Apr 12 2011 · webOS
I ran into a bug with the webOS mojo framework a while ago, which I nailed down thanks to this forum post. Simply put, calling this.controller.modelChanged on a list doesn’t work properly if the user has scrolled down the list. With the dotspott webOS app I notice a gray rectangle popping up, obscuring the last 2 items in the list.
Calling this.controller.modelChanged on a list that has been scrolled past renderLimit will blank out the screen and not show the changes. This happens because modelChanged handler in the List widget resets renderOffset to 0. In other words the list widget assumes that the user is at the top of the list when modelChanged event happens. This is a pretty nasty bug.
The solution is to use mojo.setLengthAndInvalidate() instead:
While Mojo has been superseded by Enyo, this is still a pretty big deal, there’s still lots of Pixi and Pre models out there with webOS 1.4.5.