ui/src/base/resize_observer.ts

// Copyright (C) 2023 The Android Open Source Project
//
// 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.

export class SimpleResizeObserver implements Disposable {
  private observer?: ResizeObserver;

  constructor(dom: Element, callback: () => void) {
    const observer = new ResizeObserver(() => {
      callback();
    });
    observer.observe(dom);
    this.observer = observer;
  }

  [Symbol.dispose]() {
    if (this.observer) {
      this.observer.disconnect();
      this.observer = undefined;
    }
  }
}