java.lang.Object
- elki.database.DatabaseEventManager

```
public class DatabaseEventManager
extends java.lang.Object
```
Class to manage database events such as insertions and removals.

Since:

0.4.0

Author:

Elke Achtert

Nested Class Summary

Nested Classes
Modifier and Type Class Description

private static class DatabaseEventManager.Type
Types for aggregation.

Field Summary

Fields
Modifier and Type	Field	Description
`private boolean`	`accumulateDataStoreEvents`	Indicates whether DataStoreEvents should be accumulated and fired as one event on demand.
`private DatabaseEventManager.Type`	`currentDataStoreEventType`	The type of the current DataStoreEvent to be accumulated.
`private java.util.List<DataStoreListener>`	`dataListenerList`	Holds the listeners for data store changes
`private HashSetModifiableDBIDs`	`dataStoreObjects`	The objects that were changed in the current DataStoreEvent.
`private java.util.List<ResultListener>`	`resultListenerList`	Holds the listeners for result changes.

Constructor Summary

Constructors
Constructor Description

DatabaseEventManager()

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`void`	`accumulateDataStoreEvents()`	Collects successive insertion, deletion or update events.
`void`	`addListener(DataStoreListener l)`	Adds a `DataStoreListener` for a `DataStoreEvent` posted after the content of the database changes.
`void`	`addListener(ResultListener l)`	Adds a `ResultListener` to be notified on new results.
`private void`	`fireObjectChanged(DBIDRef object, DatabaseEventManager.Type type)`	Handles a DataStoreEvent with the specified type.
`void`	`fireObjectInserted(DBIDRef insertion)`	Event when a new object was inserted.
`protected void`	`fireObjectRemoved(DBIDRef deletion)`	Event when an objects was removed / deleted.
`private void`	`fireObjectsChanged(DBIDs objects, DatabaseEventManager.Type type)`	Handles a DataStoreEvent with the specified type.
`void`	`fireObjectsInserted(DBIDs insertions)`	Event when new objects are inserted.
`protected void`	`fireObjectsRemoved(DBIDs deletions)`	Event when objects were removed / deleted.
`void`	`fireObjectsUpdated(DBIDRef update)`	Event when an object was changed / updated.
`void`	`fireObjectsUpdated(DBIDs updates)`	Event when objects have changed / were updated.
`void`	`fireResultAdded(java.lang.Object r, java.lang.Object parent)`	Informs all registered `ResultListener` that a new result was added.
`void`	`fireResultRemoved(java.lang.Object r, java.lang.Object parent)`	Informs all registered `ResultListener` that a new result has been removed.
`void`	`flushDataStoreEvents()`	Fires all collected insertion, deletion or update events as one DataStoreEvent, i.e. notifies all registered DataStoreListener how the content of the database has been changed since `accumulateDataStoreEvents()` was called.
`void`	`removeListener(DataStoreListener l)`	Removes a `DataStoreListener` previously added with `addListener(DataStoreListener)`.
`void`	`removeListener(ResultListener l)`	Removes a `ResultListener` previously added with `addListener(ResultListener)`.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - dataListenerList
```
private java.util.List<DataStoreListener> dataListenerList
```
    Holds the listeners for data store changes
  - resultListenerList
```
private java.util.List<ResultListener> resultListenerList
```
    Holds the listeners for result changes.
  - accumulateDataStoreEvents
```
private boolean accumulateDataStoreEvents
```
    Indicates whether DataStoreEvents should be accumulated and fired as one event on demand.
  - currentDataStoreEventType
```
private DatabaseEventManager.Type currentDataStoreEventType
```
    The type of the current DataStoreEvent to be accumulated.
  - dataStoreObjects
```
private HashSetModifiableDBIDs dataStoreObjects
```
    The objects that were changed in the current DataStoreEvent.
- Constructor Detail
  - DatabaseEventManager
```
public DatabaseEventManager()
```
- Method Detail
  - accumulateDataStoreEvents
```
public void accumulateDataStoreEvents()
```
    Collects successive insertion, deletion or update events. The accumulated event will be fired when flushDataStoreEvents() is called or a different event type occurs.
    
    See Also:
    
    flushDataStoreEvents(), DataStoreEvent
  - flushDataStoreEvents
```
public void flushDataStoreEvents()
```
    Fires all collected insertion, deletion or update events as one DataStoreEvent, i.e. notifies all registered DataStoreListener how the content of the database has been changed since accumulateDataStoreEvents() was called.
    
    See Also:
    
    accumulateDataStoreEvents, DataStoreListener, DataStoreEvent
  - addListener
```
public void addListener(DataStoreListener l)
```
    Adds a DataStoreListener for a DataStoreEvent posted after the content of the database changes.
    
    Parameters:
    
    l - the listener to add
    
    See Also:
    
    removeListener(DataStoreListener), DataStoreListener, DataStoreEvent
  - removeListener
```
public void removeListener(DataStoreListener l)
```
    Removes a DataStoreListener previously added with addListener(DataStoreListener).
    
    Parameters:
    
    l - the listener to remove
    
    See Also:
    
    addListener(DataStoreListener), DataStoreListener, DataStoreEvent
  - addListener
```
public void addListener(ResultListener l)
```
    Adds a ResultListener to be notified on new results.
    
    Parameters:
    
    l - the listener to add
    
    See Also:
    
    removeListener(ResultListener), ResultListener
  - removeListener
```
public void removeListener(ResultListener l)
```
    Removes a ResultListener previously added with addListener(ResultListener).
    
    Parameters:
    
    l - the listener to remove
    
    See Also:
    
    addListener(ResultListener), ResultListener
  - fireObjectsInserted
```
public void fireObjectsInserted(DBIDs insertions)
```
    Event when new objects are inserted.
    
    Parameters:
    
    insertions - the objects that have been inserted
  - fireObjectInserted
```
public void fireObjectInserted(DBIDRef insertion)
```
    Event when a new object was inserted.
    
    Parameters:
    
    insertion - the object that was inserted
  - fireObjectsUpdated
```
public void fireObjectsUpdated(DBIDs updates)
```
    Event when objects have changed / were updated.
    
    Parameters:
    
    updates - the objects that have been updated
  - fireObjectsUpdated
```
public void fireObjectsUpdated(DBIDRef update)
```
    Event when an object was changed / updated.
    
    Parameters:
    
    update - the object that was updated
  - fireObjectsRemoved
```
protected void fireObjectsRemoved(DBIDs deletions)
```
    Event when objects were removed / deleted.
    
    Parameters:
    
    deletions - the objects that have been removed
  - fireObjectRemoved
```
protected void fireObjectRemoved(DBIDRef deletion)
```
    Event when an objects was removed / deleted.
    
    Parameters:
    
    deletion - the object that has was removed
  - fireObjectsChanged
```
private void fireObjectsChanged(DBIDs objects,
                                DatabaseEventManager.Type type)
```
    Handles a DataStoreEvent with the specified type. If the current event type is not equal to the specified type, the events accumulated up to now will be fired first. The new event will be aggregated and fired on demand if accumulateDataStoreEvents is set, otherwise all registered DataStoreListener will be notified immediately that the content of the database has been changed.
    
    Parameters:
    
    objects - the objects that have been changed, i.e. inserted, deleted or updated
  - fireObjectChanged
```
private void fireObjectChanged(DBIDRef object,
                               DatabaseEventManager.Type type)
```
    Handles a DataStoreEvent with the specified type. If the current event type is not equal to the specified type, the events accumulated up to now will be fired first. The new event will be aggregated and fired on demand if accumulateDataStoreEvents is set, otherwise all registered DataStoreListener will be notified immediately that the content of the database has been changed.
    
    Parameters:
    
    object - the object that has been changed, i.e. inserted, deleted or updated
  - fireResultAdded
```
public void fireResultAdded(java.lang.Object r,
                            java.lang.Object parent)
```
    Informs all registered ResultListener that a new result was added.
    
    Parameters:
    
    r - New child result added
    
    parent - Parent result that was added to
  - fireResultRemoved
```
public void fireResultRemoved(java.lang.Object r,
                              java.lang.Object parent)
```
    Informs all registered ResultListener that a new result has been removed.
    
    Parameters:
    
    r - result that has been removed
    
    parent - Parent result that has been removed

Class DatabaseEventManager

Nested Class Summary

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

dataListenerList

resultListenerList

accumulateDataStoreEvents

currentDataStoreEventType

dataStoreObjects

Constructor Detail

DatabaseEventManager

Method Detail

accumulateDataStoreEvents

flushDataStoreEvents

addListener

removeListener

addListener

removeListener

fireObjectsInserted

fireObjectInserted

fireObjectsUpdated

fireObjectsUpdated

fireObjectsRemoved

fireObjectRemoved

fireObjectsChanged

fireObjectChanged

fireResultAdded

fireResultRemoved