Tree (Google Web Toolkit Javadoc)

java.lang.Object
- com.google.gwt.user.client.ui.UIObject
- - com.google.gwt.user.client.ui.Widget
  - - com.google.gwt.user.client.ui.Tree

All Implemented Interfaces:

HasAllFocusHandlers, HasAllKeyHandlers, HasAllMouseHandlers, HasBlurHandlers, HasFocusHandlers, HasKeyDownHandlers, HasKeyPressHandlers, HasKeyUpHandlers, HasMouseDownHandlers, HasMouseMoveHandlers, HasMouseOutHandlers, HasMouseOverHandlers, HasMouseUpHandlers, HasMouseWheelHandlers, HasAttachHandlers, HasCloseHandlers<TreeItem>, HasOpenHandlers<TreeItem>, HasSelectionHandlers<TreeItem>, HasHandlers, EventListener, Focusable, HasAnimation, HasFocus, HasTreeItems, HasTreeItems.ForIsWidget, HasVisibility, HasWidgets, HasWidgets.ForIsWidget, IsWidget, SourcesFocusEvents, SourcesKeyboardEvents, SourcesMouseEvents, SourcesTreeEvents, java.lang.Iterable<Widget>
```
public class Tree
extends Widget
implements HasTreeItems.ForIsWidget, HasWidgets.ForIsWidget, SourcesTreeEvents, HasFocus, HasAnimation, HasAllKeyHandlers, HasAllFocusHandlers, HasSelectionHandlers<TreeItem>, HasOpenHandlers<TreeItem>, HasCloseHandlers<TreeItem>, SourcesMouseEvents, HasAllMouseHandlers
```
A standard hierarchical tree widget. The tree contains a hierarchy of TreeItems that the user can open, close, and select.

CSS Style Rules

.gwt-Tree

the tree itself

.gwt-Tree .gwt-TreeItem

a tree item

.gwt-Tree .gwt-TreeItem-selected

a selected tree item

Example
```
public class TreeExample implements EntryPoint {

  @Override
  public void onModuleLoad() {
    // Create a tree with a few items in it.
    TreeItem root = new TreeItem();
    root.setText("root");
    root.addTextItem("item0");
    root.addTextItem("item1");
    root.addTextItem("item2");

    // Add a CheckBox to the tree
    TreeItem item = new TreeItem(new CheckBox("item3"));
    root.addItem(item);

    Tree t = new Tree();
    t.addItem(root);

    // Add it to the root panel.
    RootPanel.get().add(t);
  }
}
```

Nested Class Summary

Nested Classes
Modifier and Type	Class and Description
`(package private) static class`	`Tree.ImageAdapter` There are several ways of configuring images for the Tree widget due to deprecated APIs.
`static interface`	`Tree.Resources` A ClientBundle that provides images for this widget.

Nested classes/interfaces inherited from class com.google.gwt.user.client.ui.UIObject
UIObject.DebugIdImpl, UIObject.DebugIdImplEnabled

Nested classes/interfaces inherited from interface com.google.gwt.user.client.ui.HasTreeItems
HasTreeItems.ForIsWidget

Nested classes/interfaces inherited from interface com.google.gwt.user.client.ui.HasWidgets
HasWidgets.ForIsWidget

Field Summary
- Fields inherited from class com.google.gwt.user.client.ui.Widget
  eventsToSink
- Fields inherited from class com.google.gwt.user.client.ui.UIObject
  DEBUG_ID_PREFIX, MISSING_ELEMENT_ERROR, SETELEMENT_TWICE_ERROR

Constructor Summary

Constructors
Constructor and Description
`Tree()` Constructs an empty tree.
`Tree(Tree.Resources resources)` Constructs a tree that uses the specified ClientBundle for images.
`Tree(Tree.Resources resources, boolean useLeafImages)` Constructs a tree that uses the specified ClientBundle for images.
`Tree(TreeImages images)` Deprecated. replaced by `Tree(Resources)`
`Tree(TreeImages images, boolean useLeafImages)` Deprecated. replaced by `Tree(Resources, boolean)`

Method Summary

Methods
Modifier and Type	Method and Description
`void`	`add(IsWidget w)` Overloaded version for IsWidget.
`void`	`add(Widget widget)` Adds the widget as a root tree item.
`HandlerRegistration`	`addBlurHandler(BlurHandler handler)` Adds a `BlurEvent` handler.
`HandlerRegistration`	`addCloseHandler(CloseHandler<TreeItem> handler)` Adds a `CloseEvent` handler.
`HandlerRegistration`	`addFocusHandler(FocusHandler handler)` Adds a `FocusEvent` handler.
`void`	`addFocusListener(FocusListener listener)` Deprecated. Use `addFocusHandler(com.google.gwt.event.dom.client.FocusHandler)` instead
`void`	`addItem(IsTreeItem isItem)` Adds an item to the root level of this tree.
`TreeItem`	`addItem(IsWidget w)` Overloaded version for IsWidget.
`TreeItem`	`addItem(SafeHtml itemHtml)` Adds a simple tree item containing the specified html.
`TreeItem`	`addItem(java.lang.String itemHtml)` Deprecated. use `addItem(SafeHtml)` instead
`void`	`addItem(TreeItem item)` Adds an item to the root level of this tree.
`TreeItem`	`addItem(Widget widget)` Adds a new tree item containing the specified widget.
`void`	`addKeyboardListener(KeyboardListener listener)` Deprecated. Use `addKeyDownHandler(com.google.gwt.event.dom.client.KeyDownHandler)`, `addKeyUpHandler(com.google.gwt.event.dom.client.KeyUpHandler)` and `addKeyPressHandler(com.google.gwt.event.dom.client.KeyPressHandler)` instead
`HandlerRegistration`	`addKeyDownHandler(KeyDownHandler handler)` Adds a `KeyDownEvent` handler.
`HandlerRegistration`	`addKeyPressHandler(KeyPressHandler handler)` Adds a `KeyPressEvent` handler.
`HandlerRegistration`	`addKeyUpHandler(KeyUpHandler handler)` Adds a `KeyUpEvent` handler.
`HandlerRegistration`	`addMouseDownHandler(MouseDownHandler handler)` Adds a `MouseDownEvent` handler.
`void`	`addMouseListener(MouseListener listener)` Deprecated. Use `addMouseOverHandler(com.google.gwt.event.dom.client.MouseOverHandler)` `addMouseMoveHandler(com.google.gwt.event.dom.client.MouseMoveHandler)`, `addMouseDownHandler(com.google.gwt.event.dom.client.MouseDownHandler)`, `addMouseUpHandler(com.google.gwt.event.dom.client.MouseUpHandler)` and `addMouseOutHandler(com.google.gwt.event.dom.client.MouseOutHandler)` instead
`HandlerRegistration`	`addMouseMoveHandler(MouseMoveHandler handler)` Adds a `MouseMoveEvent` handler.
`HandlerRegistration`	`addMouseOutHandler(MouseOutHandler handler)` Adds a `MouseOutEvent` handler.
`HandlerRegistration`	`addMouseOverHandler(MouseOverHandler handler)` Adds a `MouseOverEvent` handler.
`HandlerRegistration`	`addMouseUpHandler(MouseUpHandler handler)` Adds a `MouseUpEvent` handler.
`HandlerRegistration`	`addMouseWheelHandler(MouseWheelHandler handler)` Adds a `MouseWheelEvent` handler.
`HandlerRegistration`	`addOpenHandler(OpenHandler<TreeItem> handler)` Adds an `OpenEvent` handler.
`HandlerRegistration`	`addSelectionHandler(SelectionHandler<TreeItem> handler)` Adds a `SelectionEvent` handler.
`TreeItem`	`addTextItem(java.lang.String itemText)` Adds a simple tree item containing the specified text.
`void`	`addTreeListener(TreeListener listener)` Deprecated. Use `addSelectionHandler(com.google.gwt.event.logical.shared.SelectionHandler<com.google.gwt.user.client.ui.TreeItem>)`, `addOpenHandler(com.google.gwt.event.logical.shared.OpenHandler<com.google.gwt.user.client.ui.TreeItem>)`, and `addCloseHandler(com.google.gwt.event.logical.shared.CloseHandler<com.google.gwt.user.client.ui.TreeItem>)` instead
`(package private) void`	`adopt(Widget widget, TreeItem treeItem)`
`void`	`clear()` Clears all tree items from the current tree.
`protected void`	`doAttachChildren()` If a widget contains one or more child widgets that are not in the logical widget hierarchy (the child is physically connected only on the DOM level), it must override this method and call `Widget.onAttach()` for each of its child widgets.
`protected void`	`doDetachChildren()` If a widget contains one or more child widgets that are not in the logical widget hierarchy (the child is physically connected only on the DOM level), it must override this method and call `Widget.onDetach()` for each of its child widgets.
`void`	`ensureSelectedItemVisible()` Ensures that the currently-selected item is visible, opening its parents and scrolling the tree as necessary.
`(package private) void`	`fireStateChanged(TreeItem item, boolean open)`
`(package private) java.util.Map<Widget,TreeItem>`	`getChildWidgets()`
`(package private) Tree.ImageAdapter`	`getImages()`
`TreeItem`	`getItem(int index)` Gets the top-level tree item at the specified index.
`int`	`getItemCount()` Gets the number of items contained at the root of this tree.
`TreeItem`	`getSelectedItem()` Gets the currently selected item.
`int`	`getTabIndex()` Gets the widget's position in the tab index.
`TreeItem`	`insertItem(int beforeIndex, SafeHtml itemHtml)` Inserts a child tree item at the specified index containing the specified html.
`TreeItem`	`insertItem(int beforeIndex, java.lang.String itemHtml)` Deprecated. use `insertItem(int, SafeHtml)` instead
`void`	`insertItem(int beforeIndex, TreeItem item)` Inserts an item into the root level of this tree.
`TreeItem`	`insertItem(int beforeIndex, Widget widget)` Inserts a child tree item at the specified index containing the specified widget.
`TreeItem`	`insertTextItem(int beforeIndex, java.lang.String itemText)` Inserts a child tree item at the specified index containing the specified text.
`boolean`	`isAnimationEnabled()` Returns true if animations are enabled, false if not.
`protected boolean`	`isKeyboardNavigationEnabled(TreeItem currentItem)` Indicates if keyboard navigation is enabled for the Tree and for a given TreeItem.
`java.util.Iterator<Widget>`	`iterator()` Gets an iterator for the contained widgets.
`(package private) void`	`maybeUpdateSelection(TreeItem itemThatChangedState, boolean isItemOpening)`
`void`	`onBrowserEvent(Event event)` Fired whenever a browser event is received.
`protected void`	`onEnsureDebugId(java.lang.String baseID)` Affected Elements: -root = The root `TreeItem`.
`protected void`	`onLoad()` This method is called immediately after a widget becomes attached to the browser's document.
`(package private) void`	`orphan(Widget widget)`
`boolean`	`remove(IsWidget w)` Overloaded version for IsWidget.
`boolean`	`remove(Widget w)` Removes a child widget.
`void`	`removeFocusListener(FocusListener listener)` Deprecated. Use the `HandlerRegistration.removeHandler()` method on the object returned by `addFocusHandler(com.google.gwt.event.dom.client.FocusHandler)` instead
`void`	`removeItem(IsTreeItem isItem)` Removes an item from the root level of this tree.
`void`	`removeItem(TreeItem item)` Removes an item from the root level of this tree.
`void`	`removeItems()` Removes all items from the root level of this tree.
`void`	`removeKeyboardListener(KeyboardListener listener)` Deprecated. Use the `HandlerRegistration.removeHandler()` method on the object returned by an addHandler method instead*
`void`	`removeMouseListener(MouseListener listener)` Deprecated. Use the `HandlerRegistration.removeHandler()` method on the object returned by an addHandler method instead*
`void`	`removeTreeListener(TreeListener listener)` Deprecated. Use the `HandlerRegistration.removeHandler()` method on the object returned by an addHandler method instead*
`void`	`setAccessKey(char key)` Sets the widget's 'access key'.
`void`	`setAnimationEnabled(boolean enable)` Enable or disable animations.
`void`	`setFocus(boolean focus)` Explicitly focus/unfocus this widget.
`void`	`setSelectedItem(TreeItem item)` Selects a specified item.
`void`	`setSelectedItem(TreeItem item, boolean fireEvents)` Selects a specified item.
`void`	`setTabIndex(int index)` Sets the widget's position in the tab index.
`(package private) static boolean`	`shouldTreeDelegateFocusToElement(Element elem)`
`(package private) void`	`showClosedImage(TreeItem treeItem)` Called only from `TreeItem`: Shows the closed image on that tree item.
`(package private) void`	`showLeafImage(TreeItem treeItem)` Called only from `TreeItem`: Shows the leaf image on a tree item.
`(package private) void`	`showOpenImage(TreeItem treeItem)` Called only from `TreeItem`: Shows the open image on a tree item.
`java.util.Iterator<TreeItem>`	`treeItemIterator()` Iterator of tree items.

Methods inherited from class com.google.gwt.user.client.ui.Widget
addAttachHandler, addBitlessDomHandler, addDomHandler, addHandler, asWidget, asWidgetOrNull, createHandlerManager, delegateEvent, ensureHandlers, fireEvent, getHandlerCount, getHandlerManager, getLayoutData, getParent, isAttached, isOrWasAttached, onAttach, onDetach, onUnload, removeFromParent, replaceElement, setLayoutData, setParent, sinkEvents

Methods inherited from class com.google.gwt.user.client.ui.UIObject
addStyleDependentName, addStyleName, ensureDebugId, ensureDebugId, ensureDebugId, getAbsoluteLeft, getAbsoluteTop, getElement, getOffsetHeight, getOffsetWidth, getStyleElement, getStyleName, getStyleName, getStylePrimaryName, getStylePrimaryName, getTitle, isVisible, isVisible, removeStyleDependentName, removeStyleName, resolvePotentialElement, setElement, setElement, setHeight, setPixelSize, setSize, setStyleDependentName, setStyleName, setStyleName, setStyleName, setStyleName, setStylePrimaryName, setStylePrimaryName, setTitle, setVisible, setVisible, setWidth, sinkBitlessEvent, toString, unsinkEvents

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface com.google.gwt.event.shared.HasHandlers
fireEvent

- Constructor Detail
  - Tree
```
public Tree()
```
    Constructs an empty tree.
  - Tree
```
public Tree(Tree.Resources resources)
```
    Constructs a tree that uses the specified ClientBundle for images.
    
    Parameters:
    resources - a bundle that provides tree specific images
  - Tree
```
public Tree(Tree.Resources resources,
    boolean useLeafImages)
```
    Constructs a tree that uses the specified ClientBundle for images. If this tree does not use leaf images, the width of the Resources's leaf image will control the leaf indent.
    
    Parameters:
    resources - a bundle that provides tree specific images
    useLeafImages - use leaf images from bundle
  - Tree
```
@Deprecated
public Tree(TreeImages images)
```
    Deprecated. replaced by Tree(Resources)
    
    Constructs a tree that uses the specified image bundle for images.
    
    Parameters:
    images - a bundle that provides tree specific images
  - Tree
```
@Deprecated
public Tree(TreeImages images,
               boolean useLeafImages)
```
    Deprecated. replaced by Tree(Resources, boolean)
    
    Constructs a tree that uses the specified image bundle for images. If this tree does not use leaf images, the width of the TreeImage's leaf image will control the leaf indent.
    
    Parameters:
    images - a bundle that provides tree specific images
    useLeafImages - use leaf images from bundle
- Method Detail
  - shouldTreeDelegateFocusToElement
```
static boolean shouldTreeDelegateFocusToElement(Element elem)
```
  - add
```
public void add(Widget widget)
```
    Adds the widget as a root tree item.
    
    Specified by:
    
    add in interface HasWidgets
    
    Parameters:
    widget - widget to add.
    See Also:
    HasWidgets.add(com.google.gwt.user.client.ui.Widget)
  - add
```
public void add(IsWidget w)
```
    Overloaded version for IsWidget.
    
    Specified by:
    
    add in interface HasWidgets.ForIsWidget
    
    See Also:
    add(Widget)
  - addBlurHandler
```
public HandlerRegistration addBlurHandler(BlurHandler handler)
```
    Description copied from interface: HasBlurHandlers
    
    Adds a BlurEvent handler.
    
    Specified by:
    
    addBlurHandler in interface HasBlurHandlers
    
    Parameters:
    handler - the blur handler
    
    Returns:
    HandlerRegistration used to remove this handler
  - addCloseHandler
```
public HandlerRegistration addCloseHandler(CloseHandler<TreeItem> handler)
```
    Description copied from interface: HasCloseHandlers
    
    Adds a CloseEvent handler.
    
    Specified by:
    
    addCloseHandler in interface HasCloseHandlers<TreeItem>
    
    Parameters:
    handler - the handler
    
    Returns:
    the registration for the event
  - addFocusHandler
```
public HandlerRegistration addFocusHandler(FocusHandler handler)
```
    Description copied from interface: HasFocusHandlers
    
    Adds a FocusEvent handler.
    
    Specified by:
    
    addFocusHandler in interface HasFocusHandlers
    
    Parameters:
    handler - the focus handler
    
    Returns:
    HandlerRegistration used to remove this handler
  - addFocusListener
```
@Deprecated
public void addFocusListener(FocusListener listener)
```
    Deprecated. Use addFocusHandler(com.google.gwt.event.dom.client.FocusHandler) instead
    
    Description copied from interface: SourcesFocusEvents
    
    Adds a listener interface to receive focus events.
    
    Specified by:
    
    addFocusListener in interface SourcesFocusEvents
    
    Parameters:
    listener - the listener interface to add
  - addItem
```
@Deprecated
public TreeItem addItem(java.lang.String itemHtml)
```
    Deprecated. use addItem(SafeHtml) instead
    
    Adds a simple tree item containing the specified html.
    
    Parameters:
    itemHtml - the text of the item to be added
    
    Returns:
    the item that was added
  - addItem
```
public TreeItem addItem(SafeHtml itemHtml)
```
    Adds a simple tree item containing the specified html.
    
    Specified by:
    
    addItem in interface HasTreeItems
    
    Parameters:
    itemHtml - the html of the item to be added
    
    Returns:
    the item that was added
  - addItem
```
public void addItem(TreeItem item)
```
    Adds an item to the root level of this tree.
    
    Specified by:
    
    addItem in interface HasTreeItems
    
    Parameters:
    item - the item to be added
  - addItem
```
public void addItem(IsTreeItem isItem)
```
    Adds an item to the root level of this tree.
    
    Specified by:
    
    addItem in interface HasTreeItems
    
    Parameters:
    isItem - the wrapper of item to be added
  - addItem
```
public TreeItem addItem(Widget widget)
```
    Adds a new tree item containing the specified widget.
    
    Specified by:
    
    addItem in interface HasTreeItems
    
    Parameters:
    widget - the widget to be added
    
    Returns:
    the new item
  - addItem
```
public TreeItem addItem(IsWidget w)
```
    Overloaded version for IsWidget.
    
    Specified by:
    
    addItem in interface HasTreeItems.ForIsWidget
    
    See Also:
    addItem(Widget)
  - addKeyboardListener
```
@Deprecated
public void addKeyboardListener(KeyboardListener listener)
```
    Deprecated. Use addKeyDownHandler(com.google.gwt.event.dom.client.KeyDownHandler), addKeyUpHandler(com.google.gwt.event.dom.client.KeyUpHandler) and addKeyPressHandler(com.google.gwt.event.dom.client.KeyPressHandler) instead
    
    Description copied from interface: SourcesKeyboardEvents
    
    Adds a listener interface to receive keyboard events.
    
    Specified by:
    
    addKeyboardListener in interface SourcesKeyboardEvents
    
    Parameters:
    listener - the listener interface to add
  - addKeyDownHandler
```
public HandlerRegistration addKeyDownHandler(KeyDownHandler handler)
```
    Description copied from interface: HasKeyDownHandlers
    
    Adds a KeyDownEvent handler.
    
    Specified by:
    
    addKeyDownHandler in interface HasKeyDownHandlers
    
    Parameters:
    handler - the key down handler
    
    Returns:
    HandlerRegistration used to remove this handler
  - addKeyPressHandler
```
public HandlerRegistration addKeyPressHandler(KeyPressHandler handler)
```
    Description copied from interface: HasKeyPressHandlers
    
    Adds a KeyPressEvent handler.
    
    Specified by:
    
    addKeyPressHandler in interface HasKeyPressHandlers
    
    Parameters:
    handler - the key press handler
    
    Returns:
    HandlerRegistration used to remove this handler
  - addKeyUpHandler
```
public HandlerRegistration addKeyUpHandler(KeyUpHandler handler)
```
    Description copied from interface: HasKeyUpHandlers
    
    Adds a KeyUpEvent handler.
    
    Specified by:
    
    addKeyUpHandler in interface HasKeyUpHandlers
    
    Parameters:
    handler - the key up handler
    
    Returns:
    HandlerRegistration used to remove this handler
  - addMouseDownHandler
```
public HandlerRegistration addMouseDownHandler(MouseDownHandler handler)
```
    Description copied from interface: HasMouseDownHandlers
    
    Adds a MouseDownEvent handler.
    
    Specified by:
    
    addMouseDownHandler in interface HasMouseDownHandlers
    
    Parameters:
    handler - the mouse down handler
    
    Returns:
    HandlerRegistration used to remove this handler
  - addMouseListener
```
@Deprecated
public void addMouseListener(MouseListener listener)
```
    Deprecated. Use addMouseOverHandler(com.google.gwt.event.dom.client.MouseOverHandler) addMouseMoveHandler(com.google.gwt.event.dom.client.MouseMoveHandler), addMouseDownHandler(com.google.gwt.event.dom.client.MouseDownHandler), addMouseUpHandler(com.google.gwt.event.dom.client.MouseUpHandler) and addMouseOutHandler(com.google.gwt.event.dom.client.MouseOutHandler) instead
    
    Description copied from interface: SourcesMouseEvents
    
    Adds a listener interface to receive mouse events.
    
    Specified by:
    
    addMouseListener in interface SourcesMouseEvents
    
    Parameters:
    listener - the listener interface to add
  - addMouseMoveHandler
```
public HandlerRegistration addMouseMoveHandler(MouseMoveHandler handler)
```
    Description copied from interface: HasMouseMoveHandlers
    
    Adds a MouseMoveEvent handler.
    
    Specified by:
    
    addMouseMoveHandler in interface HasMouseMoveHandlers
    
    Parameters:
    handler - the mouse move handler
    
    Returns:
    HandlerRegistration used to remove this handler
  - addMouseOutHandler
```
public HandlerRegistration addMouseOutHandler(MouseOutHandler handler)
```
    Description copied from interface: HasMouseOutHandlers
    
    Adds a MouseOutEvent handler.
    
    Specified by:
    
    addMouseOutHandler in interface HasMouseOutHandlers
    
    Parameters:
    handler - the mouse out handler
    
    Returns:
    HandlerRegistration used to remove this handler
  - addMouseOverHandler
```
public HandlerRegistration addMouseOverHandler(MouseOverHandler handler)
```
    Description copied from interface: HasMouseOverHandlers
    
    Adds a MouseOverEvent handler.
    
    Specified by:
    
    addMouseOverHandler in interface HasMouseOverHandlers
    
    Parameters:
    handler - the mouse over handler
    
    Returns:
    HandlerRegistration used to remove this handler
  - addMouseUpHandler
```
public HandlerRegistration addMouseUpHandler(MouseUpHandler handler)
```
    Description copied from interface: HasMouseUpHandlers
    
    Adds a MouseUpEvent handler.
    
    Specified by:
    
    addMouseUpHandler in interface HasMouseUpHandlers
    
    Parameters:
    handler - the mouse up handler
    
    Returns:
    HandlerRegistration used to remove this handler
  - addMouseWheelHandler
```
public HandlerRegistration addMouseWheelHandler(MouseWheelHandler handler)
```
    Description copied from interface: HasMouseWheelHandlers
    
    Adds a MouseWheelEvent handler.
    
    Specified by:
    
    addMouseWheelHandler in interface HasMouseWheelHandlers
    
    Parameters:
    handler - the mouse wheel handler
    
    Returns:
    HandlerRegistration used to remove this handler
  - addOpenHandler
```
public final HandlerRegistration addOpenHandler(OpenHandler<TreeItem> handler)
```
    Description copied from interface: HasOpenHandlers
    
    Adds an OpenEvent handler.
    
    Specified by:
    
    addOpenHandler in interface HasOpenHandlers<TreeItem>
    
    Parameters:
    handler - the handler
    
    Returns:
    the registration for the event
  - addSelectionHandler
```
public HandlerRegistration addSelectionHandler(SelectionHandler<TreeItem> handler)
```
    Description copied from interface: HasSelectionHandlers
    
    Adds a SelectionEvent handler.
    
    Specified by:
    
    addSelectionHandler in interface HasSelectionHandlers<TreeItem>
    
    Parameters:
    handler - the handler
    
    Returns:
    the registration for the event
  - addTextItem
```
public TreeItem addTextItem(java.lang.String itemText)
```
    Adds a simple tree item containing the specified text.
    
    Specified by:
    
    addTextItem in interface HasTreeItems
    
    Parameters:
    itemText - the text of the item to be added
    
    Returns:
    the item that was added
  - addTreeListener
```
@Deprecated
public void addTreeListener(TreeListener listener)
```
    Deprecated. Use addSelectionHandler(com.google.gwt.event.logical.shared.SelectionHandler<com.google.gwt.user.client.ui.TreeItem>), addOpenHandler(com.google.gwt.event.logical.shared.OpenHandler<com.google.gwt.user.client.ui.TreeItem>), and addCloseHandler(com.google.gwt.event.logical.shared.CloseHandler<com.google.gwt.user.client.ui.TreeItem>) instead
    
    Description copied from interface: SourcesTreeEvents
    
    Adds a listener interface to receive tree events.
    
    Specified by:
    
    addTreeListener in interface SourcesTreeEvents
    
    Parameters:
    listener - the listener interface to add
  - clear
```
public void clear()
```
    Clears all tree items from the current tree.
    
    Specified by:
    
    clear in interface HasWidgets
  - ensureSelectedItemVisible
```
public void ensureSelectedItemVisible()
```
    Ensures that the currently-selected item is visible, opening its parents and scrolling the tree as necessary.
  - getItem
```
public TreeItem getItem(int index)
```
    Gets the top-level tree item at the specified index.
    
    Parameters:
    index - the index to be retrieved
    
    Returns:
    the item at that index
  - getItemCount
```
public int getItemCount()
```
    Gets the number of items contained at the root of this tree.
    
    Returns:
    this tree's item count
  - getSelectedItem
```
public TreeItem getSelectedItem()
```
    Gets the currently selected item.
    
    Returns:
    the selected item
  - getTabIndex
```
public int getTabIndex()
```
    Description copied from interface: Focusable
    
    Gets the widget's position in the tab index.
    
    Specified by:
    
    getTabIndex in interface Focusable
    
    Returns:
    the widget's tab index
  - insertItem
```
@Deprecated
public TreeItem insertItem(int beforeIndex,
                             java.lang.String itemHtml)
```
    Deprecated. use insertItem(int, SafeHtml) instead
    
    Inserts a child tree item at the specified index containing the specified html.
    
    Parameters:
    beforeIndex - the index where the item will be inserted
    itemHtml - the html to be added
    
    Returns:
    the item that was added
    
    Throws:
    
    java.lang.IndexOutOfBoundsException - if the index is out of range
  - insertItem
```
public TreeItem insertItem(int beforeIndex,
                  SafeHtml itemHtml)
```
    Inserts a child tree item at the specified index containing the specified html.
    
    Parameters:
    beforeIndex - the index where the item will be inserted
    itemHtml - the html of the item to be added
    
    Returns:
    the item that was added
    
    Throws:
    
    java.lang.IndexOutOfBoundsException - if the index is out of range
  - insertItem
```
public void insertItem(int beforeIndex,
              TreeItem item)
```
    Inserts an item into the root level of this tree.
    
    Parameters:
    beforeIndex - the index where the item will be inserted
    item - the item to be added
    
    Throws:
    
    java.lang.IndexOutOfBoundsException - if the index is out of range
  - insertItem
```
public TreeItem insertItem(int beforeIndex,
                  Widget widget)
```
    Inserts a child tree item at the specified index containing the specified widget.
    
    Parameters:
    beforeIndex - the index where the item will be inserted
    widget - the widget to be added
    
    Returns:
    the item that was added
    
    Throws:
    
    java.lang.IndexOutOfBoundsException - if the index is out of range
  - insertTextItem
```
public TreeItem insertTextItem(int beforeIndex,
                      java.lang.String itemText)
```
    Inserts a child tree item at the specified index containing the specified text.
    
    Parameters:
    beforeIndex - the index where the item will be inserted
    itemText - the text of the item to be added
    
    Returns:
    the item that was added
    
    Throws:
    
    java.lang.IndexOutOfBoundsException - if the index is out of range
  - isAnimationEnabled
```
public boolean isAnimationEnabled()
```
    Description copied from interface: HasAnimation
    
    Returns true if animations are enabled, false if not.
    
    Specified by:
    
    isAnimationEnabled in interface HasAnimation
  - iterator
```
public java.util.Iterator<Widget> iterator()
```
    Description copied from interface: HasWidgets
    
    Gets an iterator for the contained widgets. This iterator is required to implement Iterator.remove().
    
    Specified by:
    
    iterator in interface HasWidgets
    
    Specified by:
    
    iterator in interface java.lang.Iterable<Widget>
  - onBrowserEvent
```
public void onBrowserEvent(Event event)
```
    Description copied from interface: EventListener
    
    Fired whenever a browser event is received.
    
    Specified by:
    
    onBrowserEvent in interface EventListener
    
    Overrides:
    
    onBrowserEvent in class Widget
    
    Parameters:
    event - the event received
  - remove
```
public boolean remove(Widget w)
```
    Description copied from interface: HasWidgets
    
    Removes a child widget.
    
    Specified by:
    
    remove in interface HasWidgets
    
    Parameters:
    w - the widget to be removed
    
    Returns:
    true if the widget was present
  - remove
```
public boolean remove(IsWidget w)
```
    Overloaded version for IsWidget.
    
    Specified by:
    
    remove in interface HasWidgets.ForIsWidget
    
    See Also:
    remove(Widget)
  - removeFocusListener
```
@Deprecated
public void removeFocusListener(FocusListener listener)
```
    Deprecated. Use the HandlerRegistration.removeHandler() method on the object returned by addFocusHandler(com.google.gwt.event.dom.client.FocusHandler) instead
    
    Description copied from interface: SourcesFocusEvents
    
    Removes a previously added listener interface.
    
    Specified by:
    
    removeFocusListener in interface SourcesFocusEvents
    
    Parameters:
    listener - the listener interface to remove
  - removeItem
```
public void removeItem(TreeItem item)
```
    Removes an item from the root level of this tree.
    
    Specified by:
    
    removeItem in interface HasTreeItems
    
    Parameters:
    item - the item to be removed
  - removeItem
```
public void removeItem(IsTreeItem isItem)
```
    Removes an item from the root level of this tree.
    
    Specified by:
    
    removeItem in interface HasTreeItems
    
    Parameters:
    isItem - the wrapper of item to be removed
  - removeItems
```
public void removeItems()
```
    Removes all items from the root level of this tree.
    
    Specified by:
    
    removeItems in interface HasTreeItems
  - removeKeyboardListener
```
@Deprecated
public void removeKeyboardListener(KeyboardListener listener)
```
    Deprecated. Use the HandlerRegistration.removeHandler() method on the object returned by an add*Handler method instead
    
    Description copied from interface: SourcesKeyboardEvents
    
    Removes a previously added listener interface.
    
    Specified by:
    
    removeKeyboardListener in interface SourcesKeyboardEvents
    
    Parameters:
    listener - the listener interface to remove
  - removeMouseListener
```
@Deprecated
public void removeMouseListener(MouseListener listener)
```
    Deprecated. Use the HandlerRegistration.removeHandler() method on the object returned by an add*Handler method instead
    
    Description copied from interface: SourcesMouseEvents
    
    Removes a previously added listener interface.
    
    Specified by:
    
    removeMouseListener in interface SourcesMouseEvents
    
    Parameters:
    listener - the listener interface to remove
  - removeTreeListener
```
@Deprecated
public void removeTreeListener(TreeListener listener)
```
    Deprecated. Use the HandlerRegistration.removeHandler() method on the object returned by an add*Handler method instead
    
    Description copied from interface: SourcesTreeEvents
    
    Removes a previously added listener interface.
    
    Specified by:
    
    removeTreeListener in interface SourcesTreeEvents
    
    Parameters:
    listener - the listener interface to remove
  - setAccessKey
```
public void setAccessKey(char key)
```
    Description copied from interface: Focusable
    
    Sets the widget's 'access key'. This key is used (in conjunction with a browser-specific modifier key) to automatically focus the widget.
    
    Specified by:
    
    setAccessKey in interface Focusable
    
    Parameters:
    key - the widget's access key
  - setAnimationEnabled
```
public void setAnimationEnabled(boolean enable)
```
    Description copied from interface: HasAnimation
    
    Enable or disable animations.
    
    Specified by:
    
    setAnimationEnabled in interface HasAnimation
    
    Parameters:
    enable - true to enable, false to disable
  - setFocus
```
public void setFocus(boolean focus)
```
    Description copied from interface: Focusable
    
    Explicitly focus/unfocus this widget. Only one widget can have focus at a time, and the widget that does will receive all keyboard events.
    
    Specified by:
    
    setFocus in interface Focusable
    
    Parameters:
    focus - whether this widget should take focus or release it
  - setSelectedItem
```
public void setSelectedItem(TreeItem item)
```
    Selects a specified item.
    
    Parameters:
    item - the item to be selected, or null to deselect all items
  - setSelectedItem
```
public void setSelectedItem(TreeItem item,
                   boolean fireEvents)
```
    Selects a specified item.
    
    Parameters:
    item - the item to be selected, or null to deselect all items
    fireEvents - true to allow selection events to be fired
  - setTabIndex
```
public void setTabIndex(int index)
```
    Description copied from interface: Focusable
    
    Sets the widget's position in the tab index. If more than one widget has the same tab index, each such widget will receive focus in an arbitrary order. Setting the tab index to -1 will cause this widget to be removed from the tab order.
    
    Specified by:
    
    setTabIndex in interface Focusable
    
    Parameters:
    index - the widget's tab index
  - treeItemIterator
```
public java.util.Iterator<TreeItem> treeItemIterator()
```
    Iterator of tree items.
    
    Returns:
    the iterator
  - doAttachChildren
```
protected void doAttachChildren()
```
    Description copied from class: Widget
    
    If a widget contains one or more child widgets that are not in the logical widget hierarchy (the child is physically connected only on the DOM level), it must override this method and call Widget.onAttach() for each of its child widgets.
    
    Overrides:
    
    doAttachChildren in class Widget
    
    See Also:
    Widget.onAttach()
  - doDetachChildren
```
protected void doDetachChildren()
```
    Description copied from class: Widget
    
    If a widget contains one or more child widgets that are not in the logical widget hierarchy (the child is physically connected only on the DOM level), it must override this method and call Widget.onDetach() for each of its child widgets.
    
    Overrides:
    
    doDetachChildren in class Widget
    
    See Also:
    Widget.onDetach()
  - isKeyboardNavigationEnabled
```
protected boolean isKeyboardNavigationEnabled(TreeItem currentItem)
```
    Indicates if keyboard navigation is enabled for the Tree and for a given TreeItem. Subclasses of Tree can override this function to selectively enable or disable keyboard navigation.
    
    Parameters:
    currentItem - the currently selected TreeItem
    
    Returns:
    true if the Tree will response to arrow keys by changing the currently selected item
  - onEnsureDebugId
```
protected void onEnsureDebugId(java.lang.String baseID)
```
    Affected Elements:
    - -root = The root TreeItem.
    Overrides:
    
    onEnsureDebugId in class UIObject
    
    Parameters:
    baseID - the base ID used by the main element
    See Also:
    UIObject.onEnsureDebugId(String)
  - onLoad
```
protected void onLoad()
```
    Description copied from class: Widget
    
    This method is called immediately after a widget becomes attached to the browser's document.
    
    Overrides:
    
    onLoad in class Widget
  - adopt
```
void adopt(Widget widget,
         TreeItem treeItem)
```
  - fireStateChanged
```
void fireStateChanged(TreeItem item,
                    boolean open)
```
  - getChildWidgets
```
java.util.Map<Widget,TreeItem> getChildWidgets()
```
  - getImages
```
Tree.ImageAdapter getImages()
```
  - maybeUpdateSelection
```
void maybeUpdateSelection(TreeItem itemThatChangedState,
                        boolean isItemOpening)
```
  - orphan
```
void orphan(Widget widget)
```
  - showClosedImage
```
void showClosedImage(TreeItem treeItem)
```
    Called only from TreeItem: Shows the closed image on that tree item.
    
    Parameters:
    treeItem - the tree item
  - showLeafImage
```
void showLeafImage(TreeItem treeItem)
```
    Called only from TreeItem: Shows the leaf image on a tree item.
    
    Parameters:
    treeItem - the tree item
  - showOpenImage
```
void showOpenImage(TreeItem treeItem)
```
    Called only from TreeItem: Shows the open image on a tree item.
    
    Parameters:
    treeItem - the tree item

Class Tree

CSS Style Rules

Example

Nested Class Summary

Nested classes/interfaces inherited from class com.google.gwt.user.client.ui.UIObject

Nested classes/interfaces inherited from interface com.google.gwt.user.client.ui.HasTreeItems

Nested classes/interfaces inherited from interface com.google.gwt.user.client.ui.HasWidgets

Field Summary

Fields inherited from class com.google.gwt.user.client.ui.Widget

Fields inherited from class com.google.gwt.user.client.ui.UIObject

Constructor Summary

Method Summary

Methods inherited from class com.google.gwt.user.client.ui.Widget

Methods inherited from class com.google.gwt.user.client.ui.UIObject

Methods inherited from class java.lang.Object

Methods inherited from interface com.google.gwt.event.shared.HasHandlers

Constructor Detail

Tree

Tree

Tree

Tree

Tree

Method Detail

shouldTreeDelegateFocusToElement

add

add

addBlurHandler

addCloseHandler

addFocusHandler

addFocusListener

addItem

addItem

addItem

addItem

addItem

addItem

addKeyboardListener

addKeyDownHandler

addKeyPressHandler

addKeyUpHandler

addMouseDownHandler

addMouseListener

addMouseMoveHandler

addMouseOutHandler

addMouseOverHandler

addMouseUpHandler

addMouseWheelHandler

addOpenHandler

addSelectionHandler

addTextItem

addTreeListener

clear

ensureSelectedItemVisible

getItem

getItemCount

getSelectedItem

getTabIndex

insertItem

insertItem

insertItem

insertItem

insertTextItem

isAnimationEnabled

iterator

onBrowserEvent

remove

remove

removeFocusListener

removeItem

removeItem

removeItems

removeKeyboardListener

removeMouseListener

removeTreeListener

setAccessKey

setAnimationEnabled

setFocus

setSelectedItem

setSelectedItem

setTabIndex