com.espertech.esper.view.internal

Class LastPostObserverView

java.lang.Object

com.espertech.esper.view.internal.LastPostObserverView

All Implemented Interfaces:

CloneableView, EventCollection, View, Viewable, Iterable<EventBean>

public final class LastPostObserverView
extends Object
implements View, CloneableView

A view that retains the last update.

Constructor Summary

Constructors

Constructor and Description
LastPostObserverView(int streamId) Ctor.

Method Summary

Modifier and Type	Method and Description
View	addView(View view) Add a view to the viewable object.
View	cloneView() Duplicates the view.
EventType	getEventType() Provides metadata information about the type of object the event collection contains.
Viewable	getParent() Returns the View's parent Viewable.
View[]	getViews() Returns all added views.
boolean	hasViews() Test is there are any views to the Viewable.
Iterator<EventBean>	iterator() Allows iteration through all elements in this event collection.
void	removeAllViews() Remove all views.
boolean	removeView(View view) Remove a view.
void	setObserver(LastPostObserver observer) Set an observer.
void	setParent(Viewable parent) Called when the View is added to a Viewable object.
void	update(EventBean[] newData, EventBean[] oldData) Notify that data has been added or removed from the Viewable parent.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Constructor Detail

LastPostObserverView

public LastPostObserverView(int streamId)

Ctor.

Parameters:

streamId - - number of the stream for which the view buffers the generated events.

Method Detail

setObserver

public void setObserver(LastPostObserver observer)

Set an observer.

Parameters:

observer - to be called when results are available

cloneView

public View cloneView()

Description copied from interface: CloneableView

Duplicates the view.

Expected to return a same view in initialized state for grouping.

Specified by:

cloneView in interface CloneableView

Returns:

cloned view

getEventType

public final EventType getEventType()

Description copied from interface: EventCollection

Provides metadata information about the type of object the event collection contains.

Specified by:

getEventType in interface EventCollection

Returns:

metadata for the objects in the collection

iterator

public final Iterator<EventBean> iterator()

Description copied from interface: EventCollection

Allows iteration through all elements in this event collection. The iterator will return the elements in the collection in their natural order, or, if there is no natural ordering, in some unpredictable order.

Specified by:

iterator in interface EventCollection

Specified by:

iterator in interface Iterable<EventBean>

Returns:

an iterator which will go through all current elements in the collection.

getParent

public Viewable getParent()

Description copied from interface: View

Returns the View's parent Viewable.

Specified by:

getParent in interface View

Returns:

viewable

setParent

public void setParent(Viewable parent)

Description copied from interface: View

Called when the View is added to a Viewable object.

Specified by:

setParent in interface View

Parameters:

parent - is the parent that this view is a child of

addView

public View addView(View view)

Description copied from interface: Viewable

Add a view to the viewable object.

Specified by:

addView in interface Viewable

Parameters:

view - to add

Returns:

view to add

getViews

public View[] getViews()

Description copied from interface: Viewable

Returns all added views.

Specified by:

getViews in interface Viewable

Returns:

list of added views

removeView

public boolean removeView(View view)

Description copied from interface: Viewable

Remove a view.

Specified by:

removeView in interface Viewable

Parameters:

view - to remove

Returns:

true to indicate that the view to be removed existed within this view, false if the view to remove could not be found

removeAllViews

public void removeAllViews()

Description copied from interface: Viewable

Remove all views.

Specified by:

removeAllViews in interface Viewable

hasViews

public boolean hasViews()

Description copied from interface: Viewable

Test is there are any views to the Viewable.

Specified by:

hasViews in interface Viewable

Returns:

true indicating there are child views, false indicating there are no child views

update

public final void update(EventBean[] newData,
                         EventBean[] oldData)

Description copied from interface: View

Notify that data has been added or removed from the Viewable parent. The last object in the newData array of objects would be the newest object added to the parent view. The first object of the oldData array of objects would be the oldest object removed from the parent view.

If the call to update contains new (inserted) data, then the first argument will be a non-empty list and the second will be empty. Similarly, if the call is a notification of deleted data, then the first argument will be empty and the second will be non-empty. Either the newData or oldData will be non-null. This method won't be called with both arguments being null, but either one could be null. The same is true for zero-length arrays. Either newData or oldData will be non-empty. If both are non-empty, then the update is a modification notification.

When update() is called on a view by the parent object, the data in newData will be in the collection of the parent, and its data structures will be arranged to reflect that. The data in oldData will not be in the parent's data structures, and any access to the parent will indicate that that data is no longer there.

Specified by:

update in interface View

Parameters:

newData - is the new data that has been added to the parent view

oldData - is the old data that has been removed from the parent view