search

IFTTT / RazzleDazzle

A simple keyframe-based animation framework for iOS, written in Swift. Perfect for scrolling app intros.
http://ifttt.github.io
MIT License
3.36k stars 292 forks source link

Animations prior to the first frame #41

Closed michaellindahl closed 8 years ago

michaellindahl commented 8 years ago

With the IF by IFTT app you can scroll back on the first page and see the animations "reverse" themselves more than their current position. The page indictor also stays centered and does not scroll. When I try replicating this with the test app I run into two issues. First, I'm unable to give the Star animation a negative keyframe. Second, if center something at the bottom on all the pages, it's centered until I scroll before the first page or after the last, in these cases it moves with the scrollview.

How is this accomplished in the IF by IFTT app?

michaellindahl commented 8 years ago

Not quite sure why I was getting the negative keyframe issue. Figured out that I needed to specify a negative page keepView(_, onPages: [-1,3]) to make the view not scroll with the content.

I added a view that was constrained to the left and right of the contentView, however this doesn't respect the negative page parameter. In order to keep this view full width at the bottom I had to change the constraint to be a width constraint rather than a left/right constraint.