/**
* Expands an item.
*
* @param itemId the item id.
* @param sendChildTree flag to indicate if client needs subtree or not (may be cached)
* @return True if the expand operation succeeded
*/
private boolean expandItem(Object itemId, boolean sendChildTree) {
// Succeeds if the node is already expanded
if (isExpanded(itemId)) {
return true;
}
// Nodes that can not have children are not expandable
if (!areChildrenAllowed(itemId)) {
return false;
}
// Expands
expanded.add(itemId);
expandedItemId = itemId;
if (initialPaint) {
markAsDirty();
} else if (sendChildTree) {
requestPartialRepaint();
}
fireExpandEvent(itemId);
return true;
}
