+package org.argeo.jcr.ui.explorer.model;
+
+import javax.jcr.Node;
+import javax.jcr.NodeIterator;
+import javax.jcr.RepositoryException;
+import javax.jcr.Workspace;
+
+import org.argeo.ArgeoException;
+import org.argeo.eclipse.ui.TreeParent;
+
+/**
+ * UI Tree component. Wraps a node of a JCR {@link Workspace}. It also keeps a
+ * reference to its parent node that can either be a {@link WorkspaceNode}, a
+ * {@link SingleJcrNode} or null if the node is "mounted" as the root of the UI
+ * tree.
+ */
+
+public class SingleJcrNode extends TreeParent implements UiNode {
+
+ private final Node node;
+ private String alias = null;
+
+ // keeps a local reference to the node's name to avoid exception when the
+ // session is lost
+ // private final String name;
+
+ /** Creates a new UiNode in the UI Tree */
+ public SingleJcrNode(TreeParent parent, Node node, String name) {
+ super(name);
+ setParent(parent);
+ this.node = node;
+ }
+
+ /**
+ * Creates a new UiNode in the UI Tree, keeping a reference to the alias of
+ * the corresponding repository in the current UI environment. It is useful
+ * to be able to mount nodes as roots of the UI tree.
+ */
+ public SingleJcrNode(TreeParent parent, Node node, String name, String alias) {
+ super(name);
+ setParent(parent);
+ this.node = node;
+ this.alias = alias;
+ }
+
+ /** returns the node wrapped by the current Ui object */
+ public Node getNode() {
+ return node;
+ }
+
+ /**
+ * Returns the alias corresponding to the repository abstraction that
+ * contains current node. If the current object is mounted as root of the UI
+ * tree, the alias is stored in the object. Otherwise, we must browse the
+ * tree backward to the RepositoryNode.
+ *
+ * Alias is then cached in the current object so that next time it will be
+ * here.
+ */
+ public String getAlias() {
+ if (alias == null) {
+ alias = ((UiNode) getParent()).getAlias();
+ }
+ return alias;
+ }
+
+ /**
+ * Override normal behaviour to initialize children only when first
+ * requested
+ */
+ @Override
+ public synchronized Object[] getChildren() {
+ if (isLoaded()) {
+ return super.getChildren();
+ } else {
+ // initialize current object
+ try {
+ NodeIterator ni = node.getNodes();
+ while (ni.hasNext()) {
+ Node curNode = ni.nextNode();
+ addChild(new SingleJcrNode(this, curNode, curNode.getName()));
+ }
+ return super.getChildren();
+ } catch (RepositoryException re) {
+ throw new ArgeoException(
+ "Unexcpected error while initializing children SingleJcrNode",
+ re);
+ }
+ }
+ }
+
+ @Override
+ public boolean hasChildren() {
+ try {
+ return node.hasNodes();
+ } catch (RepositoryException re) {
+ throw new ArgeoException(
+ "Unexpected error while checking children node existence",
+ re);
+ }
+ }
+
+}