Java 类com.google.gwt.dom.client.LIElement 实例源码

@Override
public void prepareToAdoptChildren() {
    if (!this.hasChildren()) {  
        // BEFORE the item is prepared to adopt children, it's just like:
        //      <li>
        //          <input type="checkbox" class="expander" disabled>   <!-- input.expander DISABLED = no child -->
        //          <span class="expander"></span>
        //          <input type="checkbox" class="selection">
        //          <!-- the widget --> <!-- if it's a text item: <label>Child Node 1</label> -->
        //          <!-- there's NO child items container -->
        //      </li>
        //
        // AFTER the item is prepared to adopt children, it's: 
        //      <li>
        //          <input type="checkbox" class="expander">            <!-- input.expander ENABLED = has child -->
        //          <span class="expander"></span>
        //          <input type="checkbox" class="selection">
        //          <!-- the widget --> <!-- if it's a text item: <label>Child Node 1</label> -->
        //          <ul class='childContainer'>                         <!-- child items container is present -->
        //              ... here will come the child items 
        //          </ul>
        //      </li>
        // 
        // [1] - Create a child items container UL by cloning the BASE_INTERNAL_ELEM
        UListElement childContainerULElem = DOM.clone(BASE_CHILD_CONTAINER_ELEM,// an UL
                                                      true)                     // deep cloning
                                               .cast();
        // [2] - set the new UL as a child of the item (the LI)
        LIElement parentLI = this.getElement().cast();
        parentLI.appendChild(childContainerULElem);
        // [3] - Change the <input type="checkbox" class="expander"> status from DISABLED to ENABLED
        InputElement expanderINPUT = parentLI.getFirstChild().cast();   // from Node to Element
        expanderINPUT.setDisabled(false);
    } else {
        throw new IllegalStateException();
    }
}

public final void appendList(ArrayList<String> choices, boolean ordered, String additionalStyle) {
   if (choices == null || choices.size() == 0) {
      return;
   }

   FlowPanel htmlList = new FlowPanel(ordered? OListElement.TAG : UListElement.TAG);

   if (additionalStyle != null && additionalStyle.length() > 0) {
      _promptChar.getElement().setAttribute("style", additionalStyle);
   }

   for (String choice : choices) {
      FlowPanel item = new FlowPanel(LIElement.TAG);
      item.getElement().setInnerText(choice);
      htmlList.add(item);
   }

   appendAndScrollOrFocusAsAppropriate(htmlList);
}

public static LIElement findTreeViewItemLIElement(final Element element) {
    LIElement outLIElement = null;

    Element currElement = element;
    while (currElement != null) {
        if (LIElement.is(currElement)) {
            Element parentElement = currElement.getParentElement();
            if (UListElement.is(parentElement) && CONTAINER_UL_CSS_CLASS_NAME.equals(parentElement.getClassName())) {
                outLIElement = currElement.cast();
            } else {
                currElement = parentElement.getParentElement();
            }
        } else {
            currElement = currElement.getParentElement();
        }
        if (outLIElement != null) break;
    }
    return outLIElement;
}

private static TreeViewItem _findItemIn(final Collection<TreeViewItem> items,
                                        final LIElement element) {
    TreeViewItem outItem = null;
    if (items != null && items.size() > 0) {
        for(TreeViewItem item : items) {
            if (outItem != null) break;
            if (item.getElement().cast() == element) {
                outItem = item;
            } else if (item.hasChildren()) {
                outItem = _findItemIn(item.getChildren(),element);  
            }
        }
    }
    return outItem;
}

private static LIElement _createBaseTagElement() {
    //      <ul class='tags'>
    //          <li><span><img />Tag1</span></li>
    //          <li><span><img />Tag1</span></li>
    //          ...
    //      </ul>
    LIElement containerLIEl = DOM.createElement("li").cast();
    SpanElement spanEl = DOM.createSpan().cast();
    ImageElement imgEl = DOM.createImg().cast();

    // assemble the structure
    spanEl.appendChild(imgEl);
    spanEl.appendChild(Document.get().createTextNode(""));
    containerLIEl.appendChild(spanEl);
    return containerLIEl;
}

@Override
    @SuppressWarnings("fallthrough")
    public void onBrowserEvent(final Event event) {
        super.onBrowserEvent(event);

        int eventType = DOM.eventGetType(event);
        Element eventTargetEl = DOM.eventGetTarget(event);

//      GWT.log("_____" + eventTargetEl.getNodeName() + ": " + event.getType());

        switch (eventType) {
        case Event.ONCLICK: {
            if (ImageElement.is(eventTargetEl)) {
                LIElement tagLIElement = _findTagLIElementContaining(eventTargetEl);
                T tag = _tagForElement(tagLIElement);
                this.removeTag(tag);
            }
            break;
        }
        }
    }

/**
 * Creates an empty tree item.
 */
TreeViewItem(final CanBePaintedAsWidget viewObjectToWidgetTransformer) {        
    // Create the item element structure
    LIElement elem = DOM.clone(BASE_ELEM,       // a simple LI  
                               true)            // deep cloning
                        .cast();
    elem.setAttribute("id",DOM.createUniqueId());       
    this.setElement(elem);

    // Set the ViewObject to Widget transformer
    _viewObjectToWidgetTransformer = viewObjectToWidgetTransformer;

    // Create the items container delegate
    _childItemsContainerDelegate = new TreeViewIsHierarchicalDelegate<TreeViewItem>(_viewObjectToWidgetTransformer,
                                                                                    this);
    // Create other delegates
    _hideDisplayDelegate = new ViewHideDisplayDelegate(this);
    _enableDisableDelegate = new ViewEnableDisableDelegate(this);

    // Create the observable delegate
    _observableDelegate = new ObservableTreeViewItemDelegate(this);
}

@Override
    public void onLazyLoadingSuccessful(final Collection<ViewObject> children) {
//      GWT.log("====>" + this.getText() + " > " + (children != null ? children.size() : 0) + " child loaded");
        // Remove the loading... label
        LabelElement loadingLabel = _childLoadingSPANElement();
        LIElement parentLI = this.getElement().cast();
        parentLI.removeChild(loadingLabel);

        // if the number of children loaded is 0 (there where no child items), hide the expander 
        // otherwise paint the children
        if (CollectionUtils.isNullOrEmpty(children)) {
            _expanderINPUTElement().setDisabled(true);
        } else {
            this.paintChildren(children);
        }
    }

private void addEntry(String entry, boolean logout) {
    AnchorElement anchor = Document.get().createAnchorElement();
    anchor.setInnerText(entry);

    Event.sinkEvents(anchor, Event.ONCLICK);
    Event.setEventListener(anchor, event -> {
        if (Event.ONCLICK == event.getTypeInt()) {
            if (!logout) {
                onRoleClicked(entry);
            } else {
                onLogoutClicked();
            }
        }
    });

    LIElement li = Document.get().createLIElement();
    li.getStyle().setCursor(Style.Cursor.POINTER);
    li.appendChild(anchor);
    roleList.appendChild((Node) li);
}

@Override
public void addSourceCodeItem(String name) {
    AnchorElement anchor = Document.get().createAnchorElement();
    String displayName = DisplayerHtmlConstants.INSTANCE.getString("displayer_source_code_" + name);
    anchor.setInnerText(displayName);

    LIElement li = Document.get().createLIElement();
    li.getStyle().setCursor(Style.Cursor.POINTER);
    li.appendChild(anchor);
    tabList.appendChild((Node) li);

    Event.sinkEvents(anchor, Event.ONCLICK);
    Event.setEventListener(anchor, event -> {
        if(Event.ONCLICK == event.getTypeInt()) {
            presenter.onSourceCodeItemSelected(name);
            if (selectedItem != null) {
                selectedItem.setClassName("");
                selectedItem.getStyle().setCursor(Style.Cursor.POINTER);
            }
            selectedItem = li;
            selectedItem.setClassName("active");
            selectedItem.getStyle().setCursor(Style.Cursor.DEFAULT);
            previewItem.setClassName("");
        }
    });
}

@Override
public void declareVariable(String var, String description) {

    SpanElement span = Document.get().createSpanElement();
    span.setInnerText(var);

    AnchorElement anchor = Document.get().createAnchorElement();
    anchor.setTitle(description);
    anchor.appendChild(span);

    LIElement li = Document.get().createLIElement();
    li.getStyle().setCursor(Style.Cursor.POINTER);
    li.appendChild(anchor);

    variablesMenu.appendChild((Node) li);

    Event.sinkEvents(anchor, Event.ONCLICK);
    Event.setEventListener(anchor, event -> {
        if(Event.ONCLICK == event.getTypeInt()) {
            presenter.onVariableSelected(var);
        }
    });
}

@Override
public void addBreadcrumbItem(String navItemName, Command onClicked) {
    LIElement li = Document.get().createLIElement();
    breadcrumb.appendChild((Node) li);

    if (onClicked != null) {
        AnchorElement anchor = Document.get().createAnchorElement();
        anchor.setInnerText(navItemName);
        li.appendChild(anchor);
        li.getStyle().setCursor(Style.Cursor.POINTER);

        Event.sinkEvents(anchor, Event.ONCLICK);
        Event.setEventListener(anchor, event -> {
            if (Event.ONCLICK == event.getTypeInt()) {
                onClicked.execute();
            }
        });
    } else {
        ((Node) li).setTextContent(navItemName);
        li.setClassName("active");
    }
}

private void addItem(UnorderedList unorderedList, String name, boolean selected, Command onSelect) {
    AnchorElement anchor = Document.get().createAnchorElement();
    anchor.setInnerText(name);

    LIElement li = Document.get().createLIElement();
    li.getStyle().setCursor(Style.Cursor.POINTER);
    li.appendChild(anchor);
    li.setClassName(selected ? "selected" : "");
    unorderedList.appendChild((Node) li);

    Event.sinkEvents(anchor, Event.ONCLICK);
    Event.setEventListener(anchor, event -> {
        if(Event.ONCLICK == event.getTypeInt()) {
            onSelect.execute();
        }
    });
}

private void addItem(UnorderedList unorderedList, String name, boolean selected, Command onSelect) {
    AnchorElement anchor = Document.get().createAnchorElement();
    anchor.setInnerText(name);

    LIElement li = Document.get().createLIElement();
    li.getStyle().setCursor(Style.Cursor.POINTER);
    li.appendChild(anchor);
    li.setClassName(selected ? "selected" : "");
    unorderedList.appendChild((Node) li);

    Event.sinkEvents(anchor, Event.ONCLICK);
    Event.setEventListener(anchor, event -> {
        if(Event.ONCLICK == event.getTypeInt()) {
            onSelect.execute();
        }
    });
}

@Override
public void addCommand(String name, Command command) {
    AnchorElement anchor = Document.get().createAnchorElement();
    anchor.setInnerText(name);

    LIElement li = Document.get().createLIElement();
    li.getStyle().setCursor(Style.Cursor.POINTER);
    li.appendChild(anchor);
    commandMenu.appendChild((Node) li);

    Event.sinkEvents(anchor, Event.ONCLICK);
    Event.setEventListener(anchor, event -> {
        if(Event.ONCLICK == event.getTypeInt()) {
            command.execute();
        }
    });
}

@Override
public void addItem(String id, String name, String description, Command onItemSelected) {
    AnchorElement anchor = Document.get().createAnchorElement();
    anchor.setInnerText(name);
    if (description != null && !description.equals(name)) {
        anchor.setTitle(description);
    }

    LIElement li = Document.get().createLIElement();
    li.getStyle().setCursor(Style.Cursor.POINTER);
    li.appendChild(anchor);
    navWidget.appendChild((Node) li);
    itemMap.put(id, li);

    Event.sinkEvents(anchor, Event.ONCLICK);
    Event.setEventListener(anchor, event -> {
        if (Event.ONCLICK == event.getTypeInt()) {
            onItemSelected.execute();
        }
    });
}

@Override
public void addItem(String name, Command onSelect) {
    AnchorElement anchor = Document.get().createAnchorElement();
    anchor.setInnerText(name);

    LIElement li = Document.get().createLIElement();
    li.getStyle().setCursor(Style.Cursor.POINTER);
    li.appendChild(anchor);
    selectorItems.appendChild((Node) li);

    Event.sinkEvents(anchor, Event.ONCLICK);
    Event.setEventListener(anchor, event -> {
        if(Event.ONCLICK == event.getTypeInt()) {
            onSelect.execute();
        }
    });
}

private void addEntry(String entry, boolean logout) {
    AnchorElement anchor = Document.get().createAnchorElement();
    anchor.setInnerText(entry);

    Event.sinkEvents(anchor, Event.ONCLICK);
    Event.setEventListener(anchor, event -> {
        if (Event.ONCLICK == event.getTypeInt()) {
            if (!logout) {
                onRoleClicked(entry);
            } else {
                onLogoutClicked();
            }
        }
    });

    LIElement li = Document.get().createLIElement();
    li.getStyle().setCursor(Style.Cursor.POINTER);
    li.appendChild(anchor);
    roleList.appendChild((Node) li);
}

@Override
public void addSourceCodeItem(String name) {
    AnchorElement anchor = Document.get().createAnchorElement();
    String displayName = DisplayerHtmlConstants.INSTANCE.getString("displayer_source_code_" + name);
    anchor.setInnerText(displayName);

    LIElement li = Document.get().createLIElement();
    li.getStyle().setCursor(Style.Cursor.POINTER);
    li.appendChild(anchor);
    tabList.appendChild((Node) li);

    Event.sinkEvents(anchor, Event.ONCLICK);
    Event.setEventListener(anchor, event -> {
        if(Event.ONCLICK == event.getTypeInt()) {
            presenter.onSourceCodeItemSelected(name);
            if (selectedItem != null) {
                selectedItem.setClassName("");
                selectedItem.getStyle().setCursor(Style.Cursor.POINTER);
            }
            selectedItem = li;
            selectedItem.setClassName("active");
            selectedItem.getStyle().setCursor(Style.Cursor.DEFAULT);
            previewItem.setClassName("");
        }
    });
}

@Override
public void declareVariable(String var, String description) {

    SpanElement span = Document.get().createSpanElement();
    span.setInnerText(var);

    AnchorElement anchor = Document.get().createAnchorElement();
    anchor.setTitle(description);
    anchor.appendChild(span);

    LIElement li = Document.get().createLIElement();
    li.getStyle().setCursor(Style.Cursor.POINTER);
    li.appendChild(anchor);

    variablesMenu.appendChild((Node) li);

    Event.sinkEvents(anchor, Event.ONCLICK);
    Event.setEventListener(anchor, event -> {
        if(Event.ONCLICK == event.getTypeInt()) {
            presenter.onVariableSelected(var);
        }
    });
}

@Override
public void addBreadcrumbItem(String navItemName, Command onClicked) {
    LIElement li = Document.get().createLIElement();
    breadcrumb.appendChild((Node) li);

    if (onClicked != null) {
        AnchorElement anchor = Document.get().createAnchorElement();
        anchor.setInnerText(navItemName);
        li.appendChild(anchor);
        li.getStyle().setCursor(Style.Cursor.POINTER);

        Event.sinkEvents(anchor, Event.ONCLICK);
        Event.setEventListener(anchor, event -> {
            if (Event.ONCLICK == event.getTypeInt()) {
                onClicked.execute();
            }
        });
    } else {
        ((Node) li).setTextContent(navItemName);
        li.setClassName("active");
    }
}

private void addItem(UnorderedList unorderedList, String name, boolean selected, Command onSelect) {
    AnchorElement anchor = Document.get().createAnchorElement();
    anchor.setInnerText(name);

    LIElement li = Document.get().createLIElement();
    li.getStyle().setCursor(Style.Cursor.POINTER);
    li.appendChild(anchor);
    li.setClassName(selected ? "selected" : "");
    unorderedList.appendChild((Node) li);

    Event.sinkEvents(anchor, Event.ONCLICK);
    Event.setEventListener(anchor, event -> {
        if(Event.ONCLICK == event.getTypeInt()) {
            onSelect.execute();
        }
    });
}

@Override
public void addCommand(String name, Command command) {
    AnchorElement anchor = Document.get().createAnchorElement();
    anchor.setInnerText(name);

    LIElement li = Document.get().createLIElement();
    li.getStyle().setCursor(Style.Cursor.POINTER);
    li.appendChild(anchor);
    commandMenu.appendChild((Node) li);

    Event.sinkEvents(anchor, Event.ONCLICK);
    Event.setEventListener(anchor, event -> {
        if(Event.ONCLICK == event.getTypeInt()) {
            command.execute();
        }
    });
}

private void addItem(UnorderedList unorderedList, String name, boolean selected, Command onSelect) {
    AnchorElement anchor = Document.get().createAnchorElement();
    anchor.setInnerText(name);

    LIElement li = Document.get().createLIElement();
    li.getStyle().setCursor(Style.Cursor.POINTER);
    li.appendChild(anchor);
    li.setClassName(selected ? "selected" : "");
    unorderedList.appendChild((Node) li);

    Event.sinkEvents(anchor, Event.ONCLICK);
    Event.setEventListener(anchor, event -> {
        if(Event.ONCLICK == event.getTypeInt()) {
            onSelect.execute();
        }
    });
}

@Override
public void addCommand(String name, Command command) {
    AnchorElement anchor = Document.get().createAnchorElement();
    anchor.setInnerText(name);

    LIElement li = Document.get().createLIElement();
    li.getStyle().setCursor(Style.Cursor.POINTER);
    li.appendChild(anchor);
    commandMenu.appendChild((Node) li);

    Event.sinkEvents(anchor, Event.ONCLICK);
    Event.setEventListener(anchor, event -> {
        if(Event.ONCLICK == event.getTypeInt()) {
            command.execute();
        }
    });
}

@Override
public void addItem(String id, String name, String description, Command onItemSelected) {
    AnchorElement anchor = Document.get().createAnchorElement();
    anchor.setInnerText(name);
    if (description != null && !description.equals(name)) {
        anchor.setTitle(description);
    }

    LIElement li = Document.get().createLIElement();
    li.getStyle().setCursor(Style.Cursor.POINTER);
    li.appendChild(anchor);
    navWidget.appendChild((Node) li);
    itemMap.put(id, li);

    Event.sinkEvents(anchor, Event.ONCLICK);
    Event.setEventListener(anchor, event -> {
        if (Event.ONCLICK == event.getTypeInt()) {
            onItemSelected.execute();
        }
    });
}

@Override
public void addItem(String name, Command onSelect) {
    AnchorElement anchor = Document.get().createAnchorElement();
    anchor.setInnerText(name);

    LIElement li = Document.get().createLIElement();
    li.getStyle().setCursor(Style.Cursor.POINTER);
    li.appendChild(anchor);
    selectorItems.appendChild((Node) li);

    Event.sinkEvents(anchor, Event.ONCLICK);
    Event.setEventListener(anchor, event -> {
        if(Event.ONCLICK == event.getTypeInt()) {
            onSelect.execute();
        }
    });
}

@Override
public void addHitPolicyOption( final GuidedDecisionTable52.HitPolicy hitPolicy ) {
    final AnchorElement anchor = Document.get()
            .createAnchorElement();
    anchor.setInnerText( HitPolicyInternationalizer.internationalize( hitPolicy ) );

    Event.sinkEvents( anchor,
                      Event.ONCLICK );
    Event.setEventListener( anchor,
                            event -> {
                                if ( Event.ONCLICK == event.getTypeInt() ) {
                                    presenter.onHitPolicySelected( hitPolicy );
                                }
                            } );

    final LIElement li = Document.get()
            .createLIElement();
    li.appendChild( anchor );
    listOfAvailableHitModes.appendChild( (Node) li );
}

/**
 * Finds the TreeView item that contains the provided {@link Element}
 * (this {@link Element} usually is the {@link EventTarget})
 * @param element
 * @param tree
 * @return
 */
public static TreeViewItem findTreeViewItemContaining(final Element element,
                                                      final TreeView tree) {
    // Find the eventTarget parent LI and the tree view item associated with it
    LIElement liElement = TreeViewUtils.findTreeViewItemLIElement(element);
    TreeViewItem item = _findItemIn(tree.getChildren(),
                                    liElement);
    return item;
}

/**
 * Inserts a tag at a position
 * @param tag
 * @param position
 */
public void insertTagAt(final T tag,final int position) {
    // Check the index 
    if (position < 0 || position > this.getTagCount()) throw new IndexOutOfBoundsException();

    // Check the tag existence
    if (_elementForTag(tag) != null) return;    // Tag already exists

    // Create the LI element for the tag
    LIElement liElement = DOM.clone(BASE_TAG_ELEM,  // a simple LI  
                                    true)           // deep cloning
                             .cast();
    // Set the span text
    liElement.getChild(0)   // span
                    .getChild(1)    // span text    (child(0) is the image)
                        .setNodeValue(tag.getCaption());

    // Physical attach.
    if (position == this.getTagCount()) {
        _tagsContainerULElement.appendChild(liElement);
    } else {
        LIElement beforeLIElem = _tagsContainerULElement.getChild(position).cast();
        _tagsContainerULElement.insertBefore(liElement,
                                           beforeLIElem);
    }
    // Logical attach.
    if (_tags == null) _tags = new LinkedHashMap<T,LIElement>();
    _insertMapEntryAt(_tags,
                      tag,liElement,
                      position);

    // Nofify observers
    _observableDelegate.notifyObserversAboutChildAddition(tag);
}

/**
 * Removes a tag
 * @param tag
 */
public void removeTag(final T tag) {
    LIElement tagLIElem = _elementForTag(tag);
    if (tagLIElem == null) return;

    // Physical detach the li from it's parent ul.
    _tagsContainerULElement.removeChild(tagLIElem);

    // Logical detach.
    _tags.remove(tag);

    // Nofify observers
    _observableDelegate.notifyObserversAboutChildRemoval(tag);
}

private T _tagForElement(final LIElement liElement) {
    T outTag = null;
    for (Map.Entry<T,LIElement> tagsMapEntry : _tags.entrySet()) {
        if (tagsMapEntry.getValue() == liElement) {
            outTag = tagsMapEntry.getKey();
            break;
        }
    }
    return outTag;
}

private static LIElement _findTagLIElementContaining(final Element element) {
    LIElement outLIElement = null;
    Element currElement = element;
    while (currElement != null) {
        if (LIElement.is(currElement)) {
            outLIElement = currElement.cast();
        } else {
            currElement = currElement.getParentElement();
        }
        if (outLIElement != null) break;
    }
    return outLIElement;
}

private static LIElement _createBaseElement() {
    //      <li>
    //          [1] --- EXPANDER --
    //          <input type="checkbox" class="expander" disabled>   <!-- input.expander DISABLED = no child -->
       //           <span class="expander"></span>
    //          
    //          [2] --- CHECK
       //           <input type="checkbox" class="selection">
    //          
    //          [3] --- WIDGET
       //           <!-- the widget --> <!-- if it's a text item: <label>Child Node 1</label> -->               
       //       </li>

    // [1] - Create the expander hidden checkbox and span to fake the expander image over the checkbox
    TreeViewExpanderDOMElements expanderDOMEls = TreeViewUtils.createExpanderDOMElements();

    // [2] - Create the selection checkbox
    InputElement checkINPUT = DOM.createInputCheck().cast();
    checkINPUT.addClassName(TreeViewUtils.CHECKER_CLASS_NAME);

    // [3] - Create the container LI
    LIElement containerLI = DOM.createElement("li").cast();
    Roles.getTreeitemRole().set(containerLI);

    // assemble the structure
    containerLI.appendChild(expanderDOMEls.getInputElement());
    containerLI.appendChild(expanderDOMEls.getSpanElement());
    containerLI.appendChild(checkINPUT);

    return containerLI;
}

@Override
public void allChildrenGone() {
    UListElement childContainerULElement = _childrenContainerULElement();
    assert(childContainerULElement != null && childContainerULElement.getChildCount() == 0);
    LIElement containerLI = this.getElement().cast();
    containerLI.removeChild(childContainerULElement);
}

@Override
public void onLazyLoadingInProgress() {
    // [1] - Create a child label element with the "loading..." text
    LabelElement loadingLabelEl = DOM.clone(BASE_LOADING_ELEM,      // a label
                                            true)                   // deep cloning
                                     .cast();
    // [2] - set the label as a child of the item (the LI) 
    LIElement parentLI = this.getElement().cast();
    parentLI.insertAfter(loadingLabelEl,
                         _widget.getElement());         // the loading label is ALLWAYS after the widget
}

/**
 * Builds the element structure:
 * <pre class='brush:html'>
 *      <ul class='treeview'>
 *          <li>
 *              <input type="checkbox" class="expander" disabled>   <!-- input.expander DISABLED = no child -->
    *               <span class="expander"></span>
    *               
    *               <!-- The root node widget -->   <!-- usually is a the tree caption -->
    *        
    *               <ul class='childContainer'>..</ul>      <!-- the child items container -->
    *           </li>
    *       </ul>
 * </pre>
 */
private void _initDOM() {
    // [1] - Create a main UL
    UListElement mainULEl = DOM.createElement("ul").cast();
    mainULEl.addClassName(TreeViewUtils.TREEVIEW_CSS_CLASS_NAME);

    // [2] - Create a single LI for the tree label and append it to the UL
    LIElement mainLIEl = DOM.createElement("li").cast();
    mainULEl.appendChild(mainLIEl);

    // [3] - Create an UL to contain the root nodes and append it to the title's LI
    _rootNodesContainerElement = DOM.createElement("ul").cast();
    _rootNodesContainerElement.addClassName(TreeViewUtils.CONTAINER_UL_CSS_CLASS_NAME);
    mainLIEl.appendChild(_rootNodesContainerElement);

    // [4] - set the widget DOM element
    this.setElement(mainULEl);      

    // Capture events
    this.sinkEvents(Event.ONMOUSEDOWN | Event.ONCLICK | Event.KEYEVENTS);   // = DOM.sinkEvents(this.getElement(),Event.ONMOUSEDOWN | Event.ONCLICK | Event.KEYEVENTS)
    DOM.sinkEvents(this.getElement(),   // main UL
                   Event.FOCUSEVENTS);

    // Add area role "tree"
    Roles.getTreeRole()
         .set(this.getElement());
}

@Override
public void addCommand(String name, Command command) {
    AnchorElement anchor = Document.get().createAnchorElement();
    anchor.setInnerText(name);

    LIElement li = Document.get().createLIElement();
    li.getStyle().setCursor(Style.Cursor.POINTER);
    li.appendChild(anchor);
    commandMenu.appendChild((Node) li);

    Event.sinkEvents(anchor, Event.ONCLICK);
    Event.setEventListener(anchor, event -> {
        if(Event.ONCLICK == event.getTypeInt()) {
            command.execute();
        }
    });
}

/**
 * @see com.google.gwt.user.client.ui.HasValue#setValue(java.lang.Object, boolean)
 */
@Override
public void setValue(CallTraceBean value, boolean fireEvents) {
    if (value != null) {
        List<TraceNodeBean> tasks = value.getTasks();
        for (TraceNodeBean task : tasks) {
            LIElement li = createTreeNode(task);
            getElement().appendChild(li);
        }
    }
}

@Override
public void redraw() {
    this.getElement().removeAllChildren();
    for (Error error : this.errors) {
        LIElement errorElement = Document.get().createLIElement();
        errorElement.setInnerText(error.getMessageKey());
        this.getElement().appendChild(errorElement);
    }
}