_startHandModeWithSpaceBar(e) {
    if (this.withSpace || this.isTextEditing) {
      return;
    }

    if (e.keyCode === keyCodes.SPACE) {
      this.withSpace = true;
      this.startHandMode();
    }
  }
Handler who turns on hand mode when the space bar is down
@param {KeyboardEvent} e - Event object
@private