**Hero** is a library for building iOS view controller transitions. It provides a declarative layer on top of the UIKit's cumbersome transition APIs. Making custom transitions an easy task for developers.

Hero is similar to Keynote's **Magic Move**. It checks the `heroID` property on all source and destination views. Every matched view pairs are then automatically transitioned from its old state to its new state.

At view controller level, Hero provides several template transitions that you can set through `heroModalAnimationType`, `heroNavigationAnimationType`, & `heroTabBarAnimationType`. These can be used as the foundation of your custom transitions. Combine with `heroID` & `heroModifiers` to make your unique transitions.

By default, Hero provides **dynamic duration** based on the [Material Design Motion Guide](https://material.io/guidelines/motion/duration-easing.html). The duration is determined by the distance & size change. It save you the hassle while providing consistent and delightful animations.

Hero does not make any assumption about how the view is built or structured. It will not modify any of your views' states other than hiding them during the animation. This makes it work with **Auto Layout**, **programmatic layout**, **UICollectionView** (without modifying its layout object), **UITableView**, **UINavigationController**, **UITabBarController**, etc...

Matched views use global coordinate space while unmatched views use local coordinate space by default. Local coordinate spaced views might be covered by other global coordinate spaced views. To solve this, use `useGlobalCoordinateSpace` modifier on the views being covered. Checkout [Coordinate Space Wiki page](https://github.com/lkzhao/Hero/wiki/Coordinate-Space) for details.

UIVisualEffectView is quite hard to animate due to the private implementation and incompatibility with `snapshotAfterScreenUpdate` and some Core Animation APIs. We are trying to get these solved as much as we can. Currently, as of 0.3.2, only unmatched UIVisualEffectView with noninteractive `.fade` animation is supported.