org.apache.commons.events.observable.standard
Class StandardModificationEvent

java.lang.Object
  java.util.EventObject
      org.apache.commons.events.observable.ModificationEvent
          org.apache.commons.events.observable.standard.StandardModificationEvent

All Implemented Interfaces:

Serializable

Direct Known Subclasses:

StandardPostModificationEvent, StandardPreModificationEvent

public class StandardModificationEvent
extends ModificationEvent

Event class that encapsulates the event information for a standard collection event. Two subclasses are provided, one for pre and one for post events.

The information stored in this event is all that is available as parameters or return values. In addition, the size method is used on the collection. All objects used are the real objects from the method calls, not clones.

Since:

Commons Events 1.0

Version:

$Revision: 155443 $ $Date: 2005-02-26 13:19:51 +0000 (Sat, 26 Feb 2005) $

Author:

Stephen Colebourne

See Also:

Serialized Form

Field Summary

protected int	index The index of the change
protected Object	object The object of the change
protected int	preSize The size before the event
protected Object	previous The result of the method call
protected int	repeat The number of changes
protected ObservableCollection	view The view that the event came from, null if none
protected int	viewOffset The offset index within the main collection of the view, -1 if none

Fields inherited from class org.apache.commons.events.observable.ModificationEvent

collection, handler, type

Fields inherited from class java.util.EventObject

source

Constructor Summary

StandardModificationEvent(ObservableCollection obsCollection, ModificationHandler handler, int type, int preSize, int index, Object object, int repeat, Object previous, ObservableCollection view, int viewOffset)
Constructor.

Method Summary

Collection	getChangeCollection() Gets the collection of changed objects.
int	getChangeIndex() Gets the index of the change.
Object	getChangeObject() Gets the object that was added/removed/set.
int	getChangeRepeat() Gets the number of times the object was added/removed.
int	getPreSize() Gets the size before the change.
Object	getPrevious() Gets the previous value that is being replaced or removed.
ObservableCollection	getView() Gets the view, null if none.
int	getViewOffset() Gets the view offset, -1 if no view or unknown offset.
boolean	isType(int eventType) Checks to see if the event is of the specified type.
boolean	isTypeAdd() Checks to see if the event is an add event (add/addAll).
boolean	isTypeBulk() Checks to see if the event is a bulk event (addAll/removeAll/retainAll/clear).
boolean	isTypeChange() Checks to see if the event is a change event (set).
boolean	isTypeReduce() Checks to see if the event is a remove event (remove/removeAll/retainAll/clear).
boolean	isView() Checks whether the event originated from a view.
String	toString() Gets a debugging string version of the event.

Methods inherited from class org.apache.commons.events.observable.ModificationEvent

getBaseCollection, getHandler, getObservedCollection, getType

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

preSize

protected final int preSize

The size before the event

index

protected final int index

The index of the change

object

protected final Object object

The object of the change

repeat

protected final int repeat

The number of changes

previous

protected final Object previous

The result of the method call

view

protected final ObservableCollection view

The view that the event came from, null if none

viewOffset

protected final int viewOffset

The offset index within the main collection of the view, -1 if none

Constructor Detail

StandardModificationEvent

public StandardModificationEvent(ObservableCollection obsCollection,
                                 ModificationHandler handler,
                                 int type,
                                 int preSize,
                                 int index,
                                 Object object,
                                 int repeat,
                                 Object previous,
                                 ObservableCollection view,
                                 int viewOffset)

Constructor.

Parameters:

obsCollection - the event source

handler - the handler

type - the event type

preSize - the size before the change

index - the index that changed

object - the value that changed

repeat - the number of repeats

previous - the previous value being removed/replaced

view - the view collection, null if event from main collection

viewOffset - the offset within the main collection of the view, -1 if unknown

Method Detail

getChangeIndex

public int getChangeIndex()

Gets the index of the change.

This is -1 when not applicable. Typically only used for List events.

Returns:

the change index

getChangeObject

public Object getChangeObject()

Gets the object that was added/removed/set.

This is null when not applicable, such as for clear().

Returns:

the changing object

getChangeCollection

public Collection getChangeCollection()

Gets the collection of changed objects.

For clear, it is an empty list. For bulk operations, it is the collection. For non-bulk operations, it is a size one list.

Returns:

the changing collection, never null

getChangeRepeat

public int getChangeRepeat()

Gets the number of times the object was added/removed.

This is normally 1, but will be used for Bag events.

Returns:

the repeat

getPrevious

public Object getPrevious()

Gets the previous value that is being replaced or removed.

This is only returned if the value definitely was previously in the collection. Bulk operatons will not return this.

Returns:

the previous value that was removed/replaced

getPreSize

public int getPreSize()

Gets the size before the change.

Returns:

the size before the change

getView

public ObservableCollection getView()

Gets the view, null if none.

A view is a subSet, headSet, tailSet, subList and so on.

Returns:

the view

isView

public boolean isView()

Checks whether the event originated from a view.

Returns:

true if event came from a view

getViewOffset

public int getViewOffset()

Gets the view offset, -1 if no view or unknown offset.

This refers to the index of the start of the view within the main collection.

Returns:

the view offset

isTypeAdd

public boolean isTypeAdd()

Checks to see if the event is an add event (add/addAll).

Returns:

true if of the specified type

isTypeReduce

public boolean isTypeReduce()

Checks to see if the event is a remove event (remove/removeAll/retainAll/clear).

Returns:

true if of the specified type

isTypeChange

public boolean isTypeChange()

Checks to see if the event is a change event (set).

Returns:

true if of the specified type

isTypeBulk

public boolean isTypeBulk()

Checks to see if the event is a bulk event (addAll/removeAll/retainAll/clear).

Returns:

true if of the specified type

isType

public boolean isType(int eventType)

Checks to see if the event is of the specified type.

This is any combination of constants from ModificationEventType.

Parameters:

eventType - an event type constant

Returns:

true if of the specified type

toString

public String toString()

Gets a debugging string version of the event.

Overrides:

toString in class ModificationEvent

Returns:

a debugging string