send/app/dragManager.js

import { checkSize } from './utils';

export default function(state, emitter) {
  emitter.on('DOMContentLoaded', () => {
    document.body.addEventListener('dragover', event => {
      if (state.route === '/') {
        event.preventDefault();
        const files = document.querySelector('.uploadedFilesWrapper');
        files.classList.add('uploadArea--noEvents');
      }
    });
    document.body.addEventListener('drop', event => {
      if (state.route === '/' && !state.uploading) {
        event.preventDefault();
        document
          .querySelector('.uploadArea')
          .classList.remove('uploadArea--dragging');

        const target = event.dataTransfer;

        checkSize(target.files, state.files);

        emitter.emit('addFiles', { files: target.files });
      }
    });
  });
}