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

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

All Implemented Interfaces:

EventListener, HasWidgets

Direct Known Subclasses:

ComplexPanel, HTMLTable, SimplePanel

public abstract class Panel

extends Widget

implements HasWidgets

Abstract base class for all panels, which are widgets that can contain other widgets.

Field Summary

Fields inherited from class java.lang.Object

typeId, typeName

Constructor Summary

Panel()

Method Summary

abstract boolean	add(Widget w) Adds a new child widget to the panel.
protected void	adopt(Widget w) This method must be called as part of the add method of any panel.
abstract void	clear() Removes all widgets from this panel.
protected void	disown(Widget w) This method must be called whenever a Widget is removed.
protected void	onAttach() This method is called when a widget is attached to the browser's document.
protected void	onDetach() This method is called when a widget is detached from the browser's document.
abstract boolean	remove(Widget w) Removes a widget from the panel.

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

getParent, isAttached, onBrowserEvent, onLoad

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

addStyleName, getAbsoluteLeft, getAbsoluteTop, getElement, getOffsetHeight, getOffsetWidth, getStyleName, isVisible, isVisible, removeStyleName, setElement, setHeight, setPixelSize, setSize, setStyleName, setStyleName, setVisible, setVisible, setWidth, sinkEvents, toString, unsinkEvents

Methods inherited from class java.lang.Object

equals, finalize, hashCode

Methods inherited from interface com.google.gwt.user.client.ui.HasWidgets

iterator

Constructor Detail

Panel

public Panel()

Method Detail

add

public abstract boolean add(Widget w)

Adds a new child widget to the panel.

Parameters:

w - the child widget to be added

Returns:

true on success (some panels place restrictions on how children may be added or inserted)

clear

public abstract void clear()

Removes all widgets from this panel.

disown

protected void disown(Widget w)

This method must be called whenever a Widget is removed. It ensures that the Widget's parent is cleared.

adopt

protected void adopt(Widget w)

This method must be called as part of the add method of any panel. It ensures that the Widget's parent is set properly.

remove

public abstract boolean remove(Widget w)

Removes a widget from the panel.

Parameters:

w - the widget to be removed

Returns:

true if the widget was present

onAttach

protected final void onAttach()

Description copied from class: Widget

This method is called when a widget is attached to the browser's document. It must not be overridden, except by Panel. To receive notification when a widget is attached to the document, override the Widget.onLoad() method.

Overrides:

onAttach in class Widget

onDetach

protected final void onDetach()

Description copied from class: Widget

This method is called when a widget is detached from the browser's document. It must not be overridden, except by Panel.

Overrides:

onDetach in class Widget