I've a scenario that requires me to detect animation stop of a periodically animated element and trigger a function. I've no control over the element's animation. The animation can be dynamic so I can't use clever setTimeout.
Long Story
The simplified form of the problem is that I'm using a third party jQuery sliding banners plugin that uses some obfuscated JavaScript to slide banners in and out. I'm in need of figuring out a hook on slideComplete sort of event, but all I have is an element id. Take this jsfiddle as an example and imagine that the javascript has been obfuscated. I need to trigger a function when the red box reaches the extremes and stops.
I'm aware of the :animated pseudo selector but I think it will need me to constantly poll the required element. I've gone through this, this, and this, but no avail. I've checked jquery promise but I couldn't figure out to use that in this scenario. This SO question is closest to my requirements but it has no answers.
P.S. Some more information that might be helpful:
The element isn't created by JavaScript, it is present on page load.
I've control over when to apply the plugin (that makes it periodically sliding banner) on the element
Most of the slideshow plugins I have used use changing classes at the end of the animation... You could extend the "addClass" method of jQuery to allow you to capture the class change as long as the plugin you use is using that method like it should:
(function($){
$.each(["addClass","removeClass"],function(i,methodname){
var oldmethod = $.fn[methodname];
$.fn[methodname] = function(){
oldmethod.apply( this, arguments );
this.trigger(methodname+"change");
return this;
}
});
})(jQuery);
I threw together a fiddle here
Even with obfuscated code you should be able to use this method to check how they are sending in the arguments to animate (I use the "options" object when I send arguments to animate usually) and wrap their callback function in an anonymous function that triggers an event...
like this fiddle
Here is the relevant block of script:
(function($){
$.each(["animate"],function(i,methodname){
var oldmethod = $.fn[methodname];
$.fn[methodname] = function(){
var args=arguments;
that=this;
var oldcall=args[2];
args[2]=function(){
oldcall();
console.log("slideFinish");
}
oldmethod.apply( this, args );
return this;
}
});
})(jQuery);
Well since you didn't give any indication as to what kind of animation is being done, I'm going to assume that its a horizontal/vertical translation, although I think this could be applied to other effects as well. Because I don't know how the animation is being accomplished, a setInterval evaluation would be the only way I can guess at how to do this.
var prevPos = 0;
var isAnimating = setInterval(function(){
if($(YOUROBJECT).css('top') == prevPos){
//logic here
}
else{
prevPos = $(YOUROBJECT).css('top');
}
},500);
That will evaluate the vertical position of the object every .5 seconds, and if the current vertical position is equal to the one taken .5 seconds ago, it will assume that animation has stopped and you can execute some code.
edit --
just noticed your jsfiddle had a horizontal translation, so the code for your jsfiddle is here http://jsfiddle.net/wZbNA/3/
Related
I'm building a website which relies on jQuery effects and I have a problem with the jQuery Slide effect.
I'm using that through a toggle function for the moment, but that will change in a later stage.
The fact is that I'm hinding an element when a certain action is executed. When you use the function slide the content beneath those elements moves when the animation is completed to take up the free space which was created with the effect.
The problem is that the content is only moved as soon as the animation is completed. Is there any way to move the content when the animation is still running. With other words, I want to move the content together with the animation, but I don't want to call the slide function on my element that should move with it.
I've created a JSFiddle to demonstrate the problem: http://jsfiddle.net/6Lg9vL8m/6/
Edit: Question update and fiddle
Here's an update to the question, and please see my original updated fiddle.
When you execute the slide effect in jQuery UI, see the bottom example on my fiddle, the box is moved up, and is somewhere placed behind an invisible screen (tough to explain).
With the animate function, see the top example in my fiddle, the area is shrinked, and that's something which I want to avoid. I want to achieve the effect such as 'Slide' does, but the content under the box must move up immediately with the animation, and not after the animation has been completed.
Edit: Reworked the correct answer in a plugin.
Thanks to the answers I've received here, I found the correct code, modified a bit, and created a plugin from it which I'll place here.
The plugin is called 'Curtain' and can be described as rising the requested element as a curtain and thus move it out of the way.
Here's the source code:
(function($) {
$.fn.curtain = function(options, callback) {
var settings = $.extend( {}, $.fn.curtain.defaults, options);
var tabContentsHeight = $(this).height();
$(this).animate({height:0}, settings.duration);
$(this).children().animate({'margin-top':'-' + tabContentsHeight + 'px'}, settings.duration, function() {
$(this).css({"margin-top":0});
if ($.isFunction(callback)) {
callback(this);
}
});
return this; // Allows chaining.
};
$.fn.curtain.defaults = {
duration: 250
};
}(jQuery));
The plugin can be called like this:
element.curtain({ duration: 250 }, function() {
// Callback function goes here.
});
If someone has remarks or a better way to solve this problem, please share it in the comments.
You can do it by using the animate function like this:
$('#square').on('mousedown', function(e) {
$(this).animate({height:-200},2500);
});
Demo
Updated code to create a "curtain raising" like animation:-
$('#square').on('mousedown', function(e) {
$(this).animate({height:-200},2500);
$(this).children().animate({"margin-top":"-400px"},2500, function() {
$(this).css({"margin-top":0})
});
});
CSS:
`#square{
overflow:hidden;
}`
Demo 2
This is the effect you wanted?
$('#square').on('click', function(e) {
$(this).animate({height :0},2500 );
});
The title of the question expresses what I think is the ultimate question behind my particular case.
My case:
Inside a click handler, I want to make an image visible (a 'loading' animation) right before a busy function starts. Then I want to make it invisible again after the function has completed.
Instead of what I expected I realize that the image never becomes visible. I guess that this is due to the browser waiting for the handler to end, before it can do any redrawing (I am sure there are good performance reasons for that).
The code (also in this fiddle: http://jsfiddle.net/JLmh4/2/)
html:
<img id="kitty" src="http://placekitten.com/50/50" style="display:none">
<div>click to see the cat </div>
js:
$(document).ready(function(){
$('#enlace').click(function(){
var kitty = $('#kitty');
kitty.css('display','block');
// see: http://unixpapa.com/js/sleep.html
function sleepStupidly(usec)
{
var endtime= new Date().getTime() + usec;
while (new Date().getTime() < endtime)
;
}
// simulates bussy proccess, calling some function...
sleepStupidly(4000);
// when this triggers the img style do refresh!
// but not before
alert('now you do see it');
kitty.css('display','none');
});
});
I have added the alert call right after the sleepStupidly function to show that in that moment of rest, the browser does redraw, but not before. I innocently expected it to redraw right after setting the 'display' to 'block';
For the record, I have also tried appending html tags, or swapping css classes, instead of the image showing and hiding in this code. Same result.
After all my research I think that what I would need is the ability to force the browser to redraw and stop every other thing until then.
Is it possible? Is it possible in a crossbrowser way? Some plugin I wasn't able to find maybe...?
I thought that maybe something like 'jquery css callback' (as in this question: In JQuery, Is it possible to get callback function after setting new css rule?) would do the trick ... but that doesn't exist.
I have also tried to separte the showing, function call and hiding in different handlers for the same event ... but nothing. Also adding a setTimeout to delay the execution of the function (as recommended here: Force DOM refresh in JavaScript).
Thanks and I hope it also helps others.
javier
EDIT (after setting my preferred answer):
Just to further explain why I selected the window.setTimeout strategy.
In my real use case I have realized that in order to give the browser time enough to redraw the page, I had to give it about 1000 milliseconds (much more than the 50 for the fiddle example). This I believe is due to a deeper DOM tree (in fact, unnecessarily deep).
The setTimeout let approach lets you do that.
Use JQuery show and hide callbacks (or other way to display something like fadeIn/fadeOut).
http://jsfiddle.net/JLmh4/3/
$(document).ready(function () {
$('#enlace').click(function () {
var kitty = $('#kitty');
// see: http://unixpapa.com/js/sleep.html
function sleepStupidly(usec) {
var endtime = new Date().getTime() + usec;
while (new Date().getTime() < endtime);
}
kitty.show(function () {
// simulates bussy proccess, calling some function...
sleepStupidly(4000);
// when this triggers the img style do refresh!
// but not before
alert('now you do see it');
kitty.hide();
});
});
});
Use window.setTimeout() with some short unnoticeable delay to run slow function:
$(document).ready(function() {
$('#enlace').click(function() {
showImage();
window.setTimeout(function() {
sleepStupidly(4000);
alert('now you do see it');
hideImage();
}, 50);
});
});
Live demo
To force redraw, you can use offsetHeight or getComputedStyle().
var foo = window.getComputedStyle(el, null);
or
var bar = el.offsetHeight;
"el" being a DOM element
I do not know if this works in your case (as I have not tested it), but when manipulating CSS with JavaScript/jQuery it is sometimes necessary to force redrawing of a specific element to make changes take effect.
This is done by simply requesting a CSS property.
In your case, I would try putting a kitty.position().left; before the function call prior to messing with setTimeout.
What worked for me is setting the following:
$(element).css('display','none');
After that you can do whatever you want, and eventually you want to do:
$(element).css('display','block');
Heyho,
I´am working on a project in my university and I´d like to use "Hammer.js".
I´ve downloaded the Carousel-Example and it works perfectly for me.
But I would like to start a the middle pane of my code and it´s not so simple I think.
It´s something like this:
http://img203.imageshack.us/img203/6326/schemeas.jpg
so Hammer.js starts always with the green screen. But I like to start with the yellow one.
I´ve added one swipe right to the init function but it looks horrible when the page is loading and could not be the goal ^^
I hope anyone of you have an idea how to solve my problem.
Try calling
carousel.showPane(1);
That will display the second pane instantly. You will want to put this near the bottom, right after where it says.
carousel.init();
If you're feeling adventurous you could try and make it automatically start with that pane as there's a variable inside the Carousel function called current_pane which is set to a default of 0 (the first pane). Altering this may work too but might require more code somewhere else. Experiment!
edit
NULL is right, it does animate it. Here's a more in depth method to set it without animation:
I found that the method responsible for changing which pane is showing was the setContainerOffset mthod which could be passed a variable to animate it. I previously told you to use showPane(2) but that then called
setContainerOffset(offset, true)
which caused the animation occur. What you should do instead is make a slightly different version of showPane...
this.setPane = function( index ) {
// between the bounds
index = Math.max(0, Math.min(index, pane_count-1));
current_pane = index;
var offset = -((100/pane_count)*current_pane);
setContainerOffset(offset, false);
};
You'll find it's almost identical to showPane except for the name and the fact that it calls setContainerOffset with animation: false. This will immediately show the pane of your choice and can be called using
carousel.setPane(index);
What I've done is added this to the init function so that it looks like this:
this.init = function() {
setPaneDimensions();
var c = this;
$(window).on("load resize orientationchange", function() {
setPaneDimensions();
c.setPane(current_pane);
//updateOffset();
})
};
Now you can change
var current_pane = 0;
to whatever you want and the carousel will always start with that pane when it's initialised! simple!
I am working on some tabbed navigation for my website and I have an issue I'd like to fix.
I've been scrambling my head all day and getting nowhere. Would really appreciate some help.
Here be the code: http://jsfiddle.net/EghAt/
1) Notice when you click Tab 1 and then immediately click Tab 2, Tab 1 continues to loop out all the results.
I would prefer if this stopped looping Tab 1 results and just started looping Tab 2 results.
Is this possible?
How do I achieve this?
Many thanks for any pointers
You can stop the previous animation in this function of yours, by adding the .stop(true, true) you see in this revised function:
function fadeOutItems(ele, delay) {
var $$ = $(ele), $n = $$.next();
// Toggle the active class
$$.toggleClass('active');
// Ensure the next element exists and has the correct nodeType
// of an unordered list aka "UL"
if ($n.length && $n[0].nodeName === 'UL') {
$('li', $n).each(function(i) {
// Determine whether to use a fade effect or a very quick
// sliding effect
delay ? $(this).stop(true, true).delay(i * 400).fadeToggle('slow') : $(this).stop(true, true).slideToggle('fast');
});
}
}
Since you call this on both the currently active tab and the newly active tab, this should stop any animations underway on the currently active tab.
See the jQuery doc on .stop() for details.
In looking at this code further, I believe it does what you literally asked for in your question (it stops the previous tab looping and starts the next tab), but I'm not sure that's actually what you want because it leaves the items in a tab only partially expanded. If that's what you want, then this will do that.
If that's not what you want, then the code will have to be modified a bit further to not only stop the currently running animations, but to put all the items for the old tab into the same state.
As I suspected, you actually want more than you asked for (per your most recent comments). You want the previously items to be hidden, no matter what state they were in previously. You can do that with this code where I changed the slideToggle() to a slideUp(). You can't use any form of toggle if the animation hasn't started yet because toggle will go the wrong way (it just reverses the state). Instead, when hiding you have to use a definitive animation that ends with the item not visible. You can use this code where I used slideUp() but you could pick something different if you wanted:
// A helper function that allows multiple LI elements to be either
// faded in or out or slide toggled up and down
function fadeOutItems(ele, show) {
var $$ = $(ele), $n = $$.next();
// Toggle the active class
$$.toggleClass('active');
// Ensure the next element exists and has the correct nodeType
// of an unordered list aka "UL"
if ($n.length && $n[0].nodeName === 'UL') {
$('li', $n).each(function(i) {
// Determine whether to use a fade effect or a very quick
// sliding effect
show ? $(this).stop(true, true).delay(i * 400).fadeToggle('slow') : $(this).stop(true, true).slideUp('fast');
});
}
}
You can see that in action here: http://jsfiddle.net/jfriend00/rzd3N/.
The problem is here.
$(this).delay(i * 400).fadeToggle('slow')
You are giving a fede effect to each element at once, by increasing delay.
It's not easy to stop it this way. The correct way to do this is to call a function which will only fade an element at a time. Then this function will be executed again at a given time interval (400 in your case), and fade the next element.
This way, passing a variable to the function, for example stopExecuting=true, will stop the effects.
Take a look at setInterval and setTimeout to achieve this.
I'm asking a question very similar to this one—dare I say identical?
An example is currently in the bottom navigation on this page.
I'm looking to display the name and link of the next and previous page when a user hovers over their respective icons. I'm pretty sure my solution will entail binding or timers, neither of which I'm seeming to understand very well at the moment.
Currently, I have:
$(document).ready(function() {
var dropdown = $('span.hide_me');
var navigator = $('a.paginate_link');
dropdown.hide();
$(navigator).hover(function(){
$(this).siblings(dropdown).fadeIn();
}, function(){
setTimeout(function(){
dropdown.fadeOut();
}, 3000);
});
});
with its respective HTML (some ExpressionEngine code included—apologies):
<p class="older_entry">Older<span class="hide_me">Older entry:
<br />
{title}</span></p>
{/exp:weblog:next_entry}
<p class="blog_home">Blog Main<span class="hide_me">Back to the blog</span></p>
{exp:weblog:prev_entry weblog="blog"}
<p class="newer_entry">Newer<span class="hide_me">Newer entry:
<br />
{title}</span></p>
This is behaving pretty strangely at the moment. Sometimes it waits three seconds, sometimes it waits one second, sometimes it doesn't fade out altogether.
Essentially, I'm looking to fade in 'span.hide_me' on hover of the icons ('a.paginate_link'), and I'd like it to remain visible when users mouse over the span.
Think anyone could help walk me through this process and understand exactly how the timers and clearing of the timers is working?
Thanks so much, Stack Overflow. You guys have been incredible as I walk down this road of learning to make the internet.
If you just want to get it working, you can try to use a tooltip plugin like this one.
If you want to understand how this should be done: first, get rid of the timeout, and make it work without it. The difference (from the user's point of view) is very small, and it simplifies stuff (developing and debugging). After you get it working like you want, put the timeout back in.
Now, the problem is you don't really want to hide the shown element on the navigator mouse-out event. You want to hide it in its own mouse out event. So I think you can just pass the first argument to the navigator hover function, and add another hover to dropdowns, that will have an empty function as a first argument, and the hiding code in its second argument.
EDIT (according to your response to stefpet's answer)
I understand that you DO want the dropdown to disappear if the mouse moves out of the navigator, UNLESS its moved to the dropdown itself. This complicates a little, but here is how it can be done: on both types of items mouse-out event, you set a timer that calls a function that hides the dropdown. lets say the timer is 1 second. on both kind of item mouse-in even, you clear this timer (see the w3school page on timing for syntax, etc). plus, in the navigator's mouse-in you have to show the dropdown.
Another issue with the timer in your code is that it will always execute when mouse-out. Due to the 3 seconds delay you might very well trigger it again when mouse-over but since the timer still exist it will fade out despite you actually have the mouse over the element.
Moving the mouse back and forth quickly will trigger multiple timers.
Try to get it to work without the timer first, then (if really needed) add the additional complexity with the delay (which you must keep track of and remove/reset depending on state).
Here was the final working code, for anyone who comes across this again. Feel free to let me know if I could have improved it in any ways:
$(document).ready(function() {
var dropdown = $('span.hide_me');
var navigator = $('a.paginate_link');
dropdown.hide();
$(navigator).hover(function(){
clearTimeout(emptyTimer);
$(this).siblings(dropdown).fadeIn();
}, function(){
emptyTimer = setTimeout(function(){
dropdown.fadeOut();
}, 500);
});
$(dropdown).hover(function(){
clearTimeout(emptyTimer);
}, function(){
emptyTimer = setTimeout(function(){
dropdown.fadeOut();
}, 500);
});
});