_fireAddText(fEvent) {
    const obj = fEvent.target;
    const e = fEvent.e || {};
    const originPointer = this.getCanvas().getPointer(e);

    if (!obj) {
      this.fire(events.ADD_TEXT, {
        originPosition: {
          x: originPointer.x,
          y: originPointer.y,
        },
        clientPosition: {
          x: e.clientX || 0,
          y: e.clientY || 0,
        },
      });
    }
  }
Fire 'addText' event if object is not selected.
@param {fabric.Event} fEvent - Current mousedown event on selected object
@private