Summary:
This diff formats the Java class files inside xplat/js/react-native-github. Since google-java-format was enabled in D16071401 we want to codemode the existing code so that users don't have to deal with formatter lint noise at diff-time.
```arc f --paths-cmd 'hg files -I "**/*.java"'```
drop-conflicts
Reviewed By: cpojer
Differential Revision: D16071725
fbshipit-source-id: fc6e3852e45742c109f0c5ac4065d64201c74204
Summary: Adds copyright headers to all files that are missing them.
Reviewed By: hramos
Differential Revision: D12837494
fbshipit-source-id: 6330a18919676dec9ff2c03b7c9329ed9127d930
Summary:
This PR adds support for Animated tracking to Animated Native Driver implementation on Android and iOS.
Animated tracking allows for animation to be started with a "dynamic" end value. Instead of passing a fixed number as end value we can pass a reference to another Animated.Value. Then when that value changes, the animation will be reconfigured to drive the animation to the new destination point. What is important is that animation will keep its state in the process of updating "toValue". That is if it is a spring animation and the end value changes while the previous animation still hasn't settled the new animation will start from the current position and will inherit current velocity. This makes end value transitions very smooth.
Animated tracking is available in JS implementation of Animated library but not in the native implementation. Therefore until now, it wasn't possible to utilize native driver when using animated tracking. Offloading animation from JS thread turns out to be crucial for gesture driven animations. This PR is a step forward towards feature parity between JS and native implementations of Animated.
Here is a link to example video that shows how tracking can be used to implement chat heads effect: https://twitter.com/kzzzf/status/958362032650244101
In addition this PR fixes an issue with frames animation driver on Android that because of rounding issues was taking one extra frame to start. Because of that change I had to update a number of Android unit tests that were relying on that behavior and running that one additional animation step prior to performing checks.
As a part of this PR I'm adding three unit tests for each of the platforms that verifies most important aspects of this implementation. Please refer to the code and look at the test cases top level comments to learn what they do.
I'm also adding a section to "Native Animated Example" screen in RNTester app that provides a test case for tracking. In the example we have blue square that fallows the red line drawn on screen. Line uses Animated.Value for it's position while square is connected via tracking spring animation to that value. So it is ought to follow the line. When user taps in the area surrounding the button new position for the red line is selected at random and the value updates. Then we can watch blue screen animate to that position.
You can also refer to this video that I use to demonstrate how tracking can be linked with native gesture events using react-native-gesture-handler lib: https://twitter.com/kzzzf/status/958362032650244101
[GENERAL][FEATURE][Native Animated] - Added support for animated tracking to native driver. Now you can use `useNativeDriver` flag with animations that track other Animated.Values
Closes https://github.com/facebook/react-native/pull/17896
Differential Revision: D6974170
Pulled By: hramos
fbshipit-source-id: 50e918b36ee10f80c1deb866c955661d4cc2619b
Summary:
As I was working on mimicking iOS animations for my ongoing work with `react-navigation`, one task I had was to match the "push from right" animation that is common in UINavigationController.
I was able to grab the exact animation values for this animation with some LLDB magic, and found that the screen is animated using a `CASpringAnimation` with the parameters:
- stiffness: 1000
- damping: 500
- mass: 3
After spending a considerable amount of time attempting to replicate the spring created with these values by CASpringAnimation by specifying values for tension and friction in the current `Animated.spring` implementation, I was unable to come up with mathematically equivalent values that could replicate the spring _exactly_.
After doing some research, I ended up disassembling the QuartzCore framework, reading the assembly, and determined that Apple's implementation of `CASpringAnimation` does not use an integrated, numerical animation model as we do in Animated.spring, but instead solved for the closed form of the equations that govern damped harmonic oscillation (the differential equations themselves are [here](https://en.wikipedia.org/wiki/Harmonic_oscillator#Damped_harmonic_oscillator), and a paper describing the math to arrive at the closed-form solution to the second-order ODE that describes the DHO is [here](http://planetmath.org/sites/default/files/texpdf/39745.pdf)).
Though we can get the currently implemented RK4 integration close by tweaking some values, it is, the current model is at it's core, an approximation. It seemed that if I wanted to implement the `CASpringAnimation` behavior _exactly_, I needed to implement the analytical model (as is implemented in `CASpringAnimation`) in `Animated`.
We add three new optional parameters to `Animated.spring` (to both the JS and native implementations):
- `stiffness`, a value describing the spring's stiffness coefficient
- `damping`, a value defining how the spring's motion should be damped due to the forces of friction (technically called the _viscous damping coefficient_).
- `mass`, a value describing the mass of the object attached to the end of the simulated spring
Just like if a developer were to specify `bounciness`/`speed` and `tension`/`friction` in the same config, specifying any of these new parameters while also specifying the aforementioned config values will cause an error to be thrown.
~Defaults for `Animated.spring` across all three implementations (JS/iOS/Android) stay the same, so this is intended to be *a non-breaking change*.~
~If `stiffness`, `damping`, or `mass` are provided in the config, we switch to animating the spring with the new damped harmonic oscillator model (`DHO` as described in the code).~
We replace the old RK4 integration implementation with our new analytic implementation. Tension/friction nicely correspond directly to stiffness/damping with the mass of the spring locked at 1. This is intended to be *a non-breaking change*, but there may be very slight differences in people's springs (maybe not even noticeable to the naked eye), given the fact that this implementation is more accurate.
The DHO animation algorithm will calculate the _position_ of the spring at time _t_ explicitly and in an analytical fashion, and use this calculation to update the animation's value. It will also analytically calculate the velocity at time _t_, so as to allow animated value tracking to continue to work as expected.
Also, docs have been updated to cover the new configuration options (and also I added docs for Animated configuration options that were missing, such as `restDisplacementThreshold`, etc).
Run tests. Run "Animated Gratuitous App" and "NativeAnimation" example in RNTester.
Closes https://github.com/facebook/react-native/pull/15322
Differential Revision: D5794791
Pulled By: hramos
fbshipit-source-id: 58ed9e134a097e321c85c417a142576f6a8952f8
Summary:
* Any animation can be looped on the javascript thread
* Only basic animations supported natively at this stage, loops run
using the native driver cannot contain animations of type sequence,
parallel, stagger, or loop
Motivation: We need a spinner in our app that is displayed and animated while the javascript thread is tied up with other tasks. This means it needs to be offloaded from the javascript thread, so that it will continue to run while those tasks are churning away.
I originally submitted PR #9513, which has served our needs, but brentvatne pointed out a better way to do it. Had hoped his suggestion would be implemented by janicduplessis or another fb employee, but after 5 months I thought I'd give it another push.
I've put together an implementation that basically matches the suggested API. Let me know what you think, and whether others can pick it up from here and get it in to core.
Personal Motivation: I am leaving my current organisation on Feb 10th, so am trying to clean thing
Closes https://github.com/facebook/react-native/pull/11973
Differential Revision: D4704381
fbshipit-source-id: 42a2cdf5d53a7c0d08f86a58485f7f38739e6cd9
Summary:
This change adds support for spring animations to be run off the JS thread on android. The implementation is based on the android spring implementation from Rebound (http://facebook.github.io/rebound/) but since only a small subset of the library is used the relevant parts are copied instead of making RN to import the whole library.
**Test Plan**
Run java tests: `buck test ReactAndroid/src/test/java/com/facebook/react/animated`
Add `useNativeDriver: true` to spring animation in animated example app, run it on android
Closes https://github.com/facebook/react-native/pull/8860
Differential Revision: D3676436
fbshipit-source-id: 3a4b1b006725a938562712989b93dd4090577c48