net.esper.view.ext
Class SortWindowView

java.lang.Object
  extended by net.esper.view.ViewSupport
      extended by net.esper.view.ext.SortWindowView
All Implemented Interfaces:
Iterable<EventBean>, EventCollection, View, Viewable, DataWindowView

public final class SortWindowView
extends ViewSupport
implements DataWindowView

Window sorting by values in the specified field extending a specified number of elements from the lowest value up or the highest value down. The view accepts 3 parameters. The first parameter is the field name to get the values to sort for, the second parameter defines whether to sort ascending or descending, the third parameter is the number of elements to keep in the sorted list. The type of the field to be sorted in the event must implement the Comparable interface. The natural order in which events arrived is used as the second sorting criteria. Thus should events arrive with equal sort values the oldest event leaves the sort window first. Old values removed from a prior view are removed from the sort view.


Field Summary
 
Fields inherited from class net.esper.view.ViewSupport
parent
 
Constructor Summary
SortWindowView()
          Default constructor - required by all views to adhere to the Java bean specification.
SortWindowView(String[] sortFieldNames, Boolean[] descendingValues, int sortWindowSize, IStreamSortedRandomAccess optionalSortedRandomAccess)
          Ctor.
 
Method Summary
 EventType getEventType()
          Provides metadata information about the type of object the event collection contains.
 Boolean[] getIsDescendingValues()
          Returns the flags indicating whether to sort in descending order on each property.
 IStreamSortedRandomAccess getOptionalSortedRandomAccess()
          Returns the friend handling the random access, cal be null if not required.
 String[] getSortFieldNames()
          Returns the field names supplying the values to sort by.
 int getSortWindowSize()
          Returns the number of elements kept by the sort window.
 boolean isEmpty()
          True to indicate the sort window is empty, or false if not empty.
 Iterator<EventBean> iterator()
          Allows iteration through all elements in this event collection.
 void setIsDescendingValues(Boolean[] isDescendingValues)
          Set the sort order for the sort properties.
 void setOptionalSortedRandomAccess(IStreamSortedRandomAccess optionalSortedRandomAccess)
          Sets the friend handling the random access, can be null if not required.
 void setParent(Viewable parent)
          Called when the View is added to a Viewable object.
 void setSortFieldNames(String[] sortFieldNames)
          Set the names of the properties to sort on.
 void setSortWindowSize(int sortWindowSize)
          Set the number of elements kept by the sort window.
 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, shallowCopyView, updateChildren, updateChildren
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 
Methods inherited from interface net.esper.view.View
getParent
 
Methods inherited from interface net.esper.view.Viewable
addView, getViews, hasViews, removeView
 

Constructor Detail

SortWindowView

public SortWindowView()
Default constructor - required by all views to adhere to the Java bean specification.


SortWindowView

public SortWindowView(String[] sortFieldNames,
                      Boolean[] descendingValues,
                      int sortWindowSize,
                      IStreamSortedRandomAccess optionalSortedRandomAccess)
Ctor.

Parameters:
sortFieldNames - is the event property names to sort
descendingValues - indicates whether to sort ascending or descending for each field
sortWindowSize - is the window size
optionalSortedRandomAccess - is the friend class handling the random access, if required by expressions
Method Detail

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
Overrides:
setParent in class ViewSupport
Parameters:
parent - is the parent that this view is a child of

getSortFieldNames

public final String[] getSortFieldNames()
Returns the field names supplying the values to sort by.

Returns:
field names to sort by

getIsDescendingValues

public final Boolean[] getIsDescendingValues()
Returns the flags indicating whether to sort in descending order on each property.

Returns:
the isDescending value for each sort property

getSortWindowSize

public final int getSortWindowSize()
Returns the number of elements kept by the sort window.

Returns:
size of window

getOptionalSortedRandomAccess

public IStreamSortedRandomAccess getOptionalSortedRandomAccess()
Returns the friend handling the random access, cal be null if not required.

Returns:
random accessor to sort window contents

setOptionalSortedRandomAccess

public void setOptionalSortedRandomAccess(IStreamSortedRandomAccess optionalSortedRandomAccess)
Sets the friend handling the random access, can be null if not required.

Parameters:
optionalSortedRandomAccess - random accessor to sort window contents

setIsDescendingValues

public final void setIsDescendingValues(Boolean[] isDescendingValues)
Set the sort order for the sort properties.

Parameters:
isDescendingValues - - the direction to sort in for each sort property

setSortFieldNames

public final void setSortFieldNames(String[] sortFieldNames)
Set the names of the properties to sort on.

Parameters:
sortFieldNames - - the names of the properties to sort on

setSortWindowSize

public final void setSortWindowSize(int sortWindowSize)
Set the number of elements kept by the sort window.

Parameters:
sortWindowSize - - size of window

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

isEmpty

public boolean isEmpty()
True to indicate the sort window is empty, or false if not empty.

Returns:
true if empty sort window