Ebook Improvements

Over the past few weeks I've done more experiments and improvements to my ebook prototype. I'm still not sure what I'm going to do with it once I'm all done, but it's been an educational exercise nonetheless. Here's what I've done so far:

I've reorganized the code and put it into a github repo. Everything I'm going to show you is available to use and fork from right here. Click on any screenshot below to see a live example.


If we are going to call this stuff books then we need good typography. Fortunately 2011 saw the widespread adoption of web fonts. We can now use any custom font we want in any webpage, which includes the iPad with the release of iOS 5. To that end I tried searching for some custom fonts that add a bit a flavor while still remaining readable. After this font test I mocked up a full page with better typography for reading. This included bigger font size contrast, looser line height, a narrower column, auto-captializing the subheading at the top, and some inline images. Overall I'm happy with what can be done in pure CSS after just a few minutes work.


When we talk about typography we also have to consider how the reader should view long form text. The world seems roughly split between scrolling and swiping between pages. I honestly hate page swiping unless the content really needs to be paginated (like a children's book). I did try some pagination experiments using CSS multi-columns but I'm not happy with the results. Perhaps with some more work they would be usable.

Instead I've worked on scrolling. Scrolling feels very natural on a touch screen device, but you still need some static navigation to know where you are, switch pages, and view the table of contents. Fortunately CSS fixed positioning is pretty well supported these days, with IFRAMES as a useful backup, so it wasn't too hard.

Interactive Chart

I cooked up a simple bubble chart using Amino and some real data from the World Data Bank. You can use the slider to move time from 1960 to the present and see how the data changes. I think this type of interactive visualization will be very useful in ebooks.

Interactive Code

To teach how to use a visual API like Canvas we should have a visual tool. We should be able to see what happens when we change variables, and actually see the code and canvas example change in real time. In my research I came across an amazing toolkit by Bret Victor called Tangle. Using that as a base I prototyped a simple tool for interactive text snippets. It rewrites any canvas javascript function you give it into a live example with formatted source. When you drag on one of the interactive variables (indicated in red) a popup appears to show you the value. As you drag left and right the value changes and the canvas updates to show the new result. This is the most direct way to learn what a function does.

Code Wrapping

Another problem with code snippets is that they often are too long to fit on a single line. I could configure a PRE tag to wrap the long lines, but whitespace is usually significant in code. I don't want to create a situation where the reader thinks something is two lines when it is really one, such as a command line example they are trying to type in. Still, we need a way to view long lines. I played with various scrolling techniques but ultimately found they added more problems than they solved. Instead I found this great technique by [name] to creatively wrap lines. A wrapped line is shown indented with an arrow symbol to indicate it is wrapped from the previous line. This removes any ambiguity.

Three Dee

The canonical example of what a digital book can do that a paper book can't is spinning an object around in 3D. I don't know how useful this will be in practice, but I wanted to prove it was possible. Using the amazing Three.js library I embedded a simple block that you can rotate using mouse drags or touch events. Three.js is really designed to use with WebGL, which isn't supported yet on most mobile platforms, but it can also render with plain canvas. It's not as fast, of course, but for simple flat shaded models it works well enough.

Putting it all together

To really show off what this can do I put together a book demo using some real content from my HTML Canvas Deep Dive presentation last summer. It has a title page, table of contents (generated with a simple nodejs script), and two full chapters with code snippets, examples, and photo slideshows. I think the results speak for themselves.

Next Steps

I don't really know what the next steps are. I'm going to finish up the canvas book (probably eight chapters by the time I'm done) and use PhoneGap to put it in the iPad, webOS, and Android app stores. After I've proven it's possible I'm not sure what to do next. I did this as an experiment to research the state of the art. I think what I've put together could become a great set of tools for building interactive ebooks since the markup you actually have to write is rather minimal. Let me know if you have a use for this code if I fully developed it.


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Posted February 22nd, 2012

Tagged: amino ebooks