react-native-reanimated/src/layoutReanimation/defaultAnimations/utils.ts

More powerful alternative to Animated library for React Native.

'use strict';

import type { UnknownRecord } from '../../common';
import type {
  AnimationFunction,
  LayoutAnimationAndConfig,
} from '../../commonTypes';
import type { TransformArray, TransformsConfig } from './types';

export function resolveTransformSlot<
  const TTransforms extends TransformArray,
  TEntry extends TTransforms[number],
>(
  entry: TEntry,
  index: number,
  values: Partial<TransformsConfig<TTransforms>> | undefined
): { key: keyof TEntry; value: TEntry[keyof TEntry] } {
  'worklet';
  const [key, defaultValue] = Object.entries(entry)[0];
  const value =
    values?.[key as keyof typeof values] ??
    (values?.transform?.[index] as UnknownRecord | undefined)?.[key] ??
    defaultValue;
  return { key: key as keyof TEntry, value };
}

export function resolveTransformValue<
  const TTransforms extends TransformArray,
  TEntry extends TTransforms[number],
>(
  entry: TEntry,
  index: number,
  values: Partial<TransformsConfig<TTransforms>> | undefined
): TEntry[keyof TEntry] {
  'worklet';
  return resolveTransformSlot(entry, index, values).value;
}

export function pickTransformValues<const TTransforms extends TransformArray>(
  defaults: TTransforms,
  values: Partial<TransformsConfig<TTransforms>> | undefined
): TTransforms {
  'worklet';
  return defaults.map((entry, index) => {
    const { key, value } = resolveTransformSlot(entry, index, values);
    return { [key]: value };
  }) as unknown as TTransforms;
}

export function animateTransformToValues<
  const TTransforms extends TransformArray,
>(
  defaults: TTransforms,
  values: Partial<TransformsConfig<TTransforms>> | undefined,
  [animation, config]: LayoutAnimationAndConfig,
  delayFunction: AnimationFunction,
  delay: number
): TTransforms {
  'worklet';
  return defaults.map((entry, index) => {
    const { key, value } = resolveTransformSlot(entry, index, values);
    return {
      [key]: delayFunction(delay, animation(value, config)),
    };
  }) as unknown as TTransforms;
}