react-native-reanimated/src/reanimated2/layoutReanimation/defaultTransitions/CurvedTransition.ts

More powerful alternative to Animated library for React Native.

'use strict';
import type {
  ILayoutAnimationBuilder,
  LayoutAnimationFunction,
} from '../animationBuilder/commonTypes';
import { BaseAnimationBuilder } from '../animationBuilder';
import type { EasingFunction } from '../../Easing';
import { Easing } from '../../Easing';
import { withTiming } from '../../animation';
import { assertEasingIsWorklet } from '../../animation/util';

/**
 * Layout transitions with a curved animation. You can modify the behavior by chaining methods like `.duration(500)` or `.delay(500)`.
 *
 * You pass it to the `layout` prop on [an Animated component](https://docs.swmansion.com/react-native-reanimated/docs/fundamentals/glossary#animated-component).
 *
 * @see https://docs.swmansion.com/react-native-reanimated/docs/layout-animations/layout-transitions#fading-transition
 */
export class CurvedTransition
  extends BaseAnimationBuilder
  implements ILayoutAnimationBuilder
{
  easingXV: EasingFunction = Easing.in(Easing.ease);
  easingYV: EasingFunction = Easing.out(Easing.ease);
  easingWidthV: EasingFunction = Easing.in(Easing.exp);
  easingHeightV: EasingFunction = Easing.out(Easing.exp);

  static createInstance<T extends typeof BaseAnimationBuilder>(
    this: T
  ): InstanceType<T> {
    return new CurvedTransition() as InstanceType<T>;
  }

  static easingX(easing: EasingFunction): CurvedTransition {
    const instance = this.createInstance();
    return instance.easingX(easing);
  }

  easingX(easing: EasingFunction): CurvedTransition {
    if (__DEV__) {
      assertEasingIsWorklet(easing);
    }
    this.easingXV = easing;
    return this;
  }

  static easingY(easing: EasingFunction): CurvedTransition {
    const instance = this.createInstance();
    return instance.easingY(easing);
  }

  easingY(easing: EasingFunction): CurvedTransition {
    if (__DEV__) {
      assertEasingIsWorklet(easing);
    }
    this.easingYV = easing;
    return this;
  }

  static easingWidth(easing: EasingFunction): CurvedTransition {
    const instance = this.createInstance();
    return instance.easingWidth(easing);
  }

  easingWidth(easing: EasingFunction): CurvedTransition {
    if (__DEV__) {
      assertEasingIsWorklet(easing);
    }
    this.easingWidthV = easing;
    return this;
  }

  static easingHeight(easing: EasingFunction): CurvedTransition {
    const instance = this.createInstance();
    return instance.easingHeight(easing);
  }

  easingHeight(easing: EasingFunction): CurvedTransition {
    if (__DEV__) {
      assertEasingIsWorklet(easing);
    }
    this.easingHeightV = easing;
    return this;
  }

  build = (): LayoutAnimationFunction => {
    const delayFunction = this.getDelayFunction();
    const callback = this.callbackV;
    const delay = this.getDelay();
    const duration = this.durationV ?? 300;
    const easing = {
      easingX: this.easingXV,
      easingY: this.easingYV,
      easingWidth: this.easingWidthV,
      easingHeight: this.easingHeightV,
    };

    return (values) => {
      'worklet';

      return {
        initialValues: {
          originX: values.currentOriginX,
          originY: values.currentOriginY,
          width: values.currentWidth,
          height: values.currentHeight,
        },
        animations: {
          originX: delayFunction(
            delay,
            withTiming(values.targetOriginX, {
              duration,
              easing: easing.easingX,
            })
          ),
          originY: delayFunction(
            delay,
            withTiming(values.targetOriginY, {
              duration,
              easing: easing.easingY,
            })
          ),
          width: delayFunction(
            delay,
            withTiming(values.targetWidth, {
              duration,
              easing: easing.easingWidth,
            })
          ),
          height: delayFunction(
            delay,
            withTiming(values.targetHeight, {
              duration,
              easing: easing.easingHeight,
            })
          ),
        },
        callback,
      };
    };
  };
}