com.yworks.yfiles.layout.hierarchic

Interface ISequenceConstraintFactory

public interface ISequenceConstraintFactory

This interface specifies the general contract for factory classes that can be used to associate sequence constraints with a graph.

Sequence constraints affect the sequence of nodes within a layer.

A ISequenceConstraintFactory has to be disposed of after use. Disposing of the factory will also remove all constraints previously specified for the factory's associated graph.

• Sequence constraints cannot be used together with swimlanes.
• Sequence constraints that are specified for a group child node will be applied to the parent node instead.
• If you manually register with the graph a IDataProvider with key LayoutKeys.NODE_ID_DPKEY, you must use the corresponding node IDs stored in this IDataProvider as arguments for all methods that create a constraint. Otherwise, you can just use the node instances themselves.

Method Summary

Modifier and Type	Method and Description
void	addPlaceAfterConstraint(Object referenceId, Object afterId) Adds a constraint that forces the Node or Edge with id after to lie after the Node or Edge with id reference.
void	addPlaceAtHeadConstraint(Object id) Adds a constraint that places a Node or Edge at the start of the sequence.
void	addPlaceAtTailConstraint(Object id) Adds a constraint that places a Node or Edge at the end of the sequence.
void	addPlaceBeforeConstraint(Object referenceId, Object beforeId) Adds a constraint that forces the Node or Edge with id before to lie before the Node or Edge with id reference.
void	dispose() Disposes of the ISequenceConstraintFactory.
Object	getMemento() Gets a token that allows to bind a constraint factory to a graph instance after creation.

Method Detail

addPlaceAfterConstraint

void addPlaceAfterConstraint(Object referenceId,
                             Object afterId)

Adds a constraint that forces the Node or Edge with id after to lie after the Node or Edge with id reference.

A constraint is only considered if both elements share at least one layer. An edge is associated with each layer that it spans, i.e., each layer between it's source and target (excluding the source and target layer).

Parameters:

referenceId - the ID of the reference node or edge

afterId - the ID of the node or edge that should be placed after the reference element

addPlaceAtHeadConstraint

void addPlaceAtHeadConstraint(Object id)

Adds a constraint that places a Node or Edge at the start of the sequence.

For edges, this constraint applies to each layer that the edge spans including the edge's source and target. Edges with recursive edge style are ignored.

Parameters:

id - the ID of the node or edge that should be placed at the start

addPlaceAtTailConstraint

void addPlaceAtTailConstraint(Object id)

Adds a constraint that places a Node or Edge at the end of the sequence.

For edges, this constraint applies to each layer that the edge spans including the edge's source and target. Edges with recursive edge style are ignored.

Parameters:

id - the ID of the node or edge that should be placed at the end

addPlaceBeforeConstraint

void addPlaceBeforeConstraint(Object referenceId,
                              Object beforeId)

Adds a constraint that forces the Node or Edge with id before to lie before the Node or Edge with id reference.

A constraint is only considered if both elements share at least one layer. An edge is associated with each layer that it spans, i.e., each layer between it's source and target (excluding the source and target layer).

Parameters:

referenceId - the ID of the reference node or edge

beforeId - the ID of the node or edge that should be placed before the reference element

dispose

void dispose()

Disposes of the ISequenceConstraintFactory.

This method should be called when the factory is not needed anymore, i.e. after the layout has been calculated. Calling this method also clears all constraints.

getMemento

Object getMemento()

Gets a token that allows to bind a constraint factory to a graph instance after creation.

This method should only be used if the constraint factory is not bound to a graph instance initially. It allows to bind this factory to a graph instance after creation.

Returns:

a token that allows to bind the constraint factory to a graph instance

See Also:

HierarchicLayoutCore.createSequenceConstraintFactory(com.yworks.yfiles.algorithms.Graph)