@Override
    public void onBrowserEvent(Event event) {
        if (event.getTypeInt() == Event.ONKEYDOWN) {
            navigate(event.getKeyCode());

        } else if (event.getTypeInt() == Event.ONCLICK) {
            final Element element = event.getEventTarget().cast();
            if (element != null) {
                final Element outer = ElementUtil.findParent(element, "cellOuter", 5);
                if (outer != null) {
                    final AbstractCell cell = elementToCell.get(outer);
                    if (cell instanceof DateCell) {
                        final DateCell dateCell = (DateCell) cell;
                        if (isActive(dateCell)) {
                            setSelected(dateCell);
                        }
                    }
                }
            }
        }
    }
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