Package com.google.gwt.user.client.ui

Class WidgetCollection

java.lang.Object

com.google.gwt.user.client.ui.WidgetCollection

All Implemented Interfaces:

Iterable<Widget>

public class WidgetCollection
extends Object
implements Iterable<Widget>

A simple collection of widgets to be used by panels and composites.

The main purpose of this specialized collection is to implement Iterator.remove() in a way that delegates removal to its panel. This makes it much easier for the panel to implement an iterator that supports removal of widgets.

Constructor Summary

Constructors

Constructor	Description
WidgetCollection(HasWidgets parent)	Constructs a new widget collection.

Method Summary

Modifier and Type	Method	Description
void	add(Widget w)	Adds a widget to the end of this collection.
boolean	contains(Widget w)	Determines whether a given widget is contained in this collection.
Widget	get(int index)	Gets the widget at the given index.
int	indexOf(Widget w)	Gets the index of the specified index.
void	insert(Widget w, int beforeIndex)	Inserts a widget before the specified index.
Iterator<Widget>	iterator()	Gets an iterator on this widget collection.
void	remove(int index)	Removes the widget at the specified index.
void	remove(Widget w)	Removes the specified widget.
int	size()	Gets the number of widgets in this collection.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Constructor Details

WidgetCollection

public WidgetCollection(HasWidgets parent)

Constructs a new widget collection.

Parameters:

parent - the container whose HasWidgets.remove(Widget) will be delegated to by the iterator's Iterator.remove() method.

Method Details

add

public void add(Widget w)

Adds a widget to the end of this collection.

Parameters:

w - the widget to be added

contains

public boolean contains(Widget w)

Determines whether a given widget is contained in this collection.

Parameters:

w - the widget to be searched for

Returns:

true if the widget is present

get

public Widget get(int index)

Gets the widget at the given index.

Parameters:

index - the index to be retrieved

Returns:

the widget at the specified index

Throws:

IndexOutOfBoundsException - if the index is out of range

indexOf

public int indexOf(Widget w)

Gets the index of the specified index.

Parameters:

w - the widget to be found

Returns:

the index of the specified widget, or -1 if it is not found

insert

public void insert(Widget w,
 int beforeIndex)

Inserts a widget before the specified index.

Parameters:

w - the widget to be inserted

beforeIndex - the index before which the widget will be inserted

Throws:

IndexOutOfBoundsException - if beforeIndex is out of range

iterator

public Iterator<Widget> iterator()

Gets an iterator on this widget collection. This iterator is guaranteed to implement remove() in terms of its containing HasWidgets.

Specified by:

iterator in interface Iterable<Widget>

Returns:

an iterator

remove

public void remove(int index)

Removes the widget at the specified index.

Parameters:

index - the index of the widget to be removed

Throws:

IndexOutOfBoundsException - if index is out of range

remove

public void remove(Widget w)

Removes the specified widget.

Parameters:

w - the widget to be removed

Throws:

NoSuchElementException - if the widget is not present

size

public int size()

Gets the number of widgets in this collection.

Returns:

the number of widgets