* each category to the tree field.
*/
private void populateCategories() {
_categoriesHashtable = _sqlManager.getCategories();
final IntEnumeration enumeration = _categoriesHashtable.keys();
int key;
Category category;
int categoryNode;
while (enumeration.hasMoreElements()) {
key = enumeration.nextElement();
category = (Category) _categoriesHashtable.get(key);
categoryNode = _treeField.addChildNode(0, category);
category.setNode(categoryNode);
}
}