code: function setDragMode(mode) {
      var options = this.options,
          dragBox = this.dragBox,
          face = this.face;
  
      if (this.ready && !this.disabled) {
        var croppable = mode === DRAG_MODE_CROP;
        var movable = options.movable && mode === DRAG_MODE_MOVE;
        mode = croppable || movable ? mode : DRAG_MODE_NONE;
        options.dragMode = mode;
        setData(dragBox, DATA_ACTION, mode);
        toggleClass(dragBox, CLASS_CROP, croppable);
        toggleClass(dragBox, CLASS_MOVE, movable);
  
        if (!options.cropBoxMovable) {
          // Sync drag mode to crop box when it is not movable
          setData(face, DATA_ACTION, mode);
          toggleClass(face, CLASS_CROP, croppable);
          toggleClass(face, CLASS_MOVE, movable);
        }
      }
  
      return this;
    }
docs: Change the drag mode.
  @param {string} mode - The new drag mode.
  @returns {Cropper} this