A few days ago, I was working on an app that used a lot of animations.

The app had a pretty simple UI: it consisted of one view controller with two subviews, and the user could tap the top subview to show or hide the bottom one.

The animation itself was very simple: just move the bottom view from its current position to another position in front of (or behind) the top view. It looked like this:

It’s not hard to imagine how we can implement such an animation using UIView ‘s animateWithDuration(_:, animations:…) method
https://t.co/XbCSJJ0DEE