Choice

Name

Description

The Choice is a Component that provides a drop-down list of choices to choose from.

Class Definition

public class java.awt.Choice extends java.awt.Component implements java.awt.ItemSelectable {
 // Constructors public Choice(); // Instance Methods public synchronized void add (String item); public synchronized void addItem (String item);  public void addItemListener (ItemListener l); public void addNotify();
public int countItems();  public String getItem (int index);
public int getItemCount(); public int getSelectedIndex();
public synchronized String getSelectedItem();
public synchronized Object[] getSelectedObjects(); public synchronized void insert (String item, int index); public synchronized void remove (int position); public synchronized void remove (String item); public synchronized void removeAll(); public void removeItemListener (ItemListener l); public synchronized void select (int pos);
public synchronized void select (String str); // Protected Instance Methods protected String paramString(); protected void processEvent (AWTEvent e); protected void processItemEvent (ItemEvent e);
}

Constructors

Choice

public Choice()

• Description
• Constructs a Choice object.

Instance Methods

add

public synchronized void add (String item)

• Parameters
• • item
  • Text for new entry.
• Throws
• • NullPointerException
  • If item is null.
• Description
• Adds a new entry to the available choices.

addItem

public synchronized void addItem (String item)

• Parameters
• • item
  • Text for new entry.
• Throws
• • NullPointerException
  • If item is null.
• Description
• Replaced by add(String).

addItemListener

public void addItemListener (ItemListener l)

• Parameters
• • l
  • The listener to be added.
• Implements
• ItemSelectable.addItemListener(ItemListener l)
• Description
• Adds a listener for the ItemEvent objects this Choice generates.

addNotify

public void addNotify()

• Overrides
• Component.addNotify()
• Description
• Creates Choice's peer.

countItems

public int countItems()

• Returns
• Number of items in the Choice.
• Description
• Replaced by getItemCount().

getItem

public String getItem (int index)

• Parameters
• • index
  • Position of entry.
• Returns
• A string for an entry at a given position.
• Throws
• • ArrayIndexOutOfBoundsException
  • If index is invalid; indices start at zero.

getItemCount

public int getItemCount()

• Returns
• Number of items in the Choice.

getSelectedIndex

public int getSelectedIndex()

• Returns
• Position of currently selected entry.

getSelectedItem

public synchronized String getSelectedItem()

• Returns
• Currently selected entry as a String.

getSelectedObjects

public synchronized Object[] getSelectedObjects()

• Implements
• ItemSelectable.getSelectedObjects()
• Description
• A single-item array containing the current selection.

insert

public synchronized void insert (String item, int index)

• Parameters
• • item
  • The string to add.
  • index
  • The position for the new string.
• Throws
• • IllegalArgumentException
  • If index is less than zero.
• Description
• Inserts item in the given position.

remove

public synchronized void remove (int position)

• Parameters
• • position
  • The index of an entry in the Choice component.
• Description
• Removes the entry in the given position.

public synchronized void remove (String string)

• Parameters
• • string
  • Text of an entry within the Choice component.
• Throws
• • IllegalArgumentException
  • If string is not in the Choice.
• Description
• Makes the first entry that matches string the selected item.

removeAll

public synchronized void removeAll()

• Description
• Removes all the entries from the Choice.

removeItemListener

public void removeItemListener (ItemListener l)

• Parameters
• • l
  • The listener to be removed.
• Implements
• ItemSelectable.removeItemListener (ItemListener l)
• Description
• Removes the specified ItemListener so it will not receive ItemEvent objects from this Choice.

select

public synchronized void select (int pos)

• Parameters
• • pos
  • The index of an entry in the Choice component.
• Throws
• • IllegalArgumentException
  • If the position is not valid.
• Description
• Makes the entry in the given position.

public synchronized void select (String str)

• Parameters
• • str
  • Text of an entry within the Choice component.
• Description
• Makes the first entry that matches str the selected item for the Choice.

Protected Instance Methods

paramString

protected String paramString()

• Returns
• A string with current settings of Choice.
• Overrides
• Component.paramString()
• Description
• Helper method for toString() to generate string of current settings.

processEvent

protected void processEvent (AWTEvent e)

• Parameters
• • e
  • The event to process.
• Description
• Low level AWTEvents are passed to this method for processing.

processItemEvent

protected void processItemEvent (ItemEvent e)

• Parameters
• • e
  • The item event to process.
• Description
• Item events are passed to this method for processing. Normally, this method is called by processEvent().

See Also

Component, ItemSelectable, String