Class ListBox

public class ListBox
extends FocusWidget
implements SourcesChangeEvents
A widget that presents a list of choices to the user, either as a list box or as a drop-down list.

CSS Style Rules

Example

public class ListBoxExample implements EntryPoint {

  public void onModuleLoad() {
    // Make a new list box, adding a few items to it.
    ListBox lb = new ListBox();
    lb.addItem("foo");
    lb.addItem("bar");
    lb.addItem("baz");
    lb.addItem("toto");
    lb.addItem("tintin");

    // Make enough room for all five items (setting this value to 1 turns it
    // into a drop-down list).
    lb.setVisibleItemCount(5);

    // Add it to the root panel.
    RootPanel.get().add(lb);
  }
}

Constructors

ListBox()Creates an empty list box.

Methods

addChangeListener(ChangeListener)Adds a listener interface to receive change events.
addItem(String)Adds an item to the list box.
clear()Removes all items from the list box.
getItemCount()Gets the number of items present in the list box.
getItemText(int)Gets the text associated with the item at the specified index.
getSelectedIndex()Gets the currently-selected item.
getVisibleItemCount()Gets the number of items that are visible.
insertItem(String, int)Inserts an item into the list box.
isItemSelected(int)Determines whether an individual list item is selected.
isMultipleSelect()Gets whether this list allows multiple selection.
onBrowserEvent(Event)
removeChangeListener(ChangeListener)Removes a previously added listener interface.
removeItem(int)Removes the item at the specified index.
setMultipleSelect(boolean)Sets whether this list allows multiple selections
setSelectedIndex(int)Sets the currently selected index.
setVisibleItemCount(int)Sets the number of items that are visible.

Constructor Detail

ListBox

public ListBox()
Creates an empty list box.

Method Detail

addChangeListener

public void addChangeListener(ChangeListener listener)
Adds a listener interface to receive change events.

Parameters

listener
the listener interface to add

addItem

public void addItem(String item)
Adds an item to the list box.

Parameters

item
the text of the item to be added

clear

public void clear()
Removes all items from the list box.

getItemCount

public int getItemCount()
Gets the number of items present in the list box.

Return Value

the number of items

getItemText

public String getItemText(int index)
Gets the text associated with the item at the specified index.

Parameters

index
the index of the item whose text is to be retrieved

Return Value

the text associated with the item

getSelectedIndex

public int getSelectedIndex()
Gets the currently-selected item. If multiple items are selected, this method will return the first selected item (isItemSelected(int) can be used to query individual items).

Return Value

the selected index, or -1 if none is selected

getVisibleItemCount

public int getVisibleItemCount()
Gets the number of items that are visible. If only one item is visible, then the box will be displayed as a drop-down list.

Return Value

the visible item count

insertItem

public void insertItem(String item, int idx)
Inserts an item into the list box.

Parameters

item
the text of the item to be inserted
idx
the index at which to insert it

isItemSelected

public boolean isItemSelected(int itemIndex)
Determines whether an individual list item is selected.

Parameters

itemIndex
the index of the item to be tested

Return Value

true if the item is selected

isMultipleSelect

public boolean isMultipleSelect()
Gets whether this list allows multiple selection.

Return Value

true if multiple selection is allowed

onBrowserEvent

public void onBrowserEvent(Event event)

Parameters

event

removeChangeListener

public void removeChangeListener(ChangeListener listener)
Removes a previously added listener interface.

Parameters

listener
the listener interface to remove

removeItem

public void removeItem(int idx)
Removes the item at the specified index.

Parameters

idx
the index of the item to be removed

setMultipleSelect

public void setMultipleSelect(boolean multiple)
Sets whether this list allows multiple selections

Parameters

multiple
true to allow multiple selections

setSelectedIndex

public void setSelectedIndex(int index)
Sets the currently selected index.

Parameters

index
the index of the item to be selected

setVisibleItemCount

public void setVisibleItemCount(int visibleItems)
Sets the number of items that are visible. If only one item is visible, then the box will be displayed as a drop-down list.

Parameters

visibleItems
the visible item count