Project Wonderland WPI MQP

First Breakthrough: HTML Rendering In-World

Today, we got HTML to render natively in-world! Don’t get too excited yet, because so far, our HTML Viewer component is a slightly modified version of Nigel Simpson’s Wonderland PDF viewer. It can only display whatever web page URL is hard-coded into the source code. Still, we’re very excited about this and will be rounding out the Wonderland HTML Viewer component during the coming days.

In any case, today was a pretty busy day for us. This morning, we called Nigel to ask him some specific questions about the logistics of modifying his PDF Viewer component to display web pages. Nigel was extremely helpful, and we’ll continue to ask him quetsions as we undoubtedly run into issues while completing the HTML Viewer.

We also (obviously) spent some time refactoring Nigel’s code to get it to render HTML in-world, and we were able to construct a (very) basic example demonstrating that making an HTML viewer for Wonderland is definitely possible.

The Cobra HTML rendering engine we’re using to accomplish this is released under an LGPL license, but it makes use of Mozilla’s Rhino ‘JavaScript for Java’ library for its JavaScript functionality. Rhino is released under a dual MPL 1.1/GPL 2.0 license. Amusingly, Rhino includes a library from Sun that it uses for debugging. We discussed these various licenses with Jordan, and how they might interact or potentially conflict with Wonderland’s own dual license. Jordan said that Cobra would have to undergo a license review by Sun’s legal department before it would be allowed to officially be included in Wonderland, but this is understandable.

Other things that happened today included a department “Tea” at 3:00, and we’ve scheduled weekly meetings (that will happen either in Wonderland or in person) with our WPI advisor, Gary Pollice. We forgot to mention that we got our badges yesterday! We feel official now.

We started the day by reading through Nigel’s notes on Wonderland’s PDF viewer, in order to prepare for our meeting with him tomorrow.

We then talked with Jordan and John about the method our HTML viewer would use to save images of web pages (to be used as textures in-world.) It seemed that the easiest way to scrape image data from Cobra would be to have Cobra render a page onscreen, convert its output to an image, and then save that image as a file. This approach is frowned upon for a number of reasons. The biggest problem is that if this code were to be theoretically integrated into Wonderland, pages would have to be rendered inside a hidden X11 session using Wonderland’s Server Master Client. This would have defeated the main purpose of creating the HTML viewer component in the first place: to ELIMINATE the act of scraping images from X11 applications.

Fortunately, after some heavy Googling, we found code on Martin Brown’s blog that significantly alleviated our fears. His code demonstrates how to make Cobra render directly to an image using headless AWT. We slightly expanded his code and added required error checking, and ended up writing a simple Java method with this signature:

public static void takeWebshot(String uri, Dimension size, File output) {}

This method uses the Cobra engine to save a PNG screenshot of a given web page. This is certainly a step in the right direction! Jordan thinks we may even be able to forgo saving PNG images, and paint AWT BufferedImages directly on objects in-world. We’ll have to continue working on the HTML viewer component and find out.

Also, today we saw a presentation from Sun’s chip design department, and got tours of two of their data centers. The presentation was very informative because none of the WPI MQP students knew too much about the SPARC architecture or about Sun’s processor line.

Tomorrow will be very busy indeed…watch out for tomorrow’s blog post!

Today was all of the WPI MQP Students’ first day at Sun.

Gerard and I have our own lab to work/collaborate in, and we each have our own Sun workstation running Ubuntu 8.04, with (much appreciated) 24.1″ LCDs.

In the morning, we met with Jordan, Nicole, and John to talk about the focus of our project. We described our overall vision of the Software Engineering Team Room to them, and then discussed a couple of ideas about what to tackle first.

We decided to start by building a single component that could be useful for both our team room project and Wonderland in general: an in-world HTML rendering engine component that doesn’t depend on an external web browser. In theory, this HTML rendering engine component could work in a similar fashion to Wonderland’s PDF viewer. This component could basically turn dynamic web pages into ‘posters’ in a team room; whenever team members enter the room, current Hudson build statistics could be displayed on a wall, etc.

We’d like to have this component make use of an EXISTING open-source HTML rendering engine, rather than write our own. We’ve played with a few engines, and so far Cobra looks like the most promising one, but further research is needed.

We spent the remainder of the day following and completing Jordan’s tutorials about creating custom cell types in Wonderland, and starting to do research for the aforementioned HTML rendering engine component.