Christian Cantrell

I just made a quick screencast to show the current state of CSS Regions, and to demonstrate some new capabilities that will be here soon. In general, there are two aspects to CSS Regions:

1. The ability to have text automatically flow between regions.
2. The ability to hook into that flow using JavaScript in order to create more dynamic layouts.

If you use Chrome (Adobe’s work on CSS Regions is in WebKit which Chrome uses), you can go ahead and see text flow already working (including Chrome for Android). Other browsers have already committed to supporting CSS Regions, and we should know more about when their implementations will land soon. Let me know below if you have any comments or questions.

I’ve been working on some CSS Regions prototypes recently (if you’re new to CSS Regions, check out this post), so when the Chrome for Android beta came out the other day, I decided to see how some of my samples looked on mobile. It turns out, they work perfectly:

The CSS Regions capabilities currently in Chrome are pretty rudimentary, but I’m also working with some nightly WebKit builds which definitely take the feature to the next level (they include CSS Object Model support which enables the scripting of CSS Regions — that’s when they get really interesting). I’ll have plenty more samples and prototypes in the near future.

If you’re building any kind of a text editor in JavaScript, you might want to be able to dynamically set or change the text selection color. I discovered it wasn’t as easy to do as I expected it to be, so I thought I’d share the code. I created this extreme (and admittedly, somewhat obnoxious) example showing the selection color changing as the mouse moves, but the core of the code is something like this:

var ss = document.styleSheets[0];
ss.insertRule('#content::selection {color: #'+
              newForegroundColor+'; background: #'+
              newBackgroundColor+';}', 0);

Note that I only tested this code in Chrome and Safari (I’m only targeting WebKit browsers for now), however it can work with Firefox with the correct "moz" prefixed style name. I haven’t yet tested or investigated IE.

If you know another way of changing text selection properties in JavaScript, let me know.

Update (12/20/2011): Now works in Firefox as well as Chrome and Safari.

Since I’m not a very good designer, I usually try to do as much styling, design, and graphics in code as I can. For instance, when I wrote this mobile compass application in HTML, I did all the graphics programmatically using Canvas and CSS.

I’m now working on a project that requires one of those loading spinner animations that Apple seems to have made famous, so naturally, I started looking into ways to create one purely in code and/or CSS (no external assets). Fortunately, I found a great post on the Signal vs. Noise blog demonstrating exactly what I wanted to do. However, I decided to take it one step further, and write some JavaScript to generate both the required CSS and the HTML. The advantage of generating everything dynamically is that you can configure things like the size, color, and the number of bars in the animation at runtime.

Here’s an example of some randomly generated loading spinner animations which are 100% CSS and HTML generated by JavaScript (Chrome and Safari only for now). If you’re interested in the code, here’s the original CSS from Signal vs. Noise, and below is my port to JavaScript (view the source of the demo to see how to use it). It only works in WebKit-based browsers for the time being, but I’ll update it as browser capabilities get better. It works in WebKit-based browser, and in Firefox.

Check out the example.

var Spinner = {
  SPINNER_ID: '_spinner',
  prefix: (navigator.userAgent.indexOf('WebKit') != -1) ? 'webkit' : 'moz',
  getSpinner: function(size, numberOfBars, color) {
    if (document.getElementById(this.SPINNER_ID) == null) {
      var style = document.createElement('style');
      style.setAttribute('id', this.SPINNER_ID);
      style.innerHTML = '@-'+this.prefix+'-keyframes fade {from {opacity: 1;} to {opacity: 0.25;}}';
      document.getElementsByTagName('head')[0].appendChild(style);
    }
    var spinner = document.createElement('div');
    spinner.style.width = size;
    spinner.style.height = size;
    spinner.style.position = 'relative';
    var rotation = 0;
    var rotateBy = 360 / numberOfBars;
    var animationDelay = 0;
    var frameRate = 1 / numberOfBars;
    for (var i = 0; i < numberOfBars; ++i) {
      var bar = document.createElement('div');
      spinner.appendChild(bar);
      bar.style.width = '12%';
      bar.style.height = '26%';
      bar.style.background = color;
      bar.style.position = 'absolute';
      bar.style.left = '44.5%';
      bar.style.top = '37%';
      bar.style.opacity = '1';
      bar.style.setProperty('-'+this.prefix+'-border-radius', '50px', null);
      bar.style.setProperty('-'+this.prefix+'-box-shadow', '0 0 3px rgba(0,0,0,0.2)', null);
      bar.style.setProperty('-'+this.prefix+'-animation', 'fade 1s linear infinite', null);
      bar.style.setProperty('-'+this.prefix+'-transform', 'rotate('+rotation+'deg) translate(0, -142%)', null);
      bar.style.setProperty('-'+this.prefix+'-animation-delay', animationDelay + 's', null);
      rotation += rotateBy;
      animationDelay -= frameRate;
    }
    return spinner;
  }
}