public void setYearAndMonthDropdownVisible(boolean dropdownVisible) {
        this.yearAndMonthDropdownVisible = dropdownVisible;
        getMonthSelector().refresh();
    }
If the <code>dropdownVisible</code> is equal to true, the user will be able to change the current month and
the current year of the date picker via two dropdown lists.
stroom-core-client-widget/src/main/java/stroom/widget/datepicker/client/CustomDatePicker.java