com.google.gwt.user.client.ui

## Class DeckPanel

- java.lang.Object
- - com.google.gwt.user.client.ui.UIObject
  - - com.google.gwt.user.client.ui.Widget
    - - com.google.gwt.user.client.ui.Panel
      - - com.google.gwt.user.client.ui.ComplexPanel
        - - com.google.gwt.user.client.ui.DeckPanel

- All Implemented Interfaces:
    HasAttachHandlers, HasHandlers, EventListener, HasAnimation, HasVisibility, HasWidgets, HasWidgets.ForIsWidget, IndexedPanel, IndexedPanel.ForIsWidget, InsertPanel, InsertPanel.ForIsWidget, IsWidget, java.lang.Iterable<Widget>

      public class DeckPanel
      extends ComplexPanel
      implements HasAnimation, InsertPanel.ForIsWidget

  A panel that displays all of its child widgets in a 'deck', where only one can be visible at a time. It is used by `TabPanel`.

  Once a widget has been added to a DeckPanel, its visibility, width, and height attributes will be manipulated. When the widget is removed from the DeckPanel, it will be visible, and its width and height attributes will be cleared.

- - ### Nested Class Summary

    - ### 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.InsertPanel

      `InsertPanel.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
    `DeckPanel()` Creates an empty deck panel.

  - ### Method Summary

    All Methods Instance Methods Concrete Methods
    Modifier and Type | Method and Description
    --- | ---
    `void` | `add(Widget w)` Adds a child widget.
    `int` | `getVisibleWidget()` Gets the index of the currently-visible widget, if any.
    `void` | `insert(IsWidget w, int beforeIndex)`
    `void` | `insert(Widget w, int beforeIndex)` Inserts a child widget before the specified index.
    `boolean` | `isAnimationEnabled()` Returns true if animations are enabled, false if not.
    `boolean` | `remove(Widget w)` Removes a child widget.
    `void` | `setAnimationEnabled(boolean enable)` Enable or disable animations.
    `void` | `showWidget(int index)` Shows the widget at the specified index.

    - ### Methods inherited from class com.google.gwt.user.client.ui.ComplexPanel

      `add, add, adjustIndex, checkIndexBoundsForAccess, checkIndexBoundsForInsertion, doLogicalClear, getChildren, getWidget, getWidgetCount, getWidgetIndex, getWidgetIndex, insert, insert, iterator, remove`

    - ### Methods inherited from class com.google.gwt.user.client.ui.Panel

      `add, adopt, clear, doAttachChildren, doDetachChildren, orphan, remove`

    - ### 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, onBrowserEvent, onDetach, onLoad, onUnload, removeFromParent, replaceElement, setLayoutData, setParent, sinkEvents, unsinkEvents`

    - ### 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, onEnsureDebugId, removeStyleDependentName, removeStyleName, resolvePotentialElement, setElement, setElement, setHeight, setPixelSize, setSize, setStyleDependentName, setStyleName, setStyleName, setStyleName, setStyleName, setStylePrimaryName, setStylePrimaryName, setTitle, setVisible, setVisible, setWidth, sinkBitlessEvent, toString`

    - ### Methods inherited from class java.lang.Object

      `clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait`

    - ### Methods inherited from interface com.google.gwt.user.client.ui.InsertPanel.ForIsWidget

      `add`

    - ### Methods inherited from interface com.google.gwt.user.client.ui.IndexedPanel.ForIsWidget

      `getWidgetIndex`

    - ### Methods inherited from interface com.google.gwt.user.client.ui.IndexedPanel

      `getWidget, getWidgetCount, getWidgetIndex, remove`

    - ### Methods inherited from interface java.lang.Iterable

      `forEach, spliterator`

- - ### Constructor Detail

    - #### DeckPanel

          public DeckPanel()

      Creates an empty deck panel.

  - ### Method Detail

    - #### add

          public void add(Widget w)

      Description copied from class: `Panel`
      Adds a child widget.

      How to Override this Method

      There are several important things that must take place in the correct order to properly add or insert a Widget to a Panel. Not all of these steps will be relevant to every Panel, but all of the steps must be considered.

      1. Validate: Perform any sanity checks to ensure the Panel can accept a new Widget. Examples: checking for a valid index on insertion; checking that the Panel is not full if there is a max capacity.
      2. Adjust for Reinsertion: Some Panels need to handle the case where the Widget is already a child of this Panel. Example: when performing a reinsert, the index might need to be adjusted to account for the Widget's removal. See `ComplexPanel.adjustIndex(Widget, int)`.
      3. Detach Child: Remove the Widget from its existing parent, if any. Most Panels will simply call `Widget.removeFromParent()` on the Widget.
      4. Logical Attach: Any state variables of the Panel should be updated to reflect the addition of the new Widget. Example: the Widget is added to the Panel's `WidgetCollection` at the appropriate index.
      5. Physical Attach: The Widget's Element must be physically attached to the Panel's Element, either directly or indirectly.
      6. Adopt: Call `Panel.adopt(Widget)` to finalize the add as the very last step.
      Specified by:
        `add` in interface `HasWidgets`
      Specified by:
        `add` in interface `InsertPanel`
      Overrides:
        `add` in class `Panel`
      Parameters:
        `w` - the widget to be added
      See Also:
        `HasWidgets.add(Widget)`

    - #### getVisibleWidget

          public int getVisibleWidget()

      Gets the index of the currently-visible widget, if any.
      Returns:
        the visible widget's index, or -1 if there is no such widget

    - #### insert

          public void insert(IsWidget w,
                             int beforeIndex)

      Specified by:
        `insert` in interface `InsertPanel.ForIsWidget`

    - #### insert

          public void insert(Widget w,
                             int beforeIndex)

      Description copied from interface: `InsertPanel`
      Inserts a child widget before the specified index. If the widget is already a child of this panel, it will be moved to the specified index.
      Specified by:
        `insert` in interface `InsertPanel`
      Parameters:
        `w` - the child widget to be inserted
        `beforeIndex` - the index before which it will be inserted

    - #### isAnimationEnabled

          public boolean isAnimationEnabled()

      Description copied from interface: `HasAnimation`
      Returns true if animations are enabled, false if not.
      Specified by:
        `isAnimationEnabled` in interface `HasAnimation`

    - #### remove

          public boolean remove(Widget w)

      Description copied from class: `Panel`
      Removes a child widget.

      How to Override this Method

      There are several important things that must take place in the correct order to properly remove a Widget from a Panel. Not all of these steps will be relevant to every Panel, but all of the steps must be considered.

      1. Validate: Make sure this Panel is actually the parent of the child Widget; return `false` if it is not.
      2. Orphan: Call `Panel.orphan(Widget)` first while the child Widget is still attached.
      3. Physical Detach: Adjust the DOM to account for the removal of the child Widget. The Widget's Element must be physically removed from the DOM.
      4. Logical Detach: Update the Panel's state variables to reflect the removal of the child Widget. Example: the Widget is removed from the Panel's `WidgetCollection`.
      Specified by:
        `remove` in interface `HasWidgets`
      Overrides:
        `remove` in class `ComplexPanel`
      Parameters:
        `w` - the widget to be removed
      Returns:
        `true` if the child was present

    - #### 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

    - #### showWidget

          public void showWidget(int index)

      Shows the widget at the specified index. This causes the currently- visible widget to be hidden.
      Parameters:
        `index` - the index of the widget to be shown