| /** |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you 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 } from 'react'; |
| import { styled, logging } from '@superset-ui/core'; |
| |
| export type BackgroundPosition = 'top' | 'bottom'; |
| interface ImageContainerProps { |
| src: string; |
| position: BackgroundPosition; |
| } |
| |
| const ImageContainer = styled.div<ImageContainerProps>` |
| background-image: url(${({ src }) => src}); |
| background-size: cover; |
| background-position: center ${({ position }) => position}; |
| display: inline-block; |
| height: calc(100% - 1px); |
| width: calc(100% - 2px); |
| margin: 1px 1px 0 1px; |
| `; |
| interface ImageLoaderProps |
| extends React.DetailedHTMLProps< |
| React.HTMLAttributes<HTMLDivElement>, |
| HTMLDivElement |
| > { |
| fallback: string; |
| src: string; |
| isLoading?: boolean; |
| position: BackgroundPosition; |
| } |
| |
| export default function ImageLoader({ |
| src, |
| fallback, |
| isLoading, |
| position, |
| ...rest |
| }: ImageLoaderProps) { |
| const [imgSrc, setImgSrc] = React.useState<string>(fallback); |
| |
| useEffect(() => { |
| if (src) { |
| fetch(src) |
| .then(response => response.blob()) |
| .then(blob => { |
| if (/image/.test(blob.type)) { |
| const imgURL = URL.createObjectURL(blob); |
| setImgSrc(imgURL); |
| } |
| }) |
| .catch(e => { |
| logging.error(e); |
| setImgSrc(fallback); |
| }); |
| } |
| |
| return () => { |
| // theres a very brief period where isLoading is false and this component is about to unmount |
| // where the stale imgSrc is briefly rendered. Setting imgSrc to fallback smoothes the transition. |
| setImgSrc(fallback); |
| }; |
| }, [src, fallback]); |
| |
| return ( |
| <ImageContainer |
| src={isLoading ? fallback : imgSrc} |
| {...rest} |
| position={position} |
| /> |
| ); |
| } |