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.

DeckPanel

public DeckPanel()

Creates an empty deck panel.

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