CodePen https://codepen.io/david263/pen/zYNaoRQ shows an example simple home page layout that fits the browser viewport perfectly and centers some div content (choose Change View > Full Page View in CodePen to see the page clearly). But note the CSS style elements used to set div heights and the many Bootstrap 5 classes used to achieve vertical centering. It took several days to get this working, but it fails to use only simple Bootstrap 5 classes.
<header id=jumbo class="px-5 d-flex justify-content-center align-items-center bg-dark" style="height:70vh">
<div class="row col-12 text-center text-light">
<h1 class="font-weight-bold display-4">Vertically Centered Jumbo Content</h1>
<h3 class="font-weight-bold">A great starter layout for a landing page</h3>
</div>
</header>
My attempt to use the usual container, row, and col classes (see https://codepen.io/david263/full/xxgzLPj) failed to achieve the full height demonstrated by the first example.
<header id=jumbo class="container-fluid bg-dark">
<div class="h-50 row align-items-center col-12 text-center text-light">
<div class="col py-auto">
<h1 class="font-weight-bold display-4">Vertically Centered Jumbo Content</h1>
<h3 class="font-weight-bold">A great starter layout for a landing page</h3>
</div>
</div>
</header>
And these difficulties were encountered before adding a background image, which doesn't seem possible in Bootstrap 5 at all.
Don't get me wrong; I'm not opposed to using CSS when necessary. It's just that it's hard to tell exactly what the limits are for Bootstrap 5 so that custom CSS becomes necessary.
Many websites have a home page containing a large photo or video in the background, with text centered horizontally and vertically in the foreground, so this example represents something that is very often used. Surely such a frequent layout must be possible in Bootstrap 5.
Bootstrap isn't a silver bullet - its a framework (think of it as a chassis that you need build on top of). Bootstrap offers a few "helper" classes so that one does not need to add a whole bunch of repetitive CSS .. but that's all it can do. A clear understanding of CSS helps a lot too in using Bootstrap.
For example, the h-50 class is only height: 50%; in CSS. That's 50% of it's parent .. but your <header id="jumbo" does not have a height .. so 50% of what .. 0 .. is unknown?? (This may vary from browser to browser)
It's not clear what you're trying to achieve - but if you head on over to https://getbootstrap.com/docs/5.0/examples/ you'll see a whole bunch of examples and starting points for you to get to where you need to be. I think the Cover example is a good spot to land on. (Once there, right click and "view page source" ...)
I have this simple html that uses a tiny bit of bootstrap:
<div id="A" class="col-4">
<div class="img" style="background-image: url(/images/image.jpg);">
</div>
<div id="B" class="col-8">
*some content*
</div>
And its corresponding CSS:
.img { width: 100%; height: 100%; }
Everything is in this pen : https://codepen.io/anon/pen/EbBGQw
The image correctly displays on the entire height of the parent div on either Chrome or Firefox, either Windows or Android :
However, on iOS devices (tested on iPhone and iPad recent browsers), the images don't show up :
I've done some digging and cleared some potential culprits :
I'm not using position: fixed;
My images aren't too large
I'm not using the background shorthand
What I have found, however, is that entering any text inside the "img" div will make the background-image appear behind the text. The image still won't cover the entire div, but it does appear.
Why is Safari not showing the image properly ? What is the best way to deal with the issue and have the image properly cover its entire div ?
When you set the height to 100% :
The height will only be as large as what is inside the element.
If there is nothing inside, the height will be 0.
If there is a paragraph (as shown here), the height will be as large as the paragraph. I suggest using either pixels, rems or ems instead.
The way you wrote your image style background did not work in chrome either. I put it in the img class instead and it worked.
If you don't want to add the background image to your img class, you could do this instead:
<div class="img" style="background-image: url('image.jpg')"><p>Testing</p></div>
.img {
width: 100%;
height: 100%;
background-image: url("image.jpg");
}
<div class="img"><p>Testing</p></div>
After more digging, and the suggestion from #Michelle Cantin, I found out that the height: 100% from my CSS is ignored by Safari.
In this great answer, a fix is proposed using position: absolute;. I applied relative position to the parent element (#A) and absolute positioning to the child (.img), which fixed the issue.
The image can be seen covering the entire left column for as heigh as the right column goes in this pen : https://codepen.io/anon/pen/bYPzew
I'm noticing an odd effect in jQuery Mobile when viewing a page's background image on a low resolution screen (or resizing your browser's window to simulate a small screen). When navigating to a page with a background image, the image appears near the bottom of the screen for a split second, before "jumping" up to the center of the screen (it should appear in the center of the screen right from the start).
I set up a fiddle to demonstrate what I'm referring to. To get the full effect, first resize the fiddle "Result" window (bottom right of the screen) to where it's approximately the size of the div with the red background. Then click on the "Image page" button.
http://jsfiddle.net/FgVz8/3/
What causes the background image to have this "jerky" behavior? And more importantly, any ideas how I can fix it?
It wouldn't be a big deal if it was just a single image, but I'm building an image gallery with back/forward buttons, and every single image (each on a separate jQM "page") that is navigated to exhibits this strange effect, so it makes for a rather "unsmooth" user experience... especially when viewing multiple images one after another.
Any help is greatly appreciated!
Edit: it looks like Stack Overflow won't let me link out to JSFiddle unless I also post my code here, so here's my code...
HTML body...
<div id="home_page" data-role="page">
<div id="content" data-role="content">
Image page
</div>
</div>
<div id="image_page" data-role="page">
<p>Test 123...</p>
</div>
CSS...
#content {
background: red;
width: 200px;
height: 250px;
}
#image_page {
background: url(http://upload.wikimedia.org/wikipedia/commons/thumb/a/aa/Logo_Google_2013_Official.svg/2000px-Logo_Google_2013_Official.svg.png);
background-size: contain;
background-repeat: no-repeat;
background-position: center;
}
I'm using a jQuery UI Theme, which is predominantly white text on a black background. I'm using a <fieldset> with a <legend> and the text of the latter is being display in black on a black background (black being the browser's default font colour).
I've tried applying various jQuery UI Theme CSS classes to the legend (e.g. "ui-widget-content"), but I get too much extra baggage, such as borders and backgrounds, when I just want the text to be white.
Before anyone says "why don't you just make the text white?", I should state that I have switchable themes, so it has to get the colour from the theme's stylesheet.
I know that I can use jQuery to apply the CSS class to all legends, when I know which one I want, thus:
$("legend").addClass("???");
Any help would be greatly appreciated.
I solved the problem by using jQuery to set the <legend> colour to be the same as that of an element with a CSS class of ui-widget-content.
$("legend").css("color", $(".ui-widget-content").css("color"));
Obviously, this depends on there actually being an element with that class present. For my purposes, I know there always will be.
In recently testing a web application on Windows/Mac desktop browsers - and then on an iPad I noticed various differences in Safari that I wasn't expecting. Even though the version # is the same.
I'd like to compose a list of those differences (for myself and others) to have as a developer reference.
e.g. in Safari on the iPad
iPad Safari takes full control of Select list/option styling
iPad opens the onscreen keyboard when an input element receives focus, thus inline floating calendar widgets (and the like) may not work as expected (or need to be altered)
iPad Safari doesn't support position:fixed like desktop Safari < iOS 5
iPad Safari (similar to iPhone/iPodTouch Safari) automatically hyperlinks 10 digit numbers to offer phone #/contact options
iPad Safari prompt('long message...','default'); shows only 1 line of the message (though it does provide scrolling of the message
I've heard from others that certain JavaScript doesn't work, etc. etc. but I have yet to fully test it thus I'd be grateful for any discoveries that you may have encountered.
A few more for you:
No Flash
Lousy iFrame support (so facebook like etc. needs a custom implementation for iPad)
Weird caching limitations
HTML textAreas doesn't get a scroll bar (you have to double-finger swipe - which of course, is amazingly intuitive)
In general. Treat it like a scaled up iPhone, not a scaled down Desktop.
I thought this might be useful: Apple's guide to preparing web content for the iPad
Just been caught out by the position:fixed issue my self
Safari on iPad has the same issue with button width/padding as on the iPhone
iPhone <button> padding unchangeable? describes this problem and a solution for removing padding on a button with text, but this does not help you if you want a button to be narrower than the padding itself (e.g. for a button that only has a small icon on it). To do that, I had to surround the button with an outer element with a defined width and overflow: hidden like so:
<span style="border: solid 1px blue; display: block; width: 16px; overflow: hidden">
<button style="-webkit-appearance: none; border-width: 0"> </button>
</span>
(the blue border is to show where the button is, it's not critical to the hack)
jQuery's offset() doesn't work: http://bugs.jquery.com/ticket/6446
It also looks like iPad Safari has issues with elements with overflow:auto; that therefore should show scrollbars (test page with div's and iframe's).
iPad Safari seems to have trouble handling background images in rare cases, showing weird lines of lower lying content.
There's not a lot about this in Google (yet).
iPad browser doesnt support file uploading(even if it supports it will useless as iPad does not have a standard File Browser). The file field appears with a Choose File button grayed out.
Beside doesn't support scrollbar in TextAea, it seems that we can using javascript to make text in TextArea selected automatically too.
This code will only move cursor to the end of text in TextArea.
<div>
<textarea id="text-embed-code" autocapitalize="off" multiline="">
There is a fox running after chrome.
</textarea>
<button onclick="testSelectText(event);">select text</button>
</div>
<script>
function testSelectText(e) {
var box = document.getElementById("text-embed-code");
box.select();
e.preventDefault();
return false;
}
</script>
There appears to be a bug in iPad Safari where a CSS element with both a background image and a background color is rendered with a slight border in the color of the background color. It should fill with the background image all the way to the edge of the rendered element.
I just had the same bug on my site, when trying to view it on an Ipad. The HTML structure is like:
<div class="main"> <!-- background-color: white -->
<div class="left"></div> <!-- background-image: url(some_transparent_png) -->
<div class="content">...</div>
<div class="right"></div> <!-- background-image: url(some_transparent_png) -->
</div>
The left layer uses a background-image, whereas the main layer uses just a background-color. The Ipad view shows a slight border at the edge of the left and right layer.
When i add
-webkit-background-size: 100% 100%;
to the left and right layer, the border disappears.
You can now control the styling of select lists on iOS by resetting it with -webkit-appearance: none;
This rule fixes animation flickering in Safari on iOS devices:
body {-webkit-transform:translate3d(0,0,0);}
There appears to be a bug in iPad Safari where a CSS element with both a background image and a background color is rendered with a slight border in the color of the background color. It should fill with the background image all the way to the edge of the rendered element.
24 bit transparent PNGS ABOVE A CERTAIN FILE SIZE don't render on the iPad2.
I can however get 8 bit ones of the same dimensions to render.
I haven't found out what this maximum file size is in order to get them to render.
I'm currently working on a small responsive web-app which makes heavy use of the iframe youtube api. Apparently the ipad version of safari doesn't support a few html5 methods which I use heavily in this project.
One of them is window.postMessage, which is a way of interacting with scripts on other pages, for example the a script that is used "within" that iframe. Autoplaying videos also doesn't work.
Frame problems. iPad Safari will both hide scrollbars and expand frames to the size of their content.
Changing the frame tag to include scrolling="yes" and noresize="noresize" appears to do nothing.
Some sites look fine on everything, even a Dreamcast browser, but not on iPad. The issue can be fixed using tables and iframes instead of normal framesetting (cols and rows, etc).
I also discovered that contenteditable is not supported in mobile safari, thus using a plain textarea is a better bet. Apple Developer Docs
position: fixed;
Does not work in iOS 4 but does work on iOS 5.