element-web/src/components/structures/BackdropPanel.tsx

51 lines
1.4 KiB
TypeScript

import React, { createRef } from "react";
interface IProps {
width?: number;
height?: number;
backgroundImage?: ImageBitmap;
blur?: string;
}
export default class BackdropPanel extends React.PureComponent<IProps> {
private canvasRef: React.RefObject<HTMLCanvasElement> = createRef();
private ctx: CanvasRenderingContext2D;
static defaultProps = {
blur: "60px",
}
public componentDidMount() {
this.ctx = this.canvasRef.current.getContext("2d");
}
public componentDidUpdate() {
if (this.props.backgroundImage) {
requestAnimationFrame(this.refreshBackdropImage);
}
}
private refreshBackdropImage = (): void => {
const { width, height, backgroundImage } = this.props;
this.canvasRef.current.width = width;
this.canvasRef.current.height = height;
const destinationX = width - backgroundImage.width;
const destinationY = height - backgroundImage.height;
this.ctx.filter = `blur(${this.props.blur})`;
this.ctx.drawImage(
backgroundImage,
Math.min(destinationX, 0),
Math.min(destinationY, 0),
Math.max(width, backgroundImage.width),
Math.max(height, backgroundImage.height),
);
}
public render() {
return <canvas ref={this.canvasRef} className="mx_BackdropPanel" />;
}
}