private void save() {
    if (!mSubjectField.getText().equals(mThread.getSubject())) {
      mThread.setSubject(mSubjectField.getText());
    }
    //        List<?> participants = mParticipantsList.getCheckedValues();
    //        Set<User> threadUser = new HashSet<>();
    //        for (Object o: participants) {
    //            threadUser.add(((UserElement) o).user);
    //        }
    //        mThread.setUser(threadUser);

    KonThread.ViewSettings newSettings;
    if (mColorOpt.isSelected()) newSettings = new KonThread.ViewSettings(mColor.getBottomBgColor());
    else if (mImgOpt.isSelected() && !mImgChooser.getSelectedFiles().isEmpty())
      newSettings =
          new KonThread.ViewSettings(mImgChooser.getSelectedFiles().get(0).getAbsolutePath());
    else newSettings = new KonThread.ViewSettings();

    if (!newSettings.equals(mThread.getViewSettings())) {
      mThread.setViewSettings(newSettings);
    }
  }