We Keep Coding

prevent animation double click issue

Hi I have problem with my slider please visit this site and check http://paruyr.bl.ee/
after click on my arrows it becomes work in an asynchronous way, ones it changes very fast and then slow and it repeats.
I think it is from start slider and stop slider.
var sliderPrev = 0,
sliderNext = 1;
$("#slider > img").fadeIn(1000);
startSlider();
function startSlider(){
count = $("#slider > img").size();
loop = setInterval(function(){
if (sliderNext>(count-1)) {
sliderNext = 0;
sliderPrev = 0;
};
$("#slider").animate({left:+(-sliderNext)*100+'%'},900);
sliderPrev = sliderNext;
sliderNext=sliderNext+1;
},6000)
}
function prev () {
var newSlide=sliderPrev-1;
showSlide(newSlide);
}
function next () {
var newSlide=sliderPrev+1;
showSlide(sliderNext);
}
function stopLoop () {
window.clearInterval(loop);
}
function showSlide(id) {
stopLoop();
if (id>(count-1)) {
id = 0;
} else if(id<0){
id=count-1;
}
$("#slider").animate({left:+(-id)*100+'%'},900);
sliderPrev = id;
sliderNext=id+1;
startSlider();
};
$("#slider, .arrows").hover(function() {
stopLoop()
}, function() {
startSlider()
});
function onlyNext () {
var newSlide=sliderPrev+1;
onlyShowSlide(newSlide);
}
function onlyShowSlide(id) {
if (id>(count-1)) {
id = 0;
} else if(id<0){
id=count-1;
}
$("#slider").animate({left:+(-id)*100+'%'},900);
sliderPrev = id;
sliderNext=id+1;
};

I think the best option would be to check if the animation is in progress and prevent the action if it is, something like this:
function prev () {
if(!$('#slider').is(":animated"))
{
var newSlide=sliderPrev-1;
showSlide(newSlide);
}
}
function next () {
if(!$('#slider').is(":animated"))
{
var newSlide=sliderPrev+1;
showSlide(sliderNext);
}
}
To illustrate the difference between this and just sticking a stop() in, check this JSFiddle. You will notice some choppy movements if you click multiple times in the stop() version.

What I would do is add a class to your slider when the animation starts and remove the class when it finishes:
$("#slider").animate({left:+(-id)*100+'%'}, {
duration: 900,
start: function() {
$('#slider').addClass('blocked');
},
complete: function() {
$('#slider').removeClass('blocked');
}
});
Now check on each click event if the slider is blocked or not:
function next () {
if (!$('#slider').hasClass('blocked')) {
var newSlide=sliderPrev+1;
showSlide(sliderNext);
}
}
This is a very simple solution, I'm sure there is a better one.
EDIT: As marcjae pointed out, you could stop the animations from queuing. This means when you double click, the slideshow still will move 2 slides. With my approach the second click will be ignored completely.

You can use a variable flag to control if the animation is still being done, or simply use .stop() to avoid stacking the animation.
$("#pull").click(function(){
$("#togle-menu").stop().slideToggle("slow");
});

It is occurring because your animations are being queued.
Try adding:
.stop( true, true )
Before each of your animation methods. i.e.
$("#slider").stop( true, true ).animate({left:+(-id)*100+'%'},900);

The answers about stop are good, but you have a bigger issue that is causing the described behavior. The issue is here:
$("#slider, .arrows").hover(function() {
stopLoop()
}, function() {
startSlider()
});
You have bound this to the .arrows as well as the #slider and the arrows are contained within the slider. So, when you mouse out of an arrow and then out of the entire slider, you are calling start twice in a row without calling stop between. You can see this if you hover onto the arrow and then off of the slider multiple times in a row. The slides will change many times after 6 seconds.
Similarly, consider the case of a single click:
Enter the `#slider` [stopLoop]
Enter the `.arrows` [stopLoop]
Click the arrow [stopLoop]
[startSlider]
Leave the `.arrows` [startSlider]
Leave the `#slider` [startSlider]
As you can see from this sequence of events, startSlider is called 3 times in a row without calling stopLoop inbetween. The result is 3 intervals created, 2 of which will not be stopped the next time stopLoop is called.
You should just have this hover on the #slider and more importantly, add a call to stopLoop as the first step in startSlider. That will ensure that the interval is always cleared before creating a new one.
$("#slider").hover(function() {
stopLoop()
}, function() {
startSlider()
});
function startSlider(){
stopLoop();
/* start the slider */
}

Anonymous function in setTimeout not working

I'm trying to create a delay between two loops of the nivo-slider.
Without the setTimeout everything works just fine (but without delay). So the folloing example works:
$('#slider').nivoSlider({
lastSlide: function(){
$('#slider').data('nivo:vars').stop = true;
// setTimeout(function() {
$('#slider').data('nivo:vars').stop = false;
// }, 2000);
},
});
If I uncomment the setTimeout-lines the slider stops but does not start again? Any ideas why?
Update:
http://jsfiddle.net/kgYNX/
2nd update:
Tried it with a wrapping function, too. The function gets called but if I use setTimeout in the new function it stops working: http://jsfiddle.net/kgYNX/1/

Solved it slightly different:
beforeChange: function(){
$('#slider').data('nivo:vars').stop = true;
var delay = 0;
if ($('#slider').data('nivo:vars').currentSlide == $('#slider').data('nivo:vars').totalSlides - 2) {
delay = 2000;
}
setTimeout(function() {
$('#slider').data('nivo:vars').stop = false;
}, delay);
}
I don't know why "totalSlides - 2", but it works: http://jsfiddle.net/kgYNX/15/

As a variant, you may add custom option to slider vars collection to prevent stop execution on lastSlide handler when slider re-enabled by timeout:
lastSlide: function () {
var dontStop = $('#slider').data('nivo:vars').dontStopOnLast;
if (!dontStop) {
$('#slider').data("nivoslider").stop();
setTimeout(function () {
$('#slider').data("nivoslider").start();
}, 2000);
}
$('#slider').data('nivo:vars').dontStopOnLast = !dontStop;
}

Timer won't die javascript

I am doing some long polling.. and I have a function to make a button blink when a certain statement is true.. Here it is:
function blinking(object, x) {
console.log(x);
if(x>0){
var existing_timer = object.data('clock');
if (existing_timer){
clearInterval(existing_timer);
}
timer = setInterval(blink, 10);
function blink() {
object.fadeOut(400, function() {
object.fadeIn(400);
});
}
}
}
Now.. Notice the timer being set as 'timer'. When someone does something that makes the statement false (making x=0), I want the timer to stop making the button blink when it sees that x=0. This may sound easy but I have tried everything ha.
I've been researching and trying different things, but It doesn't seem to work.

If your variable timer is global, then you should be able to clear the interval using that:
clearInterval(timer);
The integer returned from the setInterval is unique to that timer, so that is what you need to clear.

Here's a simple implementation.
http://jsfiddle.net/AQgBc/
var $led = $('#led'),
blinkState = 0,
blinkTimer,
blinkDuration = 300,
blink = function () {
if (blinkState) {
$led.toggleClass('on');
}
console.log('blink');
blinkTimer = setTimeout(blink, blinkDuration);
};
$('button').on('click', function () {
blinkState = (blinkState) ? 0 : 1;
});
blink();
I just wrote my own without duplicating yours, but the most relevant issue, I think, is just using a setTimeout rather than worrying about a setInterval and clearing that interval.
Edit in response to comment:
If you want it to blink until a user action, then stop polling, it's even simpler.
http://jsfiddle.net/AQgBc/1/
var $led = $('#led'),
blinkState = 1,
blinkTimer,
blinkDuration = 300,
blink = function () {
if (blinkState) {
console.log('blink');
$led.toggleClass('on');
blinkTimer = setTimeout(blink, blinkDuration);
}
};
$('button').on('click', function () {
blinkState = (blinkState) ? 0 : 1;
});
blink();

How to create a looped animation with JQuery

I have been sitting on this for a few hours and cannot figure this out. I am trying to create an slideshow (3 slides) that loops endlessly. Each slide is a li inside #slideshow. I have walked through this with a debugger and all variables get set correctly, but I don't understand why the animations dont actually happen. I have this which ends up displaying all images on the page:
$(document).ready(function() {
$slideshow = $('#slideshow');
$slideshowItems = $slideshow.find('li');
$slideshowItems.hide();
nextI = function(x) {
if ((x+1) < $slideshowItems.length) {
return x+1;
}
else {
return 0;
}
}
animation = function(i) {
$slideshowItems.eq(i).fadeIn(500).delay(1000).fadeOut(500, animation(nextI(i)));
}
animation(0);
If I do:
$slideshowItems.eq(0).fadeIn(500).delay(1000).fadeOut(500,
$slideshowItems.eq(1).fadeIn(500).delay(1000).fadeOut(500,
$slideshowItems.eq(2).fadeIn(500).delay(1000).fadeOut(500));
This works as expected, but it seems ugly and does not loop.
Any idea why I can't get this to work? I feel it is something with my expectations of how JQuery/ JS modifies the DOM or the sequence that the browser uses to execute animations. Thank you for the help!

var $slideshowItems = $('#slideshow').find('li'),
i = 0;
(function loop() {
$slideshowItems.eq( i ).fadeIn(500).delay(1000).fadeOut(500, loop);
i = ++i % $slideshowItems.length;
})();
JSFIDDLE DEMO

You should specify a callback method but your "animation(nextI(i))" returns nothing, so nothing remains to do after the fade out is complete.
Something like this I think will work:
var animation = function(i) {
$slideshowItems.eq(i).fadeIn(500).delay(1000).fadeOut(500, function (){
animation(nextI(i));
});
}

I would try setting that as a function and then using setInterval:
setInterval(function(){
$slideshowItems.eq(0).fadeIn(500).delay(1000).fadeOut(500, function() {
$slideshowItems.eq(1).fadeIn(500).delay(1000).fadeOut(500, function() {
$slideshowItems.eq(2).fadeIn(500).delay(1000).fadeOut(500);
});
});
}, 6000); // 6000 milliseconds before loops

Javascript "while hovered" loop

Can anybody help me on this one...I have a button which when is hovered, triggers an action. But I'd like it to repeat it for as long as the button is hovered.
I'd appreciate any solution, be it in jquery or pure javascript - here is how my code looks at this moment (in jquery):
var scrollingposition = 0;
$('#button').hover(function(){
++scrollingposition;
$('#object').css("right", scrollingposition);
});
Now how can i put this into some kind of while loop, so that #object is moving px by px for as #button is hovered, not just when the mouse enters it?

OK... another stab at the answer:
$('myselector').each(function () {
var hovered = false;
var loop = window.setInterval(function () {
if (hovered) {
// ...
}
}, 250);
$(this).hover(
function () {
hovered = true;
},
function () {
hovered = false;
}
);
});
The 250 means the task repeats every quarter of a second. You can decrease this number to make it faster or increase it to make it slower.

Nathan's answer is a good start, but you should also use window.clearInterval when the mouse leaves the element (mouseleave event) to cancel the repeated action which was set up using setInterval(), because this way the "loop" is running only when the mouse pointer enters the element (mouseover event).
Here is a sample code:
function doSomethingRepeatedly(){
// do this repeatedly when hovering the element
}
var intervalId;
$(document).ready(function () {
$('#myelement').hover(function () {
var intervalDelay = 10;
// call doSomethingRepeatedly() function repeatedly with 10ms delay between the function calls
intervalId = setInterval(doSomethingRepeatedly, intervalDelay);
}, function () {
// cancel calling doSomethingRepeatedly() function repeatedly
clearInterval(intervalId);
});
});
I created a sample code on jsFiddle which demonstrates how to scroll the background-image of an element left-to-right and then backwards on hover with the code shown above:
http://jsfiddle.net/Sk8erPeter/HLT3J/15/

If its an animation you can "stop" an animation half way through. So it looks like you're moving something to the left so you could do:
var maxScroll = 9999;
$('#button').hover(
function(){ $('#object').animate({ "right":maxScroll+"px" }, 10000); },
function(){ $('#object').stop(); } );

var buttonHovered = false;
$('#button').hover(function () {
buttonHovered = true;
while (buttonHovered) {
...
}
},
function () {
buttonHovered = false;
});
If you want to do this for multiple objects, it might be better to make it a bit more object oriented than a global variable though.
Edit:
Think the best way of dealing with multiple objects is to put it in an .each() block:
$('myselector').each(function () {
var hovered = false;
$(this).hover(function () {
hovered = true;
while (hovered) {
...
}
},
function () {
hovered = false;
});
});
Edit2:
Or you could do it by adding a class:
$('selector').hover(function () {
$(this).addClass('hovered');
while ($(this).hasClass('hovered')) {
...
}
}, function () {
$(this).removeClass('hovered');
});

var scrollingposition = 0;
$('#button').hover(function(){
var $this = $(this);
var $obj = $("#object");
while ( $this.is(":hover") ) {
scrollingposition += 1;
$obj.css("right", scrollingposition);
}
});