material-motion/src/operators/timestamp.ts

Makes it easy to add rich, interactive motion to your application.

/** @license
 *  Copyright 2016 - present The Material Motion Authors. All Rights Reserved.
 *
 *  Licensed under the Apache License, Version 2.0 (the "License"); you may not
 *  use this file except in compliance with the License. You may obtain a copy
 *  of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 *  License for the specific language governing permissions and limitations
 *  under the License.
 */

import {
  Constructor,
  Dict,
  MotionMappable,
  ObservableWithMotionOperators,
  Timestamped,
} from '../types';

export interface MotionTimestampable<T> {
  timestamp(): ObservableWithMotionOperators<Timestamped<T>>;
}

export function withTimestamp<T, S extends Constructor<MotionMappable<T>>>(superclass: S): S & Constructor<MotionTimestampable<T>> {
  return class extends superclass implements MotionTimestampable<T> {
    timestamp(): ObservableWithMotionOperators<Timestamped<T>> {
      return this._map({
        transform: timestamp,
      });
    }
  };
}

export function timestamp<T>(value: T): Timestamped<T> {
  return {
    value,
    timestamp: performance.now(),
  };
}