frontend/src/components/PreloadImages.js

/**
 * Copyright 2025 Google LLC
 *
 * 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 React, { useEffect, useState } from 'react';

const PreloadImages = ({ imageSources, children }) => {
  const [loaded, setLoaded] = useState(false);

  useEffect(() => {
    let loadedCount = 0;
    imageSources.forEach(src => {
      const img = new Image();
      img.src = src;
      img.onload = () => {
        loadedCount++;
        if (loadedCount === imageSources.length) {
          setLoaded(true);
        }
      };
    });
  }, [imageSources]);

  if (!loaded) {
    return <div>Loading images...</div>;
  }
  return <>{children}</>;
};

export default PreloadImages;