Package 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.HasWidgets

HasWidgets.ForIsWidget

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

IndexedPanel.ForIsWidget

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

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

Method Summary

Modifier and Type	Method	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.IndexedPanel

getWidget, getWidgetCount, getWidgetIndex, remove

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

getWidgetIndex

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

add

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