Class Panel

public class Panel
extends Widget
implements HasWidgets

// Superclass of HTMLTable, SimplePanel, ComplexPanel
Abstract base class for all panels, which are widgets that can contain other widgets.

Methods

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

Return Value

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

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.

Parameters

w

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.

Parameters

w

onAttach

protected void onAttach()
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 onLoad method.

onDetach

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

remove

public abstract boolean remove(Widget w)
Removes a widget from the panel.

Parameters

w
the widget to be removed

Return Value

true if the widget was present