I am using the awesome compass style to generate sprites for my style sheets. I can generate sprites and use them as backgrounds, which is all working fine.
The problem is that previously I have used background-position to position my backgrounds within an element.
For example here's one:
background: left bottom url('../images/bottom-bg.png) no-repeat;
The height of the containing element is variable, and this places the background on the bottom and works beautifully.
However, if I switch to compass sprites and use #extend .system-bottom-bg;, the background-position property is used to grab the appropriate position of the image from the sprite map.
In such a case, how can I use css sprites and still be able to position the background on the bottom of an element?
Upon further research, it seems that due to the limitations of background-position, this is not possible. A decent list of shortfalls with CSS sprites is outlined here: http://www.onderhond.com/blog/work/css-sprites-pros-and-cons.
As background-position is used to to define the position an image occupies in a sprite sheet, we can't use it to define how that portion of the sprite sheet will appear on the page. The article linked above offers some solutions that may be implemented in the future.
One possible solution is to put the image as the last item in the sprite sheet, and then insert a huge amount of space between this image and the previous image. Obviously this is not a very neat solution, but given that compass does not allow us to set the position of images within a sprite sheet, this is not possible anyway.
My solution was to change my markup so that setting background-position: left bottom is not required, and I can just set the sprite image as the background image.
Related
I'm getting started with responsive design and just built this very basic "responsive" image sequence http://goo.gl/iMGRkL using the img tag.
Now I'm trying to do the same but using background-image instead of the image tag.
Is it possible without Javascript? I tried a few different approaches, including this http://goo.gl/AstSdl, but no luck so far.
Thanks in advance.
If you are using the css property "background" or "background-image", a good way to do it is to give the particular background image a parent such as a header, div, or section. Then you can use the css values "center" to center it in the parent container, and "cover" to make the image cover the parent div container. You can also play around with pixel and percentage values here. Another thing that is very important is to set the background repeat to "no-repeat" in your css so it doesn't repeat. This code will make it so that the image will cover the parent container at any width or height.
ex: background: #ffa949 url('example.jpg') no-repeat center / cover;
After doing that, the image may still looked a bit scrunched so it would probably still be a good idea to add some media queries.
I'm trying to make a thumbnail which on hover will move it's image (that's longer than the wrapper) all the way to the left using only CSS and using the img element and not a div with background-image.
The problem I have is that I don't know how could I find how much to move it given the fact that the images have different widths.
I did a demo where the left image moves correctly because I calculated how much it needs to be moved and the right image with the same CSS moving incorrectly.
It's not clear why you're restricting yourself to manipulating the img element alone and not exploring more usual background-image sprite-like hover event manipulations.
Take a look at this Codrops article and their demo's here (note there are 5 demo's in the menu).
The techniques offered don't produce the exact end result you're after, but they do include the structure for the type of events and manipulations you'd need to use.
Is the background-position css property used to indicated where in the element should the image be displayed (like this) or what part of the image should be displayed (like when using sprites) ?
In my instance i have a div of let's say 300px width, i want the image to be shown in the right part of that element so normally i just added a center right to my background declaration, though now my image is a spirit so how can i control the coordinate of the image that i want to display ?
Seems to me that this background property act in 2 different way.. Am i missing something ?
If the place where you want to put element of the sprite is larger then the element then you need to put white space (trasnparent) around it. And you can't use keywords like center, you need to use pixels, because you will center whole sprite and not your element.
Using sprites is like using window where background is larger then background image so you need to position the window (actually you position the background).
If your container is larger than the background sprite image part you want to display then the other part of image will also be displayed. Better use Sprite cow to generate sprite it will give you the css for different parts of sprite image
http://www.spritecow.com/
Good day, I have a DIV of fixed width and height on my HTML page. In normal state it should show image A on the background and in hover state it should show image B. I know how to do it using CSS and two image files A and B. Somewhere I saw those two images (A and B) put into a single image file and then they somehow wrote CSS so that in normal state the DIV showed upper half of the image on the background and in a hover state it showed the bottom half of the image. Could you please advise CSS code to achieve this? The DIV has no position set but it is a child of a DIV with relative position. Thank you in advance.
Vojtech
This is called CSS spriting and is an awesome technique that everyone should use.
See this answer for a good overview. What it comes down to is having a DOM element with a defined height and width and using a background image that is larger than that area. Then you can selectively show only portions of that background image using background-position
I need to create this layout and I'd like to do as much of it as possible with CSS, rather than using images and whatever.
As such, how can I do this in CSS? (if at all?)
As you can see, there is the image behind, with the button overlaid with padding. The bit that I'm struggling with is creating the curves on the IMAGE above and to the left of the button and bottom to the right of the button (I've pointed them out on the pic below).
Any help would be great.
Thanks
I know just enough CSS to be dangerous so I can't detail every step, but I think you can approach it like this:
Split the background image into two separate images both at a z-index of 0 at the height of the top of the grey box. I think you can use two div's that reference the same original image with different offsets (similar to CSS Sprites) but I don't know the details of how to do that. The left edge of the lower div would start where the grey box ends. Round the lower-left corner of each "image" div.
Add the grey box at a z-index of 1 with appropriate rounding, and then the blue box at a z-index of 2, again with appropriate rounding.
The background of the block element containing all of this would also have to be grey to match the grey border and properly fill in grey where your right-most arrow is pointing.
You don't have to split your image at all, only the container divs.
Let me detail a bit:
You can have your image set as a background image instead of putting it in a src attribute of an img tag. This technique is most commonly used when working with CSS sprites.
So, if you have you uppermost div at a constant width and height, if you try to apply the background image in it, you'll see it fits very nice.
On the bottom, you have two divs or whatever block element you'll like, just be sure to put fixed width and height, so the background will be applied and you will be able to actually see it.
Then all you have to do is fiddle with css background-position to adjust the SE chunk of image.
I'll be putting a small demo together to better illustrate the idea.
After you have a big div at the top, and two smaller at the bottom, where two of them share the same background-image, but with different background-position, you can safely add some css3 border-radius to fit your roundness needs. You can also use some tool like http://css3generator.com/ to add a compatibility layer on all browsers with ease.
That is very easy to realize with pure css. The page you have shown is divided into 3 divs without any margin. You only need to set the right border radius for each div.
This is a function of the background image, which is a css element if that's what you mean, but it is not a seperate attribute for a selector, at least not in standard CSS. Wait until CSS3 becomes more prevelant, then it's corner-radius or some such thing.
Well it's 3 probably 3 seperate divs, a hole "burned" into the background image, or a div being overlayed for the button.
The best way to figure out how it's done is to read the source of the page you found it on.
For convenience:
If you have a webkit based browser like chrome or safari then enable developper mode mouse over the button "right click" and choose inspect element. Otherwise you can pour over the page source until you find what you want.