java.awt.event

Class FocusEvent

Implemented Interfaces:
Serializable

public class FocusEvent
extends ComponentEvent

This class represents an event generated when a focus change occurs for a component. There are both temporary changes, such as when focus is stolen during a sroll then returned, and permanent changes, such as when the user TABs through focusable components.
Since:
1.1
See Also:
FocusAdapter, FocusListener, Serialized Form

Field Summary

static int
FOCUS_FIRST
This is the first id in the range of ids used by this class.
static int
FOCUS_GAINED
This is the event id for a focus gained event.
static int
FOCUS_LAST
This is the last id in the range of ids used by this class.
static int
FOCUS_LOST
This is the event id for a focus lost event.

Fields inherited from class java.awt.event.ComponentEvent

COMPONENT_FIRST, COMPONENT_HIDDEN, COMPONENT_LAST, COMPONENT_MOVED, COMPONENT_RESIZED, COMPONENT_SHOWN

Fields inherited from class java.awt.AWTEvent

ACTION_EVENT_MASK, ADJUSTMENT_EVENT_MASK, COMPONENT_EVENT_MASK, CONTAINER_EVENT_MASK, FOCUS_EVENT_MASK, HIERARCHY_BOUNDS_EVENT_MASK, HIERARCHY_EVENT_MASK, INPUT_METHOD_EVENT_MASK, INVOCATION_EVENT_MASK, ITEM_EVENT_MASK, KEY_EVENT_MASK, MOUSE_EVENT_MASK, MOUSE_MOTION_EVENT_MASK, MOUSE_WHEEL_EVENT_MASK, PAINT_EVENT_MASK, RESERVED_ID_MAX, TEXT_EVENT_MASK, WINDOW_EVENT_MASK, WINDOW_FOCUS_EVENT_MASK, WINDOW_STATE_EVENT_MASK, consumed, id

Fields inherited from class java.util.EventObject

source

Constructor Summary

FocusEvent(Component source, int id)
Initializes a new instance of FocusEvent with the specified source and id.
FocusEvent(Component source, int id, boolean temporary)
Initializes a new instance of FocusEvent with the specified source, id, and temporary status.
FocusEvent(Component source, int id, boolean temporary, Component opposite)
Initializes a new instance of FocusEvent with the specified source, id, temporary status, and opposite counterpart.

Method Summary

Component
getOppositeComponent()
Returns the component which received the opposite focus event.
boolean
isTemporary()
This method tests whether or not the focus change is temporary or permanent.
String
paramString()
Returns a string identifying this event.

Methods inherited from class java.awt.event.ComponentEvent

getComponent, paramString

Methods inherited from class java.awt.AWTEvent

consume, getID, isConsumed, paramString, setSource, toString

Methods inherited from class java.util.EventObject

getSource, toString

Methods inherited from class java.lang.Object

clone, equals, extends Object> getClass, finalize, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

FOCUS_FIRST

public static final int FOCUS_FIRST
This is the first id in the range of ids used by this class.
Field Value:
1004

FOCUS_GAINED

public static final int FOCUS_GAINED
This is the event id for a focus gained event.
Field Value:
1004

FOCUS_LAST

public static final int FOCUS_LAST
This is the last id in the range of ids used by this class.
Field Value:
1005

FOCUS_LOST

public static final int FOCUS_LOST
This is the event id for a focus lost event.
Field Value:
1005

Constructor Details

FocusEvent

public FocusEvent(Component source,
                  int id)
Initializes a new instance of FocusEvent with the specified source and id. Note that an invalid id leads to unspecified results.
Parameters:
source - the component that is gaining or losing focus
id - the event id
Throws:
IllegalArgumentException - if source is null

FocusEvent

public FocusEvent(Component source,
                  int id,
                  boolean temporary)
Initializes a new instance of FocusEvent with the specified source, id, and temporary status. Note that an invalid id leads to unspecified results.
Parameters:
source - the component that is gaining or losing focus
id - the event id
temporary - true if the focus change is temporary
Throws:
IllegalArgumentException - if source is null

FocusEvent

public FocusEvent(Component source,
                  int id,
                  boolean temporary,
                  Component opposite)
Initializes a new instance of FocusEvent with the specified source, id, temporary status, and opposite counterpart. Note that an invalid id leads to unspecified results.
Parameters:
source - the component that is gaining or losing focus
id - the event id
temporary - true if the focus change is temporary
opposite - the component receiving the opposite focus event, or null
Throws:
IllegalArgumentException - if source is null

Method Details

getOppositeComponent

public Component getOppositeComponent()
Returns the component which received the opposite focus event. If this component gained focus, the opposite lost focus; likewise if this component is giving up focus, the opposite is gaining it. If this information is unknown, perhaps because the opposite is a native application, this returns null.
Returns:
the component with the focus opposite, or null
Since:
1.4

isTemporary

public boolean isTemporary()
This method tests whether or not the focus change is temporary or permanent.
Returns:
true if the focus change is temporary

paramString

public String paramString()
Returns a string identifying this event. This is formatted as: (getID() == FOCUS_GAINED ? "FOCUS_GAINED" : "FOCUS_LOST") + (isTemporary() ? ",temporary," : ",permanent,") + "opposite=" + getOppositeComponent().
Overrides:
paramString in interface ComponentEvent
Returns:
a string identifying this event

FocusEvent.java -- generated for a focus change Copyright (C) 1999, 2002, 2005 Free Software Foundation, Inc. This file is part of GNU Classpath. GNU Classpath is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2, or (at your option) any later version. GNU Classpath is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with GNU Classpath; see the file COPYING. If not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. Linking this library statically or dynamically with other modules is making a combined work based on this library. Thus, the terms and conditions of the GNU General Public License cover the whole combination. As a special exception, the copyright holders of this library give you permission to link this library with independent modules to produce an executable, regardless of the license terms of these independent modules, and to copy and distribute the resulting executable under terms of your choice, provided that you also meet, for each linked independent module, the terms and conditions of the license of that module. An independent module is a module which is not derived from or based on this library. If you modify this library, you may extend this exception to your version of the library, but you are not obligated to do so. If you do not wish to do so, delete this exception statement from your version.