Java Doc for Choice.java in  » 6.0-JDK-Core » AWT » java » awt » Java Source Code / Java DocumentationJava Source Code and Java Documentation

The following code example produces a pop-up menu:

 Choice ColorChooser = new Choice();
 ColorChooser.add("Green");
 ColorChooser.add("Red");
 ColorChooser.add("Blue");
 

After this choice menu has been added to a panel, it appears as follows in its normal state:

In the picture, "Green" is the current choice. Pushing the mouse button down on the object causes a menu to appear with the current choice highlighted.

Some native platforms do not support arbitrary resizing of Choice components and the behavior of setSize()/getSize() is bound by such limitations. Native GUI Choice components' size are often bound by such attributes as font size and length of items contained within the Choice.

version:
   1.100 05/05/07
author:
   Sami Shaio
author:
   Arthur van Hoff
since:
   JDK1.0

This method is not called unless item events are enabled for this component.

Note that this method should be primarily used to initially select an item in this component.

Note that this method should be primarily used to initially select an item in this component.

By default, the first item added to the choice menu becomes the selected item, until a different selection is made by the user by calling one of the select methods.
exception:
  HeadlessException - if GraphicsEnvironment.isHeadless()returns true
See Also:   java.awt.GraphicsEnvironment.isHeadless
See Also:   Choice.select(int)
See Also:   Choice.select(java.lang.String)

Adds an item to this Choice menu.
Parameters:
  item - the item to be added
exception:
  NullPointerException - if the item's value is equal tonull

Refer to AWT Threading Issues for details on AWT's threading model.
Parameters:
  l - the item listener
See Also:   Choice.removeItemListener
See Also:   Choice.getItemListeners
See Also:   Choice.select
See Also:   java.awt.event.ItemEvent
See Also:   java.awt.event.ItemListener
since:
   JDK1.1

You can specify the listenerType argument with a class literal, such as FooListener.class. For example, you can query a Choice c for its item listeners with the following code:

ItemListener[] ils = (ItemListener[])(c.getListeners(ItemListener.class));

If the item is the first one being added to the choice, then the item becomes selected. Otherwise, if the selected item was one of the items shifted, the first item in the choice becomes the selected item. If the selected item was no among those shifted, it remains the selected item.
Parameters:
  item - the non-null item to be inserted
Parameters:
  index - the position at which the item should be inserted
exception:
  IllegalArgumentException - if index is less than 0

Note that if the event parameter is null the behavior is unspecified and may result in an exception.
Parameters:
  e - the event
See Also:   java.awt.event.ItemEvent
See Also:   Choice.processItemEvent
since:
   JDK1.1

This method is not called unless item events are enabled for this component. Item events are enabled when one of the following occurs:

• An ItemListener object is registered via addItemListener.
• Item events are enabled via enableEvents.

Note that if the event parameter is null the behavior is unspecified and may result in an exception.
Parameters:
  e - the item event
See Also:   java.awt.event.ItemEvent
See Also:   java.awt.event.ItemListener
See Also:   Choice.addItemListener(ItemListener)
See Also:   java.awt.Component.enableEvents
since:
   JDK1.1

Refer to AWT Threading Issues for details on AWT's threading model.
Parameters:
  l - the item listener
See Also:   Choice.addItemListener
See Also:   Choice.getItemListeners
See Also:   java.awt.event.ItemEvent
See Also:   java.awt.event.ItemListener
since:
   JDK1.1

Note that this method should be primarily used to initially select an item in this component. Programmatically calling this method will not trigger an ItemEvent. The only way to trigger an ItemEvent is by user interaction.
Parameters:
  pos - the positon of the selected item
exception:
  IllegalArgumentException - if the specifiedposition is greater than thenumber of items or less than zero
See Also:   Choice.getSelectedItem
See Also:   Choice.getSelectedIndex

Note that this method should be primarily used to initially select an item in this component. Programmatically calling this method will not trigger an ItemEvent. The only way to trigger an ItemEvent is by user interaction.
Parameters:
  str - the specified string
See Also:   Choice.getSelectedItem
See Also:   Choice.getSelectedIndex