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:
java.lang.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(java.lang.String sortFieldName, boolean isDescending, int size)
          Constructor.
 
Method Summary
 java.lang.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.
 java.lang.String getSortFieldName()
          Returns the field name supplying the values to sort by.
 int getSortWindowSize()
          Returns the number of elements kept by the sort window.
 boolean isDescending()
          Returns an indication of sort order.
 java.util.Iterator<EventBean> iterator()
          Allows iteration through all elements in this event collection.
 void setDescending(boolean descending)
          Set the sort order for the sort window.
 void setParent(Viewable parent)
          Called when the View is added to a Viewable object.
 void setSortFieldName(java.lang.String sortFieldName)
          Sets the field name supplying the values to sort by.
 void setSortWindowSize(int sortWindowSize)
          Sets the number of elements kept by the sort window.
 java.lang.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(java.lang.String sortFieldName,
                      boolean isDescending,
                      int size)
Constructor.

Parameters:
sortFieldName - is the name of the field in the event to get the values to sort
isDescending - true if the sort should be descending, false if ascending
size - is the specified number of elements to keep in the sort
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

getSortFieldName

public final java.lang.String getSortFieldName()
Returns the field name supplying the values to sort by.

Returns:
field name to sort by

setSortFieldName

public final void setSortFieldName(java.lang.String sortFieldName)
Sets the field name supplying the values to sort by.

Parameters:
sortFieldName - field name to sort by

isDescending

public final boolean isDescending()
Returns an indication of sort order.

Returns:
true for descending sorts, false for ascending sort

setDescending

public final void setDescending(boolean descending)
Set the sort order for the sort window.

Parameters:
descending - is true to set the descending and false for ascending sorting.

getSortWindowSize

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

Returns:
size of window

setSortWindowSize

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

Parameters:
sortWindowSize - size of window

attachesTo

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

toString

public final java.lang.String toString()
Overrides:
toString in class java.lang.Object