com.yworks.yfiles.layout.tree

Class DefaultNodePlacer

java.lang.Object

com.yworks.yfiles.layout.tree.AbstractNodePlacer

com.yworks.yfiles.layout.tree.DefaultNodePlacer

All Implemented Interfaces:

IFromSketchNodePlacer, INodePlacer, ICloneable, Cloneable

public class DefaultNodePlacer
extends AbstractNodePlacer
implements IFromSketchNodePlacer, ICloneable

DefaultNodePlacer is the default implementation of interface INodePlacer.

Layout Style

The layout style can be customized in several ways. Subtrees sharing the same local root node are either placed above or below each other.

Each layer in the tree uses different configurations of DefaultNodePlacer

Features

TreeLayout.SubtreeShapes can be arranged in each main direction specified in ChildPlacement. That way, the subtrees of the same graph can have different directions.

This node placer aligns the local root node according to a chosen alignment.

There are various routing styles that result in different edge routes.

Field Summary

Fields inherited from class com.yworks.yfiles.layout.tree.AbstractNodePlacer

graph

Constructor Summary

Constructors

Constructor and Description
DefaultNodePlacer() Creates a new DefaultNodePlacer instance with default settings.
DefaultNodePlacer(ChildPlacement childPlacement, double verticalDistance, double horizontalDistance) Creates a new DefaultNodePlacer instance with customized child placement, vertical and horizontal distance.
DefaultNodePlacer(ChildPlacement childPlacement, RootAlignment rootAlignment, double verticalDistance, double horizontalDistance) Creates a new DefaultNodePlacer instance with customized child placement, root alignment, vertical and horizontal distance.
DefaultNodePlacer(ChildPlacement childPlacement, RootAlignment rootAlignment, RoutingStyle routingStyle, double verticalDistance, double horizontalDistance) Creates a new DefaultNodePlacer instance with customized child placement, root alignment, routing style, vertical and horizontal distance.
DefaultNodePlacer(ChildPlacement childPlacement, RootAlignment rootAlignment, RoutingStyle routingStyle, double verticalDistance, double horizontalDistance, double minFirstSegmentLength, double minLastSegmentLength, double minSlope, double minSlopeHeight) Creates a new DefaultNodePlacer instance with custom settings.

Method Summary

Modifier and Type	Method and Description
protected void	calculateParentConnector(LayoutGraph graph, Node localRoot, INodeLayout rootLayout, TreeLayout.SubtreeShape subtreeShape, Edge parentEdge, IEdgeLayout parentEdgeLayout, byte direction) Calculates the bends for the connector to the parent node.
protected void	calculateSlopedSourceEdgeLayout(INodeLayout rootLayout, TreeLayout.SubtreeShape childShape, Edge edge, double childForkCoordinate, double rootForkCoordinate) Calculates the routing of the source side of the edge to the given child node.
protected void	calculateSourceEdgeLayout(INodeLayout rootLayout, TreeLayout.SubtreeShape childShape, Edge edge) Calculates the routing of the source side of the edge to the given child node.
protected void	calculateTargetEdgeLayout(INodeLayout rootLayout, TreeLayout.SubtreeShape childShape, Edge edge) Calculates the routing of the target side of the edge to the given child node.
Comparator<Object>	createComparator() Creates a Comparator for outgoing edges which takes the initial coordinates of the edges' targets into account.
Comparator<Object>	createFromSketchComparator() Delegates to createComparator().
protected ParentConnectorDirection	determineChildConnector(Node child) Determines a connector direction for the given child node depending on the selected child placement.
ChildPlacement	getChildPlacement() Gets the direction in which the child nodes are placed with respect to their parent node.
double	getHorizontalDistance() Gets the horizontal distance between nodes or TreeLayout.SubtreeShapes.
double	getMinimumFirstSegmentLength() Gets the minimum length for the first segment of an edge.
double	getMinimumLastSegmentLength() Gets the minimum length for the last segment of an edge.
double	getMinimumSlope() Gets the minimum slope of the edge segments.
double	getMinimumSlopeHeight() Gets the minimum height for sloped edge segments.
RootAlignment	getRootAlignment() Gets how the root node is aligned with its children and their TreeLayout.SubtreeShapes.
RoutingStyle	getRoutingStyle() Gets the style in which edge paths are routed.
double	getVerticalAlignment() Gets the relative vertical alignment of nodes with the same parent.
double	getVerticalDistance() Gets the vertical distance between nodes or TreeLayout.SubtreeShapes.
protected TreeLayout.SubtreeShape	placeSubtree(Node localRoot, ParentConnectorDirection parentConnectorDirection) Arranges the root node and its children.
void	setChildPlacement(ChildPlacement value) Sets the direction in which the child nodes are placed with respect to their parent node.
void	setHorizontalDistance(double value) Sets the horizontal distance between nodes or TreeLayout.SubtreeShapes.
void	setMinimumFirstSegmentLength(double value) Sets the minimum length for the first segment of an edge.
void	setMinimumLastSegmentLength(double value) Sets the minimum length for the last segment of an edge.
void	setMinimumSlope(double value) Sets the minimum slope of the edge segments.
void	setMinimumSlopeHeight(double value) Sets the minimum height for sloped edge segments.
void	setRootAlignment(RootAlignment value) Sets how the root node is aligned with its children and their TreeLayout.SubtreeShapes.
void	setRoutingStyle(RoutingStyle value) Sets the style in which edge paths are routed.
void	setVerticalAlignment(double value) Sets the relative vertical alignment of nodes with the same parent.
void	setVerticalDistance(double value) Sets the vertical distance between nodes or TreeLayout.SubtreeShapes.

Methods inherited from class com.yworks.yfiles.layout.tree.AbstractNodePlacer

clone, createProcessor, determineChildConnectors, getNodeShape, getSubtreeShape, placeSubtree

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.yworks.yfiles.layout.tree.INodePlacer

createProcessor, determineChildConnectors, placeSubtree

Methods inherited from interface com.yworks.yfiles.utils.ICloneable

clone

Constructor Detail

DefaultNodePlacer

public DefaultNodePlacer()

Creates a new DefaultNodePlacer instance with default settings.

DefaultNodePlacer

public DefaultNodePlacer(ChildPlacement childPlacement,
                         double verticalDistance,
                         double horizontalDistance)

Creates a new DefaultNodePlacer instance with customized child placement, vertical and horizontal distance.

Throws:

IllegalArgumentException - if the placement specifier is unknown or if the horizontal/vertical distance is negative

Parameters:

childPlacement - the child placement specifier describing the style of the arrangement

verticalDistance - the vertical distance between the TreeLayout.SubtreeShapes

horizontalDistance - the horizontal distance between the TreeLayout.SubtreeShapes

See Also:

setChildPlacement(ChildPlacement), setVerticalDistance(double), setHorizontalDistance(double)

DefaultNodePlacer

public DefaultNodePlacer(ChildPlacement childPlacement,
                         RootAlignment rootAlignment,
                         double verticalDistance,
                         double horizontalDistance)

Creates a new DefaultNodePlacer instance with customized child placement, root alignment, vertical and horizontal distance.

Throws:

IllegalArgumentException - if the placement specifier or the root alignment specifier is unknown or if the horizontal/vertical distance is negative

Parameters:

childPlacement - the child placement specifier describing the style of the arrangement

rootAlignment - the alignment specifier describing how the root node is aligned with its child nodes

verticalDistance - the vertical distance between the TreeLayout.SubtreeShapes

horizontalDistance - the horizontal distance between the TreeLayout.SubtreeShapes

See Also:

setChildPlacement(ChildPlacement), setRootAlignment(RootAlignment), setVerticalDistance(double), setHorizontalDistance(double)

DefaultNodePlacer

public DefaultNodePlacer(ChildPlacement childPlacement,
                         RootAlignment rootAlignment,
                         RoutingStyle routingStyle,
                         double verticalDistance,
                         double horizontalDistance)

Creates a new DefaultNodePlacer instance with customized child placement, root alignment, routing style, vertical and horizontal distance.

Throws:

IllegalArgumentException - if the placement specifier or the root alignment or the routing style is unknown or if the horizontal/vertical distance is negative

Parameters:

childPlacement - the child placement specifier describing the style of the arrangement

rootAlignment - the alignment specifier describing how the root node is aligned with its child nodes

routingStyle - the routing style specifier

verticalDistance - the vertical distance between the TreeLayout.SubtreeShapes

horizontalDistance - the horizontal distance between the TreeLayout.SubtreeShapes

See Also:

setChildPlacement(ChildPlacement), setRootAlignment(RootAlignment), setRoutingStyle(RoutingStyle), setVerticalDistance(double), setHorizontalDistance(double)

DefaultNodePlacer

public DefaultNodePlacer(ChildPlacement childPlacement,
                         RootAlignment rootAlignment,
                         RoutingStyle routingStyle,
                         double verticalDistance,
                         double horizontalDistance,
                         double minFirstSegmentLength,
                         double minLastSegmentLength,
                         double minSlope,
                         double minSlopeHeight)

Creates a new DefaultNodePlacer instance with custom settings.

Throws:

IllegalArgumentException - if the placement specifier or the root alignment or the routing style is unknown or if the horizontal/vertical distance or the minimum first/last segment length or the minimum slope or the minimum vertical height is negative

Parameters:

childPlacement - the child placement specifier describing the style of the arrangement

rootAlignment - the alignment specifier describing how the root node is aligned with its child nodes

routingStyle - the routing style specifier

verticalDistance - the vertical distance between the TreeLayout.SubtreeShapes

horizontalDistance - the horizontal distance between the TreeLayout.SubtreeShapes

minFirstSegmentLength - the minimum length of the first edge segment (connected to the root node)

minLastSegmentLength - the minimum length of the last edge segment (connected to the child node)

minSlope - the minimum slope between the root node and the TreeLayout.SubtreeShapes

minSlopeHeight - the minimum vertical height of sloped edge segments

See Also:

setChildPlacement(ChildPlacement), setRootAlignment(RootAlignment), setRoutingStyle(RoutingStyle), setVerticalDistance(double), setHorizontalDistance(double), setMinimumFirstSegmentLength(double), setMinimumLastSegmentLength(double), setMinimumSlope(double), setMinimumSlopeHeight(double)

Method Detail

calculateParentConnector

protected void calculateParentConnector(LayoutGraph graph,
                                        Node localRoot,
                                        INodeLayout rootLayout,
                                        TreeLayout.SubtreeShape subtreeShape,
                                        Edge parentEdge,
                                        IEdgeLayout parentEdgeLayout,
                                        byte direction)

Calculates the bends for the connector to the parent node.

This implementation adds bends to the connector for edges that route the edges around the child node in case there are PortConstraints that conflict with the direction of the child placement.

This method is called in placeSubtree(Node, ParentConnectorDirection) to route the edges after the TreeLayout.SubtreeShapes are arranged. It may be overridden to customize the routing style.

Parameters:

graph - the input graph

localRoot - the local root node whose connector is calculated and stored in the given subtree shape

rootLayout - the INodeLayout of the root node

subtreeShape - the shape of the whole subtree of the local root

parentEdge - the incoming edge of the local root node that will be the connector for the given subtree shape

parentEdgeLayout - the current IEdgeLayout of the connector edge

direction - the direction specifier as defined in the INodePlacer interface which should be used for the connector

See Also:

AbstractNodePlacer.determineChildConnectors(Node, com.yworks.yfiles.algorithms.IDataMap)

calculateSlopedSourceEdgeLayout

protected void calculateSlopedSourceEdgeLayout(INodeLayout rootLayout,
                                               TreeLayout.SubtreeShape childShape,
                                               Edge edge,
                                               double childForkCoordinate,
                                               double rootForkCoordinate)

Calculates the routing of the source side of the edge to the given child node.

This method delegates to calculateSourceEdgeLayout(INodeLayout, TreeLayout.SubtreeShape, Edge) if the routing style is not RoutingStyle.FORK. It may be overridden to implement a custom routing style.

Parameters:

rootLayout - the INodeLayout of the local root node

childShape - the TreeLayout.SubtreeShape instance of the corresponding child's subtree

edge - the edge

rootForkCoordinate - the y-coordinate of the first bend of the edge if the placement is horizontal, the x-coordinate otherwise

childForkCoordinate - the y-coordinate of the second (= last) bend of the edge if the placement is horizontal, the x-coordinate otherwise

calculateSourceEdgeLayout

protected void calculateSourceEdgeLayout(INodeLayout rootLayout,
                                         TreeLayout.SubtreeShape childShape,
                                         Edge edge)

Calculates the routing of the source side of the edge to the given child node.

This implementation adds bends to the IEdgeLayout of the given edge according to the specified routing style and child placement. It also updates the target points in the TreeLayout.SubtreeShape.

This method is called by calculateSlopedSourceEdgeLayout(INodeLayout, TreeLayout.SubtreeShape, Edge, double, double) to route the edges. It may be overridden to implement a custom edge routing style.

Parameters:

rootLayout - the INodeLayout of the local root node

childShape - the TreeLayout.SubtreeShape of the child's subtree that is connected through the given edge

edge - the edge

calculateTargetEdgeLayout

protected void calculateTargetEdgeLayout(INodeLayout rootLayout,
                                         TreeLayout.SubtreeShape childShape,
                                         Edge edge)

Calculates the routing of the target side of the edge to the given child node.

This implementation just resets the current IEdgeLayout.

This method is called by placeSubtree(Node, ParentConnectorDirection) after the shapes of the local root's children are placed. It may be overridden to add some target points to the edge.

Parameters:

rootLayout - the INodeLayout of the local root node

childShape - the TreeLayout.SubtreeShape of the child's subtree that is connected through the given edge

edge - the edge

createComparator

public Comparator<Object> createComparator()

Creates a Comparator for outgoing edges which takes the initial coordinates of the edges' targets into account.

Child nodes are sorted in a way that the layout will resemble the current arrangement of the nodes. This is especially useful for interactive or incremental layout calculation.

Returns:

a Comparator that considers the initial coordinates of the nodes

createFromSketchComparator

public Comparator<Object> createFromSketchComparator()

Delegates to createComparator().

Specified by:

createFromSketchComparator in interface IFromSketchNodePlacer

Returns:

the From Sketch Comparator

See Also:

createComparator()

determineChildConnector

protected ParentConnectorDirection determineChildConnector(Node child)

Determines a connector direction for the given child node depending on the selected child placement.

If the child nodes are placed below the root node, the edge should connect north. If they are placed above the root node it should connect south. The vertical placements are handled analogous.

Specified by:

determineChildConnector in class AbstractNodePlacer

Parameters:

child - the child node

Returns:

the connector direction depending on the child placement

See Also:

getChildPlacement()

getChildPlacement

public ChildPlacement getChildPlacement()

Gets the direction in which the child nodes are placed with respect to their parent node.

Subtrees can be placed below, above, left or right of their roots.

Throws:

IllegalArgumentException - if an unknown placement specifier is set

Default Value:

The default value is ChildPlacement.HORIZONTAL_DOWNWARD

Returns:

one of the valid placement specifiers

See Also:

setChildPlacement(ChildPlacement)

getHorizontalDistance

public double getHorizontalDistance()

Gets the horizontal distance between nodes or TreeLayout.SubtreeShapes.

The distance needs to be non-negative.

Throws:

IllegalArgumentException - if the specified distance is negative

Default Value:

The default value is 40.

Returns:

the non-negative horizontal distance

See Also:

setHorizontalDistance(double)

getMinimumFirstSegmentLength

public double getMinimumFirstSegmentLength()

Gets the minimum length for the first segment of an edge.

During layout calculation, the edges of the tree are directed. Hence, the first segment is always the segment that is attached to the source, which is the local root node.

The length needs to be non-negative.

Throws:

IllegalArgumentException - if the minimum segment length is negative

Default Value:

The default value is 0.

Returns:

the non-negative minimum segment length

See Also:

setMinimumFirstSegmentLength(double)

getMinimumLastSegmentLength

public double getMinimumLastSegmentLength()

Gets the minimum length for the last segment of an edge.

During layout calculation, the edges of the tree are directed. Hence, the last segment is always the segment that is attached to the target, which is a child node.

The length needs to be non-negative.

Throws:

IllegalArgumentException - if the minimum segment length is negative

Default Value:

The default value is 0.

Returns:

the non-negative minimum segment length

See Also:

setMinimumLastSegmentLength(double)

getMinimumSlope

public double getMinimumSlope()

Gets the minimum slope of the edge segments.

These sloped segments are between the vertical first and last segment of the edge.

The segments may become steeper but they will have at least the specified slope. Negative minimum slopes can lead to edge routes looking like spider legs.

The actual slopes also depend on the vertical distance slope segments can have.

Default Value:

The default value is 0.

Returns:

the minimum slope

See Also:

setMinimumSlopeHeight(double), setMinimumSlope(double)

getMinimumSlopeHeight

public double getMinimumSlopeHeight()

Gets the minimum height for sloped edge segments.

These sloped segments are between the vertical first and last segment of the edge.

The segments may become steeper to reach the specified height.

The actual slopes also depend on the MinimumSlope minimum slope} segments can have.

Default Value:

The default value is 0.

Returns:

the minimum height for sloped segments

See Also:

setMinimumSlope(double), setMinimumSlopeHeight(double)

getRootAlignment

public RootAlignment getRootAlignment()

Gets how the root node is aligned with its children and their TreeLayout.SubtreeShapes.

Throws:

IllegalArgumentException - if an unknown root alignment specifier is set

Default Value:

The default value is RootAlignment.CENTER

Returns:

one of the valid root alignment specifiers

See Also:

setRootAlignment(RootAlignment)

getRoutingStyle

public RoutingStyle getRoutingStyle()

Gets the style in which edge paths are routed.

Throws:

IllegalArgumentException - if the specified routing style is unknown

Default Value:

The default value is RoutingStyle.FORK

Returns:

the routing style specifier

See Also:

setRoutingStyle(RoutingStyle)

getVerticalAlignment

public double getVerticalAlignment()

Gets the relative vertical alignment of nodes with the same parent.

All values between 0 and 1 result in a valid alignment.

• 0 - nodes are top-aligned
• 0.5 - nodes are center-aligned
• 1 - nodes are bottom-aligned

Values outside the interval [0,1] will result in a more compact node placement with unaligned nodes.

Default Value:

The default value is -1. Nodes are not aligned.

Returns:

the relative vertical alignment of nodes that have the same parent node

See Also:

setVerticalAlignment(double)

getVerticalDistance

public double getVerticalDistance()

Gets the vertical distance between nodes or TreeLayout.SubtreeShapes.

The distance needs to be non-negative.

Throws:

IllegalArgumentException - if the specified distance is negative

Default Value:

The default value is 40.

Returns:

the non-negative vertical distance

See Also:

setVerticalDistance(double)

placeSubtree

protected TreeLayout.SubtreeShape placeSubtree(Node localRoot,
                                               ParentConnectorDirection parentConnectorDirection)

Arranges the root node and its children.

Specified by:

placeSubtree in class AbstractNodePlacer

Parameters:

localRoot - the local root node

parentConnectorDirection - the direction of the connector

Returns:

the merged TreeLayout.SubtreeShape containing the local root and all its subtrees

setChildPlacement

public void setChildPlacement(ChildPlacement value)

Sets the direction in which the child nodes are placed with respect to their parent node.

Subtrees can be placed below, above, left or right of their roots.

Throws:

IllegalArgumentException - if an unknown placement specifier is set

Default Value:

The default value is ChildPlacement.HORIZONTAL_DOWNWARD

Parameters:

value - one of the valid placement specifiers

See Also:

getChildPlacement()

setHorizontalDistance

public void setHorizontalDistance(double value)

Sets the horizontal distance between nodes or TreeLayout.SubtreeShapes.

The distance needs to be non-negative.

Throws:

IllegalArgumentException - if the specified distance is negative

Default Value:

The default value is 40.

Parameters:

value - the non-negative horizontal distance

See Also:

getHorizontalDistance()

setMinimumFirstSegmentLength

public void setMinimumFirstSegmentLength(double value)

Sets the minimum length for the first segment of an edge.

During layout calculation, the edges of the tree are directed. Hence, the first segment is always the segment that is attached to the source, which is the local root node.

The length needs to be non-negative.

Throws:

IllegalArgumentException - if the minimum segment length is negative

Default Value:

The default value is 0.

Parameters:

value - the non-negative minimum segment length

See Also:

getMinimumFirstSegmentLength()

setMinimumLastSegmentLength

public void setMinimumLastSegmentLength(double value)

Sets the minimum length for the last segment of an edge.

During layout calculation, the edges of the tree are directed. Hence, the last segment is always the segment that is attached to the target, which is a child node.

The length needs to be non-negative.

Throws:

IllegalArgumentException - if the minimum segment length is negative

Default Value:

The default value is 0.

Parameters:

value - the non-negative minimum segment length

See Also:

getMinimumLastSegmentLength()

setMinimumSlope

public void setMinimumSlope(double value)

Sets the minimum slope of the edge segments.

These sloped segments are between the vertical first and last segment of the edge.

The segments may become steeper but they will have at least the specified slope. Negative minimum slopes can lead to edge routes looking like spider legs.

The actual slopes also depend on the vertical distance slope segments can have.

Default Value:

The default value is 0.

Parameters:

value - the minimum slope

See Also:

setMinimumSlopeHeight(double), getMinimumSlope()

setMinimumSlopeHeight

public void setMinimumSlopeHeight(double value)

Sets the minimum height for sloped edge segments.

These sloped segments are between the vertical first and last segment of the edge.

The segments may become steeper to reach the specified height.

The actual slopes also depend on the MinimumSlope minimum slope} segments can have.

Default Value:

The default value is 0.

Parameters:

value - the minimum height for sloped segments

See Also:

setMinimumSlope(double), getMinimumSlopeHeight()

setRootAlignment

public void setRootAlignment(RootAlignment value)

Sets how the root node is aligned with its children and their TreeLayout.SubtreeShapes.

Throws:

IllegalArgumentException - if an unknown root alignment specifier is set

Default Value:

The default value is RootAlignment.CENTER

Parameters:

value - one of the valid root alignment specifiers

See Also:

getRootAlignment()

setRoutingStyle

public void setRoutingStyle(RoutingStyle value)

Sets the style in which edge paths are routed.

Throws:

IllegalArgumentException - if the specified routing style is unknown

Default Value:

The default value is RoutingStyle.FORK

Parameters:

value - the routing style specifier

See Also:

getRoutingStyle()

setVerticalAlignment

public void setVerticalAlignment(double value)

Sets the relative vertical alignment of nodes with the same parent.

All values between 0 and 1 result in a valid alignment.

• 0 - nodes are top-aligned
• 0.5 - nodes are center-aligned
• 1 - nodes are bottom-aligned

Values outside the interval [0,1] will result in a more compact node placement with unaligned nodes.

Default Value:

The default value is -1. Nodes are not aligned.

Parameters:

value - the relative vertical alignment of nodes that have the same parent node

See Also:

getVerticalAlignment()

setVerticalDistance

public void setVerticalDistance(double value)

Sets the vertical distance between nodes or TreeLayout.SubtreeShapes.

The distance needs to be non-negative.

Throws:

IllegalArgumentException - if the specified distance is negative

Default Value:

The default value is 40.

Parameters:

value - the non-negative vertical distance

See Also:

getVerticalDistance()