Opera CTO and CSS (Cascading Style Sheets) creator Håkon Wium Lie wants page-based navigation to replace the browser scroll bar, which he believes is outdated.
"About 2,000 years ago, people used scrolls. That's how they recorded information. The Romans tore the scrolls apart, and binded the pages together as books," Lie said. "Books are much easier to handle than scrolls."
Lie has authored a proposed extension for CSS, called CSS Generated Content For Paged Media (GCPM), which, if standardised and implemented in browsers, would give browsers the ability to do e-reader-like navigation.
Last week, Lie met with publishers in New York, pitching the standard as an easier and lower-cost alternative to building and maintaining dedicated e-readers. This week he'll meet with other CSS designers at the W3C Technical Plenary/Advisory Committee Meetings Week, taking place in Santa Clara, California, to discuss folding this set of specifications into the upcoming version 3 of CSS.
Opera itself has posted some sample pages, and a downloadable Opera Reader that mimics the functionality of a browser supporting this extension.
These days, many text-based web pages, including this news story, are formatted as a single column of text. Lengthy texts may be divided across multiple web pages, with a "next page" button at the bottom of each. If the text fills up more than a single browser screen, the browser provides a scroll bar to move up and down the page.
Browsers deployed scroll bars because they "allowed any screen to show any document," Lie said. But, he argued, the scroll bar - an idea borrowed from desktop applications such as word processors and photo editors - places limitations on how content is rendered and viewed.
One problem is that the material being displayed rarely fits neatly into the browser window. The reader may see half-lines, or bits of an image, at the top or at the bottom of the page. "You never hit the line exactly," Lie said. The approach also limits how pages are designed, with many sites defaulting to a single column of text per page, rarely taking advantage of how a browser can move its view horizontally as well as vertically. Also, printing web pages can be problematic, with the browser not having any instructions how to break up the web page across multiple printed pages.
"The page can have a much more beautiful presentation," Lie said. "The flipping of the page becomes an event. I think few people would sit and read 'Alice in Wonderland' with a scroll bar."
The goal behind the specification is to provide a minimal set of markup to "turn any website into a paged experience," Lie said. It provides rule-sets to address formatting issues such as setting the number of columns per page, how to paginate a site and how to hyphenate text.
Using a tablet, Lie demonstrated how a web page could be viewed with a browser that supported this markup. He presented a mockup of a newspaper, complete with multiple columns and full-page ads. The experience of moving through the paper closely resembled that of using the Amazon Kindle reader for tablets, or a stand-alone magazine app such as that from "The New Yorker."
The reader could flip to the next page by swiping a finger across the screen from right to left, and jump to the index by swiping up. Nowhere in the demo did a scroll bar appear. On the desktop, a user could navigate with a mouse, or with the arrow keys and the page-up or page-down keys, or with a pop-up navigator.
"Authors should be able to create pages without having to hire expensive app developers, and do it in languages they know and in code they recognise," Lie said. "It doesn't take much code to do this."
An obvious market for the technology would be that of book and periodical publishers, who could redesign their websites to look like their printed editions, Lie said. They could even use CSS as the common code-base for all the editions of their products. Beyond the publishing industry, the stylesheet extension could also help web application developers build apps that more closely resemble native desktop and mobile applications. .
"We're putting this out as a 'lab build' to let people play with it," Lie said.
At present, no browser supports this CSS markup, even Opera's own. But Lie hopes browser makers see the value in this markup, as a way to promote greater use of the web in general. Much as CSS provided the basis for web developers to design pages with a certain degree of elegance, GCPM would provide the basis for formatting pages in a more stylish manner.
"We're web fundamentalists," he said, referring to Opera. "We feel all the information that mankind produces should be on the web. And once it's there, we should have a good way of presenting it."