react-native/Libraries/Animated/src/nodes/AnimatedNode.js

A framework for building native apps using React

/**
 * Copyright (c) 2015-present, Facebook, Inc.
 * All rights reserved.
 *
 * This source code is licensed under the BSD-style license found in the
 * LICENSE file in the root directory of this source tree. An additional grant
 * of patent rights can be found in the PATENTS file in the same directory.
 *
 * @providesModule AnimatedNode
 * @flow
 * @format
 */
'use strict';

const NativeAnimatedHelper = require('../NativeAnimatedHelper');

const invariant = require('fbjs/lib/invariant');

// Note(vjeux): this would be better as an interface but flow doesn't
// support them yet
class AnimatedNode {
  __attach(): void {}
  __detach(): void {
    if (this.__isNative && this.__nativeTag != null) {
      NativeAnimatedHelper.API.dropAnimatedNode(this.__nativeTag);
      this.__nativeTag = undefined;
    }
  }
  __getValue(): any {}
  __getAnimatedValue(): any {
    return this.__getValue();
  }
  __addChild(child: AnimatedNode) {}
  __removeChild(child: AnimatedNode) {}
  __getChildren(): Array<AnimatedNode> {
    return [];
  }

  /* Methods and props used by native Animated impl */
  __isNative: boolean;
  __nativeTag: ?number;
  __makeNative() {
    if (!this.__isNative) {
      throw new Error('This node cannot be made a "native" animated node');
    }
  }
  __getNativeTag(): ?number {
    NativeAnimatedHelper.assertNativeAnimatedModule();
    invariant(
      this.__isNative,
      'Attempt to get native tag from node not marked as "native"',
    );
    if (this.__nativeTag == null) {
      const nativeTag: ?number = NativeAnimatedHelper.generateNewNodeTag();
      NativeAnimatedHelper.API.createAnimatedNode(
        nativeTag,
        this.__getNativeConfig(),
      );
      this.__nativeTag = nativeTag;
    }
    return this.__nativeTag;
  }
  __getNativeConfig(): Object {
    throw new Error(
      'This JS animated node type cannot be used as native animated node',
    );
  }
  toJSON(): any {
    return this.__getValue();
  }
}

module.exports = AnimatedNode;