Div Float Issue: It seems that divs automatically clear:left - image

I have a series of images, all of which have width:400px, but have varying heights. They are in the following container:
#content {width:808px;margin:0 auto;margin-top:100px}
All the ODD images have the following code:
{float:left;clear:left;margin:2px}
All the EVEN images have the following code:
{float:right;clear:right;margin:2px}
In theory shouldn't every ODD image be on the left, stacked ontop of each other and every EVEN image should be on the right stacked on top of each other.
Instead I get this:
It's as though some of the images on the right are clear:left or clear:both, right?
Any thoughts?
Thanks

take, for example, this code:
<div>Airplane</div>
<div style="float: left;">Symba</div><div style="float:right;">Chewbacca(?)</div>
you wouldn't expect the top of Chewbacca(?) to line up with the top of Airplane! it will line up with the top of Symba.
Symba has float: left, so is forced below the Airplane. whether Airplane happens to be floating or not doesn't matter anymore.
I've seen layouts that do what you want, by applying float:left to ALL the elements, and then using some Javascript to tidy up the white space once the page is done loading (float: left on its own won't do it, as you may have already noticed). I don't like that solution myself, but the only other alternative I can think of is to pre-sort the images in to two columns, and split them accordingly:
<div style="float:left">
<div>Myst(?)</div>
<div>Airplane</div>
<div>Symba</div>
</div>
<div style="float:right">
<div>Coastline</div>
<div>Painter</div>
<div>Chewbacca(?)</div>
</div>
but if you want the columns to always be equal height, that may not work for you, unless you know the heights of the images in advance, and can put things into columns based on that. (loop over, keeping a tally of the current height, and always adding to the shorter column; something like that.)

Related

<li> elements clearing the row above

Is there a way to have a list of elements always clear the row above them without putting CSS on individual li elements?
Situation: Im building a site that's using the Business Catalyst CMS. I have a list of products which are built using lists. It all works fine except when you move the screen in and one of the product headings goes over three lines it makes the row under jump and only show one or two products instead of three.
See sample:
http://sklzaustralia.businesscatalyst.com/baseball-softball
Move the screen in until there is a gap on one of the rows. This gap is what I'm trying to avoid.
The products are imported with a module so I can add css to individual list items. It needs to be a general or solution.
I also know if I add a height to the it will solve this but that makes the responsive aspect messy as I need to pick a height that works across all screen sizes. So if its right for large screen, the gap is too large for small screen layout.
An ideas on fixing this problem...?
I ran into the same issue with an ecommerce site where product titles ranged from 2 words to 6 or more, and also included a short description underneath the product image.
You need to evaluate the elements within the
<div class="shop-product-small clear">
...and unfortunately define heights and min-heights to make sure each product div is always the same height. Play with font-size as well at a smaller #media width.
Set the width for li to be 50% when it falls below a breakpoint (when the gap appears).
Or just add .col-xs-6 to your li if you are using bootstrap.

Layout using Singularity

I've been trying to create a couple of typical layout examples using Singularity, and I have a question about grid-span and floats.
I've created a sample scss stylesheet and html layout. Here's the complete example on Sassmeister.
http://sassmeister.com/gist/a7ca98b7520b12bd6241
My question is whether the containing content div <div id="content"> is necessary? I'm having to use it with a clearfix mixin in order to 'pull' the div down and keep the footer below the content section and aside.
Is there another way to achieve this layout with Singularity, without having to use the surrounding clearfix div? Is there an option for grid-span in the main section that will either not use a float, or self clear this section?
To understand your problem you have to learn how floats and clearing work.
0.
When you float an element, it is removed from the flow. It's vertical height does not count when calculating the height of the container.
1.
The intended usage of floats is to add images to a long sheet of text. The text would wrap around the floated image and increase its overall height and stretching the container vertically, just like an object submerged into water increases the height of water surface.
Before:
After:
2.
If the floated image is located very close to the bottom of the text, it will pop it's bottom out of the bottom of the container, just like an iceberg exposing it's top from the water.
3.
Now imagine that your text is comprised of paragraphs and each paragraph starts with a title. When there's an image floated at the bottom of a paragraph, the image would stretch into the next paragraph, pushing the next paragraph's title aside.
4.
If you don't want that to happen, you apply clearing to paragraph titles:
h2 { clear: both; }
This basically tells the titles: don't let floated images push you aside, let them push you down instead.
5.
But web pages have become more than formatted text, and HTML/CSS didn't provide any means of formatting layouts. So we started using floats for layouts. It's ugly, it's like using wallpaper to sew your clothes, but we have no better option (until Flexbox becomes a thing, and it seems to already).
What happens when you float all content in a container? There will be no flow left, no text to stretch the container vertically, and it's height will be zero (plus border and padding):
6.
You already know that in order to make containers regain their height (wrap around the floated content) we have to apply a clearfix to the container. But what a clearfix actually is?
When you apply a clearfix to a container, you use :after in CSS to create an additional element within the container, after all it's content. Then you apply clearing to the little mother fcuker:
.container:after {
content: '';
display: block;
clear: both;
}
7.
Now back to your question! What's the alternative of using the clearfix?
You've probably have guessed already.
If you've got got content below the floated element, simply apply clear: both to the next element below the floated one! Just like we did in #4 for paragraph titles.
In your case:
footer { clear: both; }
And here's a demo: http://sassmeister.com/gist/df8af8a3c7f8d3df2796

Skrollr.js relative key frames and best practices

I'm not sure if something I want to do is possible with skrollr, it doesn't seem to be possible but maybe I am misunderstanding. I would like to be able to describe keyframes in scroll points relative to other keyframe events, as in "start this animation event 500px after another element's animation event", and wondering what the best practice is. I am working on a large page of multiple sections of animated content. Each section scrolls to the top, then becomes temporarily fixed as multiple animations occur within the section on many key frames, then once that section's animations are done it scrolls up off the screen and the next section comes into view and does it's own animating, and so on (not unlike the main skrollr demo but more complex with many more animation events). My main issue is that I want to be able to easily edit in the future each sections' animation timings independently, for example to adjust little details here and there as needed, anticipating some back-and-forth with the artists and clients I'm working with. But when relying on an absolute scrollTop for all timings, this becomes problematic because one little timing change means I have to adjust all subsequent timings throughout the remainder of the page. To get around this I am using constants to denote the start of each animated section so that at least I can have each animated section be timed relative to its start, as in:
<style type="text/css">
#fixedanimatedcontent1, #fixedanimatedcontent2 {position: fixed;}
</style>
<section id="fixedanimatedcontent1" data-_fixedanimstart1--630="top:100%;" data-_fixedanimstart1="top:0%;" data-_fixedanimstart1-1500="top:0%;" data-_fixedanimstart2="top:-100%;">
<div data-_fixedanimstart1="width: 0%;" data-_fixedanimstart1-470="width: 100%"></div>
<img src="x.png" data-_fixedanimstart1-270="opacity: 0;" data-_fixedanimstart1-670="opacity: 1;" data-_fixedanimstart1-1170="opacity: 0;" />
</section>
<section id="fixedanimatedcontent2" data-_fixedanimstart2--630="top:100%;" data-_fixedanimstart2="top:0%;" data-_fixedanimstart2-2000="top:0%;" data-_fixedanimstart3="top:-100%;">
<img src="y.png" data-_fixedanimstart2-500="opacity: 0;" data-_fixedanimstart2-1000="opacity: 1;" data-_fixedanimstart2-1500="opacity: 0;" />
</section>
But even still, for complex sequences making a small timing change will be a bit of a mess, requiring at the least changing all key frame offsets within that section, and probably also changing constant values. Looking at my example above, 2 questions:
1) Is there a way to describe a relative keyframe that, let's say, begins 500px after section #fixedanimatedcontent2's top=0%? I know I can do data-top, but in my setup #fixedanimatedcontent2 becomes fixed at the top for some time once it hits the top. So how do I describe a keyframe that I want to begin 500px of scrolling after #fixedanimatedcontent2 hits data-top? Is this not possible within the syntax of "relative key frames" since offsets are only relative to element position in the viewport? If this were doable somehow, I wouldn't have to rely on constants so much...
2) How about a keyframe that begins when section #fixedanimatedcontent2's <img> reaches an opacity of 1? That way I could later if I needed make a change in the length of that <img>'s opacity interpolation without having to change all subsequent key frame timings. Pretty sure this is not possible but had to ask...
So: Am I misunderstanding what is the best way to do this sort of relative sequencing most efficiently? Or is using constants as in the example above the best practice?
(this was a really verbose post, sorry!)
It is very well possible in skrollrjs. I am telling nothing different from skrollrjs documentation. If you look carefully there, there are two modes for keyframes
absolute
relative
I think you wanted to use relative mode. So, i would answer each of your questions orderly.
1) Is there a way to describe a relative keyframe that, let's say, begins 500px after section #fixedanimatedcontent2's top=0%? I know I can do data-top, but in my setup #fixedanimatedcontent2 becomes fixed at the top for some time once it hits the top. So how do I describe a keyframe that I want to begin 500px of scrolling after #fixedanimatedcontent2 hits data-top? Is this not possible within the syntax of "relative key frames" since offsets are only relative to element position in the viewport? If this were doable somehow, I wouldn't have to rely on constants so much...
Answer:- It is possible to do that. In relative mode of work, you can define your relative targets and you can define css accordingly. So for your element #fixedanimatedcontent2 when reaches top i would use like following html
You can use following cheatseet for this. This is helpful.
https://ihatetomatoes.net/skrollr-cheatsheet/
I think all you need is already described if you read carefully
https://github.com/Prinzhorn/skrollr

Why does CSS2.1 define overflow values other than "visible" to establish a new block formatting context?

The CSS2.1 spec mandates that overflow other than visible establish a new "block formatting context". This strikes me as odd, that a property whose obvious purpose is to hide overflow without affecting layout, actually does affect layout in a major way.
It seems like overflow values other than visible combine two completely unrelated features: whether a BFC is created and whether the overflow is hidden. It’s not like "overflow:hidden" is completely meaningless without a BFC, because floats historically can overflow their parent element, hiding the overflow without changing the layout seems sensible.
What are the reasons behind this decision, assuming they are known? Have the people who worked on the spec described why this was decided to be the case?
I asked about this on the mailing list on your behalf; the thread can be found here. In summary, this has to do with scrolling content for the most part:
Fundamentally, because if the spec didn't say this, then having floats intersect with something that's scrollable would require the browser to rewrap (around intruding floats) the contents of the scrollable element every time it scrolls. This is technically what
CSS 2.0 required, but it was never implemented, and it would have been a huge problem for speed of scrolling.
-David
Most likely, it refers to scrollable content in a box that may occur outside of the float's parent but would intersect with the float. I don't think this is related to rewrapping content around a float within a scrollable container, as that already happens naturally, plus the float would clip into the container and scroll along with the rest of its content anyway.
Finally this makes sense to me. In fact, I'm going to provide an example here so hopefully it makes sense to you and anyone else who may be wondering. Consider a scenario involving two boxes with the same fixed height and overflow: visible (the default), of which the first contains a float that stretches beyond its parent's height:
<div>
<p>...</p>
</div>
<div>
<p>...</p>
<p>...</p>
</div>
/* Presentational properties omitted */
div {
height: 80px;
}
div:first-child:before {
float: left;
height: 100px;
margin: 10px;
content: 'Float';
}
Notice the similarity to one of the examples given in section 9.5. The second box here is simply shown to have overflowing content for the purposes of this answer.
This is fine since the content will never be scrolled, but when overflow is set to something other than visible, that causes the content to not only be clipped by the bounds of the box, but also to become scrollable. If the second box has overflow: auto, this is what it would look like had a browser implemented the original CSS2 spec:
Because of the float, attempting to scroll the content would cause the browser to have to rewrap it so it doesn't become obscured by the float (and what should happen to the part that scrolls out of the top edge?). It would probably look something like this when scrolled to the bottom:
The catch here is that the browser has to rewrap the content every time it repaints it during scrolling. For browsers that are capable of pixel-based smooth scrolling — which is to say, all of them — I can see why it would be a performance disaster! (And a user experience one, too.)
But that's for when the user can scroll the content, right? This would make sense for overflow: auto and overflow: scroll, but what about overflow: hidden?
Well, a common misconception is that a container with overflow: hidden simply hides content by clipping and cannot be scrolled. This is not completely true:
While scrolling UI is not provided, the content is still scrollable programmatically, and a number of pages perform just such scrolling (e.g. by setting scrollTop on the relevant element).
-Boris
Indeed, this is what it'd look like if the second box was set to overflow: hidden and then scrolled to the bottom with the following JavaScript:
var div = document.getElementsByTagName('div')[1];
div.scrollTop = div.scrollHeight;
Again, notice that the content would have to be rewrapped to avoid being obscured by the float.
Even though this wouldn't be as painful for performance as had scrolling UI been available, my best guess is that they made boxes with any overflow value other than visible generate a new BFC mainly for the sake of consistency.
And so, this change was brought about in CSS2.1, documented here. Now if you apply an overflow value other than visible only to the second box, what a browser does is push the entire box aside to make way for the float, because the box now creates a new block formatting context that encloses its contents, instead of flowing around the float. This particular behavior is specified in the following paragraph:
The border box of a table, a block-level replaced element, or an element in the normal flow that establishes a new block formatting context (such as an element with 'overflow' other than 'visible') must not overlap the margin box of any floats in the same block formatting context as the element itself. If necessary, implementations should clear the said element by placing it below any preceding floats, but may place it adjacent to such floats if there is sufficient space. They may even make the border box of said element narrower than defined by section 10.3.3. CSS2 does not define when a UA may put said element next to the float or by how much said element may become narrower.
Here's what it looks like with overflow: auto for example:
Note that there is no clearance; if the second box had clear: left or clear: both it would be pushed down, not to the side, regardless of whether it established its own BFC.
If you apply overflow: auto to the first box instead, the float is clipped into its containing box with the rest of the content due to its fixed height, which is set to 80px in the example code given above:
If you revert the first box to height: auto (the default value), either by overriding or removing the height: 80px declaration from above, it then stretches to the height of the float:
This happens to be new in CSS2.1 as well, in that an element with height: auto that generates a new block formatting context (i.e. a block formatting context root) will stretch vertically to the height of its floats, and not just enough to contain its in-flow content unlike a regular box. The changes are documented here and here. The change leading to the side-effect of shrinking the box so that it does not intersect the float is documented here.
In both of these cases, no matter what you do to the second box, it will never be affected by the float because it has been restricted by the bounds of its container.
I know this will be a speculative answer, however after reading the specifications a few times here is my view on this:
What section 9.4.1 is talking about is any block element that does not fully contain or does not fill the containment space. For example when you float an element it is no longer filling 100% of the parent, like in-flow elements do. Inline blocks, table cells, and table captions are also elements that you can affect height and width but that are not intrinsically 100% of the parent (yes table>tr>td is one that would fill 100% of it's parent but it is designed to allow for multiple td's so the td doesn't count as it will automatically shrink to accommodate additional td's) this also applies to any overflow other than visible because it breaks the containment of the block element.
So if I am reading this correctly the way it works is the 9.4.1 section is referring to block elements that break the default containment rules of the block elements as specified by section 9.2.1

transform: scale immensely slow in all versions of firefox

Please check this:
http://users.telenet.be/prullen/grid.html
This has a normal speed in safari, but the zoom effect is really slow in firefox.
Interestingly, if I add:
.item {
width:100px;
height:100px;
}
it seems to speed up a little (still not completely fluent). But that is not the size my images are at, so it looks messed up:
http://users.telenet.be/prullen/grid2.html
If I set the item width/height to the size of my images, thing slow down again:
.item {
width:160px;
height:160px;
}
http://users.telenet.be/prullen/grid3.html
Any ideas as that what is the reason of this? I'm out of ideas, I've removed/added statements but nothing seems to help. This is tested in different firefox versions up to version 10.
Thanks,
Wesley
To get your animation boosted, you can remove the box-shadow property from #container .item .thumbnail, this property is heavy and slows your animation.
But if you still want the shadow effect, you can try putting it behind as a background and not as a part of the animation.
It should take some change, but removing the box-shadow property from the animated div will make it faster. The "item zoom" div is the one responsible for the animation. By splitting the "zoom" class from the "item" class, and applying the right css properties on each, the animation shall work faster. (I've tried it with firebug)
HTML:
<div class="item">
<div class="zoom">
<div class="thumbnail">
<img src="...">
</div>
</div>
</div>
Position your elements absolutely so they are not part of the normal flow of the document. This will make it so the browser doesn't try to redraw the page every-time an animation plays.
When elements are relatively positioned, they can affect each-other when one is changed, so they all have to be redrawn to make sure that changing one element didn't affect all of them.
I created a demo and absolutely positioned the elements, you can see that the animations are much more efficient.
Here is a demo: http://jsfiddle.net/QLTbU/

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