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java.lang.Object java.util.EventObject java.awt.AWTEvent java.awt.event.HierarchyEvent
public class HierarchyEvent
Disabled: no SafeJ information.
An event which indicates a change to the Component
hierarchy to which Component
belongs.
Hierarchy events are provided for notification purposes ONLY. The AWT will automatically handle changes to the hierarchy internally so that GUI layout and displayability works properly regardless of whether a program is receiving these events or not.
This event is generated by a Container object (such as a Panel) when the
Container is added, removed, moved, or resized, and passed down the
hierarchy. It is also generated by a Component object when that object's
addNotify
, removeNotify
, show
, or
hide
method is called. The ANCESTOR_MOVED
and
ANCESTOR_RESIZED
events are dispatched to every HierarchyBoundsListener
or
HierarchyBoundsAdapter
object which registered to receive
such events using the Component's addHierarchyBoundsListener
method. (HierarchyBoundsAdapter
objects implement the
HierarchyBoundsListener
interface.) The HIERARCHY_CHANGED
events are
dispatched to every HierarchyListener
object which registered
to receive such events using the Component's addHierarchyListener
method. Each such listener object gets this HierarchyEvent
when the event occurs.
An unspecified behavior will be caused if the id
parameter
of any particular HierarchyEvent
instance is not
in the range from HIERARCHY_FIRST
to HIERARCHY_LAST
.
The changeFlags
parameter of any HierarchyEvent
instance takes one of the following
values:
HierarchyEvent.PARENT_CHANGED
HierarchyEvent.DISPLAYABILITY_CHANGED
HierarchyEvent.SHOWING_CHANGED
HierarchyListener
,
HierarchyBoundsAdapter
,
HierarchyBoundsListener
,
Serialized FormField Summary | |
---|---|
static int |
ANCESTOR_MOVED
The event id indicating an ancestor-Container was moved. |
static int |
ANCESTOR_RESIZED
The event id indicating an ancestor-Container was resized. |
static int |
DISPLAYABILITY_CHANGED
A change flag indicates that the HIERARCHY_CHANGED event
was generated due to the changing of the hierarchy displayability. |
static int |
HIERARCHY_CHANGED
The event id indicating that modification was made to the entire hierarchy tree. |
static int |
HIERARCHY_FIRST
Marks the first integer id for the range of hierarchy event ids. |
static int |
HIERARCHY_LAST
Marks the last integer id for the range of ancestor event ids. |
static int |
PARENT_CHANGED
A change flag indicates that the HIERARCHY_CHANGED event
was generated by a reparenting operation. |
static int |
SHOWING_CHANGED
A change flag indicates that the HIERARCHY_CHANGED event
was generated due to the changing of the hierarchy showing state. |
Fields inherited from class java.util.EventObject |
---|
source |
Constructor Summary | |
---|---|
HierarchyEvent(Component source,
int id,
Component changed,
Container changedParent)
Constructs an HierarchyEvent object to identify a
change in the Component hierarchy. |
|
HierarchyEvent(Component source,
int id,
Component changed,
Container changedParent,
long changeFlags)
Constructs an HierarchyEvent object to identify
a change in the Component hierarchy. |
Method Summary | |
---|---|
Component |
getChanged()
Returns the Component at the top of the hierarchy which was changed. |
Container |
getChangedParent()
Returns the parent of the Component returned by
getChanged() . |
long |
getChangeFlags()
Returns a bitmask which indicates the type(s) of HIERARCHY_CHANGED events represented in this event object. |
Component |
getComponent()
Returns the originator of the event. |
String |
paramString()
Returns a parameter string identifying this event. |
Methods inherited from class java.awt.AWTEvent |
---|
consume, getID, isConsumed, setSource, toString |
Methods inherited from class java.util.EventObject |
---|
getSource |
Methods inherited from class java.lang.Object |
---|
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait |
Field Detail |
---|
public static final int HIERARCHY_FIRST
public static final int HIERARCHY_CHANGED
public static final int ANCESTOR_MOVED
public static final int ANCESTOR_RESIZED
public static final int HIERARCHY_LAST
public static final int PARENT_CHANGED
HIERARCHY_CHANGED
event
was generated by a reparenting operation.
public static final int DISPLAYABILITY_CHANGED
HIERARCHY_CHANGED
event
was generated due to the changing of the hierarchy displayability.
To discern the
current displayability of the hierarchy, call the
Component.isDisplayable
method. Displayability changes occur
in response to explicit or implicit calls of the
Component.addNotify
and
Component.removeNotify
methods.
Component.isDisplayable()
,
Component.addNotify()
,
Component.removeNotify()
,
Constant Field Valuespublic static final int SHOWING_CHANGED
HIERARCHY_CHANGED
event
was generated due to the changing of the hierarchy showing state.
To discern the
current showing state of the hierarchy, call the
Component.isShowing
method. Showing state changes occur
when either the displayability or visibility of the
hierarchy occurs. Visibility changes occur in response to explicit
or implicit calls of the Component.show
and
Component.hide
methods.
Component.isShowing()
,
Component.addNotify()
,
Component.removeNotify()
,
Component.show()
,
Component.hide()
,
Constant Field ValuesConstructor Detail |
---|
public HierarchyEvent(Component source, int id, Component changed, Container changedParent)
HierarchyEvent
object to identify a
change in the Component
hierarchy.
This method throws an
IllegalArgumentException
if source
is null
.
source
- The Component
object that
originated the eventid
- An integer indicating the type of event.
For information on allowable values, see
the class description for HierarchyEvent
changed
- The Component
at the top of
the hierarchy which was changedchangedParent
- The parent of the changed
component.
This
may be the parent before or after the
change, depending on the type of change
IllegalArgumentException
- if source
is null
EventObject.getSource()
,
AWTEvent.getID()
,
getChanged()
,
getChangedParent()
public HierarchyEvent(Component source, int id, Component changed, Container changedParent, long changeFlags)
HierarchyEvent
object to identify
a change in the Component
hierarchy.
This method throws an
IllegalArgumentException
if source
is null
.
source
- The Component
object that
originated the eventid
- An integer indicating the type of event.
For information on allowable values, see
the class description for HierarchyEvent
changed
- The Component
at the top
of the hierarchy which was changedchangedParent
- The parent of the changed
component.
This
may be the parent before or after the
change, depending on the type of changechangeFlags
- A bitmask which indicates the type(s) of
the HIERARCHY_CHANGED
events
represented in this event object.
For information on allowable values, see
the class description for HierarchyEvent
IllegalArgumentException
- if source
is nullEventObject.getSource()
,
AWTEvent.getID()
,
getChanged()
,
getChangedParent()
,
getChangeFlags()
Method Detail |
---|
public Component getComponent()
Component
object that originated
the event, or null
if the object is not a
Component
.public Component getChanged()
public Container getChangedParent()
getChanged()
. For a HIERARCHY_CHANGED event where the
change was of type PARENT_CHANGED via a call to
Container.add
, the parent returned is the parent
after the add operation. For a HIERARCHY_CHANGED event where
the change was of type PARENT_CHANGED via a call to
Container.remove
, the parent returned is the parent
before the remove operation. For all other events and types,
the parent returned is the parent during the operation.
public long getChangeFlags()
public String paramString()
paramString
in class AWTEvent
|
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