<table align="center" id="content" class="hidden_content">
      <tr>
        <td id="container1" width="250" height="300" border="1" valign="top"></td>
        <td id="container2" width="250" height="300" border="1" valign="top">
        <table id="editForm">
        <tr>
       	  <td id="field1_label"></td><td id="field1"></td>
        </tr>
        <tr>
       	  <td id="field2_label"></td><td id="field2"></td>
        </tr>
        <tr>
       	  <td id="field3_label"></td><td id="field3"></td>
        </tr>
        </tr>
        <tr>
       	  <td colspan="2" align="left" id="save_button"></td>
        </tr>
        </table>
        </td>    <tr>
       	  <td colspan="2" id="field4"></td>
    
      </tr>
    </table> 

public class Testgwt implements EntryPoint {
	/**
	 * The message displayed to the user when the server cannot be reached or
	 * returns an error.
	 */
	private static final String SERVER_ERROR = "An error occurred while "
			+ "attempting to contact the server. Please check your network "
			+ "connection and try again.";
	
	private static final String LOGIN_ERROR = "Username or login is not valid";
	
	private static final Integer MAX_ATTEMTS_NUMBER = new Integer(3);
	
	private static final long HOURS_NUMBER = 24;
	
	private Integer loginAttempts = new Integer(0);
	
	

	/**
	 * Create a remote service proxy to talk to the server-side Greeting service.
	 */
	private final GreetingServiceAsync greetingService = GWT
			.create(GreetingService.class);

	/**
	 * This is the entry point method.
	 */
	public void onModuleLoad() {
		final Button sendButton = new Button("Send");
		final TextBox nameField = new TextBox();
		final TextBox passwordField = new TextBox();
		final Label errorLabel = new Label();

		// We can add style names to widgets
		sendButton.addStyleName("sendButton");
		String cookieValue = Cookies.getCookie("invalid_login");
		if (cookieValue != null) {
			loginAttempts = new Integer(cookieValue);
			if (loginAttempts.equals(MAX_ATTEMTS_NUMBER)) {
				sendButton.setText("The account is locked");
				sendButton.setEnabled(false);
			}
		}
		// Add the nameField and sendButton to the RootPanel
		// Use RootPanel.get() to get the entire body element
		RootPanel.get("nameFieldContainer").add(nameField);
		RootPanel.get("passwordFieldContainer").add(passwordField);
		RootPanel.get("sendButtonContainer").add(sendButton);
		RootPanel.get("errorLabelContainer").add(errorLabel);

		// Focus the cursor on the name field when the app loads
		nameField.setFocus(true);
		nameField.selectAll();

		// Create the popup dialog box
		final DialogBox dialogBox = new DialogBox();
		dialogBox.setText("Remote Procedure Call");
		dialogBox.setAnimationEnabled(true);
		final Button closeButton = new Button("Close");
		// We can set the id of a widget by accessing its Element
		closeButton.getElement().setId("closeButton");
		final HTML serverResponseLabel = new HTML();
		VerticalPanel dialogVPanel = new VerticalPanel();
		dialogVPanel.addStyleName("dialogVPanel");
		dialogVPanel.add(serverResponseLabel);
		dialogVPanel.setHorizontalAlignment(VerticalPanel.ALIGN_RIGHT);
		dialogVPanel.add(closeButton);
		dialogBox.setWidget(dialogVPanel);

		// Add a handler to close the DialogBox
		closeButton.addClickHandler(new ClickHandler() {
			public void onClick(ClickEvent event) {
				dialogBox.hide();
				if (loginAttempts < MAX_ATTEMTS_NUMBER) {
					sendButton.setEnabled(true);
					sendButton.setFocus(true);
				} else {
					sendButton.setText("The account is locked");
				}
			}
		});
		
		final List<Building> buildings = new ArrayList<Building>();
	    greetingService.listBuildings(new AsyncCallback<List<Building>>() {
			@Override
			public void onFailure(Throwable caught) {
				// TODO Auto-generated method stub
			}
			@Override
			public void onSuccess(List<Building> result) {
				buildings.addAll(result);
			}
	    });

		// Create a handler for the sendButton and nameField
		class MyHandler implements ClickHandler, KeyUpHandler {
			/**
			 * Fired when the user clicks on the sendButton.
			 */
			public void onClick(ClickEvent event) {
				sendNameToServer();
			}

			/**
			 * Fired when the user types in the nameField.
			 */
			public void onKeyUp(KeyUpEvent event) {
				if (event.getNativeKeyCode() == KeyCodes.KEY_ENTER) {
					sendNameToServer();
				}
			}

			/**
			 * Send the name from the nameField to the server and wait for a response.
			 */
			private void sendNameToServer() {
				// First, we validate the input.
				errorLabel.setText("");
				String name = nameField.getText();
				String password = passwordField.getText();
				if (!FieldVerifier.isValidName(name)) {
					errorLabel.setText("Username can not be empty");
					return;
				}

				// Then, we send the input to the server.
				sendButton.setEnabled(false);
				serverResponseLabel.setText("");

				greetingService.greetServer(name, password,
						new AsyncCallback<String>() {
							public void onFailure(Throwable caught) {
								// Show the RPC error message to the user
								dialogBox
										.setText("Remote Procedure Call - Failure");
								serverResponseLabel
										.addStyleName("serverResponseLabelError");
								String errorMessage = caught.getMessage();
								if (errorMessage.equals(LOGIN_ERROR)) {
									serverResponseLabel.setHTML(LOGIN_ERROR);
									Date now = new Date();
									long nowLong = now.getTime();
									nowLong = nowLong + (1000 * 60 * 60 * HOURS_NUMBER);
									if (loginAttempts < MAX_ATTEMTS_NUMBER) {
										loginAttempts++;
										Cookies.setCookie("invalid_login", loginAttempts.toString(), new Date(nowLong));
									} else {
										sendButton.setText("The account is locked");
										sendButton.setEnabled(false);
									}
								} else {
									serverResponseLabel.setHTML(SERVER_ERROR);
								}
								dialogBox.center();
								closeButton.setFocus(true);
							}

							public void onSuccess(String result) {
								Cookies.removeCookie("invalid_login");
				        		RootPanel.get("loginForm").addStyleName("hidden");
				        		RootPanel.get("content").removeStyleName("hidden_content");
				        		TreeItem buildingsI = new TreeItem();
				        		for (int i = 0; i < buildings.size(); i++) {
				        			Building house = buildings.get(i);
				        			TreeItem building = new TreeItem();
				        			building.setUserObject(house);
				        			building.setText(house.getStreet() + ", " + house.getNumber());
				        			if (house.getFloors().size() > 0) {
					        			for (Floor floor : house.getFloors()) {
					        				TreeItem floorItem = new TreeItem();
					        				if (floor.getId() != 0) {
						        				floorItem.setUserObject(floor);
						        				floorItem.setText(floor.getNumber().toString());
						        				building.addItem(floorItem);
					        				}
					        				List<TreeItem> items = new ArrayList<TreeItem>();
					        				if (floor.getFlats().size() > 0) {
					        					for (Flat flat : floor.getFlats()) {
					        						if (flat.getId() != 0) {
						        						TreeItem flatItem = new TreeItem();
						        						flatItem.setUserObject(flat);
						        						flatItem.setText(flat.getFlatNumber().toString());
						        						items.add(flatItem);
					        						}
					        					}
					        					Collections.sort(items, new FlatTreeItemComparator());
					        					for (TreeItem item : items) {
					        						floorItem.addItem(item);
					        					}
					        				}
					        			}
				        			}
				        			buildingsI.addItem(building);
				        		}
				        		Tree buildingsTree = new Tree();
				        		buildingsTree.addSelectionHandler(new SelectionHandler<TreeItem>() {
									@Override
									public void onSelection(SelectionEvent<TreeItem> event) {
										final TreeItem editedItem = event.getSelectedItem();
										Object userObject = event.getSelectedItem().getUserObject();
										RootPanel.get("field1").clear();
										RootPanel.get("field1_label").clear();
										RootPanel.get("field2").clear();
										RootPanel.get("field2_label").clear();
										RootPanel.get("field3").clear();
										RootPanel.get("field3_label").clear();
										RootPanel.get("field4").clear();
										RootPanel.get("save_button").clear();
										if (userObject instanceof Building) {
											Building building = (Building) event.getSelectedItem().getUserObject();
											TextBox buildingStreetField = new TextBox();
											buildingStreetField.setText(building.getStreet());
											buildingStreetField.setReadOnly(true);
											RootPanel.get("field1").add(buildingStreetField);
											RootPanel.get("field1_label").add(new Label("Street"));
											TextBox buildingNumberField = new TextBox();
											buildingNumberField.setText(building.getNumber().toString());
											buildingNumberField.setReadOnly(true);
											RootPanel.get("field2").add(buildingNumberField);
											RootPanel.get("field2_label").add(new Label("Number"));
										}
										if (userObject instanceof Floor) {
											Floor floor = (Floor) event.getSelectedItem().getUserObject();
											TextBox floorNumberField = new TextBox();
											floorNumberField.setText(floor.getNumber().toString());
											floorNumberField.setReadOnly(true);
											RootPanel.get("field1").add(floorNumberField);
											RootPanel.get("field1_label").add(new Label("Floor"));
											TextBox flatsNumberField = new TextBox();
											flatsNumberField.setText((new Integer(floor.getFlats().size())).toString());
											flatsNumberField.setReadOnly(true);
											RootPanel.get("field2").add(flatsNumberField);
											RootPanel.get("field2_label").add(new Label("Number of flats"));
										}
										if (userObject instanceof Flat) {
											Flat flat = (Flat) event.getSelectedItem().getUserObject();
											TextBox flatNumberField = new TextBox();
											flatNumberField.setText(flat.getFlatNumber().toString());
											flatNumberField.setReadOnly(true);
											RootPanel.get("field1").add(flatNumberField);
											RootPanel.get("field1_label").add(new Label("Flat"));
											final TextBox areaField = new TextBox();
											areaField.setText(flat.getArea().toString());
											RootPanel.get("field2").add(areaField);
											RootPanel.get("field2_label").add(new Label("Area"));

											final DateBox toCommissionField = new DateBox();
											DateTimeFormat dateFormat = DateTimeFormat.getFormat("yyyy-MM-dd");
											toCommissionField.setFormat(new DateBox.DefaultFormat(dateFormat));
											toCommissionField.setValue(flat.getToCommission(), true);
											RootPanel.get("field3").add(toCommissionField);
											RootPanel.get("field3_label").add(new Label("To commission"));
											final TextBox flatIdField = new TextBox();
											flatIdField.setVisible(false);
											flatIdField.setText(flat.getId().toString());
											RootPanel.get("field4").add(flatIdField);
											Button saveButton = new Button("save");
											saveButton.addClickHandler(new ClickHandler(){
												@Override
												public void onClick(ClickEvent event) {
													greetingService.saveFlat(
															new Integer(areaField.getText()),
															toCommissionField.getValue(),
															new Integer(flatIdField.getText()), 
													new AsyncCallback<String>() {
														@Override
														public void onFailure(Throwable caught) {
															DialogBox errorMessage = new DialogBox();
															errorMessage.setText("Database error: " + caught.getMessage());
															errorMessage.center();
															errorMessage.show();
														}
														@Override
														public void onSuccess(String result) {
															final String res = result;
															TreeItem parentItem = editedItem.getParentItem();
															Flat flat = (Flat) editedItem.getUserObject();
															flat.setArea(new Integer(res));
															editedItem.setUserObject(flat);
															flat.setToCommission(toCommissionField.getValue());
															List<TreeItem> items = new ArrayList<TreeItem>();
															for (int i = 0; i < parentItem.getChildCount(); i++) {
																TreeItem childItem = parentItem.getChild(i);
																Flat childItemFlat = (Flat) childItem.getUserObject();
																if (childItemFlat.getId().equals(flat.getId())) {
																	items.add(editedItem);
																} else {
																	items.add(childItem);
																}
															}
															Collections.sort(items, new FlatTreeItemComparator());
															for (TreeItem item : items) {
																parentItem.addItem(item);
															}
															final DialogBox successMessage = new DialogBox();
															successMessage.setText("Changes saved");
															successMessage.setWidth("200px");
															successMessage.setHeight("150px");
															Button closeButton = new Button("close");
															successMessage.add(closeButton);
															successMessage.center();
															successMessage.show();
															
															closeButton.addClickHandler(new ClickHandler() {
																public void onClick(ClickEvent event) {
																	successMessage.hide();
																}
															});
														}
													});
												}
											});
											RootPanel.get("save_button").add(saveButton);
										}
									}
				           		});
				        		buildingsTree.addItem(buildingsI);
				        		RootPanel.get("container1").add(buildingsTree);
							}
						});
			}
		}

		// Add a handler to send the name to the server
		MyHandler handler = new MyHandler();
		sendButton.addClickHandler(handler);
		nameField.addKeyUpHandler(handler);
	}
}