Thomas Fuchs
Hi, I'm Thomas Fuchs. I'm the author of Zepto.js, of script.aculo.us, and I'm a Ruby on Rails core alumnus. With Amy Hoy I'm building cheerful software, like Freckle Time Tracking and Every Time Zone and write books like Retinafy.me.
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Scrolling DOM elements to the top, a Zepto plugin

January 19th, 2014

There’s bunches of plugins, extensions and techniques to smoothly scroll page elements, but most of them are convoluted messes and probably do more than you need. I like “small and works well”, and it’s a good exercise for those JavaScript and DOM muscles to write a small plugin from time to time.

My goal was to have an animated “scroll to top” for the mobile version of Freckle—normally the browser would take care of that (tap status bar to scroll to top), but in a more complex layout the built-in mechanisms for this quickly fail and you’ll have to implement some of the interactions users expect (like tap status bar to scroll to top) yourself. Specifically, this is for the native app wrapper (Cordova) I use for Freckle’s upcoming mobile app. It’s hooked up so that taps on the statusbar invoke a JavaScript method.

During development of this I needed the same thing for arbitrary scroll positions as well, so “scrolltotop” is a bit of a misnomer now. Anyway, here’s the annotated code:

Often, writing your own specialized plug-in is faster than trying to understand and configure existing code. If you do, share it! :)