FocusEvent JDK 1.6)

Description

public class FocusEvent

A low-level event which indicates that a Component has gained or lost the input focus.

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.

See also: FocusAdapter FocusListener Tutorial: Writing a Focus Listener

Constructors

public FocusEvent (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 - if source is null

public FocusEvent (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 - if source is null

public FocusEvent (Component source, int id, boolean temporary, Component opposite)

Constructs a FocusEvent object with the specified temporary state and opposite Component.

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 - if source is null
Since: 1.4

Methods

Hide/Show inherited methods

protected void consume () [Inherited From AWTEvent]

Consumes this event, if this event can be consumed.

public Component getComponent () [Inherited From ComponentEvent]

Returns the originator of the event.

Returns the originator of the event.
Returns: the Component object that originated the event, or null if the object is not a Component.

public int getID () [Inherited From AWTEvent]

Returns the event type.

public Component getOppositeComponent ()

Returns the other Component involved in this focus change.

public Object getSource () [Inherited From EventObject]

The object on which the Event initially occurred.

protected boolean isConsumed () [Inherited From AWTEvent]

Returns whether this event has been consumed.

public boolean isTemporary ()

Identifies the focus change event as temporary or permanent.

Identifies the focus change event as temporary or permanent.
Returns: true if the focus change is temporary; false otherwise

public String paramString () [Overrides ComponentEvent]

Returns a parameter string identifying this event.

public void setSource (Object newSource) [Inherited From AWTEvent]

Retargets an event to a new source.

public String toString () [Inherited From AWTEvent]

Returns a String representation of this object.

Fields

Hide/Show inherited fields

publicfinalstatic long ACTION_EVENT_MASK = "128" [Inherited From AWTEvent]

The event mask for selecting action events.

publicfinalstatic long ADJUSTMENT_EVENT_MASK = "256" [Inherited From AWTEvent]

The event mask for selecting adjustment events.

publicfinalstatic long COMPONENT_EVENT_MASK = "1" [Inherited From AWTEvent]

The event mask for selecting component events.

publicfinalstatic int COMPONENT_FIRST = "100" [Inherited From ComponentEvent]

The first number in the range of ids used for component events.

publicfinalstatic int COMPONENT_HIDDEN = "103" [Inherited From ComponentEvent]

This event indicates that the component was rendered invisible.

publicfinalstatic int COMPONENT_LAST = "103" [Inherited From ComponentEvent]

The last number in the range of ids used for component events.

publicfinalstatic int COMPONENT_MOVED = "100" [Inherited From ComponentEvent]

This event indicates that the component's position changed.

publicfinalstatic int COMPONENT_RESIZED = "101" [Inherited From ComponentEvent]

This event indicates that the component's size changed.

publicfinalstatic int COMPONENT_SHOWN = "102" [Inherited From ComponentEvent]

This event indicates that the component was made visible.

protected boolean consumed [Inherited From AWTEvent]

Controls whether or not the event is sent back down to the peer once the source has processed it - false means it's sent to the peer; true means it's not.

publicfinalstatic long CONTAINER_EVENT_MASK = "2" [Inherited From AWTEvent]

The event mask for selecting container events.

publicfinalstatic long FOCUS_EVENT_MASK = "4" [Inherited From AWTEvent]

The event mask for selecting focus events.

publicfinalstatic int FOCUS_FIRST = "1004"

The first number in the range of ids used for focus events.

publicfinalstatic int FOCUS_GAINED = "1004"

This event indicates that the Component is now the focus owner.

publicfinalstatic int FOCUS_LAST = "1005"

The last number in the range of ids used for focus events.

publicfinalstatic int FOCUS_LOST = "1005"

This event indicates that the Component is no longer the focus owner.

publicfinalstatic long HIERARCHY_BOUNDS_EVENT_MASK = "65536" [Inherited From AWTEvent]

The event mask for selecting hierarchy bounds events.

publicfinalstatic long HIERARCHY_EVENT_MASK = "32768" [Inherited From AWTEvent]

The event mask for selecting hierarchy events.

protected int id [Inherited From AWTEvent]

The event's id.

publicfinalstatic long INPUT_METHOD_EVENT_MASK = "2048" [Inherited From AWTEvent]

The event mask for selecting input method events.

publicfinalstatic long INVOCATION_EVENT_MASK = "16384" [Inherited From AWTEvent]

The event mask for selecting invocation events.

publicfinalstatic long ITEM_EVENT_MASK = "512" [Inherited From AWTEvent]

The event mask for selecting item events.

publicfinalstatic long KEY_EVENT_MASK = "8" [Inherited From AWTEvent]

The event mask for selecting key events.

publicfinalstatic long MOUSE_EVENT_MASK = "16" [Inherited From AWTEvent]

The event mask for selecting mouse events.

publicfinalstatic long MOUSE_MOTION_EVENT_MASK = "32" [Inherited From AWTEvent]

The event mask for selecting mouse motion events.

publicfinalstatic long MOUSE_WHEEL_EVENT_MASK = "131072" [Inherited From AWTEvent]

The event mask for selecting mouse wheel events.

pack-privatetransient Component opposite

The other Component involved in this focus change.

publicfinalstatic long PAINT_EVENT_MASK = "8192" [Inherited From AWTEvent]

The event mask for selecting paint events.

publicfinalstatic int RESERVED_ID_MAX = "1999" [Inherited From AWTEvent]

The maximum value for reserved AWT event IDs.

protectedtransient Object source [Inherited From EventObject]

The object on which the Event initially occurred.

pack-private boolean temporary

A focus event can have two different levels, permanent and temporary.

publicfinalstatic long TEXT_EVENT_MASK = "1024" [Inherited From AWTEvent]

The event mask for selecting text events.

publicfinalstatic long WINDOW_EVENT_MASK = "64" [Inherited From AWTEvent]

The event mask for selecting window events.

publicfinalstatic long WINDOW_FOCUS_EVENT_MASK = "524288" [Inherited From AWTEvent]

The event mask for selecting window focus events.

publicfinalstatic long WINDOW_STATE_EVENT_MASK = "262144" [Inherited From AWTEvent]

The event mask for selecting window state events.