code: void zApplyVisibilityOfButtons() {
          boolean showNextMonth = settings.getVisibleNextMonthButton();
          boolean showNextYear = settings.getVisibleNextYearButton();
          boolean showPreviousMonth = settings.getVisiblePreviousMonthButton();
          boolean showPreviousYear = settings.getVisiblePreviousYearButton();
          boolean showMonthMenu = settings.getVisibleMonthMenuButton();
          boolean showTodayButton = settings.getVisibleTodayButton();
  
          boolean yearMenuSetting = settings.getVisibleYearMenuButton();
          boolean yearEditorPanelIsDisplayed = (yearEditorPanel.getParent() != null);
  
          boolean clearButtonSetting = settings.getVisibleClearButton();
          boolean emptyDatesAllowed = settings.getAllowEmptyDates();
  
          buttonNextMonth.setVisible(showNextMonth);
          buttonNextYear.setVisible(showNextYear);
          buttonPreviousMonth.setVisible(showPreviousMonth);
          buttonPreviousYear.setVisible(showPreviousYear);
          labelMonth.setVisible(showMonthMenu);
          labelSetDateToToday.setVisible(showTodayButton);
  
          boolean showYearMenu = ((yearMenuSetting) && (!yearEditorPanelIsDisplayed));
          labelYear.setVisible(showYearMenu);
  
          // Note: I had considered centering the today label in the CalendarPanel whenever the 
          // clear label was hidden. However, it still looks better when it is aligned to the left.
          boolean showClearButton = (clearButtonSetting && emptyDatesAllowed);
          labelClearDate.setVisible(showClearButton);
  
          boolean showMonthAndYearInnerPanel = (showMonthMenu || showYearMenu
              || yearEditorPanelIsDisplayed);
          boolean showHeaderControlsPanel = (showMonthAndYearInnerPanel
              || showNextMonth || showNextYear || showPreviousMonth || showPreviousYear);
          monthAndYearInnerPanel.setVisible(showMonthAndYearInnerPanel);
          headerControlsPanel.setVisible(showHeaderControlsPanel);
  
          boolean showFooterPanel = (showTodayButton || showClearButton);
          footerPanel.setVisible(showFooterPanel);
      }
docs: zApplyVisibilityOfButtons, This sets visibility of button controls for this calendar,
  according to the current settings.