react-native/Libraries/Animated
Janic Duplessis cd1d652af4 Add AnimatedDiffClamp node
Summary:
This adds a new type of node that clamps an animated value between 2 values with a special twist, it is based on the difference between the previous value so getting far from a bound doesn't matter and as soon as we start getting closer again the value will start changing. The main use case for this node is to create a collapsible navbar when scrolling a scrollview. This is a pretty in apps (fb, youtube, twitter, all use something like this).

It updates using the following: `value = clamp(value + diff, min, max)` where `diff` is the difference with the previous value.

This gives the following output for parameters min = 0, max = 30:
```
  in     out
  0      0
  15     15
  30     30
  100    30
  90     20
  30     0
  50     20
```

One issue I see is that this node is pretty specific to this use case but I can't see another simple way to do this with Animated that can also be offloaded to native easily. I'd be glad to discuss other solutions if some
Closes https://github.com/facebook/react-native/pull/9419

Differential Revision: D3753920

fbshipit-source-id: 40a749d38fd003aab2d3cb5cb8f0535e467d8a2a
2016-08-23 14:13:52 -07:00
..
examples Make fbsource and GitHub consistent 2016-02-25 17:13:25 -08:00
release Initial web implementation 2015-09-22 11:58:37 -07:00
src Add AnimatedDiffClamp node 2016-08-23 14:13:52 -07:00