But of course, doing pen-style operations instead of declarative markup is precisely what gets you the speed and fluidity of a native app.
When you open a video with many subtitles in the current iPad app, the UI freezes for a couple seconds. Why is that? Well, WebKit is laying out the DOM for a few thousand <li> tags (the subtitles). That takes a lot of time. I'm the iOS developer of the Khan app; I worked with John Resig who did the JS side. Ultimately we decided poor subtitle performance wasn't a big deal.
UIKit could easily add a table class that didn't have such complicated requirements. But then it would be slow, just like WebKit.
When you open a video with many subtitles in the current iPad app, the UI freezes for a couple seconds. Why is that? Well, WebKit is laying out the DOM for a few thousand <li> tags (the subtitles). That takes a lot of time. I'm the iOS developer of the Khan app; I worked with John Resig who did the JS side. Ultimately we decided poor subtitle performance wasn't a big deal.
UIKit could easily add a table class that didn't have such complicated requirements. But then it would be slow, just like WebKit.