Files
react-native/Libraries/Animated/nodes/AnimatedAddition.js
T
Moti Zilberman 7b86fa2b79 Distinguish between string/number-valued interpolation nodes at the type level
Summary:
Changelog:
[General][Fixed] - Improved Flow type inference in Animated `.interpolate()`

Improves the ergonomics of `.interpolate()` by allowing Flow to infer the correct type for `outputRange`. This is achieved by adding a new type parameter `OutputT` to `interpolate()` (and `Animated.Interpolation` and `InterpolationConfigType`), which Flow infers as either `number` or `string` based on usage.

Admittedly, at the call site, this is not that much safer compared to something like `outputRange: $ReadOnlyArray<number | string>`, but it does document the intent of the API a bit better and provide some downstream type safety. For example, we can now express `Animated.Number` (D35869375) more precisely by excluding string-valued interpolation nodes.

Reviewed By: javache

Differential Revision: D35869725

fbshipit-source-id: e03ec22e9b3368ee196b392af011062ac99d8bb9
2022-05-03 12:04:02 -07:00

67 lines
1.7 KiB
JavaScript

/**
* Copyright (c) Meta Platforms, Inc. and affiliates.
*
* This source code is licensed under the MIT license found in the
* LICENSE file in the root directory of this source tree.
*
* @flow
* @format
*/
'use strict';
const AnimatedInterpolation = require('./AnimatedInterpolation');
const AnimatedNode = require('./AnimatedNode');
const AnimatedValue = require('./AnimatedValue');
const AnimatedWithChildren = require('./AnimatedWithChildren');
import type {PlatformConfig} from '../AnimatedPlatformConfig';
import type {InterpolationConfigType} from './AnimatedInterpolation';
class AnimatedAddition extends AnimatedWithChildren {
_a: AnimatedNode;
_b: AnimatedNode;
constructor(a: AnimatedNode | number, b: AnimatedNode | number) {
super();
this._a = typeof a === 'number' ? new AnimatedValue(a) : a;
this._b = typeof b === 'number' ? new AnimatedValue(b) : b;
}
__makeNative(platformConfig: ?PlatformConfig) {
this._a.__makeNative(platformConfig);
this._b.__makeNative(platformConfig);
super.__makeNative(platformConfig);
}
__getValue(): number {
return this._a.__getValue() + this._b.__getValue();
}
interpolate<OutputT: number | string>(
config: InterpolationConfigType<OutputT>,
): AnimatedInterpolation<OutputT> {
return new AnimatedInterpolation(this, config);
}
__attach(): void {
this._a.__addChild(this);
this._b.__addChild(this);
}
__detach(): void {
this._a.__removeChild(this);
this._b.__removeChild(this);
super.__detach();
}
__getNativeConfig(): any {
return {
type: 'addition',
input: [this._a.__getNativeTag(), this._b.__getNativeTag()],
};
}
}
module.exports = AnimatedAddition;