Overriding CSS background image styles - both images are loaded? - html

If I have 2 CSS styles that assign background images to an element, and one style overrides the other. Will both images be downloaded by the browser or just the overriding one?
I reason I'm asking is I recently attended a workshop on conditional stylesheets for mobile devices. If I override my normal bg images with smaller ones to save bandwidth, will the larger images be loaded anyway? This seemed to be what the guy was saying but it seems strange to me it would work this way.

It seems in some cases the answer is yes:
http://www.cloudfour.com/css-media-query-for-mobile-is-fools-gold/
http://www.cloudfour.com/examples/mediaqueries/image-test/#t4

The overridden image will not be loaded.
Just to be clear, for example: http://jsfiddle.net/thirtydot/MjKfG/1/show/
<div id="test">test</div>
div {
background: url(http://dummyimage.com/600x400/000/fff)
}
#test {
background: url(http://dummyimage.com/200);
width: 200px;
height: 200px
}
Only http://dummyimage.com/200 will be loaded.
This is true in at least Chrome, Safari, Firefox, IE8/9, Opera.
I'd guess it's true in all browsers, because it's a simple and effective optimization.

The answer is NO. The first one was overridden won't load the background property. Why? Because browsers load your css file first before loading any other resources. They handle css files first then start loading images based on order and overriding order.
For example:
div {
border: solid 1px #000000;
background: url('images/sprites.png') no-repeat x y;
}
.mobile div {
border: solid 1px #000000;
background: url('images/sprites_mobile.png') no-repeat x y;
}
Browsers will process this css for your mobile to become like this:
div {
border: solid 1px #000000;
background: url('images/sprites_mobile.png') no-repeat x y;
}
And now, browsers already ignored the sprites_mobile.png for loading.

Can you not do an experiment and view the web log files to see what is happening?
Otherwise why not have a little PHP to select the appropriate style sheets depending on the device.

Related

How can I remove the single pixel space between these elements on retina displays?

http://jsfiddle.net/36ykrp9x/5/
HTML
<div class="container">
<button>O</button><button>O</button>
</div>
CSS
.container {
width: 100%;
background-color: rgb(120, 200, 200);
text-align: center;
}
button {
border: 0;
width: 3rem;
height: 3rem;
opacity: 0.8;
background-color: gray;
}
This above code best captures the visual bug I am interested in solving. I should note that this does not appear to affect Firefox or Safari's latest versions. I am currently on Chrome 39. If you are on a retina display and a recent version of Chrome and do not already see the thin line between the elements, try resizing the window a bit. A thin line between the buttons will flicker in and out of presence.
For my purposes, there is at least one element above the button group in the hierarchy with 100% width, and the buttons must be horizontally centered within it. The buttons themselves must have opacity between 0 and 1. They can be divs, or any other element for that matter - but I have indeed tried others and found the problem remains.
Unfortunately, centering the button group within a fixed-width element doesn't appear to solve this issue for me, as the fixed-width button group must ultimately also be centered somehow which appears to resurrect the issue. Nudging with margins can lead to overlapping which is more obvious with elements that have such opacity - which is really no better than having the gap in the first place.
It is worth noting that indeed using background-color: rgba(r,g,b,a) addresses the problem for most intents and purposes, but I am very interested in resolving this without it if only to see that it's possible.
I am not particularly interested in solutions that involve JavaScript. Am I out of luck?
Based on the information you provided, and my own experience with Google Chrome, I'm led to the suggestion that this is a browser bug in Chrome, considering it only occurs in Chrome on a Retina screen, and other browsers such as Safari and Firefox do not exhibit the problem. Your HTML and CSS looks perfect so I don't see issues here.
You can verify that this is a browser rendering issue by also checking this in a latest version of Opera (on your Retina display), as Opera now uses the same Blink rendering engine as Chrome (which is forked from Webkit). If Opera exhibits the same issue then its a Engine issue which should be logged as a bug.
Unless someone else figures out a way around it, I am normally inclined to leave browser rendering bugs like this alone where possible so that you're not hacking code in your site, and when the bug is fixed, you don't have to do anything to your site.
The problem is with jsfiddle.net. I have the same 1 pixel space in Chrome 40 on retina. Try this: http://dabblet.com/gist/c0068a79fc0268482ee1
or the following code, loaded directly:
<!doctype html>
<html>
<head>
<meta charset="utf-8">
<title>Untitled Document</title>
<style>
.container {
width: 100%;
background-color: rgb(120, 200, 200);
text-align: center;
}
button {
border: 0;
width: 3rem;
height: 3rem;
opacity: 0.8;
background-color: gray;
}
</style>
</head>
<body>
<div class="container">
<button>O</button><button>O</button>
</div>
</body>
</html>

Transparent background rendering White in Internet Explorer

In my page layout I have two <div> tags. One, with id #image-panel and the other with #image-content-panel.
The two <div>s are stacked on top of each other using position: absolute. #image-content-panel (has higher z-index) is on top of #image-panel.
Both <div>s have background: transparent.
The page renders fine in Chrome, Safari, and Firefox i.e. I can see the image through the text (heading and paragraph etc.). But in IE (version 8) #image-content-panel is being redered with a white background.
You can see screenshots below:
Rendering in Crome, Safari, Mozilla
Rendering in IE 8
Relevant CSS and HTML code :
HTML Code
CSS Code
I'd like the page to render same in IE too.
Any help is appreciated.
Please propose an Alternative solution too if this can't be fixed.
UPDATE
The Jquery Cycle Plugin will add a background colour to elements in older versions of IE.
You need to set the cleartypeNoBg option to true in your Cycle initialisation.
$("#image-content-panel").cycle({
fx : 'scrollRight',
speed : 2700,
cleartypeNoBg: true
});
EDIT The below is not relevent
IE8 doesn't support rgba values and will fallback to a solid colour. If you don't define a fallback it will default to white which is what you are seeing.
There's a couple of ways to handle this.
1. Accept IE8's limitations.
#header {
z-index: 100 !important;
width: 100%;
height: 50px;
background: rgb(0,0,0);
background: rgba(0,0,0,0.6);
margin: 10px 0 0 0;
}
#header will have a solid black background in browsers that don;t support rgba. Semi opaque in browsers that do.
2.Use a filter
#header {
z-index: 100 !important;
width: 100%;
height: 50px;
background: rgba(0,0,0,0.6);
-ms-filter: "progid:DXImageTransform.Microsoft.gradient(startColorstr=#99000000, endColorstr=#99000000)"
margin: 10px 0 0 0;
}
#header will have 60% transparent black background in IE8 and proper browsers. Personally, I hate using filters. They make your markup hideous and are difficult to maintain unless you are excellent at converting rgb to hex codes in your head (which I'm not). Also, this particular filter is IE8+. It will not work in IE7, though there are other filters that will work in IE6-7. You should also probably separate this out in to an IE8 specific stylesheet or use some other method to prevent IE9 from using the filter as IE9 supports rgba.
3.Use a 1px x 1px black, semi-transparent .png
#header {
z-index: 100 !important;
width: 100%;
height: 50px;
background: url(background.png) repeat;
margin: 10px 0 0 0;
}
This is the route I usually go down simply because it's simple. It takes seconds to create a .png if you need to change the alpha and you don't need to worry about browser inconsistencies.
As others have said, IE8 doesn't support RGBA colour values.
There is a hack you can use to work around this though: I recommend trying out CSS3Pie on your site; it implements a number of modern CSS features into old versions of IE, including RGBA colours in backgrounds.
Hope that helps.

hr not seen when printing

I'm writing some html to be shown in the screen and sent by e-mail too (I'm making it with tables). I want to sepair the sections. I've tried putting some hr tags and it's seen properly in the navigators (Internet Explorer 9 and Firefox 10) and in the email managers (Outlook 2010, Hotmail and GMail). Well, if I print it (in the navigators) I don't see the hr tags. I have the same problem with a label whose background color is seen in the navigators and email managers but when the document is printed is not seen. (The css file is the same for showing in screen and for printing).
Thanks for your answers.
You can make an <hr> that's printable without changing browser settings like this:
hr {
display: block;
height: 1px;
background: transparent;
width: 100%;
border: none;
border-top: solid 1px #aaa;
}
caveat: I only tested in chrome.
The background not printing is a preference setting in your browser. It's off by default to save ink. But if the hr (or any construct) is white and is showing on the coloured background on your screen, you might want to switch this setting on.
Make printable without changing browser settings:
hr {
border-top: solid 1px #000 !important;
}
caveat: Tested in Chrome, Firefox, Microsoft Edge.

Button border colors in non-IE6 browsers

I am updating an IE6-era website so that cosmetic differences in modern (IE8, Firefox 4 in this scenario) browsers are eliminated, or at least reduced.
We've ran into an issue with buttons, which are styled using background-color: #EFEFEF; and border: 1px. In IE6 this border setting neatly reduces the border on buttons.
However, in IE8 and Firefox 4 setting a CSS style of border: 1px completely removes the border.
I've tried using border_SIDE_color to set the color of the relevant sides of the button appropriately but this has no impact.
What approach should I use instead? This is a large legacy website, containing many buttons so I am looking for a CSS-only solution, if one exists. Forcing IE8 into compatibility mode is also not an option.
Try setting border-style: outset;. Or use the shorthand version with the other styles you're already using:
.mybutton {
border: outset #EFEFEF 1px;
}

How can I increase a scrollbar's width using CSS?

Is it possible to increase the width of a scrollbar on a <div> element placed inside the <body>?
I am not talking about the default scrollbar on the browser itself, this page runs in full screen mode and because the browser scrollbar never comes into picture, the inner <div> element has its own scrollbar.
This can be done in WebKit-based browsers (such as Chrome and Safari) with only CSS:
::-webkit-scrollbar {
width: 2em;
height: 2em
}
::-webkit-scrollbar-button {
background: #ccc
}
::-webkit-scrollbar-track-piece {
background: #888
}
::-webkit-scrollbar-thumb {
background: #eee
}​
JSFiddle Demo
References:
Custom Scrollbars in WebKit | CSS-Tricks
WebKit scrollbar demo from CSS-Tricks
15 Different scrollbar configurations
If you are talking about the scrollbar that automatically appears on a div with overflow: scroll (or auto), then no, that's still a native scrollbar rendered by the browser using normal OS widgets, and not something that can be styled(*).
Whilst you can replace it with a proxy made out of stylable divs and JavaScript as suggested by Matt, I wouldn't recommend it for the general case. Script-driven scrollbars never quite behave exactly the same as real OS scrollbars, causing usability and accessibility problems.
(*: Except for the IE colouring styles, which I wouldn't really recommend either. Apart from being IE-only, using them forces IE to fall back from using nice scrollbar images from the current Windows theme to ugly old Win95-style scrollbars.)
You can stablish specific toolbar for div
div::-webkit-scrollbar {
width: 12px;
}
div::-webkit-scrollbar-track {
-webkit-box-shadow: inset 0 0 6px rgba(0,0,0,0.3);
border-radius: 10px;
}
see demo in jsfiddle.net
This sets the scrollbar width:
::-webkit-scrollbar {
width: 8px; // for vertical scroll bar
height: 8px; // for horizontal scroll bar
}
// for Firefox add this class as well
.thin_scroll{
scrollbar-width: thin; // auto | thin | none | <length>;
}
Yes.
If the scrollbar is not the browser scrollbar, then it will be built of regular HTML elements (probably divs and spans) and can thus be styled (or will be Flash, Java, etc and can be customized as per those environments).
The specifics depend on the DOM structure used.
My experience with trying to use CSS to modify the scroll bars is don't. Only IE will let you do this.