rowid,title,contents,year,author,author_slug,published,url,topic 110,Shiny Happy Buttons,"Since Mac OS X burst onto our screens, glossy, glassy, shiny buttons have been almost de rigeur, and have essentially, along with reflections and rounded corners, become a cliché of Web 2.0 “design”. But if you can’t beat ‘em you’d better join ‘em. So, in this little contribution to our advent calendar, we’re going to take a plain old boring HTML button, and 2.0 it up the wazoo. But, here’s the catch. We’ll use no images, either in our HTML or our CSS. No sliding doors, no image replacement techniques. Just straight up, CSS, CSS3 and a bit of experimental CSS. And, it will be compatible with pretty much any browser (though with some progressive enhancement for those who keep up with the latest browsers). The HTML We’ll start with our HTML. OK, so it’s not shiny yet – but boy will it ever be. Before styling, that’s going to look like this. Ironically, depending on the operating system and browser you are using, it may well be a shiny button already, but that’s not the point. We want to make it shiny 2.0. Our mission is to make it look something like this If you want to follow along at home keep in mind that depending on which browser you are using you may see fewer of the CSS effects we’ve added to create the button. As of writing, only in Safari are all the effects we’ll apply supported. Taking a look at our finished product, here’s what we’ve done to it: We’ve given the button some padding and a width. We’ve changed the text color, and given the text a drop shadow. We’ve given the button a border. We’ve given the button some rounded corners. We’ve given the button a drop shadow. We’ve given the button a gradient background. and remember, all without using any images. Styling the button So, let’s get to work. First, we’ll add given the element some padding and a width: button { padding: .5em; width: 15em; } Next, we’ll add the text color, and the drop shadow: color: #ffffff; text-shadow: 1px 1px 1px #000; A note on text-shadow If you’ve not seen text-shadows before well, here’s the quick back-story. Text shadow was introduced in CSS2, but only supported in Safari (version 1!) some years later. It was removed from CSS2.1, but returned in CSS3 (in the text module). It’s now supported in Safari, Opera and Firefox (3.1). Internet Explorer has a shadow filter, but the syntax is completely different. So, how do text-shadows work? The three length values specify respectively a horizontal offset, a vertical offset and a blur (the greater the number the more blurred the shadow will be), and finally a color value for the shadow. Rounding the corners Now we’ll add a border, and round the corners of the element: border: solid thin #882d13; -webkit-border-radius: .7em; -moz-border-radius: .7em; border-radius: .7em; Here, we’ve used the same property in three slightly different forms. We add the browser specific prefix for Webkit and Mozilla browsers, because right now, both of these browsers only support border radius as an experimental property. We also add the standard property name, for browsers that do support the property fully in the future. The benefit of the browser specific prefix is that if a browser only partly supports a given property, we can easily avoid using the property with that browser simply by not adding the browser specific prefix. At present, as you might guess, border-radius is supported in Safari and Firefox, but in each the relevant prefix is required. border-radius takes a length value, such as pixels. (It can also take two length values, but that’s for another Christmas.) In this case, as with padding, I’ve used ems, which means that as the user scales the size of text up and down, the radius will scale as well. You can test the difference by making the radius have a value of say 5px, and then zooming up and down the text size. We’re well and truly on the way now. All we need to do is add a shadow to the button, and then a gradient background. In CSS3 there’s the box-shadow property, currently only supported in Safari 3. It’s very similar to text-shadow – you specify a horizontal and vertical offset, a blur value and a color. -webkit-box-shadow: 2px 2px 3px #999; box-shadow: 2px 2px 2px #bbb; Once more, we require the “experimental” -webkit- prefix, as Safari’s support for this property is still considered by its developers to be less than perfect. Gradient Background So, all we have left now is to add our shiny gradient effect. Now of course, people have been doing this kind of thing with images for a long time. But if we can avoid them all the better. Smaller pages, faster downloads, and more scalable designs that adapt better to the user’s font size preference. But how can we add a gradient background without an image? Here we’ll look at the only property that is not as yet part of the CSS standard – Apple’s gradient function for use anywhere you can use images with CSS (in this case backgrounds). In essence, this takes SVG gradients, and makes them available via CSS syntax. Here’s what the property and its value looks like: background-image: -webkit-gradient(linear, left top, left bottom, from(#e9ede8), to(#ce401c),color-stop(0.4, #8c1b0b)); Zooming in on the gradient function, it has this basic form: -webkit-gradient(type, point, point, from(color), to(color),color-stop(where, color)); Which might look complicated, but is less so than at first glance. The name of the function is gradient (and in this case, because it is an experimental property, we use the -webkit- prefix). You might not have seen CSS functions before, but there are others, including the attr() function, used with generated content. A function returns a value that can be used as a property value – here we are using it as a background image. Next we specify the type of the gradient. Here we have a linear gradient, and there are also radial gradients. After that, we specify the start and end points of the gradient – in our case the top and bottom of the element, in a vertical line. We then specify the start and end colors – and finally one stop color, located at 40% of the way down the element. Together, this creates a gradient that smoothly transitions from the start color in the top, vertically to the stop color, then smoothly transitions to the end color. There’s one last thing. What color will the background of our button be if the browser doesn’t support gradients? It will be white (or possibly some default color for buttons). Which may make the text difficult or impossible to read. So, we’ll add a background color as well (see why the validator is always warning you when a color but not a background color is specified for an element?). If we put it all together, here’s what we have: button { width: 15em; padding: .5em; color: #ffffff; text-shadow: 1px 1px 1px #000; border: solid thin #882d13; -webkit-border-radius: .7em; -moz-border-radius: .7em; border-radius: .7em; -webkit-box-shadow: 2px 2px 3px #999; box-shadow: 2px 2px 2px #bbb; background-color: #ce401c; background-image: -webkit-gradient(linear, left top, left bottom, from(#e9ede8), to(#ce401c),color-stop(0.4, #8c1b0b)); } Which looks like this in various browsers: In Safari (3) In Firefox 3.1 (3.0 supports border-radius but not text-shadow) In Opera 10 and of course in Internet Explorer (version 8 shown here) But it looks different in different browsers Yes, it does look different in different browsers, but we all know the answer to the question “do web sites need to look the same in every browser?“. Even if you really think sites should look the same in every browser, hopefully this little tutorial has whet your appetite for what CSS3 and experimental CSS that’s already supported in widely used browsers (and we haven’t even touched on animations and similar effects!). I hope you’ve enjoyed out little CSSMas present, and look forward to seeing your shiny buttons everywhere on the web. Oh, and there’s just a bit of homework – your job is to use the :hover selector, and make a gradient in the hover state.",2008,John Allsopp,johnallsopp,2008-12-18T00:00:00+00:00,https://24ways.org/2008/shiny-happy-buttons/,code 177,"HTML5: Tool of Satan, or Yule of Santa?","It would lead to unseasonal arguments to discuss the title of this piece here, and the arguments are as indigestible as the fourth turkey curry of the season, so we’ll restrict our article to the practical rather than the philosophical: what HTML5 can you reasonably expect to be able to use reliably cross-browser in the early months of 2010? The answer is that you can use more than you might think, due to the seasonal tinsel of feature-detection and using the sparkly pixie-dust of IE-only VML (but used in a way that won’t damage your Elf). Canvas canvas is a 2D drawing API that defines a blank area of the screen of arbitrary size, and allows you to draw on it using JavaScript. The pictures can be animated, such as in this canvas mashup of Wolfenstein 3D and Flickr. (The difference between canvas and SVG is that SVG uses vector graphics, so is infinitely scalable. It also keeps a DOM, whereas canvas is just pixels so you have to do all your own book-keeping yourself in JavaScript if you want to know where aliens are on screen, or do collision detection.) Previously, you needed to do this using Adobe Flash or Java applets, requiring plugins and potentially compromising keyboard accessibility. Canvas drawing is supported now in Opera, Safari, Chrome and Firefox. The reindeer in the corner is, of course, Internet Explorer, which currently has zero support for canvas (or SVG, come to that). Now, don’t pull a face like all you’ve found in your Yuletide stocking is a mouldy satsuma and a couple of nuts—that’s not the end of the story. Canvas was originally an Apple proprietary technology, and Internet Explorer had a similar one called Vector Markup Language which was submitted to the W3C for standardisation in 1998 but which, unlike canvas, was not blessed with retrospective standardisation. What you need, then, is some way for Internet Explorer to translate canvas to VML on-the-fly, while leaving the other, more standards-compliant browsers to use the HTML5. And such a way exists—it’s a JavaScript library called excanvas. It’s downloadable from http://code.google.com/p/explorercanvas/ and it’s simple to include it via a conditional comment in the head for IE: Simply include this, and your canvas will be natively supported in the modern browsers (and the library won’t even be downloaded) whereas IE will suddenly render your canvas using its own VML engine. Be sure, however, to check it carefully, as the IE JavaScript engine isn’t so fast and you’ll need to be sure that performance isn’t too degraded to use. Forms Since the beginning of the Web, developers have been coding forms, and then writing JavaScript to check whether an input is a correctly formed email address, URL, credit card number or conforms to some other pattern. The cumulative labour of the world’s developers over the last 15 years makes whizzing round in a sleigh and delivering presents seem like popping to the corner shop in comparison. With HTML5, that’s all about to change. As Yaili began to explore on Day 3, a host of new attributes to the input element provide built-in validation for email address formats (input type=email), URLs (input type=url), any pattern that can be expressed with a JavaScript-syntax regex (pattern=""[0-9][A-Z]{3}"") and the like. New attributes such as required, autofocus, input type=number min=3 max=50 remove much of the tedious JavaScript from form validation. Other, really exciting input types are available (see all input types). The datalist is reminiscent of a select box, but allows the user to enter their own text if they don’t want to choose one of the pre-defined options. input type=range is rendered as a slider, while input type=date pops up a date picker, all natively in the browser with no JavaScript required at all. Currently, support is most complete in an experimental implementation in Opera and a number of the new attributes in Webkit-based browsers. But don’t let that stop you! The clever thing about the specification of the new Web Forms is that all the new input types are attributes (rather than elements). input defaults to input type=text, so if a browser doesn’t understand a new HTML5 type, it gracefully degrades to a plain text input. So where does that leave validation in those browsers that don’t support Web Forms? The answer is that you don’t retire your pre-existing JavaScript validation just yet, but you leave it as a fallback after doing some feature detection. To detect whether (say) input type=email is supported, you make a new input type=email with JavaScript but don’t add it to the page. Then, you interrogate your new element to find out what its type attribute is. If it’s reported back as “email”, then the browser supports the new feature, so let it do its work and don’t bring in any JavaScript validation. If it’s reported back as “text”, it’s fallen back to the default, indicating that it’s not supported, so your code should branch to your old validation routines. Alternatively, use the small (7K) Modernizr library which will do this work for you and give you JavaScript booleans like Modernizr.inputtypes[email] set to true or false. So what does this buy you? Well, first and foremost, you’re future-proofing your code for that time when all browsers support these hugely useful additions to forms. Secondly, you buy a usability and accessibility win. Although it’s tempting to style the stuffing out of your form fields (which can, incidentally, lead to madness), whatever your branding people say, it’s better to leave forms as close to the browser defaults as possible. A browser’s slider and date pickers will be the same across different sites, making it much more comprehensible to users. And, by using native controls rather than faking sliders and date pickers with JavaScript, your forms are much more likely to be accessible to users of assistive technology. HTML5 DOCTYPE You can use the new DOCTYPE !doctype html now and – hey presto – you’re writing HTML5, as it’s pretty much a superset of HTML4. There are some useful advantages to doing this. The first is that the HTML5 validator (I use http://html5.validator.nu) also validates ARIA information, whereas the HTML4 validator doesn’t, as ARIA is a new spec developed after HTML4. (Actually, it’s more accurate to say that it doesn’t validate your ARIA attributes, but it doesn’t automatically report them as an error.) Another advantage is that HTML5 allows tabindex as a global attribute (that is, on any element). Although originally designed as an accessibility bolt-on, I ordinarily advise you don’t use it; a well-structured page should provide a logical tab order through links and form fields already. However, tabindex=""-1"" is a legal value in HTML5 as it allows for the element to be programmatically focussable by JavaScript. It’s also very useful for correcting a bug in Internet Explorer when used with a keyboard; in-page links go nowhere if the destination doesn’t have a proprietary property called hasLayout set or a tabindex of -1. So, whether it is the tool of Satan or yule of Santa, HTML5 is just around the corner. Some you can use now, and by the end of 2010 I predict you’ll be able to use a whole lot more as new browser versions are released.",2009,Bruce Lawson,brucelawson,2009-12-05T00:00:00+00:00,https://24ways.org/2009/html5-tool-of-satan-or-yule-of-santa/,code 235,"Real Animation Using JavaScript, CSS3, and HTML5 Video","When I was in school to be a 3-D animator, I read a book called Timing for Animation. Though only 152 pages long, it’s essentially the bible for anyone looking to be a great animator. In fact, Pixar chief creative officer John Lasseter used the first edition as a reference when he was an animator at Walt Disney Studios in the early 1980s. In the book, authors John Halas and Harold Whitaker advise: Timing is the part of animation which gives meaning to movement. Movement can easily be achieved by drawing the same thing in two different positions and inserting a number of other drawings between the two. The result on the screen will be movement; but it will not be animation. But that’s exactly what we’re doing with CSS3 and JavaScript: we’re moving elements, not animating them. We’re constantly specifying beginning and end states and allowing the technology to interpolate between the two. And yet, it’s the nuances within those middle frames that create the sense of life we’re looking for. As bandwidth increases and browser rendering grows more consistent, we can create interactions in different ways than we’ve been able to before. We’re encountering motion more and more on sites we’d generally label ‘static.’ However, this motion is mostly just movement, not animation. It’s the manipulation of an element’s properties, most commonly width, height, x- and y-coordinates, and opacity. So how do we create real animation? The metaphor In my experience, animation is most believable when it simulates, exaggerates, or defies the real world. A bowling ball falls differently than a racquetball. They each have different weights and sizes, which affect the way they land, bounce, and impact other objects. This is a major reason that JavaScript animation frequently feels mechanical; it doesn’t complete a metaphor. Expanding and collapsing a
feels very different than a opening a door or unfolding a piece of paper, but it often shouldn’t. The interaction itself should tie directly to the art direction of a page. Physics Understanding the physics of a situation is key to creating convincing animation, even if your animation seeks to defy conventional physics. Isaac Newton’s first law of motion’s_laws_of_motion states, “Every body remains in a state of rest or uniform motion (constant velocity) unless it is acted upon by an external unbalanced force.” Once a force acts upon an object, the object’s shape can change accordingly, depending on the strength of the force and the mass of the object. Another nugget of wisdom from Halas and Whitaker: All objects in nature have their own weight, construction, and degree of flexibility, and therefore each behaves in its own individual way when a force acts upon it. This behavior, a combination of position and timing, is the basis of animation. The basic question which an animator is continually asking himself is this: “What will happen to this object when a force acts upon it?” And the success of his animation largely depends on how well he answers this question. In animating with CSS3 and JavaScript, keep physics in mind. How ‘heavy’ is the element you’re interacting with? What kind of force created the action? A gentle nudge? A forceful shove? These subtleties will add a sense of realism to your animations and make them much more believable to your users. Misdirection Magicians often use misdirection to get their audience to focus on one thing rather than another. They fool us into thinking something happened that actually didn’t. Animation is the same, especially on a screen. By changing the arrangement of pixels on screen at a fast enough rate, your eyes fool your mind into thinking an object is actually in motion. Another important component of misdirecting in animation is the use of multiple objects. Try to recall a cartoon where a character vanishes. More often, the character makes some sort of exaggerated motion (this is called anticipation) then disappears, and a puff a smoke follows. That smoke is an extra element, but it goes a long way into make you believe that character actually disappeared. Very rarely does a vanishing character’s opacity simply go from one hundred per cent to zero. That’s not believable. So why do we do it with
s? Armed with the ammunition of metaphors and misdirection, let’s code an example. Shake, rattle, and roll (These demos require at least a basic understanding of jQuery and CSS3. Run away if your’re afraid, or brush up on CSS animation and resources for learning jQuery. Also, these demos use WebKit-specific features and are best viewed in the latest version of Safari, so performance in other browsers may vary.) We often see the design pattern of clicking a link to reveal content. Our “first demo”:”/examples/2010/real-animation/demo1/ shows us exactly that. It uses jQuery’s “ slideDown()”:http://api.jquery.com/slideDown/ method, as many instances do. But what force acted on the
that caused it to open? Did pressing the button unlatch some imaginary hook? Did it activate an unlocking sequence with some gears? Take 2 Our second demo is more explicit about what happens: the button fell on the
and shook its content loose. Here’s how it’s done. function clickHandler(){ $('#button').addClass('animate'); return false; } Clicking the link adds a class of animate to our button. That class has the following CSS associated with it: In our keyframe definition, we’ve specified from and to states. This is great, because we can be explicit about how an object starts and finishes moving. What’s also extra handy is that these CSS keyframes broadcast events that you can react to with JavaScript. In this example, we’re listening to the webkitAnimationEnd event and opening the
only when the sequence is complete. Here’s that code. function attachAnimationEventHandlers(){ var wrap = document.getElementById('wrap'); wrap.addEventListener('webkitAnimationEnd', function($e) { switch($e.animationName){ case ""ANIMATE"" : openMain(); break; default: } }, false); } function openMain(){ $('#main .inner').slideDown('slow'); } (For more info on handling animation events, check out the documentation at the Safari Reference Library.) Take 3 The problem with the previous demo is that the subtleties of timing aren’t evident. It still feels a bit choppy. For our third demo, we’ll use percentages instead of keywords so that we can insert as many points as we need to communicate more realistic timing. The percentages allow us to add the keys to well-timed animation: anticipation, hold, release, and reaction. Take 4 The button animation is starting to feel much better, but the reaction of the
opening seems a bit slow. This fourth demo uses jQuery’s delay() method to time the opening precisely when we want it. Since we know the button’s animation is one second long and its reaction starts at eighty per cent of that, that puts our delay at 800ms (eighty per cent of one second). However, here’s a little pro tip: let’s start the opening at 750ms instead. The extra fifty milliseconds makes it feel more like the opening is a reaction to the exact hit of the button. Instead of listening for the webkitAnimationEnd event, we can start the opening as soon as the button is clicked, and the movement plays on the specified delay. function clickHandler(){ $('#button').addClass('animate'); openMain(); return false; } function openMain(){ $('#main .inner').delay(750).slideDown('slow'); } Take 5 We can tweak the timing of that previous animation forever, but that’s probably as close as we’re going to get to realistic animation with CSS and JavaScript. However, for some extra sauce, we could relegate the whole animation in our final demo to a video sequence which includes more nuances and extra elements for misdirection. Here’s the basis of video replacement. Add a