MASS REFORMAT.

According to http://toolkit.intra.itmill.com/trac/itmilltoolkit/wiki/CodingConventions

svn changeset:2864/svn branch:trunk

1 files changed, 950 insertions, 952 deletions

diff --git a/src/com/itmill/toolkit/ui/Tree.java b/src/com/itmill/toolkit/ui/Tree.java
index a86717eb84..2042d4b312 100644
--- a/src/com/itmill/toolkit/ui/Tree.java
+++ b/src/com/itmill/toolkit/ui/Tree.java
@@ -59,957 +59,955 @@ import com.itmill.toolkit.terminal.Resource;
  * @since 3.0
  */
 public class Tree extends AbstractSelect implements Container.Hierarchical,
-		Action.Container {
-
-	/* Static members ***************************************************** */
-
-	private static final Method EXPAND_METHOD;
-
-	private static final Method COLLAPSE_METHOD;
-
-	static {
-		try {
-			EXPAND_METHOD = ExpandListener.class.getDeclaredMethod(
-					"nodeExpand", new Class[] { ExpandEvent.class });
-			COLLAPSE_METHOD = CollapseListener.class.getDeclaredMethod(
-					"nodeCollapse", new Class[] { CollapseEvent.class });
-		} catch (java.lang.NoSuchMethodException e) {
-			// This should never happen
-			e.printStackTrace();
-			throw new java.lang.RuntimeException(
-					"Internal error, please report");
-		}
-	}
-
-	/* Private members **************************************************** */
-
-	/**
-	 * Set of expanded nodes.
-	 */
-	private final HashSet expanded = new HashSet();
-
-	/**
-	 * List of action handlers.
-	 */
-	private LinkedList actionHandlers = null;
-
-	/**
-	 * Action mapper.
-	 */
-	private KeyMapper actionMapper = null;
-
-	/**
-	 * Is the tree selectable .
-	 */
-	private boolean selectable = true;
-
-	/**
-	 * Flag to indicate sub-tree loading
-	 */
-	private boolean partialUpdate = false;
-
-	/**
-	 * Holds a itemId which was recently expanded
-	 */
-	private Object expandedItemId;
-
-	/**
-	 * a flag which indicates initial paint. After this flag set true partial
-	 * updates are allowed.
-	 */
-	private boolean initialPaint = true;
-
-	/* Tree constructors ************************************************** */
-
-	/**
-	 * Creates a new empty tree.
-	 */
-	public Tree() {
-	}
-
-	/**
-	 * Creates a new empty tree with caption.
-	 * 
-	 * @param caption
-	 */
-	public Tree(String caption) {
-		setCaption(caption);
-	}
-
-	/**
-	 * Creates a new tree with caption and connect it to a Container.
-	 * 
-	 * @param caption
-	 * @param dataSource
-	 */
-	public Tree(String caption, Container dataSource) {
-		setCaption(caption);
-		setContainerDataSource(dataSource);
-	}
-
-	/* Expanding and collapsing ******************************************* */
-
-	/**
-	 * Check is an item is expanded
-	 * 
-	 * @param itemId
-	 *            the item id.
-	 * @return true iff the item is expanded.
-	 */
-	public boolean isExpanded(Object itemId) {
-		return this.expanded.contains(itemId);
-	}
-
-	/**
-	 * Expands an item.
-	 * 
-	 * @param itemId
-	 *            the item id.
-	 * @return True iff the expand operation succeeded
-	 */
-	public boolean expandItem(Object itemId) {
-		return expandItem(itemId, true);
-	}
-
-	/**
-	 * Expands an item.
-	 * 
-	 * @param itemId
-	 *            the item id.
-	 * @param sendChildTree
-	 * 		flag to indicate if client needs subtree or not (may be cached)
-	 * @return True iff 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
-		this.expanded.add(itemId);
-
-		this.expandedItemId = itemId;
-		if (this.initialPaint) {
-			requestRepaint();
-		} else if(sendChildTree) {
-			requestPartialRepaint();
-		}
-		fireExpandEvent(itemId);
-
-		return true;
-	}
-
-	public void requestRepaint() {
-		super.requestRepaint();
-		this.partialUpdate = false;
-	}
-
-	private void requestPartialRepaint() {
-		super.requestRepaint();
-		this.partialUpdate = true;
-	}
-
-	/**
-	 * Expands the items recursively
-	 * 
-	 * Expands all the children recursively starting from an item. Operation
-	 * succeeds only if all expandable items are expanded.
-	 * 
-	 * @param startItemId
-	 * @return True iff the expand operation succeeded
-	 */
-	public boolean expandItemsRecursively(Object startItemId) {
-
-		boolean result = true;
-
-		// Initial stack
-		Stack todo = new Stack();
-		todo.add(startItemId);
-
-		// Expands recursively
-		while (!todo.isEmpty()) {
-			Object id = todo.pop();
-			if (areChildrenAllowed(id) && !expandItem(id, false)) {
-				result = false;
-			}
-			if (hasChildren(id)) {
-				todo.addAll(getChildren(id));
-			}
-		}
-		requestRepaint();
-		return result;
-	}
-
-	/**
-	 * Collapses an item.
-	 * 
-	 * @param itemId
-	 *            the item id.
-	 * @return True iff the collapse operation succeeded
-	 */
-	public boolean collapseItem(Object itemId) {
-
-		// Succeeds if the node is already collapsed
-		if (!isExpanded(itemId)) {
-			return true;
-		}
-
-		// Collapse
-		this.expanded.remove(itemId);
-		requestRepaint();
-		fireCollapseEvent(itemId);
-
-		return true;
-	}
-
-	/**
-	 * Collapses the items recursively.
-	 * 
-	 * Collapse all the children recursively starting from an item. Operation
-	 * succeeds only if all expandable items are collapsed.
-	 * 
-	 * @param startItemId
-	 * @return True iff the collapse operation succeeded
-	 */
-	public boolean collapseItemsRecursively(Object startItemId) {
-
-		boolean result = true;
-
-		// Initial stack
-		Stack todo = new Stack();
-		todo.add(startItemId);
-
-		// Collapse recursively
-		while (!todo.isEmpty()) {
-			Object id = todo.pop();
-			if (areChildrenAllowed(id) && !collapseItem(id)) {
-				result = false;
-			}
-			if (hasChildren(id)) {
-				todo.addAll(getChildren(id));
-			}
-		}
-
-		return result;
-	}
-
-	/**
-	 * Getter for property selectable.
-	 * 
-	 * <p>
-	 * The tree is selectable by default.
-	 * </p>
-	 * 
-	 * @return the Value of property selectable.
-	 */
-	public boolean isSelectable() {
-		return this.selectable;
-	}
-
-	/**
-	 * Setter for property selectable.
-	 * 
-	 * <p>
-	 * The tree is selectable by default.
-	 * </p>
-	 * 
-	 * @param selectable
-	 *            the New value of property selectable.
-	 */
-	public void setSelectable(boolean selectable) {
-		if (this.selectable != selectable) {
-			this.selectable = selectable;
-			requestRepaint();
-		}
-	}
-
-	/* Component API ****************************************************** */
-
-	/**
-	 * Gets the UIDL tag corresponding to the component.
-	 * 
-	 * @see com.itmill.toolkit.ui.AbstractComponent#getTag()
-	 */
-	public String getTag() {
-		return "tree";
-	}
-
-	/**
-	 * Called when one or more variables handled by the implementing class are
-	 * changed.
-	 * 
-	 * @see com.itmill.toolkit.terminal.VariableOwner#changeVariables(Object
-	 *      source, Map variables)
-	 */
-	public void changeVariables(Object source, Map variables) {
-
-		if (!isSelectable() && variables.containsKey("selected")) {
-			// Not-selectable is a special case, AbstractSelect does not support
-			// TODO could be optimized.
-			variables = new HashMap(variables);
-			variables.remove("selected");
-		}
-
-		// Collapses the nodes
-		if (variables.containsKey("collapse")) {
-			String[] keys = (String[]) variables.get("collapse");
-			for (int i = 0; i < keys.length; i++) {
-				Object id = this.itemIdMapper.get(keys[i]);
-				if (id != null && isExpanded(id)) {
-					this.expanded.remove(id);
-					fireCollapseEvent(id);
-				}
-			}
-		}
-
-		// Expands the nodes
-		if (variables.containsKey("expand")) {
-			boolean sendChildTree = false;
-			if(variables.containsKey("requestChildTree")) {
-				sendChildTree = true;
-			}
-			String[] keys = (String[]) variables.get("expand");
-			for (int i = 0; i < keys.length; i++) {
-				Object id = this.itemIdMapper.get(keys[i]);
-				if (id != null) {
-					expandItem(id, sendChildTree);
-				}
-			}
-		}
-
-		// Selections are handled by the select component
-		super.changeVariables(source, variables);
-
-		// Actions
-		if (variables.containsKey("action")) {
-
-			StringTokenizer st = new StringTokenizer((String) variables
-					.get("action"), ",");
-			if (st.countTokens() == 2) {
-				Object itemId = this.itemIdMapper.get(st.nextToken());
-				Action action = (Action) this.actionMapper.get(st.nextToken());
-				if (action != null && containsId(itemId)
-						&& this.actionHandlers != null) {
-					for (Iterator i = this.actionHandlers.iterator(); i
-							.hasNext();) {
-						((Action.Handler) i.next()).handleAction(action, this,
-								itemId);
-					}
-				}
-			}
-		}
-	}
-
-	/**
-	 * Paints any needed component-specific things to the given UIDL stream.
-	 * 
-	 * @see com.itmill.toolkit.ui.AbstractComponent#paintContent(PaintTarget)
-	 */
-	public void paintContent(PaintTarget target) throws PaintException {
-		this.initialPaint = false;
-
-		if (this.partialUpdate) {
-			target.addAttribute("partialUpdate", true);
-			target.addAttribute("rootKey", this.itemIdMapper
-					.key(this.expandedItemId));
-		} else {
-
-			// Focus control id
-			if (getFocusableId() > 0) {
-				target.addAttribute("focusid", getFocusableId());
-			}
-
-			// The tab ordering number
-			if (getTabIndex() > 0) {
-				target.addAttribute("tabindex", getTabIndex());
-			}
-
-			// Paint tree attributes
-			if (isSelectable()) {
-				target.addAttribute("selectmode", (isMultiSelect() ? "multi"
-						: "single"));
-			} else {
-				target.addAttribute("selectmode", "none");
-			}
-			if (isNewItemsAllowed()) {
-				target.addAttribute("allownewitem", true);
-			}
-
-			if (isNullSelectionAllowed()) {
-				target.addAttribute("nullselect", true);
-			}
-
-		}
-
-		// Initialize variables
-		Set actionSet = new LinkedHashSet();
-		String[] selectedKeys;
-		if (isMultiSelect()) {
-			selectedKeys = new String[((Set) getValue()).size()];
-		} else {
-			selectedKeys = new String[(getValue() == null ? 0 : 1)];
-		}
-		int keyIndex = 0;
-		LinkedList expandedKeys = new LinkedList();
-
-		// Iterates through hierarchical tree using a stack of iterators
-		Stack iteratorStack = new Stack();
-		Collection ids;
-		if (this.partialUpdate) {
-			ids = getChildren(this.expandedItemId);
-		} else {
-			ids = rootItemIds();
-		}
-
-		if (ids != null) {
-			iteratorStack.push(ids.iterator());
-		}
-
-		while (!iteratorStack.isEmpty()) {
-
-			// Gets the iterator for current tree level
-			Iterator i = (Iterator) iteratorStack.peek();
-
-			// If the level is finished, back to previous tree level
-			if (!i.hasNext()) {
-
-				// Removes used iterator from the stack
-				iteratorStack.pop();
-
-				// Closes node
-				if (!iteratorStack.isEmpty()) {
-					target.endTag("node");
-				}
-			}
-
-			// Adds the item on current level
-			else {
-				Object itemId = i.next();
-
-				// Starts the item / node
-				boolean isNode = areChildrenAllowed(itemId)
-						&& hasChildren(itemId);
-				if (isNode) {
-					target.startTag("node");
-				} else {
-					target.startTag("leaf");
-				}
-
-				// Adds the attributes
-				target.addAttribute("caption", getItemCaption(itemId));
-				Resource icon = getItemIcon(itemId);
-				if (icon != null) {
-					target.addAttribute("icon", getItemIcon(itemId));
-				}
-				String key = this.itemIdMapper.key(itemId);
-				target.addAttribute("key", key);
-				if (isSelected(itemId)) {
-					target.addAttribute("selected", true);
-					selectedKeys[keyIndex++] = key;
-				}
-				if (areChildrenAllowed(itemId) && isExpanded(itemId)) {
-					target.addAttribute("expanded", true);
-					expandedKeys.add(key);
-				}
-
-				// Actions
-				if (this.actionHandlers != null) {
-					ArrayList keys = new ArrayList();
-					for (Iterator ahi = this.actionHandlers.iterator(); ahi
-							.hasNext();) {
-						Action[] aa = ((Action.Handler) ahi.next()).getActions(
-								itemId, this);
-						if (aa != null) {
-							for (int ai = 0; ai < aa.length; ai++) {
-								String akey = this.actionMapper.key(aa[ai]);
-								actionSet.add(aa[ai]);
-								keys.add(akey);
-							}
-						}
-					}
-					target.addAttribute("al", keys.toArray());
-				}
-
-				// Adds the children if expanded, or close the tag
-				if (isExpanded(itemId) && hasChildren(itemId)
-						&& areChildrenAllowed(itemId)) {
-					iteratorStack.push(getChildren(itemId).iterator());
-				} else {
-					if (isNode) {
-						target.endTag("node");
-					} else {
-						target.endTag("leaf");
-					}
-				}
-			}
-		}
-
-		// Actions
-		if (!actionSet.isEmpty()) {
-			target.addVariable(this, "action", "");
-			target.startTag("actions");
-			for (Iterator i = actionSet.iterator(); i.hasNext();) {
-				Action a = (Action) i.next();
-				target.startTag("action");
-				if (a.getCaption() != null) {
-					target.addAttribute("caption", a.getCaption());
-				}
-				if (a.getIcon() != null) {
-					target.addAttribute("icon", a.getIcon());
-				}
-				target.addAttribute("key", this.actionMapper.key(a));
-				target.endTag("action");
-			}
-			target.endTag("actions");
-		}
-
-		if (this.partialUpdate) {
-			this.partialUpdate = false;
-		} else {
-			// Selected
-			target.addVariable(this, "selected", selectedKeys);
-
-			// Expand and collapse
-			target.addVariable(this, "expand", new String[] {});
-			target.addVariable(this, "collapse", new String[] {});
-
-			// New items
-			target.addVariable(this, "newitem", new String[] {});
-		}
-	}
-
-	/* Container.Hierarchical API ***************************************** */
-
-	/**
-	 * Tests if the Item with given ID can have any children.
-	 * 
-	 * @see com.itmill.toolkit.data.Container.Hierarchical#areChildrenAllowed(Object)
-	 */
-	public boolean areChildrenAllowed(Object itemId) {
-		return ((Container.Hierarchical) this.items).areChildrenAllowed(itemId);
-	}
-
-	/**
-	 * Gets the IDs of all Items that are children of the specified Item.
-	 * 
-	 * @see com.itmill.toolkit.data.Container.Hierarchical#getChildren(Object)
-	 */
-	public Collection getChildren(Object itemId) {
-		return ((Container.Hierarchical) this.items).getChildren(itemId);
-	}
-
-	/**
-	 * Gets the ID of the parent Item of the specified Item.
-	 * 
-	 * @see com.itmill.toolkit.data.Container.Hierarchical#getParent(Object)
-	 */
-	public Object getParent(Object itemId) {
-		return ((Container.Hierarchical) this.items).getParent(itemId);
-	}
-
-	/**
-	 * Tests if the Item specified with <code>itemId</code> has any child
-	 * Items, that is, is it a leaf Item.
-	 * 
-	 * @see com.itmill.toolkit.data.Container.Hierarchical#hasChildren(Object)
-	 */
-	public boolean hasChildren(Object itemId) {
-		return ((Container.Hierarchical) this.items).hasChildren(itemId);
-	}
-
-	/**
-	 * Tests if the Item specified with <code>itemId</code> is a root Item.
-	 * 
-	 * @see com.itmill.toolkit.data.Container.Hierarchical#isRoot(Object)
-	 */
-	public boolean isRoot(Object itemId) {
-		return ((Container.Hierarchical) this.items).isRoot(itemId);
-	}
-
-	/**
-	 * Gets the IDs of all Items in the container that don't have a parent.
-	 * 
-	 * @see com.itmill.toolkit.data.Container.Hierarchical#rootItemIds()
-	 */
-	public Collection rootItemIds() {
-		return ((Container.Hierarchical) this.items).rootItemIds();
-	}
-
-	/**
-	 * Sets the given Item's capability to have children.
-	 * 
-	 * @see com.itmill.toolkit.data.Container.Hierarchical#setChildrenAllowed(Object,
-	 *      boolean)
-	 */
-	public boolean setChildrenAllowed(Object itemId, boolean areChildrenAllowed) {
-		boolean success = ((Container.Hierarchical) this.items)
-				.setChildrenAllowed(itemId, areChildrenAllowed);
-		if (success) {
-			fireValueChange(false);
-		}
-		return success;
-	}
-
-	/**
-	 * Sets the parent of an Item.
-	 * 
-	 * @see com.itmill.toolkit.data.Container.Hierarchical#setParent(Object,
-	 *      Object)
-	 */
-	public boolean setParent(Object itemId, Object newParentId) {
-		boolean success = ((Container.Hierarchical) this.items).setParent(
-				itemId, newParentId);
-		if (success) {
-			requestRepaint();
-		}
-		return success;
-	}
-
-	/* Overriding select behavior******************************************** */
-
-	/**
-	 * Sets the Container that serves as the data source of the viewer.
-	 * 
-	 * @see com.itmill.toolkit.data.Container.Viewer#setContainerDataSource(Container)
-	 */
-	public void setContainerDataSource(Container newDataSource) {
-
-		// Assure that the data source is ordered by making unordered
-		// containers ordered by wrapping them
-		if (Container.Hierarchical.class.isAssignableFrom(newDataSource
-				.getClass())) {
-			super.setContainerDataSource(newDataSource);
-		} else {
-			super.setContainerDataSource(new ContainerHierarchicalWrapper(
-					newDataSource));
-		}
-	}
-
-	/* Expand event and listener ****************************************** */
-
-	/**
-	 * Event to fired when a node is expanded. ExapandEvent is fired when a node
-	 * is to be expanded. it can me used to dynamically fill the sub-nodes of
-	 * the node.
-	 * 
-	 * @author IT Mill Ltd.
-	 * @version
-	 * @VERSION@
-	 * @since 3.0
-	 */
-	public class ExpandEvent extends Component.Event {
-
-		/**
-		 * Serial generated by eclipse.
-		 */
-		private static final long serialVersionUID = 3832624001804481075L;
-
-		private final Object expandedItemId;
-
-		/**
-		 * New instance of options change event
-		 * 
-		 * @param source
-		 *            the Source of the event.
-		 * @param expandedItemId
-		 */
-		public ExpandEvent(Component source, Object expandedItemId) {
-			super(source);
-			this.expandedItemId = expandedItemId;
-		}
-
-		/**
-		 * Node where the event occurred.
-		 * 
-		 * @return the Source of the event.
-		 */
-		public Object getItemId() {
-			return this.expandedItemId;
-		}
-	}
-
-	/**
-	 * Expand event listener.
-	 * 
-	 * @author IT Mill Ltd.
-	 * @version
-	 * @VERSION@
-	 * @since 3.0
-	 */
-	public interface ExpandListener {
-
-		/**
-		 * A node has been expanded.
-		 * 
-		 * @param event
-		 *            the Expand event.
-		 */
-		public void nodeExpand(ExpandEvent event);
-	}
-
-	/**
-	 * Adds the expand listener.
-	 * 
-	 * @param listener
-	 *            the Listener to be added.
-	 */
-	public void addListener(ExpandListener listener) {
-		addListener(ExpandEvent.class, listener, EXPAND_METHOD);
-	}
-
-	/**
-	 * Removes the expand listener.
-	 * 
-	 * @param listener
-	 *            the Listener to be removed.
-	 */
-	public void removeListener(ExpandListener listener) {
-		removeListener(ExpandEvent.class, listener, EXPAND_METHOD);
-	}
-
-	/**
-	 * Emits the expand event.
-	 * 
-	 * @param itemId
-	 *            the item id.
-	 */
-	protected void fireExpandEvent(Object itemId) {
-		fireEvent(new ExpandEvent(this, itemId));
-	}
-
-	/* Collapse event ****************************************** */
-
-	/**
-	 * Collapse event
-	 * 
-	 * @author IT Mill Ltd.
-	 * @version
-	 * @VERSION@
-	 * @since 3.0
-	 */
-	public class CollapseEvent extends Component.Event {
-
-		/**
-		 * Serial generated by eclipse.
-		 */
-		private static final long serialVersionUID = 3257009834783290160L;
-
-		private final Object collapsedItemId;
-
-		/**
-		 * New instance of options change event.
-		 * 
-		 * @param source
-		 *            the Source of the event.
-		 * @param collapsedItemId
-		 */
-		public CollapseEvent(Component source, Object collapsedItemId) {
-			super(source);
-			this.collapsedItemId = collapsedItemId;
-		}
-
-		/**
-		 * Gets tge Collapsed Item id.
-		 * 
-		 * @return the collapsed item id.
-		 */
-		public Object getItemId() {
-			return this.collapsedItemId;
-		}
-	}
-
-	/**
-	 * Collapse event listener.
-	 * 
-	 * @author IT Mill Ltd.
-	 * @version
-	 * @VERSION@
-	 * @since 3.0
-	 */
-	public interface CollapseListener {
-
-		/**
-		 * A node has been collapsed.
-		 * 
-		 * @param event
-		 *            the Collapse event.
-		 */
-		public void nodeCollapse(CollapseEvent event);
-	}
-
-	/**
-	 * Adds the collapse listener.
-	 * 
-	 * @param listener
-	 *            the Listener to be added.
-	 */
-	public void addListener(CollapseListener listener) {
-		addListener(CollapseEvent.class, listener, COLLAPSE_METHOD);
-	}
-
-	/**
-	 * Removes the collapse listener.
-	 * 
-	 * @param listener
-	 *            the Listener to be removed.
-	 */
-	public void removeListener(CollapseListener listener) {
-		removeListener(CollapseEvent.class, listener, COLLAPSE_METHOD);
-	}
-
-	/**
-	 * Emits collapse event.
-	 * 
-	 * @param itemId
-	 *            the item id.
-	 */
-	protected void fireCollapseEvent(Object itemId) {
-		fireEvent(new CollapseEvent(this, itemId));
-	}
-
-	/* Action container *************************************************** */
-
-	/**
-	 * Adds an action handler.
-	 * 
-	 * @see com.itmill.toolkit.event.Action.Container#addActionHandler(Action.Handler)
-	 */
-	public void addActionHandler(Action.Handler actionHandler) {
-
-		if (actionHandler != null) {
-
-			if (this.actionHandlers == null) {
-				this.actionHandlers = new LinkedList();
-				this.actionMapper = new KeyMapper();
-			}
-
-			if (!this.actionHandlers.contains(actionHandler)) {
-				this.actionHandlers.add(actionHandler);
-				requestRepaint();
-			}
-		}
-	}
-
-	/**
-	 * Removes an action handler.
-	 * 
-	 * @see com.itmill.toolkit.event.Action.Container#removeActionHandler(Action.Handler)
-	 */
-	public void removeActionHandler(Action.Handler actionHandler) {
-
-		if (this.actionHandlers != null
-				&& this.actionHandlers.contains(actionHandler)) {
-
-			this.actionHandlers.remove(actionHandler);
-
-			if (this.actionHandlers.isEmpty()) {
-				this.actionHandlers = null;
-				this.actionMapper = null;
-			}
-
-			requestRepaint();
-		}
-	}
-
-	/**
-	 * Gets the visible item ids.
-	 * 
-	 * @see com.itmill.toolkit.ui.Select#getVisibleItemIds()
-	 */
-	public Collection getVisibleItemIds() {
-
-		LinkedList visible = new LinkedList();
-
-		// Iterates trough hierarchical tree using a stack of iterators
-		Stack iteratorStack = new Stack();
-		Collection ids = rootItemIds();
-		if (ids != null) {
-			iteratorStack.push(ids.iterator());
-		}
-		while (!iteratorStack.isEmpty()) {
-
-			// Gets the iterator for current tree level
-			Iterator i = (Iterator) iteratorStack.peek();
-
-			// If the level is finished, back to previous tree level
-			if (!i.hasNext()) {
-
-				// Removes used iterator from the stack
-				iteratorStack.pop();
-			}
-
-			// Adds the item on current level
-			else {
-				Object itemId = i.next();
-
-				visible.add(itemId);
-
-				// Adds children if expanded, or close the tag
-				if (isExpanded(itemId) && hasChildren(itemId)) {
-					iteratorStack.push(getChildren(itemId).iterator());
-				}
-			}
-		}
-
-		return visible;
-	}
-
-	/**
-	 * Tree does not support <code>setNullSelectionItemId</code>.
-	 * 
-	 * @see com.itmill.toolkit.ui.AbstractSelect#setNullSelectionItemId(java.lang.Object)
-	 */
-	public void setNullSelectionItemId(Object nullSelectionItemId)
-			throws UnsupportedOperationException {
-		if (nullSelectionItemId != null) {
-			throw new UnsupportedOperationException();
-		}
-
-	}
-
-	/**
-	 * Adding new items is not supported.
-	 * 
-	 * @throws UnsupportedOperationException
-	 *             if set to true.
-	 * @see com.itmill.toolkit.ui.Select#setNewItemsAllowed(boolean)
-	 */
-	public void setNewItemsAllowed(boolean allowNewOptions)
-			throws UnsupportedOperationException {
-		if (allowNewOptions) {
-			throw new UnsupportedOperationException();
-		}
-	}
-
-	/**
-	 * Focusing to this component is not supported.
-	 * 
-	 * @throws UnsupportedOperationException
-	 *             if invoked.
-	 * @see com.itmill.toolkit.ui.AbstractField#focus()
-	 */
-	public void focus() throws UnsupportedOperationException {
-		throw new UnsupportedOperationException();
-	}
-
-	/**
-	 * Tree does not support lazy options loading mode. Setting this true will
-	 * throw UnsupportedOperationException.
-	 * 
-	 * @see com.itmill.toolkit.ui.Select#setLazyLoading(boolean)
-	 */
-	public void setLazyLoading(boolean useLazyLoading) {
-		if (useLazyLoading) {
-			throw new UnsupportedOperationException(
-					"Lazy options loading is not supported by Tree.");
-		}
-	}
+        Action.Container {
+
+    /* Static members ***************************************************** */
+
+    private static final Method EXPAND_METHOD;
+
+    private static final Method COLLAPSE_METHOD;
+
+    static {
+        try {
+            EXPAND_METHOD = ExpandListener.class.getDeclaredMethod(
+                    "nodeExpand", new Class[] { ExpandEvent.class });
+            COLLAPSE_METHOD = CollapseListener.class.getDeclaredMethod(
+                    "nodeCollapse", new Class[] { CollapseEvent.class });
+        } catch (java.lang.NoSuchMethodException e) {
+            // This should never happen
+            e.printStackTrace();
+            throw new java.lang.RuntimeException(
+                    "Internal error, please report");
+        }
+    }
+
+    /* Private members **************************************************** */
+
+    /**
+     * Set of expanded nodes.
+     */
+    private final HashSet expanded = new HashSet();
+
+    /**
+     * List of action handlers.
+     */
+    private LinkedList actionHandlers = null;
+
+    /**
+     * Action mapper.
+     */
+    private KeyMapper actionMapper = null;
+
+    /**
+     * Is the tree selectable .
+     */
+    private boolean selectable = true;
+
+    /**
+     * Flag to indicate sub-tree loading
+     */
+    private boolean partialUpdate = false;
+
+    /**
+     * Holds a itemId which was recently expanded
+     */
+    private Object expandedItemId;
+
+    /**
+     * a flag which indicates initial paint. After this flag set true partial
+     * updates are allowed.
+     */
+    private boolean initialPaint = true;
+
+    /* Tree constructors ************************************************** */
+
+    /**
+     * Creates a new empty tree.
+     */
+    public Tree() {
+    }
+
+    /**
+     * Creates a new empty tree with caption.
+     * 
+     * @param caption
+     */
+    public Tree(String caption) {
+        setCaption(caption);
+    }
+
+    /**
+     * Creates a new tree with caption and connect it to a Container.
+     * 
+     * @param caption
+     * @param dataSource
+     */
+    public Tree(String caption, Container dataSource) {
+        setCaption(caption);
+        setContainerDataSource(dataSource);
+    }
+
+    /* Expanding and collapsing ******************************************* */
+
+    /**
+     * Check is an item is expanded
+     * 
+     * @param itemId
+     *                the item id.
+     * @return true iff the item is expanded.
+     */
+    public boolean isExpanded(Object itemId) {
+        return expanded.contains(itemId);
+    }
+
+    /**
+     * Expands an item.
+     * 
+     * @param itemId
+     *                the item id.
+     * @return True iff the expand operation succeeded
+     */
+    public boolean expandItem(Object itemId) {
+        return expandItem(itemId, true);
+    }
+
+    /**
+     * Expands an item.
+     * 
+     * @param itemId
+     *                the item id.
+     * @param sendChildTree
+     *                flag to indicate if client needs subtree or not (may be
+     *                cached)
+     * @return True iff 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) {
+            requestRepaint();
+        } else if (sendChildTree) {
+            requestPartialRepaint();
+        }
+        fireExpandEvent(itemId);
+
+        return true;
+    }
+
+    public void requestRepaint() {
+        super.requestRepaint();
+        partialUpdate = false;
+    }
+
+    private void requestPartialRepaint() {
+        super.requestRepaint();
+        partialUpdate = true;
+    }
+
+    /**
+     * Expands the items recursively
+     * 
+     * Expands all the children recursively starting from an item. Operation
+     * succeeds only if all expandable items are expanded.
+     * 
+     * @param startItemId
+     * @return True iff the expand operation succeeded
+     */
+    public boolean expandItemsRecursively(Object startItemId) {
+
+        boolean result = true;
+
+        // Initial stack
+        Stack todo = new Stack();
+        todo.add(startItemId);
+
+        // Expands recursively
+        while (!todo.isEmpty()) {
+            Object id = todo.pop();
+            if (areChildrenAllowed(id) && !expandItem(id, false)) {
+                result = false;
+            }
+            if (hasChildren(id)) {
+                todo.addAll(getChildren(id));
+            }
+        }
+        requestRepaint();
+        return result;
+    }
+
+    /**
+     * Collapses an item.
+     * 
+     * @param itemId
+     *                the item id.
+     * @return True iff the collapse operation succeeded
+     */
+    public boolean collapseItem(Object itemId) {
+
+        // Succeeds if the node is already collapsed
+        if (!isExpanded(itemId)) {
+            return true;
+        }
+
+        // Collapse
+        expanded.remove(itemId);
+        requestRepaint();
+        fireCollapseEvent(itemId);
+
+        return true;
+    }
+
+    /**
+     * Collapses the items recursively.
+     * 
+     * Collapse all the children recursively starting from an item. Operation
+     * succeeds only if all expandable items are collapsed.
+     * 
+     * @param startItemId
+     * @return True iff the collapse operation succeeded
+     */
+    public boolean collapseItemsRecursively(Object startItemId) {
+
+        boolean result = true;
+
+        // Initial stack
+        Stack todo = new Stack();
+        todo.add(startItemId);
+
+        // Collapse recursively
+        while (!todo.isEmpty()) {
+            Object id = todo.pop();
+            if (areChildrenAllowed(id) && !collapseItem(id)) {
+                result = false;
+            }
+            if (hasChildren(id)) {
+                todo.addAll(getChildren(id));
+            }
+        }
+
+        return result;
+    }
+
+    /**
+     * Getter for property selectable.
+     * 
+     * <p>
+     * The tree is selectable by default.
+     * </p>
+     * 
+     * @return the Value of property selectable.
+     */
+    public boolean isSelectable() {
+        return selectable;
+    }
+
+    /**
+     * Setter for property selectable.
+     * 
+     * <p>
+     * The tree is selectable by default.
+     * </p>
+     * 
+     * @param selectable
+     *                the New value of property selectable.
+     */
+    public void setSelectable(boolean selectable) {
+        if (this.selectable != selectable) {
+            this.selectable = selectable;
+            requestRepaint();
+        }
+    }
+
+    /* Component API ****************************************************** */
+
+    /**
+     * Gets the UIDL tag corresponding to the component.
+     * 
+     * @see com.itmill.toolkit.ui.AbstractComponent#getTag()
+     */
+    public String getTag() {
+        return "tree";
+    }
+
+    /**
+     * Called when one or more variables handled by the implementing class are
+     * changed.
+     * 
+     * @see com.itmill.toolkit.terminal.VariableOwner#changeVariables(Object
+     *      source, Map variables)
+     */
+    public void changeVariables(Object source, Map variables) {
+
+        if (!isSelectable() && variables.containsKey("selected")) {
+            // Not-selectable is a special case, AbstractSelect does not support
+            // TODO could be optimized.
+            variables = new HashMap(variables);
+            variables.remove("selected");
+        }
+
+        // Collapses the nodes
+        if (variables.containsKey("collapse")) {
+            String[] keys = (String[]) variables.get("collapse");
+            for (int i = 0; i < keys.length; i++) {
+                Object id = itemIdMapper.get(keys[i]);
+                if (id != null && isExpanded(id)) {
+                    expanded.remove(id);
+                    fireCollapseEvent(id);
+                }
+            }
+        }
+
+        // Expands the nodes
+        if (variables.containsKey("expand")) {
+            boolean sendChildTree = false;
+            if (variables.containsKey("requestChildTree")) {
+                sendChildTree = true;
+            }
+            String[] keys = (String[]) variables.get("expand");
+            for (int i = 0; i < keys.length; i++) {
+                Object id = itemIdMapper.get(keys[i]);
+                if (id != null) {
+                    expandItem(id, sendChildTree);
+                }
+            }
+        }
+
+        // Selections are handled by the select component
+        super.changeVariables(source, variables);
+
+        // Actions
+        if (variables.containsKey("action")) {
+
+            StringTokenizer st = new StringTokenizer((String) variables
+                    .get("action"), ",");
+            if (st.countTokens() == 2) {
+                Object itemId = itemIdMapper.get(st.nextToken());
+                Action action = (Action) actionMapper.get(st.nextToken());
+                if (action != null && containsId(itemId)
+                        && actionHandlers != null) {
+                    for (Iterator i = actionHandlers.iterator(); i.hasNext();) {
+                        ((Action.Handler) i.next()).handleAction(action, this,
+                                itemId);
+                    }
+                }
+            }
+        }
+    }
+
+    /**
+     * Paints any needed component-specific things to the given UIDL stream.
+     * 
+     * @see com.itmill.toolkit.ui.AbstractComponent#paintContent(PaintTarget)
+     */
+    public void paintContent(PaintTarget target) throws PaintException {
+        initialPaint = false;
+
+        if (partialUpdate) {
+            target.addAttribute("partialUpdate", true);
+            target.addAttribute("rootKey", itemIdMapper.key(expandedItemId));
+        } else {
+
+            // Focus control id
+            if (getFocusableId() > 0) {
+                target.addAttribute("focusid", getFocusableId());
+            }
+
+            // The tab ordering number
+            if (getTabIndex() > 0) {
+                target.addAttribute("tabindex", getTabIndex());
+            }
+
+            // Paint tree attributes
+            if (isSelectable()) {
+                target.addAttribute("selectmode", (isMultiSelect() ? "multi"
+                        : "single"));
+            } else {
+                target.addAttribute("selectmode", "none");
+            }
+            if (isNewItemsAllowed()) {
+                target.addAttribute("allownewitem", true);
+            }
+
+            if (isNullSelectionAllowed()) {
+                target.addAttribute("nullselect", true);
+            }
+
+        }
+
+        // Initialize variables
+        Set actionSet = new LinkedHashSet();
+        String[] selectedKeys;
+        if (isMultiSelect()) {
+            selectedKeys = new String[((Set) getValue()).size()];
+        } else {
+            selectedKeys = new String[(getValue() == null ? 0 : 1)];
+        }
+        int keyIndex = 0;
+        LinkedList expandedKeys = new LinkedList();
+
+        // Iterates through hierarchical tree using a stack of iterators
+        Stack iteratorStack = new Stack();
+        Collection ids;
+        if (partialUpdate) {
+            ids = getChildren(expandedItemId);
+        } else {
+            ids = rootItemIds();
+        }
+
+        if (ids != null) {
+            iteratorStack.push(ids.iterator());
+        }
+
+        while (!iteratorStack.isEmpty()) {
+
+            // Gets the iterator for current tree level
+            Iterator i = (Iterator) iteratorStack.peek();
+
+            // If the level is finished, back to previous tree level
+            if (!i.hasNext()) {
+
+                // Removes used iterator from the stack
+                iteratorStack.pop();
+
+                // Closes node
+                if (!iteratorStack.isEmpty()) {
+                    target.endTag("node");
+                }
+            }
+
+            // Adds the item on current level
+            else {
+                Object itemId = i.next();
+
+                // Starts the item / node
+                boolean isNode = areChildrenAllowed(itemId)
+                        && hasChildren(itemId);
+                if (isNode) {
+                    target.startTag("node");
+                } else {
+                    target.startTag("leaf");
+                }
+
+                // Adds the attributes
+                target.addAttribute("caption", getItemCaption(itemId));
+                Resource icon = getItemIcon(itemId);
+                if (icon != null) {
+                    target.addAttribute("icon", getItemIcon(itemId));
+                }
+                String key = itemIdMapper.key(itemId);
+                target.addAttribute("key", key);
+                if (isSelected(itemId)) {
+                    target.addAttribute("selected", true);
+                    selectedKeys[keyIndex++] = key;
+                }
+                if (areChildrenAllowed(itemId) && isExpanded(itemId)) {
+                    target.addAttribute("expanded", true);
+                    expandedKeys.add(key);
+                }
+
+                // Actions
+                if (actionHandlers != null) {
+                    ArrayList keys = new ArrayList();
+                    for (Iterator ahi = actionHandlers.iterator(); ahi
+                            .hasNext();) {
+                        Action[] aa = ((Action.Handler) ahi.next()).getActions(
+                                itemId, this);
+                        if (aa != null) {
+                            for (int ai = 0; ai < aa.length; ai++) {
+                                String akey = actionMapper.key(aa[ai]);
+                                actionSet.add(aa[ai]);
+                                keys.add(akey);
+                            }
+                        }
+                    }
+                    target.addAttribute("al", keys.toArray());
+                }
+
+                // Adds the children if expanded, or close the tag
+                if (isExpanded(itemId) && hasChildren(itemId)
+                        && areChildrenAllowed(itemId)) {
+                    iteratorStack.push(getChildren(itemId).iterator());
+                } else {
+                    if (isNode) {
+                        target.endTag("node");
+                    } else {
+                        target.endTag("leaf");
+                    }
+                }
+            }
+        }
+
+        // Actions
+        if (!actionSet.isEmpty()) {
+            target.addVariable(this, "action", "");
+            target.startTag("actions");
+            for (Iterator i = actionSet.iterator(); i.hasNext();) {
+                Action a = (Action) i.next();
+                target.startTag("action");
+                if (a.getCaption() != null) {
+                    target.addAttribute("caption", a.getCaption());
+                }
+                if (a.getIcon() != null) {
+                    target.addAttribute("icon", a.getIcon());
+                }
+                target.addAttribute("key", actionMapper.key(a));
+                target.endTag("action");
+            }
+            target.endTag("actions");
+        }
+
+        if (partialUpdate) {
+            partialUpdate = false;
+        } else {
+            // Selected
+            target.addVariable(this, "selected", selectedKeys);
+
+            // Expand and collapse
+            target.addVariable(this, "expand", new String[] {});
+            target.addVariable(this, "collapse", new String[] {});
+
+            // New items
+            target.addVariable(this, "newitem", new String[] {});
+        }
+    }
+
+    /* Container.Hierarchical API ***************************************** */
+
+    /**
+     * Tests if the Item with given ID can have any children.
+     * 
+     * @see com.itmill.toolkit.data.Container.Hierarchical#areChildrenAllowed(Object)
+     */
+    public boolean areChildrenAllowed(Object itemId) {
+        return ((Container.Hierarchical) items).areChildrenAllowed(itemId);
+    }
+
+    /**
+     * Gets the IDs of all Items that are children of the specified Item.
+     * 
+     * @see com.itmill.toolkit.data.Container.Hierarchical#getChildren(Object)
+     */
+    public Collection getChildren(Object itemId) {
+        return ((Container.Hierarchical) items).getChildren(itemId);
+    }
+
+    /**
+     * Gets the ID of the parent Item of the specified Item.
+     * 
+     * @see com.itmill.toolkit.data.Container.Hierarchical#getParent(Object)
+     */
+    public Object getParent(Object itemId) {
+        return ((Container.Hierarchical) items).getParent(itemId);
+    }
+
+    /**
+     * Tests if the Item specified with <code>itemId</code> has any child
+     * Items, that is, is it a leaf Item.
+     * 
+     * @see com.itmill.toolkit.data.Container.Hierarchical#hasChildren(Object)
+     */
+    public boolean hasChildren(Object itemId) {
+        return ((Container.Hierarchical) items).hasChildren(itemId);
+    }
+
+    /**
+     * Tests if the Item specified with <code>itemId</code> is a root Item.
+     * 
+     * @see com.itmill.toolkit.data.Container.Hierarchical#isRoot(Object)
+     */
+    public boolean isRoot(Object itemId) {
+        return ((Container.Hierarchical) items).isRoot(itemId);
+    }
+
+    /**
+     * Gets the IDs of all Items in the container that don't have a parent.
+     * 
+     * @see com.itmill.toolkit.data.Container.Hierarchical#rootItemIds()
+     */
+    public Collection rootItemIds() {
+        return ((Container.Hierarchical) items).rootItemIds();
+    }
+
+    /**
+     * Sets the given Item's capability to have children.
+     * 
+     * @see com.itmill.toolkit.data.Container.Hierarchical#setChildrenAllowed(Object,
+     *      boolean)
+     */
+    public boolean setChildrenAllowed(Object itemId, boolean areChildrenAllowed) {
+        boolean success = ((Container.Hierarchical) items).setChildrenAllowed(
+                itemId, areChildrenAllowed);
+        if (success) {
+            fireValueChange(false);
+        }
+        return success;
+    }
+
+    /**
+     * Sets the parent of an Item.
+     * 
+     * @see com.itmill.toolkit.data.Container.Hierarchical#setParent(Object,
+     *      Object)
+     */
+    public boolean setParent(Object itemId, Object newParentId) {
+        boolean success = ((Container.Hierarchical) items).setParent(itemId,
+                newParentId);
+        if (success) {
+            requestRepaint();
+        }
+        return success;
+    }
+
+    /* Overriding select behavior******************************************** */
+
+    /**
+     * Sets the Container that serves as the data source of the viewer.
+     * 
+     * @see com.itmill.toolkit.data.Container.Viewer#setContainerDataSource(Container)
+     */
+    public void setContainerDataSource(Container newDataSource) {
+
+        // Assure that the data source is ordered by making unordered
+        // containers ordered by wrapping them
+        if (Container.Hierarchical.class.isAssignableFrom(newDataSource
+                .getClass())) {
+            super.setContainerDataSource(newDataSource);
+        } else {
+            super.setContainerDataSource(new ContainerHierarchicalWrapper(
+                    newDataSource));
+        }
+    }
+
+    /* Expand event and listener ****************************************** */
+
+    /**
+     * Event to fired when a node is expanded. ExapandEvent is fired when a node
+     * is to be expanded. it can me used to dynamically fill the sub-nodes of
+     * the node.
+     * 
+     * @author IT Mill Ltd.
+     * @version
+     * @VERSION@
+     * @since 3.0
+     */
+    public class ExpandEvent extends Component.Event {
+
+        /**
+         * Serial generated by eclipse.
+         */
+        private static final long serialVersionUID = 3832624001804481075L;
+
+        private final Object expandedItemId;
+
+        /**
+         * New instance of options change event
+         * 
+         * @param source
+         *                the Source of the event.
+         * @param expandedItemId
+         */
+        public ExpandEvent(Component source, Object expandedItemId) {
+            super(source);
+            this.expandedItemId = expandedItemId;
+        }
+
+        /**
+         * Node where the event occurred.
+         * 
+         * @return the Source of the event.
+         */
+        public Object getItemId() {
+            return expandedItemId;
+        }
+    }
+
+    /**
+     * Expand event listener.
+     * 
+     * @author IT Mill Ltd.
+     * @version
+     * @VERSION@
+     * @since 3.0
+     */
+    public interface ExpandListener {
+
+        /**
+         * A node has been expanded.
+         * 
+         * @param event
+         *                the Expand event.
+         */
+        public void nodeExpand(ExpandEvent event);
+    }
+
+    /**
+     * Adds the expand listener.
+     * 
+     * @param listener
+     *                the Listener to be added.
+     */
+    public void addListener(ExpandListener listener) {
+        addListener(ExpandEvent.class, listener, EXPAND_METHOD);
+    }
+
+    /**
+     * Removes the expand listener.
+     * 
+     * @param listener
+     *                the Listener to be removed.
+     */
+    public void removeListener(ExpandListener listener) {
+        removeListener(ExpandEvent.class, listener, EXPAND_METHOD);
+    }
+
+    /**
+     * Emits the expand event.
+     * 
+     * @param itemId
+     *                the item id.
+     */
+    protected void fireExpandEvent(Object itemId) {
+        fireEvent(new ExpandEvent(this, itemId));
+    }
+
+    /* Collapse event ****************************************** */
+
+    /**
+     * Collapse event
+     * 
+     * @author IT Mill Ltd.
+     * @version
+     * @VERSION@
+     * @since 3.0
+     */
+    public class CollapseEvent extends Component.Event {
+
+        /**
+         * Serial generated by eclipse.
+         */
+        private static final long serialVersionUID = 3257009834783290160L;
+
+        private final Object collapsedItemId;
+
+        /**
+         * New instance of options change event.
+         * 
+         * @param source
+         *                the Source of the event.
+         * @param collapsedItemId
+         */
+        public CollapseEvent(Component source, Object collapsedItemId) {
+            super(source);
+            this.collapsedItemId = collapsedItemId;
+        }
+
+        /**
+         * Gets tge Collapsed Item id.
+         * 
+         * @return the collapsed item id.
+         */
+        public Object getItemId() {
+            return collapsedItemId;
+        }
+    }
+
+    /**
+     * Collapse event listener.
+     * 
+     * @author IT Mill Ltd.
+     * @version
+     * @VERSION@
+     * @since 3.0
+     */
+    public interface CollapseListener {
+
+        /**
+         * A node has been collapsed.
+         * 
+         * @param event
+         *                the Collapse event.
+         */
+        public void nodeCollapse(CollapseEvent event);
+    }
+
+    /**
+     * Adds the collapse listener.
+     * 
+     * @param listener
+     *                the Listener to be added.
+     */
+    public void addListener(CollapseListener listener) {
+        addListener(CollapseEvent.class, listener, COLLAPSE_METHOD);
+    }
+
+    /**
+     * Removes the collapse listener.
+     * 
+     * @param listener
+     *                the Listener to be removed.
+     */
+    public void removeListener(CollapseListener listener) {
+        removeListener(CollapseEvent.class, listener, COLLAPSE_METHOD);
+    }
+
+    /**
+     * Emits collapse event.
+     * 
+     * @param itemId
+     *                the item id.
+     */
+    protected void fireCollapseEvent(Object itemId) {
+        fireEvent(new CollapseEvent(this, itemId));
+    }
+
+    /* Action container *************************************************** */
+
+    /**
+     * Adds an action handler.
+     * 
+     * @see com.itmill.toolkit.event.Action.Container#addActionHandler(Action.Handler)
+     */
+    public void addActionHandler(Action.Handler actionHandler) {
+
+        if (actionHandler != null) {
+
+            if (actionHandlers == null) {
+                actionHandlers = new LinkedList();
+                actionMapper = new KeyMapper();
+            }
+
+            if (!actionHandlers.contains(actionHandler)) {
+                actionHandlers.add(actionHandler);
+                requestRepaint();
+            }
+        }
+    }
+
+    /**
+     * Removes an action handler.
+     * 
+     * @see com.itmill.toolkit.event.Action.Container#removeActionHandler(Action.Handler)
+     */
+    public void removeActionHandler(Action.Handler actionHandler) {
+
+        if (actionHandlers != null && actionHandlers.contains(actionHandler)) {
+
+            actionHandlers.remove(actionHandler);
+
+            if (actionHandlers.isEmpty()) {
+                actionHandlers = null;
+                actionMapper = null;
+            }
+
+            requestRepaint();
+        }
+    }
+
+    /**
+     * Gets the visible item ids.
+     * 
+     * @see com.itmill.toolkit.ui.Select#getVisibleItemIds()
+     */
+    public Collection getVisibleItemIds() {
+
+        LinkedList visible = new LinkedList();
+
+        // Iterates trough hierarchical tree using a stack of iterators
+        Stack iteratorStack = new Stack();
+        Collection ids = rootItemIds();
+        if (ids != null) {
+            iteratorStack.push(ids.iterator());
+        }
+        while (!iteratorStack.isEmpty()) {
+
+            // Gets the iterator for current tree level
+            Iterator i = (Iterator) iteratorStack.peek();
+
+            // If the level is finished, back to previous tree level
+            if (!i.hasNext()) {
+
+                // Removes used iterator from the stack
+                iteratorStack.pop();
+            }
+
+            // Adds the item on current level
+            else {
+                Object itemId = i.next();
+
+                visible.add(itemId);
+
+                // Adds children if expanded, or close the tag
+                if (isExpanded(itemId) && hasChildren(itemId)) {
+                    iteratorStack.push(getChildren(itemId).iterator());
+                }
+            }
+        }
+
+        return visible;
+    }
+
+    /**
+     * Tree does not support <code>setNullSelectionItemId</code>.
+     * 
+     * @see com.itmill.toolkit.ui.AbstractSelect#setNullSelectionItemId(java.lang.Object)
+     */
+    public void setNullSelectionItemId(Object nullSelectionItemId)
+            throws UnsupportedOperationException {
+        if (nullSelectionItemId != null) {
+            throw new UnsupportedOperationException();
+        }
+
+    }
+
+    /**
+     * Adding new items is not supported.
+     * 
+     * @throws UnsupportedOperationException
+     *                 if set to true.
+     * @see com.itmill.toolkit.ui.Select#setNewItemsAllowed(boolean)
+     */
+    public void setNewItemsAllowed(boolean allowNewOptions)
+            throws UnsupportedOperationException {
+        if (allowNewOptions) {
+            throw new UnsupportedOperationException();
+        }
+    }
+
+    /**
+     * Focusing to this component is not supported.
+     * 
+     * @throws UnsupportedOperationException
+     *                 if invoked.
+     * @see com.itmill.toolkit.ui.AbstractField#focus()
+     */
+    public void focus() throws UnsupportedOperationException {
+        throw new UnsupportedOperationException();
+    }
+
+    /**
+     * Tree does not support lazy options loading mode. Setting this true will
+     * throw UnsupportedOperationException.
+     * 
+     * @see com.itmill.toolkit.ui.Select#setLazyLoading(boolean)
+     */
+    public void setLazyLoading(boolean useLazyLoading) {
+        if (useLazyLoading) {
+            throw new UnsupportedOperationException(
+                    "Lazy options loading is not supported by Tree.");
+        }
+    }
 
 }