pybricks-code/src/components/OpenFileButton.tsx

// SPDX-License-Identifier: MIT
// Copyright (c) 2020 The Pybricks Authors

import React from 'react';
import Button from 'react-bootstrap/Button';
import Image from 'react-bootstrap/Image';
import OverlayTrigger from 'react-bootstrap/OverlayTrigger';
import Tooltip from 'react-bootstrap/Tooltip';
import Dropzone, { FileRejection } from 'react-dropzone';

export interface OpenFileButtonProps {
    /** A unique id for each instance. */
    readonly id: string;
    /** The accepted file extension */
    readonly fileExtension: string;
    /** Tooltip text that appears when hovering over the button. */
    readonly tooltip: string;
    /** Icon shown on the button. */
    readonly icon: string;
    /** When true or undefined, the button is enabled. */
    readonly enabled?: boolean;
    /** Callback that is called when a file has been selected and opened for reading. */
    readonly onFile: (data: ArrayBuffer) => void;
    /** Callback that is called when a file has been rejected (e.g. bad file extension). */
    readonly onReject: (file: File) => void;
    /** If defined, will call custom function instead of opening file browser. */
    readonly onClick?: () => void;
}

/**
 * Button that opens a file chooser dialog or accepts files dropped on it.
 */
class OpenFileButton extends React.Component<OpenFileButtonProps> {
    constructor(props: OpenFileButtonProps) {
        super(props);
        this.onDropAccepted = this.onDropAccepted.bind(this);
        this.onDropRejected = this.onDropRejected.bind(this);
    }

    private onDropAccepted(acceptedFiles: File[]): void {
        // should only be one file since multiple={false}
        acceptedFiles.forEach((f) => {
            const reader = new FileReader();

            reader.onabort = (): void => console.error('file reading was aborted');
            reader.onerror = (): void => console.error('file reading has failed');
            reader.onload = (): void => {
                const binaryStr = reader.result;
                if (binaryStr === null) {
                    throw Error('Unexpected null binaryStr');
                }
                if (typeof binaryStr === 'string') {
                    throw Error('Unexpected string binaryStr');
                }
                this.props.onFile(binaryStr);
            };
            reader.readAsArrayBuffer(f);
        });
    }

    private onDropRejected(fileRejections: FileRejection[]): void {
        // should only be one file since multiple={false}
        fileRejections.forEach((r) => {
            this.props.onReject(r.file);
        });
    }

    render(): JSX.Element {
        return (
            <Dropzone
                onDropAccepted={this.onDropAccepted}
                onDropRejected={this.onDropRejected}
                accept={this.props.fileExtension}
                multiple={false}
                noClick={this.props.onClick !== undefined}
                noKeyboard={this.props.onClick !== undefined}
            >
                {({ getRootProps, getInputProps }): JSX.Element => (
                    <OverlayTrigger
                        placement="bottom"
                        overlay={
                            <Tooltip id={`${this.props.id}-tooltip`}>
                                {this.props.tooltip}.
                            </Tooltip>
                        }
                    >
                        <Button
                            {...getRootProps()}
                            variant="light"
                            disabled={this.props.enabled === false}
                            style={
                                this.props.enabled === false
                                    ? { pointerEvents: 'none' }
                                    : undefined
                            }
                            // onClick={this.props.onClick}
                            // breaks Dropzone when this.props.onClick is undefined
                            // so we have to do it the long way
                            {...(this.props.onClick
                                ? { onClick: this.props.onClick }
                                : {})}
                        >
                            <input {...getInputProps()} />
                            <Image src={this.props.icon} alt={this.props.id} />
                        </Button>
                    </OverlayTrigger>
                )}
            </Dropzone>
        );
    }
}

export default OpenFileButton;