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

java.lang.Object
  com.google.gwt.user.client.ui.WidgetCollection

All Implemented Interfaces:

java.lang.Iterable<Widget>

public class WidgetCollection
extends java.lang.Object
implements java.lang.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.

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.

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:

java.lang.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:

java.lang.IndexOutOfBoundsException - if beforeIndex is out of range

iterator

public java.util.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 java.lang.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:

java.lang.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:

java.util.NoSuchElementException - if the widget is not present

size

public int size()

Gets the number of widgets in this collection.

Returns:

the number of widgets