com.google.gwt.user.client.ui
Class ComplexPanel

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

All Implemented Interfaces:

HasHandlers, EventListener, HasWidgets, IndexedPanel, java.lang.Iterable<Widget>

Direct Known Subclasses:

AbsolutePanel, CellPanel, DeckPanel, DockLayoutPanel, FlowPanel, HTMLPanel, LayoutPanel, StackPanel

public abstract class ComplexPanel
extends Panel
implements IndexedPanel

Abstract base class for panels that can contain multiple child widgets.

Nested Class Summary

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

UIObject.DebugIdImpl, UIObject.DebugIdImplEnabled

Field Summary

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

DEBUG_ID_PREFIX

Constructor Summary

ComplexPanel()

Method Summary

Widget	getWidget(int index) Gets the child widget at the specified index.
int	getWidgetCount() Gets the number of child widgets in this panel.
int	getWidgetIndex(Widget child) Gets the index of the specified child widget.
java.util.Iterator<Widget>	iterator() Gets an iterator for the contained widgets.
boolean	remove(int index) Removes the widget at the specified index.
boolean	remove(Widget w) Removes a child widget.

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

add, clear

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

fireEvent, getLayoutData, getParent, isAttached, onBrowserEvent, removeFromParent, setLayoutData, sinkEvents

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

addStyleDependentName, addStyleName, ensureDebugId, ensureDebugId, getAbsoluteLeft, getAbsoluteTop, getElement, getOffsetHeight, getOffsetWidth, getStyleName, getStylePrimaryName, getTitle, isVisible, isVisible, removeStyleDependentName, removeStyleName, setHeight, setPixelSize, setSize, setStyleDependentName, setStyleName, setStyleName, setStylePrimaryName, setTitle, setVisible, setVisible, setWidth, toString, unsinkEvents

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

ComplexPanel

public ComplexPanel()

Method Detail

getWidget

public Widget getWidget(int index)

Description copied from interface: IndexedPanel

Gets the child widget at the specified index.

Specified by:

getWidget in interface IndexedPanel

Parameters:

index - the child widget's index

Returns:

the child widget

getWidgetCount

public int getWidgetCount()

Description copied from interface: IndexedPanel

Gets the number of child widgets in this panel.

Specified by:

getWidgetCount in interface IndexedPanel

Returns:

the number of children

getWidgetIndex

public int getWidgetIndex(Widget child)

Description copied from interface: IndexedPanel

Gets the index of the specified child widget.

Specified by:

getWidgetIndex in interface IndexedPanel

Parameters:

child - the widget to be found

Returns:

the widget's index, or -1 if it is not a child of this panel

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>

remove

public boolean remove(int index)

Description copied from interface: IndexedPanel

Removes the widget at the specified index.

Specified by:

remove in interface IndexedPanel

Parameters:

index - the index of the widget to be removed

Returns:

false if the widget is not present

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

Specified by:

remove in class Panel

Parameters:

w - the widget to be removed

Returns:

true if the child was present