public void setKeyboardSelectedCell(final int index) {
        if (index != keyboardSelectionIndex) {
            if (keyboardSelectedCell != null) {
                keyboardSelectedCell.setKeyboardSelected(false);
            }
            if (index >= 0 && index < cellList.size()) {
                final DateCell cell = getCell(index);
                if (cell != null) {
                    cell.setKeyboardSelected(true);
                }
                keyboardSelectedCell = cell;
            }
            keyboardSelectionIndex = index;
        }
    }
Highlighting, selectable cell grid. Used to help construct the default
calendar view.
stroom-core-client-widget/src/main/java/stroom/widget/datepicker/client/DateGrid.java