ilog.views.graphlayout
Class IlvLayoutGraphicFilter

java.lang.Object
  ilog.views.graphlayout.IlvLayoutGraphicFilter

All Implemented Interfaces:

IlvGraphicFilter

public class IlvLayoutGraphicFilter
extends Object
implements IlvGraphicFilter

This class allows you to perform the layout on a subgraph; that is, on a subset of the nodes and links of the original grapher (IlvGrapher). The accept(ilog.views.IlvGraphic) method of the filter is called by the IlvGrapherAdapter to know for any node and link whether the node or link must be taken into account or if it must be completely ignored.

To install a filter on an IlvGrapherAdapter instance, use the method IlvGrapherAdapter.setFilter(ilog.views.graphlayout.IlvLayoutGraphicFilter).

Note that all overridden implementations of the method accept(ilog.views.IlvGraphic) must respect the following rules:

• A link cannot be accepted by the filter if any of its end nodes (origin or destination nodes) are not accepted.
• During a layout session, that is, during the period of time while the method IlvGraphLayout.performLayout() is running, the filter must always return the same value for the same node or link. In other words, the structure of the graph must not change while the layout is running.
• If the filter returns a value for a given node or link that is different from the value in the previous layout session, this is equivalent to a change of the structure of the graph. Therefore, you need to notify the grapher adapter that the structure of the underlying graph has changed. You can use the following code (in your subclass of IlvLayoutGraphicFilter):

   IlvGraphModel model = getGrapherAdapter();
  
   int type = GraphModelEvent.STRUCTURE_CHANGED;
  
   // Version #1: there is a single node (or link) that the filter now
   //              accepts while previously it rejected it 
   type |= GraphModelEvent.NODE_ADDED; // or LINK_ADDED
   model.fireGraphModelEvent(nodeOrLink, type, false);
  
   // Version #2: there is a single node (or link) that the filter now
   //             rejects while previously it accepted it
   type |= GraphModelEvent.NODE_REMOVED; // or LINK_REMOVED
   model.fireGraphModelEvent(nodeOrLink, type, false);
  
   // Version #3: there are several nodes and links that were previously
   //             rejected and now are accepted and vice-versa
   // You can either fire a global STRUCTURE_CHANGED event:
   type |= GraphModelEvent.STRUCTURE_CHANGED;
   model.fireGraphModelEvent(null, type, false);
   // or browse each of these nodes or links and throw an individual event
   // (use the value true for the adjusting flag, and call 
   // model.adjustmentEnd() at the end).
   grapherAdapter.fireGraphModelEvent(null, GraphModelEvent.STRUCTURE_CHANGED, false);
   

See Also:

IlvGrapherAdapter.setFilter(ilog.views.graphlayout.IlvLayoutGraphicFilter)

Constructor Summary

IlvLayoutGraphicFilter()
Creates a new IlvLayoutGraphicFilter.

IlvLayoutGraphicFilter(IlvGraphLayout layout)
Deprecated. Beginning with JViews 3.0, you should use the constructor without any arguments and specify the filter using the method IlvGrapherAdapter.setFilter(ilog.views.graphlayout.IlvLayoutGraphicFilter).

Method Summary

boolean	accept(IlvGraphic nodeOrLink) Returns true if the graphic object nodeOrLink is a node or a link that must be taken into account during the layout.
IlvGrapherAdapter	getGrapherAdapter() Returns the IlvGrapherAdapter with which the filter is associated.
IlvGraphLayout	getLayout() Deprecated. Beginning with JViews 3.0, the filter is no longer associated with a layout instance

Methods inherited from class java.lang.Object

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

Constructor Detail

IlvLayoutGraphicFilter

public IlvLayoutGraphicFilter()

Creates a new IlvLayoutGraphicFilter. To install a filter on an IlvGrapherAdapter instance, use the method IlvGrapherAdapter.setFilter.

Since:

JViews 3.0

See Also:

IlvGrapherAdapter.setFilter(ilog.views.graphlayout.IlvLayoutGraphicFilter)

IlvLayoutGraphicFilter

public IlvLayoutGraphicFilter(IlvGraphLayout layout)

Deprecated. Beginning with JViews 3.0, you should use the constructor without any arguments and specify the filter using the method IlvGrapherAdapter.setFilter(ilog.views.graphlayout.IlvLayoutGraphicFilter).

Creates a new IlvLayoutGraphicFilter This creates a filter for the layout instance layout. To install a filter on an IlvGrapherAdapter instance, use the method IlvGrapherAdapter.setFilter(ilog.views.graphlayout.IlvLayoutGraphicFilter).

See Also:

IlvLayoutGraphicFilter()

Method Detail

getGrapherAdapter

public IlvGrapherAdapter getGrapherAdapter()

Returns the IlvGrapherAdapter with which the filter is associated.

getLayout

public IlvGraphLayout getLayout()

Deprecated. Beginning with JViews 3.0, the filter is no longer associated with a layout instance

Returns the layout instance with which the filter is associated.

accept

public boolean accept(IlvGraphic nodeOrLink)

Returns true if the graphic object nodeOrLink is a node or a link that must be taken into account during the layout. If no layers are specified using the method IlvGrapherAdapter.addLayer(ilog.views.IlvManagerLayer) on the adapter instance on which the filter is installed, or if all the layers of the IlvGrapher are specified, the method returns true for node or link contained in the grapher encapsulated by the adapter. Otherwise, it returns true only for objects on the specified layers.

This method can be overridden in order to specify other conditions for filtering the nodes and the links. The overridden implementation should first check if the node or link is accepted in the superclass:

 if (!super.accept(nodeOrLink))
   return false;
 

Only after that other specific filtering rules should be applied.

Note that any overridden implementation of this method must respect the following rules:

• A link cannot be accepted by the filter if any of its end nodes (origin or destination nodes) are not accepted.
• During a layout session, that is between the beginning and until the end of the execution of a layout, the filter must always return the same value for the same node or link.
• If the filter returns a value for a given node or link that is different from the value in the previous layout session, this is equivalent to a change of the structure of the graph. Therefore, you need to notify the grapher adapter that the structure of the attached graph has changed. You can use the following code (in your subclass of IlvLayoutGraphicFilter):

   IlvGraphModel model = getGrapherAdapter();
  
   int type = GraphModelEvent.STRUCTURE_CHANGED;
  
   // Version #1: there is a single node (or link) that the filter now
   //              accepts while previously it rejected it 
   type |= GraphModelEvent.NODE_ADDED; // or LINK_ADDED
   model.fireGraphModelEvent(nodeOrLink, type, false);
  
   // Version #2: there is a single node (or link) that the filter now
   //             rejects while previously it accepted it
   type |= GraphModelEvent.NODE_REMOVED; // or LINK_REMOVED
   model.fireGraphModelEvent(nodeOrLink, type, false);
  
   // Version #3: there are several nodes and links that were previously
   //             rejected and now are accepted and vice-versa
   // You can either fire a global STRUCTURE_CHANGED event:
   type |= GraphModelEvent.STRUCTURE_CHANGED;
   model.fireGraphModelEvent(null, type, false);
   // or browse each of these nodes or links and throw an individual event
   // (use the value true for the adjusting flag, and call 
   // model.adjustmentEnd() at the end).
   

The method throws a RuntimeException if the layout instance has no attached grapher.

Specified by:

accept in interface IlvGraphicFilter