Animated graph

animatedGraph.js

/**
* Animated works by building a directed acyclic graph of dependencies
* transparently when you render your Animated components.
*
*               new Animated.Value(0)
*     .interpolate()        .interpolate()    new Animated.Value(1)
*         opacity               translateY      scale
*          style                         transform
*         View#234                         style
*                                         View#123
*
* A) Top Down phase
* When an Animated.Value is updated, we recursively go down through this
* graph in order to find leaf nodes: the views that we flag as needing
* an update.
*
* B) Bottom Up phase
* When a view is flagged as needing an update, we recursively go back up
* in order to build the new value that it needs. The reason why we need
* this two-phases process is to deal with composite props such as
* transform which can receive values from multiple parents.
*/