java.awt.event
Class FocusEventjava.lang.Object | +--java.util.EventObject | +--java.awt.AWTEvent | +--java.awt.event.ComponentEvent | +--java.awt.event.FocusEvent
- All Implemented Interfaces:
- Serializable
- public class FocusEvent
- extends ComponentEvent
A low-level event which indicates that a Component has gained or lost the input focus. This low-level event is generated by a Component (such as a TextField). The event is passed to every FocusListener or FocusAdapter object which registered to receive such events using the Component's addFocusListener method. ( FocusAdapter objects implement the FocusListener interface.) Each such listener object gets this FocusEvent when the event occurs.
There are two levels of focus events: permanent and temporary. Permanent focus change events occur when focus is directly moved from one Component to another, such as through a call to requestFocus() or as the user uses the TAB key to traverse Components. Temporary focus change events occur when focus is temporarily lost for a Component as the indirect result of another operation, such as Window deactivation or a Scrollbar drag. In this case, the original focus state will automatically be restored once that operation is finished, or, for the case of Window deactivation, when the Window is reactivated. Both permanent and temporary focus events are delivered using the FOCUS_GAINED and FOCUS_LOST event ids; the level may be distinguished in the event using the isTemporary() method.
- Since:
- 1.1
- See Also:
- FocusAdapter, FocusListener, Tutorial: Writing a Focus Listener, Reference: The Java Class Libraries (update file), Serialized Form
Field Summary
static int FOCUS_FIRST
The first number in the range of ids used for focus events.static int FOCUS_GAINED
This event indicates that the Component is now the focus owner.static int FOCUS_LAST
The last number in the range of ids used for focus events.static int FOCUS_LOST
This event indicates that the Component is no longer the focus owner.
Fields inherited from class java.awt.event.ComponentEvent COMPONENT_FIRST, COMPONENT_HIDDEN, COMPONENT_LAST, COMPONENT_MOVED, COMPONENT_RESIZED, COMPONENT_SHOWN