ilog.views.graphlayout.hierarchical

Class IlvSameLevelConstraint

java.lang.Object

ilog.views.graphlayout.hierarchical.IlvHierarchicalConstraint

ilog.views.graphlayout.hierarchical.IlvSameLevelConstraint

All Implemented Interfaces:

IlvPersistentObject

public class IlvSameLevelConstraint
extends IlvHierarchicalConstraint

The class IlvSameLevelConstraint is a constraint that forces two nodes to be placed at the same level.

The constraint is evaluated, if the incremental mode is disabled. If the incremental mode is enabled, the constraint is only evaluated if at least one of the nodes is marked for incremental recalculation, because otherwise, the incremental positions of the nodes are dominant.

Among the constraints, this kind has the highest priority. If several conflicting constraints are specified (such as the node must be placed in a lower level than another node and at the same level as this other node), the constraints with lower priority are ignored during layout.

The automatic conflict resolution can handle conflicting constraints. However, to speedup the layout, it is recommended to specify constraints in a way such that there are no conflicts.

The same level constraint has the same priority as the group spread constraint, because both cannot be conflicting. In fact, there are two ways of forcing two nodes to the same level: use the same level constraint, or use a group spread constraint of a group of two nodes with spread size 0.

In recursive layout mode (see IlvHierarchicalLayout.setRecursiveLayoutMode(boolean)), both nodes of the same level constraint must belong to the same subgraph, and the constraint must be installed at the layout instance that is attached to this subgraph. It is not possible to have a same level constraint containing nodes of different subgraphs.

Since:

JViews 5.0

See Also:

IlvHierarchicalLayout.addConstraint(IlvHierarchicalConstraint), IlvHierarchicalLayout.setIncrementalMode(boolean), IlvHierarchicalLayout.markForIncremental(Object)

Constructor Summary

Constructors

Constructor and Description
IlvSameLevelConstraint(IlvInputStream stream) Creates a new IlvSameLevelConstraint from an IlvInputStream.
IlvSameLevelConstraint(IlvSameLevelConstraint source) Creates a new IlvSameLevelConstraint by copying an existing one.
IlvSameLevelConstraint(Object node1, Object node2) Creates a new IlvSameLevelConstraint .

Method Summary

Modifier and Type	Method and Description
IlvHierarchicalConstraint	copy() Copies the constraint.
Object	getFirstNode() Returns the first node of this constraint.
Object	getSecondNode() Returns the second node of this constraint.
void	write(IlvOutputStream stream) Writes the constraint to the output stream.

Methods inherited from class ilog.views.graphlayout.hierarchical.IlvHierarchicalConstraint

getPriority, setPriority

Methods inherited from class java.lang.Object

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

Constructor Detail

IlvSameLevelConstraint

public IlvSameLevelConstraint(Object node1,
                              Object node2)

Creates a new IlvSameLevelConstraint .

The following example shows how to use the constraint:

 layout.addConstraint(new IlvSameLevelConstraint(node1, node2)); 

This forces node1 to be placed at the same level as node2.

Parameters:

node1 - The one node.

node2 - The other node.

See Also:

IlvHierarchicalLayout.addConstraint(IlvHierarchicalConstraint)

IlvSameLevelConstraint

public IlvSameLevelConstraint(IlvSameLevelConstraint source)

Creates a new IlvSameLevelConstraint by copying an existing one.

Parameters:

source - The origin of the copy.

IlvSameLevelConstraint

public IlvSameLevelConstraint(IlvInputStream stream)
                       throws IOException,
                              IlvReadFileException

Creates a new IlvSameLevelConstraint from an IlvInputStream.

Parameters:

stream - The input stream from which the property must be read.

Throws:

IlvReadFileException - if an error occurs while reading.

IOException

Method Detail

copy

public IlvHierarchicalConstraint copy()

Copies the constraint.

Specified by:

copy in class IlvHierarchicalConstraint

write

public void write(IlvOutputStream stream)
           throws IOException

Writes the constraint to the output stream.

Specified by:

write in interface IlvPersistentObject

Overrides:

write in class IlvHierarchicalConstraint

Parameters:

stream - The output stream.

Throws:

IOException - standard IO error.

getFirstNode

public final Object getFirstNode()

Returns the first node of this constraint.

getSecondNode

public final Object getSecondNode()

Returns the second node of this constraint.