edit
Since originally posting this question, I've gone down a couple more paths trying to solve the issue. It's still not solved, but now my questions are different. The original question is below, and then I'll add a section below that with updates.
original question
I'm working on a Rails 4 application and having some trouble with JavaScript and the Chartkick gem.
I have two JavaScript functions that make it so that a user can click an icon and an element will drop down below the icon/appear on the page, and the icon will switch from a right-pointing arrow to a down-pointing arrow. The code is this:
function ReverseDisplay(d)
{
if(document.getElementById(d).style.display == "none")
{
document.getElementById(d).style.display = "block";
}
else
{
document.getElementById(d).style.display = "none";
}
}
$(function() {
$('.toggle-icon').click(function() {
$(this).find('i').toggleClass('fa-arrow-circle-o-right fa-arrow-circle-o-down');
});
});
And the haml:
%a{href: "javascript:ReverseDisplay('toggle-stats#{item.id}')", class: 'toggle-icon'}
%i.fa.fa-arrow-circle-o-right
%div{id: "toggle-stats#{item.id}", style: "display: none;"}
= the items to be displayed
It works. However, I expect the items that drop down to take up the full width of the page, like so:
But instead, when I first click the toggle icon, they show up squished, like this:
If I then resize the browser just a tiny bit, the graph pops out to full-width, and it stays that way no matter what I do from there. I can't figure out how to get ahold of the generated mark-up, because this chart comes from Chartkick, as a gem. The generated html in the browser has this line:
<div dir="ltr" style="position: relative; width: 300px; height: 300px;">
Where the width: 300px is what's being changed to width: 1000px when I change the browser size. I don't have to change the browser size permanently or significantly. Once that width has changed to 1000px the first time it stays there - but the minute I refresh the page and click the icon to toggle the chart again, it's back to 300px. I don't know how to hook into this div, because it's generated by the gem and I don't know how to add a class to it. I've tried adding styling to a parent element that ensures all of that parent elements' children are width: 100%, but that doesn't do anything.
Anyway, I don't think that adding a class to it is the solution here. I just have no idea what is - I don't JavaScript incredibly well. I'm pretty much completely new to all front-end work as a whole. What's going on here, and how can I make these charts always be the full width of the page when they're toggled?
Notes: Am testing this in Chrome. I tested in Firefox and it does the same thing.
OK, I'm starting to wonder if this has something to do with the fact that I'm using a JavaScript function in order to capture dynamic item IDs - a page may have any number of these toggle-able charts, and so calling a jQuery function on each id seems impossible, because I don't know what ID is.
I removed the jQuery call, however, and the problem persists.
One of those times when rubber-ducking the Stack Overflow question box has not yet answered my question. So I guess I'll submit and hope for outside help here. :/
adjusted question
This question in the Github issues for Chartkick has lead me down a different path. The solution is not necessarily in attempting to restyle the charts at all. Instead, what I'm trying to do is trigger a resize event, because the chart automatically regenerates when the browser window is resized. This is both what's causing the problem and where the solution seems to lie.
My code:
.row
.col-sm-12
%h3.title-block.second-child
Stats by Video
.panel-groupd#faqList
- #claim.presenter.videos.each_with_index do |video, index|
.panel.panel-default
.panel-heading
%h4.panel-title
%a.chart{data: { toggle: "collapse", parent: "#faqList" }, href: "#video#{index}" }
= "'#{video.title}' at #{video.event.display_name} on #{display_date(video.recorded_at)}"
%div.panel-collapse.collapse{id: "#video#{index}"}
.panel-body
- if video.impressions.count > 0
%h4
Impressions by Hours (24 hours)
= line_chart video.impressions.group_by_day(:created_at, range: 1.day.ago...Time.now).count
...a couple more charts
:javascript
$(".chart").click(function() {
window.dispatchEvent(new Event('resize'));
});
So the intention here is that when I click the .panel-heading, this both drops down the .panel-body with the charts in it and resizes the window, which makes the charts resize correctly (or, rather, should).
It kind of works, in that, when I first click the .panel-heading trigger, it does not resize the charts, but when I click it again, the charts are resized perfectly for a split second... just before they become hidden from view again. :(
I've tried adding a time out to the javascript, like so:
:javascript
$(".chart").click(function() {
setTimeout(1000);
window.dispatchEvent(new Event('resize'));
});
But it doesn't appear to do anything at all.
So what I'm wondering here is how to get this resize event to work once the dropdown .panel-body is out so that the charts will resize appropriately on their own.
Here's a screen cast of the current problem, in case I didn't describe it clearly enough:
https://youtu.be/5quMGABoDs8
I don't know anything about Ruby or Chartkick, but in order to override that inline styling, you would have to use !importantin the css.
So, if you try that technique of giving all the children of the parent element width: 100% again, you might want to implement it something like this:
.importantRule { width: 100% !important; }
$( "parentElement > childElement" ).addClass('importantRule');
(First line goes in your CSS file, second line goes in JS)
I am trying to build a split layout gallery where the images will only be fully revealed when the user clicks on a button. I managed to split the screen in two and show the pictures at full size but I am struggling to find an effective way to actually reveal the other side of the image without resizing.
This is where I am at right now:
http://jsfiddle.net/Bb844/
I have already tried the jQuery slideToggle() method but it would not deliver the result I am looking for. The idea is not to overlap class="left" with class="right", but rather, to drag class="left" –and vice-versa– off the viewfinder with an animation effect similar to that of the slideToogle method.
The function should be activated through the class="square" element.
Is there any way to achieve this?
How does this look?
I changed your HTML a bit and made your CSS fit the new HTML setup. The only thing to note is the jQuery is set up to where you need to have the .side a .square is affecting directly after the .square. Then I used the following to do the sliding action you're looking for
$('.square').click(function() { // Fire when square is clicked
if(!$(this).hasClass("active")) { // If not fullscreen already
$(".active").removeClass("active"); // Remove other active class(es)
$(this).addClass("active"); // Make this have class active
$('.side').stop().animate({"width":"0%"}); // Shrink the other elements
// Make the nearest side full screen
$(this).nextAll(".side").stop().animate({ "width":"100%"});
} else { // If it's already open, put it back to the default
$(this).removeClass("active");
$(".side").stop().animate({"width":"50%"});
}
});
I have a script that adds full images dynamically over thumbnails when you hover over them. I've also given the full images a CSS :hover style to make them expand to a larger width (where normally they are constrained to the dimensions of the thumbnail). This works fine if the image loads quickly or is cached, but if the full image takes a long time to load and you don't move the mouse while it's loading, then once it does appear it will usually stay at the thumbnail width (the non-:hover style) until you move the mouse again. I get this behavior in all browsers that I've tried it in. I'm wondering if this is a bug, and if there's a way to fix or work around it.
It may be worth noting that I've also tried to do the same thing in Javascript with .on('mouseenter'), and encountered the same problem.
Due to the nature of the issue, it can be hard to reproduce, especially if you have a fast connection. I chose a largish photo from Wikipedia to demonstrate, but to make it work you might have to change it to something especially large or from a slow domain. Also note that you may have to clear the cache for successive retries.
If you still can't reproduce, you can add an artificial delay to the fullimage.load before the call to anchor.show().
HTML:
<img id="image" src="http://upload.wikimedia.org/wikipedia/commons/thumb/3/32/Cairo_International_Stadium.jpg/220px-Cairo_International_Stadium.jpg" />
CSS:
.kiyuras-image {
position: absolute;
top: 8px;
left: 8px;
max-width: 220px;
}
.kiyuras-image:hover {
max-width: 400px;
}
JS:
$(function () {
var fullimageurl = 'http://upload.wikimedia.org/wikipedia/commons/3/32/Cairo_International_Stadium.jpg';
var fullimage = $('<img/>')
.addClass('kiyuras-image')
.load(function () {
anchor.show();
});
var anchor = $('<a/>').hide().append(fullimage);
$('body').prepend(anchor);
$("#image").on('mouseenter', function () {
fullimage.attr('src',fullimageurl);
$(this).off('mouseenter');
});
});
JS Bin
Updated JS Bin with 1.5-second delay added (Hopefully makes issue clearer)
Again: Reproducing the issue involves clearing your cache of the large image, and then hovering over the original image to initial the loading of large image, then not moving your mouse while it's loading. Intended behavior is for the large image to properly take on the :hover pseudo-class when it eventually loads. Issue I see when it takes longer than ~0.75 secs to load is that it does not take on :hover until you jiggle the mouse a little.
Edit: See my comments on #LucaFagioli's answer for further details of my use case.
Edit, the sequel: I thought I already did this, but I just tried to reproduce the issue in Firefox and I couldn't. Perhaps this is a Chrome bug?
Most browsers update their hover states only when the cursor moves over an element by at least one pixel. When the cursor enters the thumbnail's img it gets hover applied and runs your mouseenter handler. If you keep your cursor still until the full-sized image loads, your old img (the thumbnail) will keep the hover state and the new one won't get it.
To get it working in these browsers, move the hover pseudo-class to a common parent element in the CSS; for example, enclose both imgs in a span.
If the selectors are correct, CSS will be applied to all elements, dynamic or otherwise. This includes all pseudo classes, and will change as attributes in the DOM change.
[Edit: while my explanation might be of interest, pozs' solution above is nicer, so I suggest using that if you can.]
The hover pseudo-class specification is quite relaxed concerning when it should be activated:
CSS does not define which elements may be in the above states,
or how the states are entered and left. Scripting may change
whether elements react to user events or not, and different
devices and UAs may have different ways of pointing to, or
activating elements.
In particular, it is not being activated when you update the visibility of the anchor element on load.
You can get around this fairly easily: copy the hover styles to a class, intercept the cursor moving over the element that it will eventually cover, and based on that add or remove your class from the element.
Demo: JS Bin (based on your delayed example).
Javascript:
$("#image")
.on('mouseenter', function () {
fullimage.attr('src',fullimageurl).toggleClass('mouseover', true);
$(this).off('mouseenter');
})
.mouseleave(function() {
fullimage.toggleClass('mouseover', false);
});
CSS:
.kiyuras-image:hover, .kiyuras-image.mouseover {
max-width: 400px;
}
TL;DR: You cannot rely on :hover applying to dynamically added elements underneath the cursor. However, there are workarounds available in both pure CSS and Javascript.
I'm upvoting both Jordan Gray and posz' answers, and I wish I could award them both the bounty. Jordan Gray addressed the issue re: the CSS specification in a somewhat conclusive way and offered (another) working fix that still allowed for :hover and other CSS effects like transitions, except on load. posz provided a solution that works even better and avoids Javascript for any of the hover events; I provide essentially the same solution here, but with a div instead of a span. I decided to award it to him, but I think Jordan's input was essential. I'm adding and accepting my own answer because I felt the need to elaborate more on all of this myself. (Edit: Changed, I accepted posz')
Jordan referenced the CSS2 spec; I will refer instead to CSS3. As far as I can tell, they don't differ on this point.
The pseudo-class in question is :hover, which refers to elements that the user has "designated with a pointing device." The exact definition of the behavior is deliberately left vague to allow for different kinds of interaction and media, which unfortunately means that the spec does not address questions like: "Should a new element that appears under the pointing device have this pseudo-class applied?" This is a hard question to answer. Which answer will align with user intent in a majority of cases? A dynamic change to a page the user is interacting with would normally be a result of ongoing user interaction or preparation for the same. Therefore, I would say yes, and most current browsers seem to agree. Normally, when you add an element under the cursor, :hover is immediately applied. You can see this here: The jsbin I originally posted. Note that if there's a delay in loading the larger image, you may have to refresh the page to get it to work, for reasons I'll go into.
Now, there's a similar case where the user activates the browser itself with the cursor held stationary over an element with a :hover rule; should it apply in that case? The mouse "hover" in this case was not a result of direct user interaction. But the pointing device is designating it, right? Besides, any movement of the mouse will certainly result in an unambiguous interaction. This is a harder question to answer, and browsers answer it in different ways. When you're activating them, Chrome and Firefox do not change :hover state until you move the mouse (Even if you activated them with a click!). Internet Explorer, on the other hand, updates :hover state as soon as it's activated. In fact, it updates it even when it's not active, as long as it's the first visible window under the mouse. You can see this yourself using the jsbin linked above.
Let's return to the first case, though, because that's where my current issue arises. In my case, the user hasn't moved the mouse for a significant length of time (over a second), and an element is added directly underneath the cursor. This could more easily be argued to be a case where user interaction is ambiguous, and where the pseudo-class should not be toggled. Personally, I think that it should still be applied. However, most browsers do not seem to agree with me. When you hover over the image for the first time and then do not move your mouse in this jsbin (Which is the one I posted in my question to demonstrate the issue, and, like the first one, has a straightforward :hover selector), the :hover class is not applied in current Chrome, Opera, and IE. (Safari also doesn't apply it, but interestingly, it does if you go on to press a key on the keyboard.) In Firefox, however, the :hover class is applied immediately. Since Chrome and Firefox were the only two I initially tested with, I thought this was a bug in Chrome. However, the spec is more or less completely silent on this point. Most implementations say nay; Firefox and I say aye.
Here are the relevant sections of the spec:
The :hover pseudo-class applies while the user designates an element with a pointing device, but does not necessarily activate it. For example, a visual user agent could apply this pseudo-class when the cursor (mouse pointer) hovers over a box generated by the element. User agents not that do not support interactive media do not have to support this pseudo-class. Some conforming user agents that support interactive media may not be able to support this pseudo-class (e.g., a pen device that does not detect hovering).
[...]
Selectors doesn't define if the parent of an element that is ‘:active’ or ‘:hover’ is also in that state.
[...]
Note: If the ‘:hover’ state applies to an element because its child is designated by a pointing device, then it's possible for ‘:hover’ to apply to an element that is not underneath the pointing device.
So! On to the workarounds! As several have zealously pointed out in this thread, Javascript and jQuery provide solutions for this as well, relying on the 'mouseover' and 'mouseenter' DOM events. I explored quite a few of those solutions myself, both before and after asking this question. However, these have their own issues, they have slightly different behavior, and they usually involve simply toggling a CSS class anyway. Besides, why use Javascript if it's not necessary?
I was interested in finding a solution that used :hover and nothing else, and this is it (jsbin). Instead of putting the :hover on the element being added, we instead put it on an existing element that contains that new element, and that takes up the same physical space; in this case, a div containing both the thumbnail and the new larger image (which, when not hovered, will be the same size as the div and thumbnail). This would seem to be fairly specific to my use case, but it could probably be accomplished in general using a positioned div with the same size as the new element.
Adding: After I finished composing this answer, pozs provided basically the same solution as above!
A compromise between this and one of the full-Javascript solutions is to have a one-time-use class that will effectively rely on Javascript/DOM hover events while adding the new element, and then remove all that and rely on :hover going forward. This is the solution Jordan Gray offered (Jsbin)
Both of these work in all the browsers I tried: Chrome, Firefox, Opera, Safari, and Internet Explorer.
From this part of your question: "This works fine if the image loads quickly or is cached, but if the full image takes a long time to load and you don't move the mouse while it's loading,"
Could it be worth while to "preload" all of the images first with JavaScript. This may allow all of the images to load successfully first, and it may be a little more user friendly for people with slower connections.
You could do something like that : http://jsfiddle.net/jR5Ba/5/
In summary, append a loading layout in front of your image, then append a div containing your large image with a .load() callback to remove your loading layer.
The fiddle above has not been simplified and cleaned up due to lack of time, but I can continue to work on it tomorrow if needed.
$imageContainer = $("#image-container");
$image = $('#image');
$imageContainer.on({
mouseenter: function (event) {
//Add a loading class
$imageContainer.addClass('loading');
$image.css('opacity',0.5);
//Insert div (for styling) containing large image
$(this).append('<div><img class="hidden large-image-container" id="'+this.id+'-large" src="'+fullimageurl+'" /></div>');
//Append large image load callback
$('#'+this.id+'-large').load(function() {
$imageContainer.removeClass('loading');
$image.css('opacity',1);
$(this).slideDown('slow');
//alert ("The image has loaded!");
});
},
mouseleave: function (event) {
//Remove loading class
$imageContainer.removeClass('loading');
//Remove div with large image
$('#'+this.id+'-large').remove();
$image.css('opacity',1);
}
});
EDIT
Here is a new version of the fiddle including the right size loading layer with an animation when the large picture is displayed : http://jsfiddle.net/jR5Ba/6/
Hope it will help
Don't let the IMG tag get added to the DOM until it has an image to download. That way the Load event won't fire until the image has been loaded. Here is the amended JS:
$(function () {
var fullimageurl = 'http://upload.wikimedia.org/wikipedia/commons/3/32/Cairo_International_Stadium.jpg';
var fullimage = $('<img/>')
.addClass('kiyuras-image')
.load(function () {
anchor.show(); // Only happens after IMG src has loaded
});
var anchor = $('<a/>').hide();
$('body').prepend(anchor);
$("#image").on('mouseenter', function () {
fullimage.attr('src',fullimageurl); // IMG has source
$(this).off('mouseenter');
anchor.append(fullimage); // Append IMG to DOM now.
});
});
I did that and it worked on Chrome (version 22.0.1229.94 m):
I changed the css as that:
.kiyuras-image{
position: absolute;
top: 8px;
left: 8px;
max-width: 400px;
}
.not-hovered{
max-width: 220px;
}
and the script this way:
$(function(){
var fullimageurl = 'http://upload.wikimedia.org/wikipedia/commons/3/32/Cairo_International_Stadium.jpg';
var fullimage = $('<img/>')
.addClass('kiyuras-image')
.load(function () {
anchor.show();
});
var anchor = $('<a/>').hide().append(fullimage);
$('body').prepend(anchor);
$('.kiyuras-image').on('mouseout',function(){
$(this).addClass('not-hovered');
});
$('.kiyuras-image').on('mouseover',function(){
$(this).removeClass('not-hovered');
});
$("#image").one('mouseover', function(){
fullimage.attr('src',fullimageurl);
});
});
Basically I think it's a Chrome bug in detecting/rendering the 'hover' status; in fact when I tried to simply change the css as:
.kiyuras-image{
position: absolute;
top: 8px;
left: 8px;
max-width: 400px;
}
.kiyuras-image:not(:hover) {
position: absolute;
top: 8px;
left: 8px;
max-width: 220px;
}
it still didn't worked.
PS: sorry for my english.
I'm not 100% sure why the :hover declaration is only triggered on slight mouse move. A possible reason could be that technically you may not really hover the element. Basically you're shoving the element under the cursor while it is loading (until the large image is completely loaded the A element has display: none and can therefore impossible be in the :hover state). At the same time, that doesn't explain the difference with smaller images though...
So, a workaround is to just use JavaScript and leave the :hover statement out of the equation. Just show the user the two different IMG elements depending on the hover state (toggles in JavaScript). As an extra advantage, the image doesn't have to be scaled up and down dynamically by the browser (visual glitch in Chrome).
See http://jsbin.com/ifitep/34/
UPDATE: By using JavaScript to add an .active class on the large image, it's entirely possible to keep using native CSS animations. See http://jsbin.com/ifitep/48
I installed jScrollPane on my website and can't make it work.
My website works as follows: from the main page, pages are loaded dynamically using jQuery's load() method. In the page I load I have the following script to launch jScrollPane:
$(function(){
$('.scroll-pane').jScrollPane();
});
Which seems to be called. No problems so far I guess. The problem is that the page, at the beginning, is not long enough to need a scrollbar. I have hidden content that shows up only on specific actions (i.e. clicking on a button shows the content of a certain paragraph), and when I click to show the content of a hidden div, the scrollbar doesn't appear.
I also tried to call $('.scroll-pane').jScrollPane(); as I show the new content (i.e. in the event that triggers .show() on the hidden div I also call $('.scroll-pane').jScrollPane();) but I had no success with that either.
Can anyone help me?
Thanks
EDIT:
I forgot to mention the structure of the page: I have a div which has class="scroll-pane" and is loaded with the page load and it contains small hidden divs that show up when clicking on particular areas. I would like to add a scroll bar to the div with the class scroll-pane in order to make the content of the showed div scrollable (right now the content stays in the size of the div but it's not scrollable since no jScrollPane scroll bar is shown).
Update:
I tried to put $('.scroll-pane').jScrollPane(); in the callback of the .show() method of my divs and tried to put class="scroll-pane" to those divs that appear, but again nothing is shown (the scroll bar doesn't appear and the div is not scrollable).
Check this demo provided by the developer of the plugin
http://jscrollpane.kelvinluck.com/examples/invisibles.html
When the element is first shown you simply have to (re)initialise the
scrollpane (or you could even use autoReinitialise if you like) and
its width and height will be calculated correctly.
All that you need is
$(function(){
$('.scroll-pane').jScrollPane({autoReinitialise: true});
});
and may be the recent version of the plugin
I suggest to use css visibility property instead auto reinitialising. Each time you call show() method, jScrollPane reinitialises itself. This takes time and has impact on animation.
If you use, say, slide..() methods, then animation starts properly, but scrollable container (and its elements) appears little bit later, and that looks bad.
var wrapper = jQuery('#gallery-album-preview-wrapper');
if (wrapper.css("visibility") == "hidden") {
wrapper.css("visibility", "visible").css("display", "none");
}
if (wrapper.is(":hidden")) {
wrapper.slideDown(1000);
} else {
wrapper.slideUp(1000);
}
So I have this page here:
http://www.eminentmedia.com/development/powercity/
As you can see when you mouse over the images the div slides up and down to show more information. Unfortunately I have 2 problems that i can't figure out and I've searched but haven't found quite the right answer through google and was hoping someone could point me in the direction of a tutorial.
The first problem is that when you mouse over an image it changes to color (loads a new image), but there's a short delay when the image is loading for the first time so the user sees white. Do I have to preload the images or something in order to fix that?
My second problem is that when you move your mouse over the 'additional content area' it goes crazy and starts going up and down a bunch of times. I just don't have any idea what would cause this but i hope one of you will!
All my code is directly in the source of that page if you would like to view the source.
Thanks in advance for your help!
Yes, you have to preload the images. Thankfully, this is simple:
var images_to_preload = ['myimage.jpg', 'myimage2.jpg', ...];
$.each(images_to_preload, function(i) {
$('<img/>').attr({src: images_to_preload[i]});
});
The other thing you have to understand is that when you use jQuery you have to truly embrace it or you will end up doing things the wrong way. For example, as soon as you find yourself repeating the same piece of code in different places, you are probably doing something wrong. Right now you have this all over the place:
<div id="service" onmouseover="javascript:mouseEnter(this.id);" onmouseout="javascript:mouseLeave(this.id);">
Get that out of your head. Now. Forever. Always. Inline javascript events are not proper, especially when you have a library like jQuery at your disposal. The proper way to do what you want is this:
$(function() {
$('div.box').hover(function() {
$(this).addClass('active');
$(this).find('div.slideup').slideDown('slow');
}, function() {
$(this).removeClass('active');
$(this).find('div.slideup').slideUp('slow');
});
});
(You have to give all the #industrial, #sustainable, etc elements a class of 'box' for the above to work)
These changes will also fix your sliding problem.
I can see your images (the ones that are changing) are set in the background of a div. Here is a jquery script that preloads every image found in a css file. I have had the same problem in the past and this script solves it. It is also very easy to use:
http://www.filamentgroup.com/lab/update_automatically_preload_images_from_css_with_jquery/
I will take a look at your other problem...
1) You should be using the jquery events to drive your mouseovers. Give each div a class to indicate that its a category container and use the hover function to produce the mouseover/mouseout action you're after.
html
<div id="industrial" class="category"></div>
Javascript
$(".category").hover(
function () {
$(this).find('.container').show();
},
function () {
$(this).find('.container').hide();
}
);
I simplified the code to just do show and hide, you'll need to use your additional code to slide up and slide down.
2) Yes, you need to preload your images. Another option would be "sprite" the images. This would involve combining both the black and white and colour versions of each image into a single image. You then set it as the div's background image and simply use CSS to adjust the background-position offset. Essentially, sliding instantly from the black and white to colour images as you rollover. This technique guarentees that both images are fully loaded.