/**
* Returns the number of children of <code>parent</code>. Returns 0 if the node is a leaf or if it
* has no children. <code>parent</code> must be a node previously obtained from this data source.
*
* @param parent a node in the tree, obtained from this data source
* @return the number of children of the node <code>parent</code>
*/
public int getChildCount(Object parent) {
if (parent instanceof CatalogDirectory) {
CatalogDirectory catDir = (CatalogDirectory) parent;
return catDir.getNumCatalogs();
}
return 0;
}
/**
* Returns the child of <code>parent</code> at index <code>index</code> in the parent's child
* array. <code>parent</code> must be a node previously obtained from this data source. This
* should not return <code>null</code> if <code>index</code> is a valid index for <code>parent
* </code> (that is <code>index >= 0 &&
* index < getChildCount(parent</code>)).
*
* @param parent a node in the tree, obtained from this data source
* @return the child of <code>parent</code> at index <code>index</code>
*/
public Object getChild(Object parent, int index) {
if (parent instanceof CatalogDirectory) {
CatalogDirectory catDir = (CatalogDirectory) parent;
if (index >= 0 && index < catDir.getNumCatalogs()) return catDir.getCatalog(index);
}
return null;
}
/**
* Returns the index of child in parent. If <code>parent</code> is <code>null</code> or <code>
* child</code> is <code>null</code>, returns -1.
*
* @param parent a note in the tree, obtained from this data source
* @param child the node we are interested in
* @return the index of the child in the parent, or -1 if either <code>child</code> or <code>
* parent</code> are <code>null</code>
*/
public int getIndexOfChild(Object parent, Object child) {
if (parent instanceof CatalogDirectory && child instanceof Catalog) {
CatalogDirectory catDir = (CatalogDirectory) parent;
Catalog cat = (Catalog) child;
return catDir.indexOf(cat);
}
return -1;
}
/**
* Returns the root of the tree. Returns <code>null</code> only if the tree has no nodes.
*
* @return the root of the tree
*/
public Object getRoot() {
CatalogDirectory rootDir = null, catDir = this;
while (catDir != null) {
rootDir = catDir;
catDir = catDir.getParent();
}
return rootDir;
}
// Return a tree model event for an operation of the given catalog
private TreeModelEvent _getTreeModelEvent(Catalog cat) {
Object source = this;
CatalogDirectory catDir = cat.getParent();
Object[] path = null;
int[] childIndices = null;
Object[] children = null;
if (catDir == null) {
// must be the tree root
path = new Catalog[1];
path[0] = cat;
childIndices = new int[] {0};
} else {
path = getPath(catDir);
childIndices = new int[] {catDir.indexOf(cat)};
}
children = new Object[] {cat};
return new TreeModelEvent(source, path, childIndices, children);
}
/** Return an array of catalogs describing the path to the given catalog or catalog directory. */
public Catalog[] getPath(Catalog cat) {
if (cat == null) return null;
List l = new Vector();
CatalogDirectory dir;
if (cat instanceof CatalogDirectory) {
dir = (CatalogDirectory) cat;
} else {
dir = cat.getParent();
l.add(cat);
}
while (dir != null) {
l.add(dir);
dir = dir.getParent();
}
int n = l.size();
Catalog[] ar = new Catalog[n];
for (int i = 0; i < n; i++) ar[n - i - 1] = (Catalog) l.get(i);
return ar;
}
