I have a block-level element of unknown width. This element needs to be horizontally centered on the page, and its position needs to be relative so that its absolutely positioned child will show up in the right place. You can see it in action here.
As far as I know, the best way to center an element of unknown width is to set its display to table. Semantically, this seems incorrect, because my element has nothing in common with a real table. Even worse, Firefox doesn't apply position to tables, so the absolutely positioned child shows up in the wrong spot:
Are there any workarounds for this that:
don't add any extra elements to the html
don't calculate and set the element's width with JavaScript
I'd like a pure CSS fix, and I'm running out of ideas...
Adding display: inline-block; to the element (#box) should suffice. This will cause it to become an inline element and still keep its "boxy" properties. Its width will automatically take up the width of its children.
Then you can set its alignment by setting text-align: center; on its parent.
IE7 does not support this display value (only on naturally inline elements), but the situation is the same with table (no support at all). You can use a hack though to make inline-block work in IE7.
jsFiddle Demo
If worst comes to worst, you could try text-align: -moz-center; which is a Firefox-specific method of centering block elements like inline-elements.
Related
Since I am having trouble with Firefox about positioning a block element by nature (header) to be inline by using display:run-in; i'm asking you for your help ! been searching for quite some time now and I cant find which CSS method could be used instead of just applying display:run-in; to the element, which is supported in all the major browsers. It is crucial that i position the element this way.
Anyone knows a method how to do this ?
If you'd like to display your element as a block element, but would position it inline, then
display: inline-block;
will do the trick for you.
The MDN still lists run-in as an experimental value, so we shouldn't be too surprised if it doesn't fully function in Firefox at this time.
As for options, there are at least two you could use: display: inline and display: inline-block.
Inline might suffice if you don't need the properties of a block element on your header. Inline-block keeps it as a block element, so you can still do nice things like give it width, height, margin and so on.
View them on JSFiddle.
Alright i found a solution ! :) Using display:inline; in a combination with float:left; will make a block element by nature use space only as much as he needs, not full 100% of its parent element.
There is just one problem with this tecnhique if you are using bigger font for lets say a heading and want to add a paragraph right after it (on the same line). If the headings font-size is a bit bigger, heading could take 2 or even more lines of space in height where paragraphs text should be,and you will have a small gap between header and another row of paragraph under it. The solution is to add display:block; and margin-top:Xpx; to the paragraph element to align it as needed.
This is the scenario.
I have a simple table with a header row including several columns which have a dynamically changing width. Within the head row there are lists of a height that is longer than the head rows height, they are however only supposed to be visible on hover, but when on hover they are supposed to be ontop of the headrow but still having the the original 100% width of the parent being the <td> element of the column.
What I did was to set position: absolute on hover but as soon as that happens the element obviously took all the width it can get, fixable only with a specificly applied width, but that doesn't really help me as the column can be resized.
My Question is if there is a way in CSS ( NOT Javascript ) to achieve a behaviour where the element would still use the parent's width.
The answer to your question will vary wildly depending on what you're trying to accomplish. Most blanket solutions require:
The addition of extra positioning elements (often added using Javascript)
Setting display: block; on the TH, TD elements (often makes the TABLE behave erratically)
The reasons for this is that adding positioning to a table cell removes it from the flow, which affects table alignment (see this bug report comment). A much longer discussion about this issue and the possible solutions can be found at Does Firefox support position: relative on table elements?
That aside…
If you are using the TABLE for site layout, stop now and re-think your choices in life. There are better options:
The best option will be the CSS3 Flexible Box Layout model, if and when it becomes widely supported. Support at the time of this writing is minimal, scattered, and doesn't always follow the same standard (caniuse.com: flexbox)
Until that becomes an option, it's a little known fact that absolutely positioned elements can be positioned inside absolutely positioned elements. See this fiddle for an example of a 100% width/height layout made possible with absolutely positioned elements. Alternatively, the same layout can be made inside a relatively positioned parent element.
If you're not using a TABLE for site layout, then there may be other options open to you. It depends on the desired effect.
Pretty simple question really when I make a div inline it seems to lose its height?
Any ideas? I'm scratching my head....
UPDATE: after fiddling around I found another display type called "inline-block" which seems to allow me to keep items inline (unordered lists for example) and then set a height for them.
Is this a solution to the problem of inline elements losing the height setting?
Inline elements don't have heights... You've reached the very essence of difference between inline and block.
The height of an inline element is dictated by the line-height of the parent element, with whose contents they're now in-line. Therefore they're unable to have an explicit height of their own.
Similarly for the width, except that's dictated by the width of the contents.
I have found that if I use an inline-block I can make elements sit inline but not lose the height.
I'm trying to make a box with rounded corners where the height and width of the div depends on the content, so it's automatically adjust to it...
You can see the example here: http://pastehtml.com/view/1duizyf.html
The problem is that i can't get the "test_mid_left" (black background) and "test_mid_right" (turquoise background) to inherit the height from the "test_mid_center" (green background). I have tried height: 100% and auto, but none of thoose work. So how do I get them to inherit the height from the content?
(The reason why I have used "min-height: xx" in the left and right content on the example is just to show which boxes I am talking about)
As already mentioned this can't be done with floats, they can't inherit heights, they're unaware of their siblings so for example the side two floats don't know the height of the centre content, so they can't inherit from anything.
Usually inherited height has to come from either an element which has an explicit height or if height: 100%; has been passed down through the display tree to it.. The only thing I'm aware of that passes on height which hasn't come from top of the "tree" is an absolutely positioned element - so you could for example absolutely position all the top right bottom left sides and corners (you know the height and width of the corners anyway) And as you seem to know the widths (of left/right borders) and heights of top/bottom) borders, and the widths of the top/bottom centers, are easy at 100% - the only thing that needs calculating is the height of the right/left sides if the content grows -
This you can do, even without using all four positioning co-ordinates which IE6 /7 doesn't support
I've put up an example based on what you gave, it does rely on a fixed width (your frame), but I think it could work with a flexible width too? the uses of this could be cool for those fancy image borders we can't get support for until multiple background images or image borders become fully available.. who knows, I was playing, so just sticking it out there!
proof of concept example is here
The Problem
When an element is floated, its parent no longer contains it because the float is removed from the flow. The floated element is out of the natural flow, so all block elements will render as if the floated element is not even there, so a parent container will not fully expand to hold the floated child element.
Take a look at the following article to get a better idea of how the CSS Float property works:
The Mystery Of The CSS Float Property
A Potential Solution
Now, I think the following article resembles what you're trying to do. Take a look at it and see if you can solve your problem.
Equal Height Columns with Cross-Browser CSS
I hope this helps.
The negative margin trick:
http://pastehtml.com/view/1dujbt3.html
Not elegant, I suppose, but it works in some cases.
You need to take out a float: left; property... because when you use float the parent div do not grub the height of it's children... If you want the parent dive to get the children height you need to give to the parent div a css property overflow:hidden;
But to solve your problem you can use display: table-cell; instead of float... it will automatically scale the div height to its parent height...
Most of the times, the Previous parent has a heigt manually set, so you can use that value as reference, no other dirty tricks will be needed, and if the number is not the same for any reason maybe a comment can be added with the original number so in case you need to change it, by searching at the all the values, this one can be adjusted or even changed, in the time someone resolve this one for us.
What's the most common way to deal with a series of block elements that need to be on a line (if javascript needs to be able to modify their widths, for example)? What are the pros and cons to applying float:left to each of them vs. using positioning to place them?
Well, if you're not too concerned with older browsers (I'm looking at you, IE6) the best way here is to go with
display:inline-block;
Basically, it creates a box-model element without clearing before or after it, so it remains in the line. Every modern browser interprets it well.
Floating would be my choice, but it really depends on what you wish to achieve. If you can provide a more specific example I would be able to give you a clear reason as to what and why I think you should use. However here is a brief set of pros and cons that I have come accross (I'm assuming that by positioning you mean absolute positioning):
Positioning pros:
very precise positioning in relation to the next ancestor marked as position relative - allows for great flexibility
allows for elements to be in a different order visually than they are in the DOM
Positioning cons:
Harder to line up with other elements since the positioned element is no longer in the document flow and also because of the level of precision required.
Other elements ignore the absolutely positioned element which means you could have a potential overlap, unless you account for the minimum and maximum size of the positioned element
harder to implement a footer if you are using absolute positioning for your columns.
Float pros:
really easy to construct simple and advanced layouts
no footer problem
no worrying about precision, browser takes care of that for you
parent container stretches
Float cons:
Lots of pitfalls for those less experienced with float layouts that may lead to many questions being asked on SO :)
As to the clear:both element that Sebastian mentioned, There's a simple way around that. Lets say you have a container div and 2 floated divs inside.
Html:
<div id="con">
<div class="float"></div>
<div class="float"></div>
</div>
CSS:
#con { background:#f0f; }
.float { float:left; width:100px; height:100px; background:#0ff; }
if you were to run this code you would notice that the container div (the magenta coloured one) is only a single pixel high whereas the floated divs were correct - which is the problem Sebastian mentioned. Now you could take his advice and add a br or float the container which would not be very semantic - so here is a slightly more elegant solution. Just add overflow:hidden; to the container div like so:
#con { background:#f0f; overflow:hidden; }
Now your container should wrap the floated divs properly.
The parent container does not stretch with them unless it is also assigned a float tag or there is a br with clear:both; at the bottom.
I would go with the float:left instead of the positioning. The browser does all the aligning when one object stretches. So there is less for you to care about.
I think i wouldn't explicitly position the elements but rather instruct the browser to use an inline layout for the elements using display:inline and let the browser handle the positioning.
regarding float vs positioning i think the only way to line them up using positioning is by using absolute positioning, and that means you need to handle re-sizes(of the browser view port) in order to keep the elements in place.
I think that by using the float property the browser handles the re-sizing issues for you and re-renders the element in the correct place.
Only disadvantage to float in situations like this for me has been that you'll either need to left justify them or right justify them -- centering is not an option. However you've mentioned you're using absolute values for widths, so you could just nest all the floated elements in a DIV element and add either margin-right or margin-left to the parent DIV to simulate center alignment.