So I've created the following function to fade elements in and passed in a div that I want to fade in which in this case is an image gallery popup that I want to show when a user clicks an image thumbnail on my site. I'm also passing in a speed value (iSpeed) which the timeout uses for it's time value. In this case I'm using 25 (25ms).
I've stepped through this function whilst doing so it appears to be functioning as expected. If the current opacity is less than 1, then it is incremented and it will recall itself after the timeout until the opacity reaches 1. When it reaches one it stops fading and returns.
So after stepping through it, I take off my breakpoints and try to see it in action but for some reason my gallery instantly appears without any sense of fading.
var Effects = new function () {
this.Fading = false;
this.FadeIn = function (oElement, iSpeed) {
//set opacity to zero if we haven't started fading yet.
if (this.Fading == false) {
oElement.style.opacity = 0;
}
//if we've reached or passed max opacity, stop fading
if (oElement.style.opacity >= 1) {
oElement.style.opacity = 1;
this.Fading = false;
return;
}
//otherwise, fade
else {
this.Fading = true;
var iCurrentOpacity = parseFloat(oElement.style.opacity);
oElement.style.opacity = iCurrentOpacity + 0.1;
setTimeout(Effects.FadeIn(oElement, iSpeed), iSpeed);
}
}
}
Here's where I'm setting up the gallery.
this.Show = function (sPage, iImagesToDisplay, oSelectedImage) {
//create and show overlay
var oOverlay = document.createElement('div');
oOverlay.id = 'divOverlay';
document.body.appendChild(oOverlay);
//create and show gallery box
var oGallery = document.createElement('div');
oGallery.id = 'divGallery';
oGallery.style.opacity = 0;
document.body.appendChild(oGallery);
//set position of gallery box
oGallery.style.top = (window.innerHeight / 2) - (oGallery.clientHeight / 2) + 'px';
oGallery.style.left = (window.innerWidth / 2) - (oGallery.clientWidth / 2) + 'px';
//call content function
ImageGallery.CreateContent(oGallery, sPage, iImagesToDisplay, oSelectedImage);
//fade in gallery
Effects.FadeIn(oGallery, 25);
}
Could anyone help me out?
Also, I'm using IE10 and I've also tried Chrome, same result.
Thanks,
Andy
This line:
setTimeout(Effects.FadeIn(oElement, iSpeed), iSpeed);
calls Effects.FadeIn with the given arguments, and feeds its return value into setTimeout. This is exactly like foo(bar()), which calls bar immediately, and then feeds its return value into foo.
Since your FadeIn function doesn't return a function, that would be the problem.
Perhaps you meant:
setTimeout(function() {
Effects.FadeIn(oElement, iSpeed);
}, iSpeed);
...although you'd be better off creating that function once and reusing it.
For instance, I think this does what you're looking for, but without recreating functions on each loop:
var Effects = new function () {
this.FadeIn = function (oElement, iSpeed) {
var fading = false;
var timer = setInterval(function() {
//set opacity to zero if we haven't started fading yet.
if (fading == false) { // Consider `if (!this.Fading)`
oElement.style.opacity = 0;
}
//if we've reached or passed max opacity, stop fading
if (oElement.style.opacity >= 1) {
oElement.style.opacity = 1;
clearInterval(timer);
}
//otherwise, fade
else {
fading = true;
var iCurrentOpacity = parseFloat(oElement.style.opacity);
oElement.style.opacity = iCurrentOpacity + 0.1;
}
}, iSpeed);
};
};
Your code has a lot of problems. The one culpable for the element appearing immediately is that you call setTimeout not with a function but with the result of a function, because Effects.FadeIn will be executed immediately.
setTimeout(function(){Effects.FadeIn(oElement, iSpeed)}, iSpeed);
will probably act as you intend.
But seriously, you probably should not re-invent this wheel. jQuery will allow you to fade elements in and out easily and CSS transitions allow you to achieve element fading with as much as adding or removing a CSS class.
T.J. and MoMolog are both right about the bug: you're invoking the Effects.FadeIn function immediately before passing the result to setTimeout—which means that Effects.FadeIn calls itself synchronously again and again until the condition oElement.style.opacity >= 1 is reached.
As you may or may not know, many UI updates that all take place within one turn of the event loop will be batched together on the next repaint (or something like that) so you won't see any sort of transition.
This jsFiddle includes the suggested JS solution, as well as an alternate approach that I think you may find to be better: simply adding a CSS class with the transition property. This will result in a smoother animation. Note that if you go this route, though, you may need to also include some vendor prefixes.
Related
so I'm trying to create a simple slide show from scratch, and so far I was able to get full screen images to fade out and fade in infinetly, but for some odd reason using setInterval(function(){fade(var)}, 3500);didn't work, maybe someone can explain why the first and last images took way longer than 3,5 seconds to fade. Meanwhile, I was trying to solve that problem by implementing a callback function in the fade(). My example has four images, and they start fading out until it reaches image one, then don't fade out image one and start fading back in image two until image 4, and do this forever, here is my recent attempt to implement a callback function:
var i = 4;
$(document).ready(function(){
fade(i, fade);
});
var fadeIN = false;
function fade(objectID, callbackfn){
var fadeTime = 3500;
if(!fadeIN){
$("#slide-"+objectID).fadeOut(fadeTime);
i--;
if(i === 1) {
fadeIN = true;
}
}
else{
i++;
$("#slide-"+objectID).fadeIn(fadeTime);
if(i === 4){
fadeIN = false;
}
}
if(arguments[1]){
callbackfn(i);
}
}
But that is not working, it fades out image 4, image 3 and stops on image 2. Maybe there is a way to evenly time the fading transitions using the setIntervel(), if so can someone tell me how? Appreciate any help.
Here is a JSFiddle to the code: http://jsfiddle.net/8kgc0chq/ it is not working tho.
Here is the doc for .fadeOut()
There is an optional argument complete:
A function to call once the animation is complete.
Put the next animation in there, they too take a complete (callback) function.
$("#id").fadeOut(fadeTime, function() {
// code to execute after animation complete
});
You need to do it properly with javascript. Easy way fails after last element.
So here is my solution. Can it be improved further, I think yes.. But it does work now. And is future proof to some extent.
I cleaned up css and changed html structure a little.
Demo: http://jsfiddle.net/8kgc0chq/3/
$(document).ready(function () {
$(window).resize(function () {
realTimeHeight();
});
realTimeHeight();
startSlides();
});
function startSlides() {
var fadeTime = 1000,
delay = 1300,
i = 0,
slides = $("#hero-slider > .slide"),
len = slides.length;
slides.hide();
var pF = $('<div class="slide">'), pB = pF.clone();
pF.attr('id', slides.eq(i).attr('id'));
$('#hero-slider').prepend(pF).prepend(pB);
setInterval(fadeThisIn, fadeTime + delay);
function fadeThisIn() {
pB.attr('id', pF.attr('id'));
i = ++i % len;
pF.hide().attr('id', slides.eq(i).attr('id')).fadeIn(fadeTime);
}
}
function realTimeHeight() {
var altura = $(window).height();
$("#hero-slider").css("height", altura);
}
I'm trying to build a simple image slider (but using a fade effect). Every two seconds, the image should change to another image. At the end, it should call repeat_sponsor() again, to start over, so it becomes a loop.
I've written this (highly ineffective) code for 5 images. Turns out I'm going to need it for around 50 images. My editor just freezes when I add too much code.
I've tried using while-loops, but I just can't figure it out how to do this the right way.
Anyone who can help me with this?
function repeat_sponsor()
{
$("#sponsor2").hide();
$("#sponsor3").hide();
$("#sponsor4").hide();
$("#sponsor5").fadeOut("slow");
$("#sponsor1").fadeIn("slow", function() {
setTimeout(function(){$("#sponsor2").fadeIn("slow", function() {
setTimeout(function(){$("#sponsor3").fadeIn("slow", function() {
setTimeout(function(){$("#sponsor4").fadeIn("slow", function() {
setTimeout(function(){$("#sponsor5").fadeIn("slow", ...
(function (){
var cnt = 50; //set to the last one...
var max=50;
function show() {
$("#sponsor" + cnt).fadeOut("slow"); //if you want the fadeout to be done before showing next, put the following code in the complete callback
cnt++;
if(cnt>max) {
cnt=1;
}
$("#sponsor" + cnt).fadeIn("slow");
window.setTimeout(show, 2000);
}
show();
})();
But the real issue is the fact you are loading tons of images from the start. You will be better off changing it so you only have a small subset of images and change the source.
You should use some sort of for loop and a class for hiding the images. and add a max value that if checks out resets c & i
var i=0;
var c=1;
function repeat_sponsor()
{
$("#sponsor"+i).fadeOut("slow");
$(".sponsers").hide()
$("#sponsor"+c).fadeIn("slow", function() {
window.setTimeout(repeat_sponsor(), 3000);
}
i++;
c++;
}
Just run a function every two seconds with setInterval and appropriately target your different sponsor divs:
var i = 1;
var max = 50;
setInterval(function() {
// Could target all other sponsor images with a class "sponsor"
$('.sponsor').fadeOut();
// Execute code on the target
$("#sponsor" + i).fadeIn();
if (i === max) {
i = 0;
}
i++;
}, 2000);
Im a really huge noob on jquery, I need to figure out how to change this code:
$('.social li').appear();
$(document.body).on('appear', '.social li', function(e, $affected) {
var fadeDelayAttr;
var fadeDelay;
$(this).each(function(){
if ($(this).data("delay")) {
fadeDelayAttr = $(this).data("delay")
fadeDelay = fadeDelayAttr;
} else {
fadeDelay = 0;
}
$(this).delay(fadeDelay).queue(function(){
$(this).addClass('animated').clearQueue();
});
})
});
to work in the way that it would start animation as soon as someone enters the landing page, right now it works good on everything besides IE10 and IE11, was told to change it to load by default not on "appear" but I tried document ready/load and I can't get it to work...
You could try fading all list items into view, each with a progessing 250ms delay:
$(window).load(function() {
$('.social li').hide().each(function(i) {
$(this).delay((i + 1) * 250).fadeIn(2000);
});
});
EDIT:
Using the same logic as your previous code to refactor, use the window.load method since the load event fires at the end of the document loading process. At this point, all of the objects in the document are in the DOM, and all the images and sub-frames etc have finished loading. So use this event to do the fading in animation of the list items into view, where their initial state will be hidden.
You have two variables declared fadeDelayAttr and fadeDelay but I noticed that only fadeDelay is being used, so fadeDelayAttr can be discarded. Also, this part of the code:
if ($(this).data("delay")) {
fadeDelayAttr = $(this).data("delay")
fadeDelay = fadeDelayAttr;
} else {
fadeDelay = 0;
}
can be simplified as the null-coalescing operator using a logical OR (||):
var fadeDelay = $(this).data("delay") || 0;
Since the fadeDelay variable gets its value from the data-delay attribute, this can then be passed in as an argument for the delay method and finally the refactored code will look like this:
$(window).load(function() {
$('.social li').hide().each(function() {
var fadeDelay = $(this).data("delay") || 0;
$(this).delay(fadeDelay).fadeIn(2000);
});
});
Working Demo
I have created a newsfeed. The feed switches every 2 seconds. You can also manually switch left/right, or click the panel from the squares at the bottom. The switching between slides is down using jQuery UI Slide.
Right now, if you are in the middle of a slide, and you click left/right/squares, then another slide occurs on top of the existing, still going slide and the whole system is messed up.
How can I prevent other actions occurring if a slide/switch is already in progress?
This is my code:
$(document).ready(function(){
newsfeedTimer = setInterval(newsfeed, displayDuration);
// Manual change of feed (LEFT)
$('#newsfeeds_wrapper > .left').click(function(event){
event.stopPropagation();
feedLeft();
clearInterval(newsfeedTimer);
newsfeedTimer = setInterval(newsfeed, displayDuration);
});
// Very similar code for feed right
// Ignore the other method of switching (if it works for above, I can implement it for this one)
});
function newsfeed() {
feedRight();
}
// Feed to the Right
// jump is used to jump multiple newsfeed instead of one at a time
function feedRight(jump)
{
jump = typeof jump !== 'undefined' ? jump : 1;
var current = $('.newsfeed:first');
var next = $('.newsfeed:nth(' + jump + ')');
current.hide('slide',{duration: transitionDuration}, function(){
// Append as many needed
for( var i = 0; i < jump; i++ ) {
$('.newsfeed:first').appendTo('#newsfeeds');
}
next.show('slide',{direction : 'right' , duration: transitionDuration});
}
I don't want to stop() an animation! I want to disable changing the slides IF there is animation happening!!
without seeing the full breadth of the code, I am shooting myself in the foot here. But here is a direction I would take it. You could also have two functions, one to bind, another to unbind. When animation is initiated, you unbind the left/right controls. When stopped, you bind. Or, set a global variable... ala.
var config = {'inProgress': false};
$('#newsfeeds_wrapper > .left').click(function(event){
if(!config.inProgress){
event.stopPropagation();
feedLeft();
clearInterval(newsfeedTimer);
newsfeedTimer = setInterval(newsfeed, displayDuration);
}
});
in your animation function. Seems like when you cut/paste, some of the code is lost, so lets just assume some animation.
when you enter your animation functions, set config.inProgress = true;
function feedRight(jump)
{
config.inProgress = true;
// removed your code, but just using for simplicity sake
// added a callback
next.show('slide',{direction : 'right' , duration: transitionDuration},
function() {
// Animation complete. Set inProgress to false
config.inProgress = false;
});
)
}
PLEASE DO NOT RECOMMEND JQUERY - I AM DOING THIS EXERCISE FOR LEARNING PURPOSES.
I have implemented a JavaScript, which rotates images (_elementSlideChange) on a timer, using a set interval of 10 seconds. Also I have added a slide functionality to this, which is 7 milliseconds (_slideImage).
The image rotates automatically every 10 seconds on page load, and I have also provided next and previous buttons, which allow the user to change the images manually.
_elementSlideChange: function () {
var myString;
var myText;
for (var i = 0; i < this._imgArray.length; i++) {
var imageArr = "url(" + this._imgArray[i].src + ")";
var imageBg = this._imageHolder.style.background + "";
if (imageArr == imageBg) {
if (i == (this._imgArray.length - 1)) {
myString = "url(" + this._imgArray[0].src + ")";
myText = this._infoArray[0];
} else {
myString = "url(" + this._imgArray[(i + 1)].src + ")";
myText = this._infoArray[i + 1];
}
}
}
this._imageNextSlide.style.background = myString;
this._imageNextSlide.style.background);
this._infoElement.innerHTML = myText;
this._myTimer = setInterval(MyProject.Utils.createDelegate(this._slideImage, this), 7);
},
_slideImage: function () {
if (parseInt(this._imageHolder.style.width) >= 0 && parseInt(this._imageNextSlide.style.width) <= 450) {
this._imageHolder.style.backgroundPosition = "right";
this._imageHolder.style.width = (parseInt(this._imageHolder.style.width) - 1) + 'px';
console.log(this._imageNextSlide.style.background);
this._imageNextSlide.style.width = (parseInt(this._imageNextSlide.style.width) + 1) + 'px';
} else {
console.log("reached 0px");
if (parseInt(this._imageHolder.style.width) == 0) {
this._imageHolder.style.background = this._imageNextSlide.style.background;
this._imageHolder.style.width = 450 + 'px';
this._imageHolder === this._imageNextSlide;
this._imageHolder.className = "orginalImage";
this._imageNextSlide.style.width = 0 + "px";
this._imageNextSlide = this._dummyImageNextSlide;
this._imagesElement.appendChild(this._imageHolder);
this._imagesElement.appendChild(this._imageNextSlide);
clearInterval(this._myTimer);
}
clearInterval(this._myTimer);
clearInterval(this._elementSlideChange);
}
}
So when the user clicks on the Next arrow button, the event listener for "click" is triggered. This creates a div for the current image on display, and creates a new div, which will contain the next image. The image slide and rotation works correctly (whether it's onLoad or onClick). The issue I have is if I click the Next button, while the new div image is sliding into position, it causes it to run into an infinite loop, so the same div with the image to be displayed keeps sliding in, and the more you click the Next button, the faster the image starts to rotate.
I have tried putting a clear interval for the image rotation and slider, but I do understand my code is wrong, which causes the infinite loop of the sliding image. And I know I am close to finishing the functionality.
Can anyone please advise where I could be going wrong? Or should I try to implement the sliding DIV in another way?
Once again please don't recommend jQuery.
And thank you for your help in advance.
Kush
To solve the issue, I did re-write the entire code, where I had a next and previous button event listener.
myProject.Utils.addHandler(this._nextImageElement, "click", myProject.Utils.createDelegate(this._changeImage, this));
Both the buttons will call the same function :
_changeImage: function (e)
In this function I check to see if the function is Transition (changing images),
I declare a boolean var forward = e.target == this._nextImageElement;
Then check to see the current index if forward ? Add 1 else minus 1
this._currentImageIndex += forward ? 1 : -1;
If its at the end of the Array and forward is true, assign the this._currentImageIndex to reset to 0 or Array.length – 1 if it’s in reverse
Then call another function which gives the ‘div’ a sliding effect. In this case call it this._transitionImage(forward);
In this function, set the this._inTranstion to true. (Because the div’s are sliding in this case).
The following code solved the issue i was having.
this._slideImageElement.style.backgroundImage = "url(\"" + this._imgArray[this._currentImageIndex].src + "\")";
this._slideImageElement.style.backgroundPosition = forward ? "left" : "right";
this._slideImageElement.style.left = forward ? "auto" : "0px";
this._slideImageElement.style.right = forward ? "0px" : "auto";
The above code is very important as the object is to place the “sliding in div” Left or Right of the current Visible “div” to the user, and this is mainly dependent on if the forward variable is true or false.
var i = 0;
Then start the transition by
setInterval( function() {
this._currentImageElement.style.backgroundPosition = (forward ? -1 : 1) * (i + 1) + "px";
this._slideImageElement.style.width = (i + 1) + "px";
Notice the forward will determine if the bgPosition will go to the left if its forward as we multiple by -1 or +1,
So for example
If the user clicks NEXT BUTTON,
Forward = true
So the first thing we do is set the
this._slideImageElement.style.backgroundPosition = "left"
Then
this._slideImageElement.style.left = "auto"
this._slideImageElement.style.right = "0px"
This means when the sliding image moves in its background position is LEFT but the div is placed on the RIGHT to 0px;
then this._currentImageElement.style.backgroundPosition = -1 * (i + 1)
Which moves the position of the currentImageElement to the left by 1px,
Increase the width of the slideImage which in this case is right of the current div,
and as the current div moves to the left the sliding image starts to appear from the right. (By default set the width of slideImageElement to 0px so the div exists but isn’t visible to the user). This gives it the slide effect of moving forward new image coming from the right.
this._slideImageElement.style.width = (i + 1) + "px";
then declare it to stop when it it’s the image width. In this case it will be 500px.
if ((i = i + 2) == 500) {
In this if statement reset the currentImageElement background and the background position “right” or “left” don’t really matter as long it has been reset.
Clear the interval
Set the transition to false again
Then call a setTimeout for the function changeImage, which will continue until the slide is completed.
The following shows the reset code as this is very important to prevent repeating the same image (This solved my entire issue)
// set the current image to the "new" current image and reset it's background position
this._currentImageElement.style.backgroundImage = "url(\"" + this._imgArray[this._currentImageIndex].src + "\")";
this._currentImageElement.style.backgroundPosition = "right";
// reset the slide image width
this._slideImageElement.style.width = "0px";
// clear the transition interval and mark as not in transition
clearInterval(this._transitionInterval);
this._inTransition = false;
// setup the next image timer
this._nextImageTimeout = setTimeout(myProject.Utils.createDelegate(this._changeImage, this), 2500);
}
I have provided a thorough detail because then it easier to understand the logic of the problem, and even if your not having the same issue, this may help you fingure out any problem.
I couldn't provide a JSfiddle, as i have created my CSS using Javascript, there are different ways of doing this, but i wanted to understand the logic behind the forward and reverse, and having a timer which continuously goes forward.
It seems like you want to cancel the animation on the slide (perhaps have it fade out while the next slide animates in, cancel its animation abruptly or let it finish and ignore the button click)
What I usually do, personally, is check for the animated state (yes, I use jquery, but you should be able to test the CSS or positioning values you are using to animate in the same way) you could even add an "active" class or data type during animation to make testing easier. Global flags work, too. If there is animation, ignore the button. (For my work... Depends on your intention)
Like I said, the problem may be with button behaviour not with the animation routine. It would be useful to see how you are calling this from the button click, and what your intended results are going to be.
How about CSS3 transitions?
transition: all 1s ease 0.5s;
Simple example on JS Fiddle.
This takes care of the animation, so you just need to set the intended destination using JavaScript, i.e.
this.style.left = '100px';
Or
this.style.top = '30px';
And CSS3 transitions will smoothly slide the element.
Cross Browser Note!
The transition property may need a vendor prefix for some browsers, I am using the latest production Firefox and you don't need -moz for that. Same goes for Opera, no '-o' required. Internet Exporer 10 needs no prefix. You may need to use -webkit for Safari / Chrome, but test without first.