Drop files from OS

Read details about HTML drag-and-drop.

$(dropzone)
  .on('drag dragstart dragend dragover dragenter dragleave drop', e => {
    e.preventDefault();
    e.stopPropagation();
  })
  .on('dragover', e => {
     // ...
  }).on('drop', function(e) {
    var droppedFiles = e.originalEvent.dataTransfer.files;
    // ...
  });