java.awt.event
Class FocusEvent

java.lang.Object sample code for java.lang.Object definition code for java.lang.Object 
  extended by java.util.EventObject sample code for java.util.EventObject definition code for java.util.EventObject 
      extended by java.awt.AWTEvent sample code for java.awt.AWTEvent definition code for java.awt.AWTEvent 
          extended by java.awt.event.ComponentEvent sample code for java.awt.event.ComponentEvent definition code for java.awt.event.ComponentEvent 
              extended by java.awt.event.FocusEvent
All Implemented Interfaces:
Serializable sample code for java.io.Serializable definition code for java.io.Serializable

public class FocusEvent
extends ComponentEvent sample code for java.awt.event.ComponentEvent definition code for java.awt.event.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 sample code for java.awt.event.FocusAdapter definition code for java.awt.event.FocusAdapter , FocusListener sample code for java.awt.event.FocusListener definition code for java.awt.event.FocusListener , Tutorial: Writing a Focus Listener, Reference: The Java Class Libraries (update file), Serialized Form

Field Summary
static int FOCUS_FIRST sample code for java.awt.event.FocusEvent.FOCUS_FIRST definition code for java.awt.event.FocusEvent.FOCUS_FIRST
          The first number in the range of ids used for focus events.
static int FOCUS_GAINED sample code for java.awt.event.FocusEvent.FOCUS_GAINED definition code for java.awt.event.FocusEvent.FOCUS_GAINED
          This event indicates that the Component is now the focus owner.
static int FOCUS_LAST sample code for java.awt.event.FocusEvent.FOCUS_LAST definition code for java.awt.event.FocusEvent.FOCUS_LAST
          The last number in the range of ids used for focus events.
static int FOCUS_LOST sample code for java.awt.event.FocusEvent.FOCUS_LOST definition code for java.awt.event.FocusEvent.FOCUS_LOST
          This event indicates that the Component is no longer the focus owner.
 
Fields inherited from class java.awt.event.ComponentEvent sample code for java.awt.event.ComponentEvent definition code for java.awt.event.ComponentEvent
COMPONENT_FIRST sample code for java.awt.event.ComponentEvent.COMPONENT_FIRST definition code for java.awt.event.ComponentEvent.COMPONENT_FIRST , COMPONENT_HIDDEN sample code for java.awt.event.ComponentEvent.COMPONENT_HIDDEN definition code for java.awt.event.ComponentEvent.COMPONENT_HIDDEN , COMPONENT_LAST sample code for java.awt.event.ComponentEvent.COMPONENT_LAST definition code for java.awt.event.ComponentEvent.COMPONENT_LAST , COMPONENT_MOVED sample code for java.awt.event.ComponentEvent.COMPONENT_MOVED definition code for java.awt.event.ComponentEvent.COMPONENT_MOVED , COMPONENT_RESIZED sample code for java.awt.event.ComponentEvent.COMPONENT_RESIZED definition code for java.awt.event.ComponentEvent.COMPONENT_RESIZED , COMPONENT_SHOWN sample code for java.awt.event.ComponentEvent.COMPONENT_SHOWN definition code for java.awt.event.ComponentEvent.COMPONENT_SHOWN
 
Fields inherited from class java.awt.AWTEvent sample code for java.awt.AWTEvent definition code for java.awt.AWTEvent
ACTION_EVENT_MASK sample code for java.awt.AWTEvent.ACTION_EVENT_MASK definition code for java.awt.AWTEvent.ACTION_EVENT_MASK , ADJUSTMENT_EVENT_MASK sample code for java.awt.AWTEvent.ADJUSTMENT_EVENT_MASK definition code for java.awt.AWTEvent.ADJUSTMENT_EVENT_MASK , COMPONENT_EVENT_MASK sample code for java.awt.AWTEvent.COMPONENT_EVENT_MASK definition code for java.awt.AWTEvent.COMPONENT_EVENT_MASK , consumed sample code for java.awt.AWTEvent.consumed definition code for java.awt.AWTEvent.consumed , CONTAINER_EVENT_MASK sample code for java.awt.AWTEvent.CONTAINER_EVENT_MASK definition code for java.awt.AWTEvent.CONTAINER_EVENT_MASK , FOCUS_EVENT_MASK sample code for java.awt.AWTEvent.FOCUS_EVENT_MASK definition code for java.awt.AWTEvent.FOCUS_EVENT_MASK , HIERARCHY_BOUNDS_EVENT_MASK sample code for java.awt.AWTEvent.HIERARCHY_BOUNDS_EVENT_MASK definition code for java.awt.AWTEvent.HIERARCHY_BOUNDS_EVENT_MASK , HIERARCHY_EVENT_MASK sample code for java.awt.AWTEvent.HIERARCHY_EVENT_MASK definition code for java.awt.AWTEvent.HIERARCHY_EVENT_MASK , id sample code for java.awt.AWTEvent.id definition code for java.awt.AWTEvent.id , INPUT_METHOD_EVENT_MASK sample code for java.awt.AWTEvent.INPUT_METHOD_EVENT_MASK definition code for java.awt.AWTEvent.INPUT_METHOD_EVENT_MASK , INVOCATION_EVENT_MASK sample code for java.awt.AWTEvent.INVOCATION_EVENT_MASK definition code for java.awt.AWTEvent.INVOCATION_EVENT_MASK , ITEM_EVENT_MASK sample code for java.awt.AWTEvent.ITEM_EVENT_MASK definition code for java.awt.AWTEvent.ITEM_EVENT_MASK , KEY_EVENT_MASK sample code for java.awt.AWTEvent.KEY_EVENT_MASK definition code for java.awt.AWTEvent.KEY_EVENT_MASK , MOUSE_EVENT_MASK sample code for java.awt.AWTEvent.MOUSE_EVENT_MASK definition code for java.awt.AWTEvent.MOUSE_EVENT_MASK , MOUSE_MOTION_EVENT_MASK sample code for java.awt.AWTEvent.MOUSE_MOTION_EVENT_MASK definition code for java.awt.AWTEvent.MOUSE_MOTION_EVENT_MASK , MOUSE_WHEEL_EVENT_MASK sample code for java.awt.AWTEvent.MOUSE_WHEEL_EVENT_MASK definition code for java.awt.AWTEvent.MOUSE_WHEEL_EVENT_MASK , PAINT_EVENT_MASK sample code for java.awt.AWTEvent.PAINT_EVENT_MASK definition code for java.awt.AWTEvent.PAINT_EVENT_MASK , RESERVED_ID_MAX sample code for java.awt.AWTEvent.RESERVED_ID_MAX definition code for java.awt.AWTEvent.RESERVED_ID_MAX , TEXT_EVENT_MASK sample code for java.awt.AWTEvent.TEXT_EVENT_MASK definition code for java.awt.AWTEvent.TEXT_EVENT_MASK , WINDOW_EVENT_MASK sample code for java.awt.AWTEvent.WINDOW_EVENT_MASK definition code for java.awt.AWTEvent.WINDOW_EVENT_MASK , WINDOW_FOCUS_EVENT_MASK sample code for java.awt.AWTEvent.WINDOW_FOCUS_EVENT_MASK definition code for java.awt.AWTEvent.WINDOW_FOCUS_EVENT_MASK , WINDOW_STATE_EVENT_MASK sample code for java.awt.AWTEvent.WINDOW_STATE_EVENT_MASK definition code for java.awt.AWTEvent.WINDOW_STATE_EVENT_MASK
 
Fields inherited from class java.util.EventObject sample code for java.util.EventObject definition code for java.util.EventObject
source sample code for java.util.EventObject.source definition code for java.util.EventObject.source
 
Constructor Summary
FocusEvent sample code for java.awt.event.FocusEvent.FocusEvent(java.awt.Component, int) definition code for java.awt.event.FocusEvent.FocusEvent(java.awt.Component, int) (Component sample code for java.awt.Component definition code for java.awt.Component  source, int id)
          Constructs a FocusEvent object and identifies it as a permanent change in focus.
FocusEvent sample code for java.awt.event.FocusEvent.FocusEvent(java.awt.Component, int, boolean) definition code for java.awt.event.FocusEvent.FocusEvent(java.awt.Component, int, boolean) (Component sample code for java.awt.Component definition code for java.awt.Component  source, int id, boolean temporary)
          Constructs a FocusEvent object and identifies whether or not the change is temporary.
FocusEvent sample code for java.awt.event.FocusEvent.FocusEvent(java.awt.Component, int, boolean, java.awt.Component) definition code for java.awt.event.FocusEvent.FocusEvent(java.awt.Component, int, boolean, java.awt.Component) (Component sample code for java.awt.Component definition code for java.awt.Component  source, int id, boolean temporary, Component sample code for java.awt.Component definition code for java.awt.Component  opposite)
          Constructs a FocusEvent object with the specified temporary state and opposite Component.
 
Method Summary
 Component sample code for java.awt.Component definition code for java.awt.Component getOppositeComponent sample code for java.awt.event.FocusEvent.getOppositeComponent() definition code for java.awt.event.FocusEvent.getOppositeComponent() ()
          Returns the other Component involved in this focus change.
 boolean isTemporary sample code for java.awt.event.FocusEvent.isTemporary() definition code for java.awt.event.FocusEvent.isTemporary() ()
          Identifies the focus change event as temporary or permanent.
 String sample code for java.lang.String definition code for java.lang.String paramString sample code for java.awt.event.FocusEvent.paramString() definition code for java.awt.event.FocusEvent.paramString() ()
          Returns a parameter string identifying this event.
 
Methods inherited from class java.awt.event.ComponentEvent sample code for java.awt.event.ComponentEvent definition code for java.awt.event.ComponentEvent
getComponent sample code for java.awt.event.ComponentEvent.getComponent() definition code for java.awt.event.ComponentEvent.getComponent()
 
Methods inherited from class java.awt.AWTEvent sample code for java.awt.AWTEvent definition code for java.awt.AWTEvent
consume sample code for java.awt.AWTEvent.consume() definition code for java.awt.AWTEvent.consume() , getID sample code for java.awt.AWTEvent.getID() definition code for java.awt.AWTEvent.getID() , isConsumed sample code for java.awt.AWTEvent.isConsumed() definition code for java.awt.AWTEvent.isConsumed() , setSource sample code for java.awt.AWTEvent.setSource(java.lang.Object) definition code for java.awt.AWTEvent.setSource(java.lang.Object) , toString sample code for java.awt.AWTEvent.toString() definition code for java.awt.AWTEvent.toString()
 
Methods inherited from class java.util.EventObject sample code for java.util.EventObject definition code for java.util.EventObject
getSource sample code for java.util.EventObject.getSource() definition code for java.util.EventObject.getSource()
 
Methods inherited from class java.lang.Object sample code for java.lang.Object definition code for java.lang.Object
clone sample code for java.lang.Object.clone() definition code for java.lang.Object.clone() , equals sample code for java.lang.Object.equals(java.lang.Object) definition code for java.lang.Object.equals(java.lang.Object) , finalize sample code for java.lang.Object.finalize() definition code for java.lang.Object.finalize() , getClass sample code for java.lang.Object.getClass() definition code for java.lang.Object.getClass() , hashCode sample code for java.lang.Object.hashCode() definition code for java.lang.Object.hashCode() , notify sample code for java.lang.Object.notify() definition code for java.lang.Object.notify() , notifyAll sample code for java.lang.Object.notifyAll() definition code for java.lang.Object.notifyAll() , wait sample code for java.lang.Object.wait() definition code for java.lang.Object.wait() , wait sample code for java.lang.Object.wait(long) definition code for java.lang.Object.wait(long) , wait sample code for java.lang.Object.wait(long, int) definition code for java.lang.Object.wait(long, int)
 

Field Detail

FOCUS_FIRST sample code for java.awt.event.FocusEvent.FOCUS_FIRST

public static final int FOCUS_FIRST
The first number in the range of ids used for focus events.

See Also:
Constant Field Values

FOCUS_LAST sample code for java.awt.event.FocusEvent.FOCUS_LAST

public static final int FOCUS_LAST
The last number in the range of ids used for focus events.

See Also:
Constant Field Values

FOCUS_GAINED sample code for java.awt.event.FocusEvent.FOCUS_GAINED

public static final int FOCUS_GAINED
This event indicates that the Component is now the focus owner.

See Also:
Constant Field Values

FOCUS_LOST sample code for java.awt.event.FocusEvent.FOCUS_LOST

public static final int FOCUS_LOST
This event indicates that the Component is no longer the focus owner.

See Also:
Constant Field Values
Constructor Detail

FocusEvent sample code for java.awt.event.FocusEvent(java.awt.Component, int, boolean, java.awt.Component) definition code for java.awt.event.FocusEvent(java.awt.Component, int, boolean, java.awt.Component)

public FocusEvent(Component sample code for java.awt.Component definition code for java.awt.Component  source,
                  int id,
                  boolean temporary,
                  Component sample code for java.awt.Component definition code for java.awt.Component  opposite)
Constructs a FocusEvent object with the specified temporary state and opposite Component. The opposite Component is the other Component involved in this focus change. For a FOCUS_GAINED event, this is the Component that lost focus. For a FOCUS_LOST event, this is the Component that gained focus. If this focus change occurs with a native application, with a Java application in a different VM, or with no other Component, then the opposite Component is null.

Note that passing in an invalid id results in unspecified behavior. This method throws an IllegalArgumentException if source is null.

Parameters:
source - the Component that originated the event
id - FOCUS_GAINED or FOCUS_LOST
temporary - true if the focus change is temporary; false otherwise
opposite - the other Component involved in the focus change, or null
Throws:
IllegalArgumentException sample code for java.lang.IllegalArgumentException definition code for java.lang.IllegalArgumentException - if source is null

FocusEvent sample code for java.awt.event.FocusEvent(java.awt.Component, int, boolean) definition code for java.awt.event.FocusEvent(java.awt.Component, int, boolean)

public FocusEvent(Component sample code for java.awt.Component definition code for java.awt.Component  source,
                  int id,
                  boolean temporary)
Constructs a FocusEvent object and identifies whether or not the change is temporary.

Note that passing in an invalid id results in unspecified behavior. This method throws an IllegalArgumentException if source is null.

Parameters:
source - the Component that originated the event
id - an integer indicating the type of event
temporary - true if the focus change is temporary; false otherwise
Throws:
IllegalArgumentException sample code for java.lang.IllegalArgumentException definition code for java.lang.IllegalArgumentException - if source is null

FocusEvent sample code for java.awt.event.FocusEvent(java.awt.Component, int) definition code for java.awt.event.FocusEvent(java.awt.Component, int)

public FocusEvent(Component sample code for java.awt.Component definition code for java.awt.Component  source,
                  int id)
Constructs a FocusEvent object and identifies it as a permanent change in focus.

Note that passing in an invalid id results in unspecified behavior. This method throws an IllegalArgumentException if source is null.

Parameters:
source - the Component that originated the event
id - an integer indicating the type of event
Throws:
IllegalArgumentException sample code for java.lang.IllegalArgumentException definition code for java.lang.IllegalArgumentException - if source is null
Method Detail

isTemporary sample code for java.awt.event.FocusEvent.isTemporary() definition code for java.awt.event.FocusEvent.isTemporary()

public boolean isTemporary()
Identifies the focus change event as temporary or permanent.

Returns:
true if the focus change is temporary; false otherwise

getOppositeComponent sample code for java.awt.event.FocusEvent.getOppositeComponent() definition code for java.awt.event.FocusEvent.getOppositeComponent()

public Component sample code for java.awt.Component definition code for java.awt.Component  getOppositeComponent()
Returns the other Component involved in this focus change. For a FOCUS_GAINED event, this is the Component that lost focus. For a FOCUS_LOST event, this is the Component that gained focus. If this focus change occurs with a native application, with a Java application in a different VM or context, or with no other Component, then null is returned.

Returns:
the other Component involved in the focus change, or null
Since:
1.4

paramString sample code for java.awt.event.FocusEvent.paramString() definition code for java.awt.event.FocusEvent.paramString()

public String sample code for java.lang.String definition code for java.lang.String  paramString()
Returns a parameter string identifying this event. This method is useful for event-logging and for debugging.

Overrides:
paramString sample code for java.awt.event.ComponentEvent.paramString() definition code for java.awt.event.ComponentEvent.paramString() in class ComponentEvent sample code for java.awt.event.ComponentEvent definition code for java.awt.event.ComponentEvent
Returns:
a string identifying the event and its attributes