So with popcorn.js you specify the div that your footnotes, etc. will populate. If you have more than one video that is using the same div for said footnotes, however, when you switch videos while a footnote is popped, it remains in the div and the next element will get placed below it, rather than replace it. I can't use a .html(' ') because all the elements are actually always there, just being shown and hidden in order. Can't hide the whole div, either.
Thoughts?
There are at least a couple ways to do this.
One option is to create two div's within that same div, with each having a CSS style of position: absolute and the parent div having position: relative. The two divs will overlap each other, and you can have each one be the target for all the footnotes in a different Popcorn instance. When you switch between the two videos, set display: none on the div for the hidden video and clear it for the visible one.
Another trick I often use for this sort of thing is to use .disable. That will hide all the footnotes for that popcorn instance. Something like this:
function activateVideo(index) {
if (activePopcorn) {
activePopcorn.disable('footnote');
//todo: make this video invisible.
}
activePopcorn = popcornInstances[index];
activePopcorn.enable('footnote');
//todo: make this video visible.
//(don't forget to range check)
}
If you want, you can disable/enable all plugins by looping through Popcorn.registryByName.
Related
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
I'm new to the site, but I'm looking into creating a very simple code which from a small collection of images, changes the photo by clicking on the right hand side of the image for "next" and left side for "previous". Ideally allowing space underneath to include text and an option of an independent text link to change the image. Best way to describe what I'm searching for is something exactly the same as this http://rowingprojects.com/cabinet/florian-roithmayr-the-y
Can anyone help? I would very much appreciate it. Thank you.
You need for this: HTML, CSS and Javascript.
In HTML:
You put down all images which you want to slide, and give them an id. Hide all, in HTML code with style's display attribute.
You need to add 2 transparent block which is always above the image left and right side. You can do this, with using CSS position, z-index, top, and left attributes. Give this elements onmouseclick and the correct JS function (nextimage, previousimage).
In JS:
You need a var, which contains the actual picture number in the array.
You need an array, with image ID's.
You need a nextimage and previousimage, which show and hide the images with styile's display attribute, these using that array and var.
If you want a title or/and description for the image, you only need to put that image in a div and formating whatever you want. But in this case you need to add id to the div not to the image. Or you can change the title/description with using JS.
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
For some reason a basic unstyled DIV element has extra height tacked onto the bottom when it contains a VIDEO element (and possibly other elements - I haven't tested with many types).
<div><video src="my_movie.ogv"></video></div>
I have the above line of code in a barebones base HTML file. With Firefox or Safari/Chrome's (if I use an .mp4 file instead of course) DOM inspectors on I see that the computed height of the DIV element is anywhere from 2-5 pixels more than the height of the VIDEO element.
This doesn't seem like expected and intentional behavior. If I put a P element in there instead of a VIDEO element, for example, the DIV doesn't have any of the extra height.
Does anyone know why the browsers are rendering this configuration of DOM elements in this way?
If your markup is as above and there are no special styles applied to it, then the behavior you see is required by the CSS box model; the space is the size of the font's descent, because the bottom of the video is placed by default on the baseline, not at the bottom of the text. In particular, see https://bugzilla.mozilla.org/show_bug.cgi?id=22274#c55 for an explanation in spec terms and https://bugzilla.mozilla.org/show_bug.cgi?id=22274#c37 for how to get rid of the space if you want to. You could also set line-height on the block to 0 to get rid of the space; which approach you take should depend on your other design constraints.
I'm using stylish to modify a website and I have this div full of text the needs to be moved upwards. The problem is the surrounding div has overflow-y:hidden to prevent text from flowing down the page. How can I allow overflow up but not down.
P.S. I know the css properties I used in the title don't exist, although if they did the style would already be done.
I needed to same, I found out you can just use clip, it's a very handy css property that isn't very much known. It does exactly what you want, you can shape the dimension of a div to your liking. With clip you for example can do something like
<div id="myBox" style="clip: rect(10px 100px 100px 10px);">This is some text to play with so you can see it is clipped.</div>