# Package com.google.gwt.user.client.ui

Widgets, Panels, and other user-interface classes. This package contains all of the high-level user-interface Widgets, along with panels and event interfaces. These classes form the bulk of the client-side libraries used by GWT applications.

- Interface Summary
  Interface | Description
  --- | ---
  AcceptsOneWidget | Implemented by displays that can be given accept an `IsWidget` to show.
  AnimatedLayout | Specifies that a panel can animate between layouts.
  AttachDetachException.Command | The command to execute when iterating through child widgets.
  ChangeListener | Deprecated. As of GWT 1.6, DOM and logical change events are separate.
  ClickListener | Deprecated. Use `ClickHandler` instead
  CustomScrollPanel.Resources | A ClientBundle of resources used by this widget.
  CustomScrollPanel.Style | Styles used by this widget.
  DialogBox.Caption | Set of characteristic interfaces supported by the `DialogBox` caption.
  DisclosureHandler | Deprecated. Use `CloseHandler` and/or `OpenHandler` instead
  DisclosurePanel.DefaultImages |
  DisclosurePanelImages | Deprecated.
  DisclosurePanelImagesRTL | Deprecated.
  FiniteWidgetIterator.WidgetProvider | Provides widgets to the iterator.
  FiresDisclosureEvents | Deprecated. Use `HasOpenHandlers` and `HasCloseHandlers` instead
  FiresFormEvents | Deprecated. This interface was specific to `FormPanel`; it is not generally useful and will be removed in a future version.
  FiresSuggestionEvents | Deprecated. Use `HasSelectionHandlers` instead.
  Focusable | A widget that implements this interface can receive keyboard focus.
  FocusListener | Deprecated. Use `FocusHandler` and/or `BlurHandler` instead
  FormHandler | Deprecated. Use `FormPanel.SubmitCompleteHandler` and/or `FormPanel.SubmitHandler` instead
  FormPanel.IFrameTemplate |
  FormPanel.SubmitCompleteHandler | Handler for `FormPanel.SubmitCompleteEvent` events.
  FormPanel.SubmitHandler | Handler for `FormPanel.SubmitEvent` events.
  HasAlignment | A widget that implements this interface has an intrinsic alignment which can be manipulated using these methods and constants.
  HasAnimation | A `Widget` that uses an animation should implement this class so users can enable or disable animations.
  HasAutoHorizontalAlignment | A widget that implements this interface can be configured to be aligned according to its contents' direction, in addition to the static alignment options offered by `HasHorizontalAlignment`.
  HasCaption | A widget that implements this interface has a caption which can be set and retrieved using these methods.
  HasConstrainedValue<T> | Implemented by widgets that pick from a set of values.
  HasDirectionalHtml | An object that implements this interface contains html that has a direction.
  HasDirectionalSafeHtml | An object that implements this interface contains html that has a direction.
  HasDirectionalText | An object that implements this interface contains text that has a direction.
  HasEnabled | A widget that implements this interface can be put in an "enabled" or "disabled" state.
  HasFocus | Deprecated. Use `Focusable` instead
  HasHorizontalAlignment | Characteristic interface which indicates that a widget can be aligned horizontally.
  HasHorizontalScrolling | Implemented by widgets that support horizontal scrolling.
  HasHTML | An object that implements this interface contains text, which can be set and retrieved using these methods.
  HasKeyPreview | Deprecated. This interface is no longer implemented by any GWT library.
  HasName | A widget that implements this interface has a 'name' associated with it, allowing it to be used with `FormPanel`.
  HasOneWidget | Implemented by panels that have only one widget.
  HasScrolling | Implemented by widgets that support scrolling.
  HasText | An object that implements this interface contains text, which can be set and retrieved using these methods.
  HasTreeItems | A widget that implements this interface contains `items` and can operate them.
  HasTreeItems.ForIsWidget | Extends this interface with convenience methods to handle `IsWidget`.
  HasValue<T> | Extends `TakesValue` to allow the value to be pulled back out, and to throw `ValueChangeEvent` events.
  HasVerticalAlignment | Characteristic interface which indicates that a widget has an associated vertical alignment.
  HasVerticalScrolling | Implemented by widgets that support vertical scrolling.
  HasVisibility | Implemented by objects that have the visibility trait.
  HasWidgets | A widget that implements this interface contains `widgets` and can enumerate them.
  HasWidgets.ForIsWidget | Extends this interface with convenience methods to handle `IsWidget`.
  HasWordWrap | A widget that implements this interface has a 'word-wrap' property that can be manipulated using these methods.
  HorizontalScrollbar | Describes a horizontal scrollbar.
  HorizontalSplitPanel.Resources | The default resources used by this widget.
  HorizontalSplitPanelImages | Deprecated. replaced by `HorizontalSplitPanel.Resources`.
  ImageBundle | Deprecated. replaced by `ClientBundle` and `ImageResource`
  ImageResourceRenderer.Template |
  IndexedPanel | Implemented by panels that impose an explicit ordering on their children.
  IndexedPanel.ForIsWidget | Extends this interface with convenience methods to handle `IsWidget`.
  InsertPanel | Implemented by `IndexedPanel`s that also allow insertions.
  InsertPanel.ForIsWidget | Extends this interface with convenience methods to handle `IsWidget`.
  IsRenderable | An interface for UI elements that can be built by first generating a piece of HTML and afterwards wrapping a root widget.
  IsTreeItem | Extended by objects which have underlying `TreeItem`.
  IsWidget | Extended by view interfaces that are likely to be implemented by Widgets.
  KeyboardListener | Deprecated. use `KeyDownHandler`, `KeyUpHandler` and/or `KeyPressHandler` instead
  LoadListener | Deprecated. use `LoadHandler` and `ErrorHandler` instead
  MenuBar.MenuBarImages | Deprecated. replaced by `MenuBar.Resources`
  MenuBar.Resources | A ClientBundle that contains the default resources for this widget.
  MouseListener | Deprecated. use `MouseDownHandler`, `MouseUpHandler`, `MouseOverHandler`, `MouseMoveHandler`, and `MouseOutHandler` instead
  MouseWheelListener | Deprecated. use `MouseWheelHandler` instead
  NamedFrame.IFrameTemplate |
  NativeHorizontalScrollbar.NativeHorizontalScrollbarUiBinder |
  NativeHorizontalScrollbar.Resources | A ClientBundle of resources used by this widget.
  NativeHorizontalScrollbar.ResourcesTransparant | A variation of `NativeHorizontalScrollbar.Resources` that renders the scrollbar semi-transparent until it is hovered.
  NativeHorizontalScrollbar.Style | Styles used by this widget.
  NativeHorizontalScrollbar.StyleTransparant | A variation of `NativeHorizontalScrollbar.Style` that renders the scrollbar semi-transparent until it is hovered.
  NativeVerticalScrollbar.NativeVerticalScrollbarUiBinder |
  NativeVerticalScrollbar.Resources | A ClientBundle of resources used by this widget.
  NativeVerticalScrollbar.ResourcesTransparant | A variation of `NativeVerticalScrollbar.Resources` that renders the scrollbar semi-transparent until it is hovered.
  NativeVerticalScrollbar.Style | Styles used by this widget.
  NativeVerticalScrollbar.StyleTransparant | A variation of `NativeVerticalScrollbar.Style` that renders the scrollbar semi-transparent until it is hovered.
  NativeVerticalScrollbar.UiBinderBundle | Client bundle used in the uibinder template.
  NativeVerticalScrollbar.UiStyle | Style used in uibinder template.
  NotificationMole.Binder |
  NotificationMole.Style | Default CSS styles for this widget.
  PopupListener | Deprecated. use `CloseHandler` instead
  PopupPanel.PositionCallback | A callback that is used to set the position of a `PopupPanel` right before it is shown.
  ProvidesResize | This tag interface specifies that the implementing widget will call `RequiresResize.onResize()` on its children whenever their size may have changed.
  RequiresResize | This interface designates that its implementor needs to be informed whenever its size is modified.
  ResizeLayoutPanel.Impl.Delegate | Delegate event handler.
  RichTextArea.BasicFormatter | Deprecated. use `RichTextArea.Formatter` instead
  RichTextArea.ExtendedFormatter | Deprecated. use `RichTextArea.Formatter` instead
  RichTextArea.Formatter | This interface is used to access full formatting options, when available.
  ScrollListener | Deprecated. use `ScrollHandler` instead
  SourcesChangeEvents | Deprecated. we have now separated dom and logical change events.
  SourcesClickEvents | Deprecated. use `HasClickHandlers` instead
  SourcesFocusEvents | Deprecated. use `HasAllFocusHandlers` instead
  SourcesKeyboardEvents | Deprecated. use `HasAllKeyHandlers` instead
  SourcesLoadEvents | Deprecated. use `HasErrorHandlers` and `HasLoadHandlers` instead
  SourcesMouseEvents | Deprecated. use `HasAllMouseHandlers` instead
  SourcesMouseWheelEvents | Deprecated. Use `HasMouseWheelHandlers` instead
  SourcesPopupEvents | Deprecated. use `HasCloseHandlers` instead
  SourcesScrollEvents | Deprecated. use `HasScrollHandlers` instead
  SourcesTabEvents | Deprecated. use `HasSelectionHandlers` and `HasBeforeSelectionHandlers` instead
  SourcesTableEvents | Deprecated. use `HasClickHandlers` instead.
  SourcesTreeEvents | Deprecated. use `HasBeforeSelectionHandlers`, `HasOpenHandlers` and `HasClickHandlers` instead
  SuggestBox.SuggestionCallback | The callback used when a user selects a `SuggestOracle.Suggestion`.
  SuggestionHandler | Deprecated. use `SelectionHandler` instead
  SuggestOracle.Callback | Callback for `SuggestOracle`.
  SuggestOracle.Suggestion | Suggestion supplied by the `SuggestOracle`.
  TabBar.Tab | Set of characteristic interfaces supported by `TabBar` tabs.
  TableListener | Deprecated. use `ClickHandler` and `HTMLTable.getCellForEvent(com.google.gwt.event.dom.client.ClickEvent)` instead
  TabListener | Deprecated. use `TabPanel.addBeforeSelectionHandler(com.google.gwt.event.logical.shared.BeforeSelectionHandler)` and/or `TabPanel.addSelectionHandler(com.google.gwt.event.logical.shared.SelectionHandler)` instead
  Tree.Resources | A ClientBundle that provides images for this widget.
  TreeImages | Deprecated. replaced by `Tree.Resources`.
  TreeListener | Deprecated. Use `SelectionHandler`, `OpenHandler`, and `CloseHandler` instead
  VerticalScrollbar | Describes a vertical scrollbar.
  VerticalSplitPanel.Resources | The default resources used by this widget.
  VerticalSplitPanelImages | Deprecated. replaced by `VerticalSplitPanel.Resources`.

- Class Summary
  Class | Description
  --- | ---
  AbsolutePanel | An absolute panel positions all of its children absolutely, allowing them to overlap.
  AbstractImagePrototype | An opaque representation of a particular image such that the image can be accessed either as an HTML fragment or as an `Image` object.
  AbstractImagePrototype.ImagePrototypeElement | This corresponds to the top Element of the DOM structure created by `AbstractImagePrototype.createElement()`.
  AbstractNativeScrollbar | Abstract parent class for scrollbars implemented using the native browser scrollbars.
  Accessibility | Deprecated. Use the new GWT ARIA library with the factory class for the ARIA roles `Roles`.
  Anchor | A widget that represents a simple <a> element.
  Button | A standard push-button widget.
  ButtonBase | Abstract base class for `Button`, `CheckBox`, `RadioButton`.
  CaptionPanel | A panel that wraps its contents in a border with a caption that appears in the upper left corner of the border.
  CaptionPanel.CaptionPanelImpl | Implementation class without browser-specific hacks.
  CaptionPanel.CaptionPanelImplMozilla | Implementation class that handles Mozilla rendering issues.
  CaptionPanel.CaptionPanelImplSafari | Implementation class that handles Safari rendering issues.
  CellPanel | A panel whose child widgets are contained within the cells of a table.
  ChangeListenerCollection | Deprecated. Widgets should now manage their own handlers via `Widget.addDomHandler(H, com.google.gwt.event.dom.client.DomEvent.Type<H>)`
  CheckBox | A standard check box widget.
  ClickListenerCollection | Deprecated. As of GWT 1.6, call ``addDomHandler`(myHandler, ClickEvent.getType())` to manage handlers for your widget instead
  ComplexPanel | Abstract base class for panels that can contain multiple child widgets.
  Composite | A type of widget that can wrap another widget, hiding the wrapped widget's methods.
  CustomButton | CustomButton is a base button class with built in support for a set number of button faces.
  CustomScrollPanel | A custom version of the `ScrollPanel` that allows user provided scrollbars.
  DateLabel | Extends `ValueLabel` for convenience when dealing with dates and `DateTimeFormat`, especially in `UiBinder` templates.
  DeckLayoutPanel | A panel that displays all of its child widgets in a 'deck', where only one can be visible at a time.
  DeckPanel | A panel that displays all of its child widgets in a 'deck', where only one can be visible at a time.
  DecoratedPopupPanel | A `PopupPanel` that wraps its content in a 3x3 grid, which allows users to add rounded corners.
  DecoratedStackPanel | A `StackPanel` that wraps each item in a 2x3 grid (six box), which allows users to add rounded corners.
  DecoratedTabBar | A `TabBar` that wraps each tab in a 2x3 grid (six box), which allows users to add rounded corners.
  DecoratedTabPanel | A `TabPanel` that uses a `DecoratedTabBar` with rounded corners.
  DecoratorPanel | A `SimplePanel` that wraps its contents in stylized boxes, which can be used to add rounded corners to a `Widget`.
  DelegatingChangeListenerCollection | Deprecated. Use `Widget.delegateEvent` instead
  DelegatingClickListenerCollection | Deprecated. Use `Widget.delegateEvent(com.google.gwt.user.client.ui.Widget, com.google.gwt.event.shared.GwtEvent<?>)` instead
  DelegatingFocusListenerCollection | Deprecated. Use `Widget.delegateEvent(com.google.gwt.user.client.ui.Widget, com.google.gwt.event.shared.GwtEvent<?>)` instead
  DelegatingKeyboardListenerCollection | Deprecated. Use `Widget.delegateEvent(com.google.gwt.user.client.ui.Widget, com.google.gwt.event.shared.GwtEvent<?>)` instead
  DialogBox | A form of popup that has a caption area at the top and can be dragged by the user.
  DialogBox.CaptionImpl | Default implementation of Caption.
  DirectionalTextHelper | A helper class for displaying bidi (i.e.
  DisclosureEvent | Deprecated. Use `CloseEvent` and `OpenEvent` instead
  DisclosurePanel | A widget that consists of a header and a content panel that discloses the content when a user clicks on the header.
  DockLayoutPanel | A panel that lays its child widgets out "docked" at its outer edges, and allows its last widget to take up the remaining space in its center.
  DockLayoutPanel.LayoutData | Layout data associated with each widget.
  DockPanel | A panel that lays its child widgets out "docked" at its outer edges, and allows its last widget to take up the remaining space in its center.
  DockPanel.DockLayoutConstant | DockPanel layout constant, used in `DockPanel.add(Widget, DockPanel.DockLayoutConstant)`.
  DockPanel.LayoutData |
  DoubleBox | A ValueBox that uses `DoubleParser` and `DoubleRenderer`.
  FileUpload | A widget that wraps the HTML <input type='file'> element.
  FiniteWidgetIterator | Iterator over a finite number of widgets, which are stored in a delegate class (usually a widget panel).
  FlexTable | A flexible table that creates cells on demand.
  FlowPanel | A panel that formats its child widgets using the default HTML layout behavior.
  FocusListenerAdapter | Deprecated. Use `FocusHandler` and `BlurHandler` instead
  FocusListenerCollection | Deprecated. Widgets should now manage their own handlers via `Widget.addDomHandler(H, com.google.gwt.event.dom.client.DomEvent.Type<H>)`
  FocusPanel | A simple panel that makes its contents focusable, and adds the ability to catch mouse and keyboard events.
  FocusWidget | Abstract base class for most widgets that can receive keyboard focus.
  FormHandlerCollection | Deprecated. Widgets should now manage their own handlers via `Widget.addDomHandler(H, com.google.gwt.event.dom.client.DomEvent.Type<H>)`
  FormPanel | A panel that wraps its contents in an HTML <FORM> element.
  FormPanel.SubmitCompleteEvent | Fired when a form has been submitted successfully.
  FormPanel.SubmitEvent | Fired when the form is submitted.
  FormSubmitCompleteEvent | Event object containing information about form submission events.
  FormSubmitEvent | Event object containing information about form submission events.
  Frame | A widget that wraps an IFRAME element, which can contain an arbitrary web site.
  Grid | A rectangular grid that can contain text, html, or a child `Widget` within its cells.
  HasHorizontalAlignment.AutoHorizontalAlignmentConstant | Type for values defined and used in `HasAutoHorizontalAlignment`.
  HasHorizontalAlignment.HorizontalAlignmentConstant | Possible return values for `HasHorizontalAlignment.getHorizontalAlignment()`, and parameter values for `HasHorizontalAlignment.setHorizontalAlignment(com.google.gwt.user.client.ui.HasHorizontalAlignment.HorizontalAlignmentConstant)`.
  HasVerticalAlignment.VerticalAlignmentConstant | Horizontal alignment constant.
  HeaderPanel | A panel that includes a header (top), footer (bottom), and content (middle) area.
  Hidden | Represents a hidden field in an HTML form.
  HorizontalPanel | A panel that lays all of its widgets out in a single horizontal column.
  HorizontalSplitPanel | Deprecated. Use `SplitLayoutPanel` instead, but understand that it is not a drop in replacement for this class.
  HTML | A widget that can contain arbitrary HTML.
  HTMLPanel | A panel that contains HTML, and which can attach child widgets to identified elements within that HTML.
  HTMLTable | HTMLTable contains the common table algorithms for `Grid` and `FlexTable`.
  Hyperlink | A widget that serves as an "internal" hyperlink.
  Image | A widget that displays the image at a given URL.
  ImageResourceRenderer | Given an `ImageResource`, renders an element to show it.
  InlineHTML | A widget that can contain arbitrary HTML.
  InlineHyperlink | A widget that serves as an "internal" hyperlink.
  InlineLabel | A widget that contains arbitrary text, not interpreted as HTML.
  IntegerBox | A ValueBox that uses `IntegerParser` and `IntegerRenderer`.
  KeyboardListenerAdapter | Deprecated. use `KeyDownHandler`, `KeyUpHandler` and/or `KeyPressHandler` instead
  KeyboardListenerCollection | Deprecated. Widgets should now manage their own handlers via `Widget.addDomHandler(H, com.google.gwt.event.dom.client.DomEvent.Type<H>)`
  Label | A widget that contains arbitrary text, not interpreted as HTML.
  LabelBase<T> | Abstract base class for all text display widgets.
  LayoutCommand | A scheduled command used by animated layouts to ensure that only layout is ever performed for a panel within a given user event.
  LayoutPanel | A panel that lays its children out in arbitrary `layers` using the `Layout` class.
  LazyPanel | Convenience class to help lazy loading.
  ListBox | A widget that presents a list of choices to the user, either as a list box or as a drop-down list.
  ListenerWrapper<T> | Deprecated. will be removed in GWT 2.7 with the handler listeners themselves
  ListenerWrapper.WrappedChangeListener | Deprecated. will be removed in GWT 2.0 along with the listeners being wrapped
  ListenerWrapper.WrappedClickListener | Deprecated. will be removed in GWT 2.0 along with the listeners being wrapped
  ListenerWrapper.WrappedFocusListener | Wrapper for a `FocusListener`.
  ListenerWrapper.WrappedKeyboardListener | Wrapper for a `KeyboardListener`.
  ListenerWrapper.WrappedLoadListener | Wrapper for a `LoadListener`.
  ListenerWrapper.WrappedLogicalChangeListener<V> | Deprecated. will be removed in GWT 2.0 along with the listeners being wrapped
  ListenerWrapper.WrappedMouseListener | Wrapper for a `MouseListener`.
  ListenerWrapper.WrappedMouseWheelListener | Wrapper for a `MouseWheelListener`.
  ListenerWrapper.WrappedOldDisclosureHandler |
  ListenerWrapper.WrappedOldFormHandler |
  ListenerWrapper.WrappedOldSuggestionHandler |
  ListenerWrapper.WrappedPopupListener |
  ListenerWrapper.WrappedScrollListener | Wrapper for a `ScrollListener`.
  ListenerWrapper.WrappedTableListener |
  ListenerWrapper.WrappedTabListener |
  ListenerWrapper.WrappedTreeListener |
  LoadListenerCollection | Deprecated. Widgets should now manage their own handlers via `Widget.addDomHandler(H, com.google.gwt.event.dom.client.DomEvent.Type<H>)`
  LongBox | A ValueBox that uses `LongParser` and `LongRenderer`.
  MenuBar | A standard menu bar widget.
  MenuItem | An entry in a `MenuBar`.
  MenuItemSeparator | A separator that can be placed in a `MenuBar`.
  MouseListenerAdapter | Deprecated. use `MouseDownHandler`, `MouseUpHandler`, `MouseOverHandler`, `MouseMoveHandler`, and/or `MouseOutHandler` instead
  MouseListenerCollection | Deprecated. Widgets should now manage their own handlers via `Widget.addDomHandler(H, com.google.gwt.event.dom.client.DomEvent.Type<H>)`
  MouseWheelListenerCollection | Deprecated. Widgets should now manage their own handlers via `Widget.addDomHandler(H, com.google.gwt.event.dom.client.DomEvent.Type<H>)`
  MouseWheelVelocity | Deprecated. use `MouseWheelEvent.getDeltaY()` instead
  MultiWordSuggestOracle | The default `SuggestOracle`.
  MultiWordSuggestOracle.MultiWordSuggestion | Suggestion class for `MultiWordSuggestOracle`.
  NamedFrame | A `Frame` that has a 'name' associated with it.
  NativeHorizontalScrollbar | A horizontal scrollbar implemented using the browsers native scrollbar.
  NativeVerticalScrollbar | A vertical scrollbar implemented using the browsers native scrollbar.
  NotificationMole | Simple widget for providing notification feedback.
  NumberLabel<T extends java.lang.Number> | Extends `ValueLabel` for convenience when dealing with numbers and `NumberFormat`, especially in `UiBinder` templates.
  Panel | Abstract base class for all panels, which are widgets that can contain other widgets.
  PasswordTextBox | A text box that visually masks its input to prevent eavesdropping.
  PopupListenerCollection | Deprecated. Widgets should now manage their own handlers via `Widget.addDomHandler(H, com.google.gwt.event.dom.client.DomEvent.Type<H>)`
  PopupPanel | A panel that can "pop up" over other widgets.
  PopupPanel.ResizeAnimation | An `Animation` used to enlarge the popup into view.
  PotentialElement | EXPERIMENTAL and subject to change.
  PrefixTree | A prefix tree (aka trie).
  PushButton | A normal push button with custom styling.
  RadioButton | A mutually-exclusive selection radio button widget.
  RenderablePanel | EXPERIMENTAL and subject to change.
  RenderableStamper | Used by `IsRenderable` to mark their root element in such a way that they can be later retrieved.
  ResetButton | A standard push-button widget which will automatically reset its enclosing `FormPanel` if any.
  ResizeComposite | A `Composite` implementation that implements `RequiresResize` and automatically delegates that interface's methods to its wrapped widget, which must itself implement `RequiresResize`.
  ResizeLayoutPanel | A simple panel that `ProvidesResize` to its one child, but does not `RequiresResize`.
  ResizeLayoutPanel.Impl | Implementation of resize event.
  ResizeLayoutPanel.ImplStandard | Implementation of resize event.
  ResizeLayoutPanel.ImplTrident | Implementation of resize event used by IE.
  RichTextArea | A rich text editor that allows complex styling and formatting.
  RichTextArea.FontSize | Font size enumeration.
  RichTextArea.Justification | Justification enumeration.
  RootLayoutPanel | A singleton implementation of `LayoutPanel` that always attaches itself to the document body (i.e.
  RootPanel | The panel to which all other widgets must ultimately be added.
  ScrollImpl | Implementation of scrolling behavior.
  ScrollImpl.ScrollImplTrident | IE does not fire a scroll event when the scrollable element or the container is resized, so we synthesize one as needed.
  ScrollListenerCollection | Deprecated. Widgets should now manage their own handlers via `Widget.addDomHandler(H, com.google.gwt.event.dom.client.DomEvent.Type<H>)`
  ScrollPanel | A simple panel that wraps its contents in a scrollable area.
  SimpleCheckBox | A simple checkbox widget, with no label.
  SimpleLayoutPanel | A simple panel that `ProvidesResize` to its one child.
  SimplePanel | Base class for panels that contain only one widget.
  SimpleRadioButton | A simple radio button widget, with no label.
  SplitLayoutPanel | A panel that adds user-positioned splitters between each of its child widgets.
  SplitPanel | Deprecated. Use `SplitLayoutPanel` instead, but understand that it is not a drop in replacement for this class.
  StackLayoutPanel | A panel that stacks its children vertically, displaying only one at a time, with a header for each child which the user can click to display.
  StackPanel | A panel that stacks its children vertically, displaying only one at a time, with a header for each child which the user can click to display.
  SubmitButton | A standard push-button widget which will automatically submit its enclosing `FormPanel` if any.
  SuggestBox | A `SuggestBox` is a text box or text area which displays a pre-configured set of selections that match the user's input.
  SuggestBox.DefaultSuggestionDisplay | The default implementation of `SuggestBox.SuggestionDisplay` displays suggestions in a `PopupPanel` beneath the `SuggestBox`.
  SuggestBox.SuggestionDisplay | Used to display suggestions to the user.
  SuggestionEvent | Event object containing information about the selection of a `SuggestOracle.Suggestion` displayed by a `SuggestBox`.
  SuggestOracle | A `SuggestOracle` can be used to create suggestions associated with a specific query string.
  SuggestOracle.Request | A `SuggestOracle` request.
  SuggestOracle.Response | `SuggestOracle` response.
  TabBar | A horizontal bar of folder-style tabs, most commonly used as part of a `TabPanel`.
  TabLayoutPanel | A panel that represents a tabbed set of pages, each of which contains another widget.
  TableListenerCollection | Deprecated. Widgets should now manage their own handlers via `Widget.addDomHandler(H, com.google.gwt.event.dom.client.DomEvent.Type<H>)`
  TabListenerCollection | Deprecated. Widgets should now manage their own handlers via `Widget.addDomHandler(H, com.google.gwt.event.dom.client.DomEvent.Type<H>)`
  TabPanel | A panel that represents a tabbed set of pages, each of which contains another widget.
  TextArea | A text box that allows multiple lines of text to be entered.
  TextBox | A standard single-line text box.
  TextBoxBase | Abstract base class for most text entry widgets.
  TextBoxBase.TextAlignConstant | Deprecated. use `ValueBoxBase.setAlignment(ValueBoxBase.TextAlignment)`
  ToggleButton | A `ToggleButton` is a stylish stateful button which allows the user to toggle between `up` and `down` states.
  Tree | A standard hierarchical tree widget.
  Tree.ImageAdapter | There are several ways of configuring images for the Tree widget due to deprecated APIs.
  TreeItem | An item that can be contained within a `Tree`.
  TreeItem.TreeItemImpl | Deprecated.
  TreeListenerCollection | Deprecated. Widgets should now manage their own handlers via `Widget.addDomHandler(H, com.google.gwt.event.dom.client.DomEvent.Type<H>)`
  UIObject | The superclass for all user-interface objects.
  UIObject.DebugIdImpl | The implementation of the set debug id method, which does nothing by default.
  UIObject.DebugIdImplEnabled | The implementation of the setDebugId method, which sets the id of the `Element`s in this `UIObject`.
  ValueBox<T> | A text box able to parse its displayed value.
  ValueBoxBase<T> | Abstract base class for all text entry widgets.
  ValueLabel<T> | A label displaying its value through a renderer.
  ValueListBox<T> | Implementation of `HasConstrainedValue` based on a `SelectElement`.
  ValuePicker<T> | Allows the user to pick a single value from a list.
  VerticalPanel | A panel that lays all of its widgets out in a single vertical column.
  VerticalSplitPanel | Deprecated. Use `SplitLayoutPanel` instead, but understand that it is not a drop in replacement for this class.
  Widget | The base class for the majority of user-interface objects.
  WidgetCollection | A simple collection of widgets to be used by `panels` and `composites`.
  WidgetIterators | A collection of convenience factories for creating iterators for widgets.

- Enum Summary
  Enum | Description
  --- | ---
  DockLayoutPanel.Direction | Used in `DockLayoutPanel.addEast(Widget, double)` et al to specify the direction in which a child widget will be added.
  PopupPanel.AnimationType | The type of animation to use when opening the popup.
  ValueBoxBase.TextAlignment | Alignment values for `ValueBoxBase.setAlignment(com.google.gwt.user.client.ui.ValueBoxBase.TextAlignment)`.

- Exception Summary
  Exception | Description
  --- | ---
  AttachDetachException | An exception that is thrown when the panel fails to attach or detach its children.

- Annotation Types Summary
  Annotation Type | Description
  --- | ---
  ImageBundle.Resource | Explicitly specifies a file name or path to the image resource to be associated with a method in an `ImageBundle`.