I´m creating a website for a photographer who would like a fine fadein on his images. I have excluded flash as a solution and would like to use those fine-looking effects of mootools fx. But the problem is that I'm really lousy when it comes to javascript. So if anyone could give me an easy solution for fading in one single image onload and when the image is loaded I would be really happy. I know there is a lot of different people out there who have this. But the problem is that i don't know how the code works even if it is a complete solution. So most important. If anyone has got the time to explain what every single line of code does i would be more than grateful. Thanks!
A simple fade-in is surely the simplest thing one can imagined:
// set-up an event on the browsers window
window.addEvents({
// be sure to fire the event once the document is fully loaded
load: function(){
// assing 'singleImage' variable to the image tag with the 'image' ID
var singleImage = $('image');
// set a bunch of CSS styles to the aforementioned image
singleImage.set('styles', {
'opacity': 0,
'visibility': 'visible'
});
// fade in the image
singleImage.fade('in');
}
});
Working example: http://jsfiddle.net/oskar/RNeS5/ (HTML, CSS, MooTools)
Related
I have an animated gif in an img tag that I start by rewriting the src attribute. The gif was created, though, to loop and I only want it to play once. Is there a way, with Javascript or jQuery, to stop an animated gif from playing more than once?
I was having the same problem with an animated gif. The solution is rather simple.
Open the Animated gif in Photoshop.
Go to the Window tab and select timeline(if the timeline is not already open).
At the bottom of the timeline panel, you will find an option, which says "Forever".
Change that to "Once".
Go to File> Export> Export for Web and save it as a gif.
That should do it.
can you find out how long the gif takes to loop once?
if so then you can stop the image like this:
pseudocode:
wait until the end of the image (when it is about to loop)
create a canvas element that has a static version of the gif as currently displayed drawn on it
hide gif
display canvas element in a way that makes it look like the gif froze
javascript:
var c = $("canvas")[0];
var w = c.width;
var h = c.height;
var img = $("img")[0];
setTimeout(function () {
c.getContext('2d').drawImage(img, 0, 0, w, h);
$(img).hide();
$(c).show();
},10000);
jsfiddle
edit:
I forgot to add reference to the original answer that I took this from, sorry
Stopping GIF Animation Programmatically
that one doesn't address the time factor you need for only one loop
Also, it has been mentioned that this approach is problamatic in certain cases (It actually didn't work when I try it in firefox right now...). so here are a few alternatives:
mentioned by Mark: edit the gif itself to avoid looping. this is the best option if you can.
but I've run into cases where it was not an option (like automated generation of images by a third party)
instead of rendering the static image with canvas, keep a static image version and switch to stop looping . this probablyhas most of the problems as the canvas thing
Based on this answer, it's kinda expensive, but it works. Let's say a single loop takes 2 seconds. At a setTimeout after 2 seconds kick in a setInterval, that would reset image source every millisecond:
setTimeout(function() {
setInterval(function() {
$('#img1').attr('src',$('#img1').attr('src'))
},1)
}, 2000)
again, probably just a proof of concept, but here's demo: http://jsfiddle.net/MEaWP/2/
Actually it is possible to make a gif to stop after just one iteration or any specific number of iterations, see an example below (if it is not already stopped), or in jsfiddle.
To do that the gif must be created with number of iterations specified. This could be done using Screen to Gif, it allows to open a gif or a bunch of images and edit it frame by frame.
This solution also allows you to reset the animation by imgElem.src = imgElem.src; but this does not work in MS IE/Edge.
Jurijs Kovzels's answer works in some condition but not in all.
This is browser-dependent.
It works well with Firefox. But In Google Chrome and Safari, it does not work if the gif is on the same server. The example he provided works because the gif is on the external server.
To restart gifs stored on the internal server, using Google Chrome and Safari, you need extra steps to make it work.
const img = document.getElementById("gif");
img.style = "display: none;";
img.style = "display: block;";
setTimeout(() => {
img.src = img.src;
}, 0);
This is inspired by this answer.
Not sure if this is the best way to respond to everyone and have it appear after all the previous answers and comments, but it seems to work.
I don't have much control over the gif. People post whatever gif they want as the "thankyou.gif in their account directory and then the ThankYou code runs whatever they've put there when a comment is submitted to a form they've posted. So some may loop, some may not, some may be short, some may be long. The solution I've come to is to tell people to make them 5 seconds, because that's when I'm going to fade them out, and I don't care if they loop or not.
Thanks for all the ideas.
I know I am pretty late here but..here it is...
I don't know if you would go to this length but let me share a trick.
Open the GIF in Macromedia Flash 8(it has deprecated since then), Export the GIF as Animated GIF. You will have to choose the file location. After that you would receive a dialog box with settings. In that, add the number of times you want the animation to happen. Click OK. Problem solved.
I am trying to build a highlighting library with JavaScript and jQuery. I am just diving into Canvasing techniques this week and did not find them to be all that difficult. However, while working today my code has simply stopped working. I know I am probably just missing something obvious but I have been stuck like this for almost 2 hours now and I need to get this project moving forward again. any help would be greatly appreciated.
$(function() {
$('area').click(function(event) {
event.preventDefault();
document.getElementById("ctx").getContext("2d").fillStyle = "#FF0000";
document.getElementById("ctx").getContext("2d").fillRect(0, 0, 200, 200);
} );
} );
I have included my Javascript only since that is the only thing I have been changing recently.
Your code works for me, assuming:
The page has a clickable area.
The page has a canvas with an #id of ctx.
Make sure those 2 things are true about your setup...
Does your canvas element have an #id of ctx? That's not fatal, but the canvas element contains a context so it's a bit misleading.
If you have a canvas element like this:
<canvas id=canvas></canvas>
Then you can get a reusable reference to the canvas's context like this:
// no need to constantly get a context reference ...
// just do it once at the start of your app
var canvas=document.getElementById('canvas');
var context=canvas.getContext('2d');
And you can reuse that context reference to do all your drawing calls:
context.fillStyle='red';
context.fillRect(0,0,200,200);
I have a problem with Safari and a map create with Leaflet: this is a little demo http://jsfiddle.net/DBJb7/ .
The CSS property 'hover' works except in Safari. I try to solve it with z-index but it doesn't work.
Does anyone have an idea ?
Edit : http://bost.ocks.org/mike/leaflet/ This project seems have the same problem.
You might try implementing the following code into your D3.js JavaScript instead of using CSS:
var feature = g.selectAll("path")
.data(collection.features)
.enter().append("path").attr('style','z-index:9999')
.on("mouseover", function() {
d3.select(this).css("fill", "green").css("stroke", "red");
})
.on("mouseout", function() {
d3.select(this).css("fill", "").css("stroke", "");
});
I have found that using the JavaScript to apply styles has been much more efficient and easier to maintain than trying to use CSS to do so, unless you are specifically using classes. In which case, I would use the .classed() method (https://github.com/mbostock/d3/wiki/Selections#wiki-classed) to manage the adding and removal of classes.
Hope this helps! If not, sorry. :-/
EDIT 1
I edited to include the mouseout functionality. After looking into this more deeply, the Leaflet thing just pulls in new images, not redrawing an SVG, which is what D3.js does. My only guess is that Safari is ignoring the z-index of your path element. This is apparent whenever you right-click on the path area and then select Inspect Element from the dropdown. On Chrome, it will show you the HTML for the path element, but on Safari, it shows you the HTML for the image being pulled in by the Leaflet stuff.
Our web app is built entirely in JS.
To make it snappy we cache resources (models) between page views and reload the resource when you view a page.
Our flow is like this:
The user is in ViewA
The user switches to ViewB
We use the cached resource to render ViewB
We start a fetch for resource
When the resource is fetched we render again
This has a nasty drawback of causing <img> tags to flicker, ever if they are the same.
The problem is that Backbone.js, which we use, doesn't tell us if anything changed when fetching a collection, just that it was fetched.
Here's a quick demo of what I mean: http://jsfiddle.net/p7DdG/
It only happens in webkit and with <img> tags, not with background images as you can see.
We think it's kinda ugly to use background-image instead of a proper img tag.
Is there any solution to this?
The problem is gone in Chrome 19, problem solved :)
Not knowing exactly how the URL of each image is being built I'm not certain this will work, but could you check the src attribute of each image tag against the one you are replacing it with before doing the replace?
e.g.
var newImageSrc = "http://www.google.com/intl/en_com/images/srpr/logo3w.png";
if (newImageSrc != $("img").attr("src")) {
$('img').replaceWith('<img src="'+newImageSrc +'">');
}
Alternatively - load the image offscreen, and attach an event handler to the onload event of the image, which moves the image to the current image's parent tag, and remove the old one.
e.g.
var oldImage = $("#oldImageId");
var newImageSrc = "http://www.google.com/intl/en_com/images/srpr/logo3w.png";
var newImage = new Image();
$(newImage).load(function (event) {
$(oldImage).parent().append(newImage);
$(oldImage).detach();
});
$(newImage).attr("src", newImageSrc);
I ran into the same problem and noticed that sometimes images do flicker and sometimes don't. Even in latest Chrome (v33 as of now).
For posterity, flickering happens with uncached images.
In my case, Cache-Control: public, max-age=31536000 totally eliminated it.
I have been working on a web application for some time now and did notice that the CPU usage was a bit high a long time ago, but the development has been halted for a while.
Recently I started developing again and discovered that the CPU usage goes high after an animated GIF image has been display as the background image.
I use Ajax to update content and apply CSS classes to elements to display a loading indicator. I remove the CSS class when the content has finished loading. If I comment out the classes in the stylesheet that contains the GIFs, everything looks normal.
I have tested it in Internet Explorer 7 and Internet Explorer 8.
What can be done to alliviate this problem?
var blabla = function() {
var element = $('id of element');
element.addClassName('a css classname');
new Ajax.Request({some parameters},
onSuccess: function() {
element.removeClassName('a CSS classname');
....
},
onFailure: function() {
element.removeClassName('a CSS classname');
....
},
onComplete: function() {
element.removeClassName('a CSS classname');
....
}
}
}
It's possible that this issue is related to how Internet Explorer loads data needed from CSS classes. Might I suggest an alternate approach: instead of using the loading animation contained within a CSS class, just put the .gif in a visible <img> tag straight into the HTML. Then, when onSuccess or another method is called, you can just run:
$("#ajax-gif").hide();
As already commented on, it looks like it doesn't have anything to do with the GIF image itself, especially not one at 20x20 pixels.
If you are changing the background of a page with a GIF image, it must redraw what's on top of it to a certain extent.
To bring down the CPU usage, either reduce what's on your page before you change the background or stop using GIF images, it's 2011!
If this problem is only occurring in Internet Explorer, it is indeed the redraw issue that commenters to Barnzy's answer have talked about. It should create similar problems across other browsers as well.
One solution would be to use the JavaScript onload event handler to preload all of your GIF images in the DOM, which would reduce the need to redraw and should stop escalating the CPU cycles.
I agree that in 2011 using GIF images is probably not the best approach for web design.