ohif-viewer/platform/viewer/src/components/ViewportGrid/ViewportPane.js

import React from 'react';
import { useDrop } from 'react-dnd';
import PropTypes from 'prop-types';
import classNames from 'classnames';
import './ViewportPane.css';

const ViewportPane = function(props) {
  const { children, onDrop, viewportIndex, className: propClassName } = props;
  const [{ hovered, highlighted }, drop] = useDrop({
    accept: 'thumbnail',
    drop: (droppedItem, monitor) => {
      const canDrop = monitor.canDrop();
      const isOver = monitor.isOver();

      if (canDrop && isOver && onDrop) {
        const { studyInstanceUid, displaySetInstanceUid } = droppedItem;

        onDrop({ viewportIndex, studyInstanceUid, displaySetInstanceUid });
      }
    },
    // Monitor, and collect props.
    // Returned as values by `useDrop`
    collect: monitor => ({
      highlighted: monitor.canDrop(),
      hovered: monitor.isOver(),
    }),
  });

  return (
    <div
      className={classNames(
        'viewport-drop-target',
        { hovered: hovered },
        { highlighted: highlighted },
        propClassName
      )}
      ref={drop}
    >
      {children}
    </div>
  );
};

ViewportPane.propTypes = {
  children: PropTypes.node.isRequired,
  viewportIndex: PropTypes.number.isRequired,
  onDrop: PropTypes.func.isRequired,
  className: PropTypes.string,
};

export default ViewportPane;