In my slideshow images are shown one for one at random, preferable in FULLSCREEN. Since the aspect-ratio of the [mostly abstract] images are different I want to insert [imageless] black space inbetween the images to let the eye adapt like insertingwhitespacebetweenwords makes the text more readable. I think the lenght of black space should be, say one tenth of a second, just a blink of an eye, so to speak. So far I have tried to do so with setTimeout to delay the concatenation of the images in the show, without succes. Ofcourse, inserting black space must be repeated between the current and next imnage. In the motionpicture camera this [analogue] technique is wel known as Maltese Cross Mechanism, which blocks incoming light when exposed filmnegative is transported to the next frame. Since I do not want to use fadein/fadeout I need total black space instead. I'm told that the browser [its graphic engine] has a delay of itself of a few millisecs, but that is too short. Appreciate any suggestion and help. Relevant piece of code in my javascript:
var currand=0
function rotateImage(){
var nextrand = Math.floor(Math.random()*(rimages.length));
// compare current image with next image0.
if (currand > rimages.length -12) {
if (nextrand > rimages.length -12) {
currand = nextrand - 12;
document.images[0].src = rimages[currand];
}
else {
currand = nextrand;
document.images[0].src = rimages[currand];
}
...etc.
var paused = false;
document.onkeydown = function(evt) {
evt = evt || window.event;
if (evt.ctrlKey && evt.keyCode == 32) {
paused = !paused;
}
};
(function loop() {
var rantime = Math.round(Math.random() * 7000) + 1000;
setTimeout(function() {
if (!paused) {
rotateImage();
}
loop();
}, rantime);
})();
I have experimented a little bit on this. Since the images are shown one for one in full screen they are not dived, except for the credits of the show (text). CSS:
#blackit { display: none; }
<body>
<script>
var timeoutID = setTimeout(function() { document.getElementById('blackit').style.display ='block'; }, 2000);
(function loop() {
timeoutID;
setTimeout(function() {
if (!paused) {
rotateImage(); }
...
Now, this works only once, at the very start of the loop, and NOT when the loop is repeated. Images remain still concatenated. Why? Thanks again!
Related
I'm fairly new to jQuery and I'm currently working on a slideshow.
The slideshow consists of a number of headers that plays automatically and shows an image that belongs to a specific header. The moment you hover over a title as a user, the slideshow stops playing automaticly and you have the control over the view.
The problem I encounter is that sometimes after mouseout(); the slideshow shows the wrong image. I would like the slideshow to continue from where it left off.
I have tried several things including this example: Stop loop on hover
Which is basically what I am looking for. Unfortunately I'm not yet skilled enough to apply this myself in jQuery or understand this particular code. I know I have to keep track of the loop in some way...
All help and tips are welcome, thanks!
var autoPlay = 0;
$(function() {
myCarousel();
$(".indexTitle").mouseenter(pauseCarousel);
$(".indexTitle").mouseout(playCarousel);
});
function myCarousel() {
var x = $(".indexTitle");
var n = $(".indexImage");
for (i = 0; i < x.length; i++) {
$(x[i]).removeClass("redStroke");
$(n[i]).removeClass("showIndexImage");
}
autoPlay++;
if (autoPlay > x.length && n.length) {
autoPlay = 1
}
$(x[autoPlay - 1]).addClass("redStroke");
$(n[autoPlay - 1]).addClass("showIndexImage");
myTimeOut = setTimeout(myCarousel, 2000); // Change image every 2.5 seconds
}
function pauseCarousel() {
console.log("Enter = Pause");
clearTimeout(myTimeOut);
$(".indexTitle").removeClass("redStroke");
$(".indexTitle").removeClass("showIndexImage");
};
function playCarousel() {
console.log("Exit = Play");
setTimeout(myTimeOut);
myCarousel();
};
My Fiddle: https://jsfiddle.net/L_03k/830adhfp/35/
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();
$("#hero-slider").css("height", altura);
}
I'm currently using the following javascript as shown below.
It's working well when I place just text within the div .image_scroll_3 but as soon as I insert images the scroll glitches and won't move past the top of the image.
Any advice would be much appreciated
JS
<script>
(function($, undefined) {
$.fn.loopScroll = function(p_options) {
var options = $.extend({
direction: "upwards",
speed: 60
}, p_options);
return this.each(function() {
var obj = $(this).find(".image_scroll_2");
var text_height = obj.find(".image_scroll_3").height();
var start_y, end_y;
if (options.direction == "downwards") {
start_y = -text_height;
end_y = 0;
} else if (options.direction == "upwards") {
start_y = 0;
end_y = -text_height;
}
var animate = function() {
// setup animation of specified block "obj"
// calculate distance of animation
var distance = Math.abs(end_y - parseInt(obj.css("top")));
//alert("animate " + obj.css("top") + "-> " + end_y + " " + distance);
//duration will be distance / speed
obj.animate(
{ top: end_y }, //scroll upwards
1500 * distance / options.speed,
"linear",
function() {
// scroll to start position
obj.css("top", start_y);
animate();
}
);
};
obj.find(".image_scroll_3").clone().appendTo(obj);
$(this).on("mouseout", function() {
obj.stop();
}).on("mouseout", function() {
animate(); // resume animation
});
obj.css("top", start_y);
animate(); // start animation
});
};
}(jQuery));
$("#example4").loopScroll({ speed: 700 });
</script>
I think the problem is that your text_height is calculated before the images are actually loaded inside your .image_scroll_3 elements. So you'll need to wait for the images to load.
Put your loopScroll call inside a $(window).load like so:
$(window).load(function(){
$('#example4').loopScroll({speed:700});
});
That massive glitch should now be gone as the fix above should have helped mitigate it.
However, there is still some unwanted jank / stutter (don't want to use the word glitch again, lets keep it reserved for the initial problem) in movement of all images if you notice and I am guessing that is probably because we are animating the whole thing too fast. Passing in speed like 100 or 200 resolves that but this is not really a solution because, ideally, you should be able to put in any speed value and it should just produce smooth animations out of it.
I am working on exactly the same thing but before that, I want to know if the above fix for the glitch helps you and we are finally done with it? Let me know.
Update:
Here is my version that I spoke of earlier, for your perusal.
Because all you are trying to do is loop images in a very linear fashion, I, for one, do not see the need to rely on animate() function of jQuery. There is requestAnimationFrame API that I have leveraged instead. In fact, in my demonstration below I have completely abandoned jQuery in favour of vanilla JavaScript only because I kept finding alternatives to pretty much everything we needed to do in this demo. But of course, this is also a very subjective matter; a taste thing; so if you want to go with jQuery, then by all means.
Another fundamental change I brought is rather than updating top values, I have resorted to updating translateY values.
Take a look at this jsFiddle and let me know if it fits your needs.
JavaScript code of which is as belows:
// [http://www.paulirish.com/2011/requestanimationframe-for-smart-animating/]
window.requestAnimFrame=(function(){return window.requestAnimationFrame||window.webkitRequestAnimationFrame||window.mozRequestAnimationFrame||function(callback){window.setTimeout(callback,1000/60);};})();
var main=null;
var imageScroll2=null;
var imageScroll3=null;
var totalHeight=null;
var initY=null;
var destY=null;
var currY=null;
var increment=null;
var direction=null;
var UP=null;
var DOWN=null;
var isPlaying=null;
function init(){
main=document.getElementById('example4');
imageScroll2=main.getElementsByClassName('image_scroll_2')[0];
imageScroll3=main.getElementsByClassName('image_scroll_3')[0];
totalHeight=imageScroll3.clientHeight;
UP='upwards';
DOWN='downwards';
isPlaying=true;
direction=UP;
increment=10;
if(direction===DOWN){
initY= -totalHeight;
destY=0;
}else{
initY=0;
destY= -totalHeight;
}
currY=initY;
imageScroll2.appendChild(imageScroll3.cloneNode(true));
if(imageScroll2.addEventListener){
imageScroll2.addEventListener('mouseover',function(){isPlaying=false;},false);
imageScroll2.addEventListener('mouseout',function(){isPlaying=true;},false);
}else{
imageScroll2.attachEvent('onmouseover',function(){isPlaying=false;});
imageScroll2.attachEvent('onmouseout',function(){isPlaying=true;});
}
requestAnimFrame(render);
}
function render(){
if(isPlaying){
imageScroll2.style.transform='translate(0px,'+currY+'px)';
if(direction===DOWN){
currY+=increment;
if(currY>=destY){currY=initY;}
}else{
currY-=increment;
if(currY<=destY){currY=initY;}
}
}
requestAnimFrame(render);
}
//
init();
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);
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.