After that, the canvas is converted to a DataURL so it can be loaded as an image. After loading the image, we iterate 40 times and call drawImage on the original canvas with an offset to make every single point into a cross-shape. Demo.
Offline Wiki for Chrome is now on the Web Store. The app that started a few months ago and took forms as Offline Dictionary. The chrome app version is much more refined, aesthetically and functionally. The search bar and autocomplete are much less obtrusive, and there’s gradients and box shadows, a sure indication of progress :)
The most significant difference, is that it includes the entire English Wikipedia, a pretty close approximation of the sum of all human knowledge. Uncompressed, it’s something like 30 gigabytes of raw text, and the compressed version that I’ve compiled for this app clocks in at around 3.7 gigabytes (3.4GB for the actual compressed dump and 0.3 for the search index file). Hosting and serving up all those gigabytes does cost money, so that’s why the app isn’t free. But it’s still a pretty good value considering the equivalent apps for iOS are twice the price.
It includes an index which lists every single article in Wikipedia, paginated and navigable through a scroll bar. There are something like 50,000 pages of the index (the exact number depends on the size of your screen), and articles are divided into columns. There’s a button which sends you to a random article, and a search bar.
However the notion of this app is pretty strange: A webapp which only serves its function when offline. However, the ease of installation and use of this app is somewhat unparalleled on the desktop space. This app allows the browsing of the database instantly after the download has begun, rather than nearly all other such apps which require the entire dump to be downloaded first. There’s no conversion process. Everything pretty much hopefully just works.
The interface is done entirely with CSS and HTML, no images except the obligatory xkcd reference. The toolbar is a css3 gradient and enclosed with HTML5 tags like <article>, <header> and <footer>. The download progress is indicated by a native <progress> bar element. The index is navigable through a slider bar created using <input type=range> and all the page titles are put automatically into columns by the css3 column layout properties.
The really cool stuff is what’s in the javascript. Probably the most significant development which has enabled this app is an awesome thing called the FileSystem API which exposes a special persistent sandboxed read/write directory which can be modified through the File API. When the page is first loaded, the process of downloading begins, and it uses the responseType attribute of the XMLHttpRequest to get the downloaded chunk (it just sets the request header to specify a range of one megabyte) as an array buffer. Array Buffers are a part of the WebGL specification which enables the storage and manipulation of binary data. It then uses BlobBuilder to convert that array buffer into Blob which can then be written using the File API to the hard disk.
To search, it reads a small portion of the index file by using a particular slice of the file, which is the equivalent of seeking on a disk. It implements binary search to quickly locate a certain article on the disk and then reads a chunk from the dump in much the same way. Then it uses a javascript implementation of the LZMA compression algorithm to decode a certain hundred-kilobyte block into raw WikiText which is then parsed into HTML.
Finally, the pushState and replaceState methods from the History API are used to handle the navigation of pages without reloading,.
Today I went to the magical Apple Store and tried out the iPad for the first time. I really have to say that it’s quite magical, though it doesn’t fulfill the criterion for Arthur C. Clarke’s Third Law despite what Jonathan Ive says. Though I really haven’t tried any large area multitouch interface before (sadly), and I would expect it to be a somewhat similar if not exact replica of the experience. Keynote and Numbers were pretty neat (I suck at typing on the iPad in any orientation, so I don’t like Pages). That’s enough to show that iPad is not just a content consumption tool as the iPod and iPhone primarily are, but also content creation.
Anyway, in a few minutes I just swapped the mousedown, mousemove, mouseup events with touchstart, touchmove, touchend events respectively in the core of VectorEditor, while adding a new MobileSafari detection script (var mobilesafari = /AppleWebKit.*Mobile/.test(navigator.userAgent);) and in a quite analogous “magical” way, VectorEditor works in iPhone/iPod Touch and theoretically iPad, Just dragging the vectoreditor files over to the Ajax Animator folder and recompiling should bring iPad support to Ajax Animator with virtually no work.
I haven’t tested it. Downloading XCode 3.2.2 right now so hopefully I can test it soon. Stupid how it’s what? 2.31 gigabytes?!
And possibly, I could use PhoneGap to hack together a App Store app which does the same thing (and maybe charge for it, which might be a bit cruel as this application is open source and works equivalently online - but I guess that’s okay for those people who don’t read my blog >:) ). Maybe get enough to buy an iPad :P
Anyway, though I’m pretty late to this and my opinion probably doesn’t matter at all, here’s a mini iPad review: It’s really really cool, feels sort of heavy, really expensive, hard to type on in any orientation (interestingly it has that little linke on the f and j keys with the keyboard which feels useless since I always thought the point of that was so you can tactile-ily or haptically or tactically or whatever the right word is, find the home row, but since there’s no physical dimension to an iPad, it just strikes me as weird and wanting of that tactile keyboard). Otherwise, browsing really really feels great. Only thing I miss is the Macbook Pro style 3 finger forward/backward gestures (@AAPL plz add this before iPad2.0, and also, get iPhoneOS 4.0 to work on my iPhone 2g or at least @DevTeam plz hack 4.0 for the 2g!).
Oh, and for those lucky enough to have a magical iPad, the URL is http://antimatter15.com/ajaxanimator/ipad/ at least until there’s enough testing to make sure that I didn’t screw up everything with my MobileSafari hacks.
