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:
Follow up to #11973 to add support to Animated.loop with useNativeDriver on iOS.
**Test plan**
Test with new UIExplorer example
Run unit tests
Closes https://github.com/facebook/react-native/pull/13359
Differential Revision: D4960754
Pulled By: javache
fbshipit-source-id: caa840281f1b060df7a2b1c50405fcae1e1b0de6
Summary:
This is one of the last feature that is missing from native animated, it was already supported on Android and this implementation is based on it.
**Test plan**
Test that the existing decay animation example now works on iOS
Run unit tests
Closes https://github.com/facebook/react-native/pull/13368
Differential Revision: D4938061
Pulled By: javache
fbshipit-source-id: 36b57b1029a542e9daf21e048a06d3b3347e9659
Summary:
Adds unit tests to the Native Animated implementation on iOS. This pretty much mirrors the tests we currently have on Android.
It also fixes 2 bugs I've found when adding the tests and pass the current time in `stepAnimation` instead of using `CACurrentMediaTime` to make testing easier.
- `stopListeningToAnimatedNodeValue` did not actually work at all, it should set the listener to nil.
- The finished value in the animation end callback was always true, this simplifies the `RCTAnimationDriver` interface to get rid of `removeAnimation` and fixes the end callback value.
**Test plan**
- Run the tests
- Make sure the UIExplorer example still works
Closes https://github.com/facebook/react-native/pull/13068
Differential Revision: D4786701
Pulled By: javache
fbshipit-source-id: a4f07e6eec1f363ca47b6f27984041793c915bfc
Summary:
Delay was broken with native animations on iOS. After checking what android does to handle delay, I noticed it does nothing at all since the delay is already handled when generating the animation frames. This removes all code that tried to handle delay on iOS since it is not needed and breaks it. Also updated an example to have delay in UI explorer.
Fixes#12388
**Test plan**
Tested that delay works in UIExplorer on iOS and Android.
Closes https://github.com/facebook/react-native/pull/12443
Differential Revision: D4582514
Pulled By: javache
fbshipit-source-id: dc53295e716c8476c71ccd578380962f056de2be
Summary:
This diff attempts to fix a number of iOS native animation bugs related to improper node invalidation and a race with view creation. The major issues were presented in #9120 as problems 3 and 3b, but I'll recap here:
The invalidation model we use is overly complicated and incomplete. The proper combination of `_needsUpdate` and `_hasUpdated` will result in nodes values being recomputed. However, we do not invalidate nodes in all the places we should, e.g. if we create a new view and attach it to an existing value node (see example in #9120). This diff chooses to remove the `_hasUpdated` flag, and simply relies on the `_needsUpdate` flag to mark a node as dirty.
We mark nodes as dirty when they are:
- created
- updated
- attached to new parents
- detached from old parents
- attached to a view
Calling `updateNodeIfNecessary` will, if necessary, compute all invalidated parent values before recomputing the node value. It will then apply the update, and mark the no
Closes https://github.com/facebook/react-native/pull/10663
Differential Revision: D4120301
Pulled By: mkonicek
fbshipit-source-id: e247afcb5d8c15999b8328c664b9f7e764d76a75
Summary:
To make React Native play nicely with our internal build infrastructure we need to properly namespace all of our header includes.
Where previously you could do `#import "RCTBridge.h"`, you must now write this as `#import <React/RCTBridge.h>`. If your xcode project still has a custom header include path, both variants will likely continue to work, but for new projects, we're defaulting the header include path to `$(BUILT_PRODUCTS_DIR)/usr/local/include`, where the React and CSSLayout targets will copy a subset of headers too. To make Xcode copy headers phase work properly, you may need to add React as an explicit dependency to your app's scheme and disable "parallelize build".
Reviewed By: mmmulani
Differential Revision: D4213120
fbshipit-source-id: 84a32a4b250c27699e6795f43584f13d594a9a82
Summary:
This adds native support for `Animated.event` on iOS.
**Test plan**
Tested in the native animated UIExplorer example that it works properly like on Android.
Closes https://github.com/facebook/react-native/pull/9598
Differential Revision: D4110331
fbshipit-source-id: 15748d23d0f475f2bcd1040ca3dca33e2620f058
Summary:
This diff adds support for native spring animations on iOS. This overlaps some spring work done by kmagiera on the Android side of things.
**Test plan (required)**
Run UIExplorer NativeAnimated examples before and after - compare the results. Pay special attention to the spring examples.
Closes https://github.com/facebook/react-native/pull/9048
Differential Revision: D4056088
Pulled By: foghina
fbshipit-source-id: a593408cb61cb850572bab4a0884f7157cece656
Adam Miskiewicz
Janic Duplessis
Mathieu Baudet
Ryan Gomba
Pieter De Baets
James Ide