net.esper.view.std
Class SizeView

java.lang.Object
  extended by net.esper.view.ViewSupport
      extended by net.esper.view.std.SizeView
All Implemented Interfaces:
Iterable<EventBean>, ContextAwareView, EventCollection, View, Viewable

public final class SizeView
extends ViewSupport
implements ContextAwareView

This view is a very simple view presenting the number of elements in a stream or view. The view computes a single long-typed count of the number of events passed through it similar to the base statistics COUNT column.


Field Summary
 
Fields inherited from class net.esper.view.ViewSupport
parent
 
Constructor Summary
SizeView()
          Constructor.
 
Method Summary
 String attachesTo(Viewable parentView)
          Return null if the view will accept being attached to a particular object.
 EventType getEventType()
          Provides metadata information about the type of object the event collection contains.
 ViewServiceContext getViewServiceContext()
          Returns the context instances used by the view.
 Iterator<EventBean> iterator()
          Allows iteration through all elements in this event collection.
 void setViewServiceContext(ViewServiceContext viewServiceContext)
          Set the services context containing service handles.
 String toString()
           
 void update(EventBean[] newData, EventBean[] oldData)
          Notify that data has been added or removed from the Viewable parent.
 
Methods inherited from class net.esper.view.ViewSupport
addView, dumpChildViews, dumpUpdateParams, findDescendent, getParent, getViews, hasViews, removeView, setParent, shallowCopyView, updateChildren, updateChildren
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 

Constructor Detail

SizeView

public SizeView()
Constructor.

Method Detail

getViewServiceContext

public ViewServiceContext getViewServiceContext()
Description copied from interface: ContextAwareView
Returns the context instances used by the view.

Specified by:
getViewServiceContext in interface ContextAwareView
Returns:
context instance

setViewServiceContext

public void setViewServiceContext(ViewServiceContext viewServiceContext)
Description copied from interface: ContextAwareView
Set the services context containing service handles.

Specified by:
setViewServiceContext in interface ContextAwareView
Parameters:
viewServiceContext - with service handles

attachesTo

public final String attachesTo(Viewable parentView)
Description copied from interface: View
Return null if the view will accept being attached to a particular object.

Specified by:
attachesTo in interface View
Parameters:
parentView - is the potential parent for this view
Returns:
null if this view can successfully attach to the parent, an error message if it cannot.

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

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

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 Iterable<EventBean>
Specified by:
iterator in interface EventCollection
Returns:
an iterator which will go through all current elements in the collection.

toString

public final String toString()
Overrides:
toString in class Object