SimplexNodePlacer

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This class is a IHierarchicLayoutNodePlacer implementation based on rank assignment.

Inheritance Hierarchy

SimplexNodePlacer

Implemented Interfaces

IHierarchicLayoutNodePlacer

Remarks

The drawer works with integer values and rounds double values to integers using sophisticated quantizing.

Default Values of Properties

barycenterMode	`true`
bendReduction	`true`
exactPlacement	`true`
fromSketchLayerAssignment	`true`
groupCompactionStrategy	NONE	No group compaction is performed.
horizontalCompaction	`false`
labelCompaction	`false`
maximumDuration	`<code>0x7FFFFFFF</code>`	The layout algorithm runs unrestricted.
minimumSublayerDistance	`15.0d`
nodeCompaction	`false`	Nodes are not placed in a compact style.
straightenEdges	`false`	A postprocessing step to reduce the number of bends is not applied.
swimLaneCrossingWeight	`0.0d`	The algorithm ignores edges crossing a swimlane border.

Type Details

yfiles module: layout-hierarchic
yfiles-umd modules: layout-familytree, layout-hierarchic, layout-radial, layout
Legacy UMD name: yfiles.hierarchic.SimplexNodePlacer

Constructors

SimplexNodePlacer

()

Creates a new instance of SimplexNodePlacer with the default settings.

ParametersOptions Overload

options - Object
A map of options to pass to the method.

nodeCompaction - boolean: Whether or not nodes should be placed in a more compact style with respect to layout width. This option sets the nodeCompaction property on the created object.
minimumSublayerDistance - number: The minimum distance between the upper and lower sublayer. This option sets the minimumSublayerDistance property on the created object.
labelCompaction - boolean: Whether or not the SimplexNodePlacer places labels in a more compact style. This option sets the labelCompaction property on the created object.
bendReduction - boolean: Whether or not an optimization step should be applied that tries to further reduce the number of bends. This option sets the bendReduction property on the created object.
horizontalCompaction - boolean: Whether or not the SimplexNodePlacer tries to create a maximally compact horizontal layout at the cost of more bends. This option sets the horizontalCompaction property on the created object.
straightenEdges - boolean: Whether or not a postprocessing step should be applied to reduce the number of bends. This option sets the straightenEdges property on the created object.
groupCompactionStrategy - GroupCompactionPolicy: The strategy used for controlling the horizontal compactness of group nodes. This option sets the groupCompactionStrategy property on the created object.
exactPlacement - boolean: Whether or not the SimplexNodePlacer enforces the placement of nodes at their exact current positions, even if this violates minimum distance constraints. This option sets the exactPlacement property on the created object.
fromSketchLayerAssignment - boolean: Whether or not the SimplexNodePlacer should try to use the coordinates given from the current sketch for the determination of the layer coordinates. This option sets the fromSketchLayerAssignment property on the created object.
maximumDuration - number: The time limit (in milliseconds) set for the layout algorithm. This option sets the maximumDuration property on the created object.
swimLaneCrossingWeight - number: The relative weight of edges crossing a swimlane relative to edges that stay in their lane. This option sets the swimLaneCrossingWeight property on the created object.
barycenterMode - boolean: Whether or not a barycenter drawing mode should be used. This option sets the barycenterMode property on the created object.
breakLongSegments - boolean: Whether or not the SimplexNodePlacer should break long edge segments in favor of a potentially more compact layout. This option sets the breakLongSegments property on the created object.

Properties

barycenterMode

: boolean

Gets or sets whether or not a barycenter drawing mode should be used.

Remarks

If this mode is enabled the resulting drawing is likely to have more bends, but may be more symmetric.

Default Value

The default value is true.

Sample Graphs

Disabling option bendReduction may produce more symmetric results.

bendReduction

: boolean

Gets or sets whether or not an optimization step should be applied that tries to further reduce the number of bends.

Default Value

The default value is true.

breakLongSegments

: boolean

Gets or sets whether or not the SimplexNodePlacer should break long edge segments in favor of a potentially more compact layout.

Remarks

A long edge is an edge that spans multiple layers. For each layer, a dummy node is necessary to model the edge path from source to target.

Not breaking such edges means that there is a constraint that enforces the alignment of all these dummy nodes (same x-coordinate). This favors straight edge paths.
Breaking an edge means that the dummy nodes are not necessarily aligned, but additional bends can be generated if that leads to a horizontally more compact layout result.

Default Value

The default value is false.

Long edges will not be broken, in favor of straight edge paths and better performance.

It is not guaranteed that enabling this setting leads to more compact results. The effect highly depends on the actual input and other algorithm settings. Breaking up the segments might still not allow to make the layout horizontally more compact.

Enabling this setting will in general negatively affect the performance, which might be considerable at least for larger graphs.

exactPlacement

: boolean

Gets or sets whether or not the SimplexNodePlacer enforces the placement of nodes at their exact current positions, even if this violates minimum distance constraints.

Default Value

The default value is true.

fromSketchLayerAssignment

: boolean

Gets or sets whether or not the SimplexNodePlacer should try to use the coordinates given from the current sketch for the determination of the layer coordinates.

Default Value

The default value is true.

Sample Graphs

groupCompactionStrategy

: GroupCompactionPolicy

Gets or sets the strategy used for controlling the horizontal compactness of group nodes.

Default Value

The default value is NONE.

No group compaction is performed.

horizontalCompaction

: boolean

Gets or sets whether or not the SimplexNodePlacer tries to create a maximally compact horizontal layout at the cost of more bends.

Remarks

For best results, breakLongSegments and labelCompaction should also be enabled.

Default Value

The default value is false.

labelCompaction

: boolean

Gets or sets whether or not the SimplexNodePlacer places labels in a more compact style.

Remarks

If this option is enabled the algorithm tries to place adjacent label elements in a stacked style, i.e., horizontally interleaving.

Default Value

The default value is false.

maximumDuration

: number

Gets or sets the time limit (in milliseconds) set for the layout algorithm.

Remarks

Values have to be greater than or equal to 0.

Default Value

The default value is <code>0x7FFFFFFF</code>.

The layout algorithm runs unrestricted.

Throws

Exception({ name: 'ArgumentError' }): if the maximum duration is negative

Restricting the maximum duration may result in a lower layout quality. Furthermore, the real runtime may exceed the maximum duration since the layout algorithm still has to find a valid solution.

minimumSublayerDistance

: number

Gets or sets the minimum distance between the upper and lower sublayer.

Remarks

A too small distance value may prevent adjacent nodes from being placed in a stacked style (horizontally interleaving) because the vertical distance between these nodes must be greater than or equal to the value specified by minimumDistance.

Values should be greater than 0.

Default Value

The default value is 15.0d.

Throws

Exception({ name: 'ArgumentError' }): if minimum sublayer distance is negative

Sample Graphs

This option is only considered if the node compaction is enabled.

nodeCompaction

: boolean

Gets or sets whether or not nodes should be placed in a more compact style with respect to layout width.

Remarks

If enabled, the algorithm may place the nodes of a layer in a stacked style (horizontally interleaving), i.e., it splits the layer into an upper and lower sublayer and places adjacent nodes into different sublayers if this reduces the width of the layer.

Default Value

The default value is false.

Nodes are not placed in a compact style.

Sample Graphs

Enabling this option increases the required layout height.

Nodes within a tabular group are never placed in a stacked style.

This option does not work with customized IDrawingDistanceCalculators, see drawingDistanceCalculator.

straightenEdges

: boolean

Gets or sets whether or not a postprocessing step should be applied to reduce the number of bends.

Remarks

Furthermore, enabling this option may violate some minimum distances specified by the user and the edge distribution is no longer uniform.

Default Value

The default value is false.

A postprocessing step to reduce the number of bends is not applied.

Sample Graphs

This option is only considered if option nodeCompaction is disabled.

swimLaneCrossingWeight

: number

Gets or sets the relative weight of edges crossing a swimlane relative to edges that stay in their lane.

Remarks

Higher values lead to more compact drawings but may cause additional bends.

Values should lie within [0,1] interval.

Default Value

The default value is 0.0d.

The algorithm ignores edges crossing a swimlane border.

Throws

Exception({ name: 'ArgumentError' }): if the relative weight does not lie within [0,1]

Sample Graphs

Methods

assignLayerCoordinates

(graph: LayoutGraph, layoutDataProvider: ILayoutDataProvider, layers: ILayers)

Assigns preliminary y-coordinates for each layer of a hierarchic layout.

Remarks

The distance between two layers will be adjusted later by the edge routing algorithm. This method is responsible for assigning the relative positions of the nodes within each layer.

Parameters

options - Object
A map of options to pass to the method.

graph - LayoutGraph: the input graph
layoutDataProvider - ILayoutDataProvider: the ILayoutDataProvider containing information about the elements
layers - ILayers: the ILayers instance that will be calculated by this method

Implements

IHierarchicLayoutNodePlacer

assignNodesToSublayer

(layerNodes: YNodeList, ldp: ILayoutDataProvider, graph: LayoutGraph, lowerSublayer: INodeMap)

Assigns the nodes of a given layer to the corresponding upper/lower sublayer if node compaction is enabled.

Remarks

Information about sublayers is given by a INodeMap whose getBoolean method has to return true for each node that should be placed in the lower sublayer (values are set by this method).

Parameters

options - Object
A map of options to pass to the method.

layerNodes - YNodeList: a list of all @link y.layout.hierarchic.incremental.NodeData#TYPE_NORMAL normal nodes} of a layer
ldp - ILayoutDataProvider: the ILayoutDataProvider implementation which provides access to the INodeData and IEdgeData instances
graph - LayoutGraph: the given graph
lowerSublayer - INodeMap: the INodeMap holding sublayer information

assignSequenceCoordinates

(graph: LayoutGraph, layoutDataProvider: ILayoutDataProvider, layers: ILayers, drawingDistanceCalculator: IDrawingDistanceCalculator)

Determines the resulting x-coordinates of a hierarchic layout.

Remarks

The minimum distance between each pair of nodes of the graph is determined by a IDrawingDistanceCalculator instance.

Parameters

options - Object
A map of options to pass to the method.

graph - LayoutGraph: the input graph
layoutDataProvider - ILayoutDataProvider: the ILayoutDataProvider containing information about the elements
layers - ILayers: the ILayers instance that will be calculated by this method
drawingDistanceCalculator - IDrawingDistanceCalculator: the given IDrawingDistanceCalculator instance

Implements

IHierarchicLayoutNodePlacer

getLayerAlignment

(graph: LayoutGraph, ldp: ILayoutDataProvider, node: YNode, layerIndex: number, minLayerHeight: number) : number

Returns the alignment of the node with a specified layer.

Remarks

This callback method is used by assignLayerCoordinates.

Parameters

options - Object
A map of options to pass to the method.

graph - LayoutGraph: the input graph
ldp - ILayoutDataProvider: the ILayoutDataProvider implementation which provides access to the INodeData and IEdgeData instances
node - YNode: the given node
layerIndex - number: the index of the layer
minLayerHeight - number: the minimum height of the layer

getMinDistance

(graph: LayoutGraph, layer: ILayer, predNode: YNode, succ: YNode) : number

Specifies the minimum allowed distance between two nodes of the same given layer.

Remarks

This callback method is used by assignSequenceCoordinates.

Parameters

options - Object
A map of options to pass to the method.

graph - LayoutGraph: the graph that contains the nodes
layer - ILayer: the layer that contains the nodes
predNode - YNode: the node to the left of the other one, may be null to indicate a border line
succ - YNode: the node to the right of the other one, may be null to indicate a border line

Returns

↪number: the minimum distance allowed between those two nodes ( >=0 )

getMinimumLayerHeight

(graph: LayoutGraph, ldp: ILayoutDataProvider, layer: ILayer) : number

Returns the minimum height of a given layer.

Remarks

This callback method is used by assignLayerCoordinates.

Parameters

options - Object
A map of options to pass to the method.

graph - LayoutGraph: the given graph
ldp - ILayoutDataProvider: the ILayoutDataProvider implementation which provides access to the INodeData and IEdgeData instances
layer - ILayer: the given ILayer object

Returns

↪number: the minimum height

isFixedNode

(graph: LayoutGraph, provider: ILayoutDataProvider, node: YNode, inLayer: boolean) : boolean

Returns whether or not the given node should be treated as a node with fixed (given) coordinates.

Remarks

This callback method is used by both assignLayerCoordinates and assignSequenceCoordinates.

If inLayer argument is true, this method is called from within the assignLayerCoordinates method.

Parameters

options - Object
A map of options to pass to the method.

graph - LayoutGraph: the given graph
provider - ILayoutDataProvider: the ILayoutDataProvider implementation which provides access to the INodeData and IEdgeData instances
node - YNode: the given node
inLayer - boolean: true if the layer coordinate of the node is queried, false if the sequence coordinate is queried

Returns

↪boolean: true if the node should be treated as fixed, false otherwise

SimplexNodePlacer

Remarks

Default Values of Properties

Type Details

See Also

Constructors

SimplexNodePlacer

ParametersOptions Overload

Properties

barycenterMode

Remarks

Default Value

See Also

Sample Graphs

bendReduction

Default Value

See Also

breakLongSegments

Remarks

Default Value

exactPlacement

Default Value

fromSketchLayerAssignment

Default Value

Sample Graphs

groupCompactionStrategy

Default Value

See Also

horizontalCompaction

Remarks

Default Value

See Also

labelCompaction

Remarks

Default Value

See Also

maximumDuration

Remarks

Default Value

Throws

minimumSublayerDistance

Remarks

Default Value

Throws

See Also

Sample Graphs

nodeCompaction

Remarks

Default Value

See Also

Sample Graphs

straightenEdges

Remarks

Default Value

See Also

Sample Graphs

swimLaneCrossingWeight

Remarks

Default Value

Throws

Sample Graphs

Methods

assignLayerCoordinates

Remarks

Parameters

Implements

assignNodesToSublayer

Remarks

Parameters

See Also

assignSequenceCoordinates

Remarks

Parameters

Implements

getLayerAlignment

Remarks

Parameters

getMinDistance

Remarks

Parameters