/** Does the actual addition of {@link UserItem}s to the top of the list. */
private void addHead() {
List<UserItem> l = head;
if (l.size() > 0) {
head = new ArrayList<UserItem>();
headKeys = new HashSet<Key>();
int offsetHeight = flowPanel.getOffsetHeight();
for (int i = l.size() - 1; i >= 0; i--) {
UserItem e = l.get(i);
RowWidget row = createRow(e);
flowPanel.insert(row, 0);
rows.put(row.getKey(), row);
}
int deltaHeight = flowPanel.getOffsetHeight() - offsetHeight;
scrollPanel.setVerticalScrollPosition(scrollPanel.getVerticalScrollPosition() + deltaHeight);
rowsAdded();
NewDataEvent.fire(this, NewDataType.NEW_DATA_SHOWN);
}
}
