyInterval(); // Start the interval
jQuery("#myDiv").hover(stopMyInterval, startMyInterval);
Set a global variable
var intID;
Assign setInterval to this variable
intID = setInterval("getSearch()",10000);
Set an id for the div
$("#divid").hover(function(){
clearInterval(intID);
},
function(){
// set the interval again
});
I think this should work:
$("#divID").hover(
function () {
PauseTheInterValThing()
},
function()
{
setInterval("getSearch()",10000);
getSearch();
}
);
The simplest way, and the shortest
Simplest method would be:
<div id="yourDiv">
EXAMPLE TEXT
</div>
<script language="Javascript">
var interval = setInterval("getSearch()",1000);
document.getElementById("yourDiv").addEventListener('mouseover', function()
{
clearInterval(interval);
},false);
document.getElementById("yourDiv").addEventListener('mouseout', function()
{
interval = setInterval("getSearch()",1000);
},false);
</script>
insert this in your dom-ready function:
var inv = setInterval("getSearch",1000);
$('#yourdiv').mouseover(function(){
clearInterval(inv);
}).mouseout(function(){
inv = setInterval("getSearch",1000);
})