y.layout
Class NodeHalo

java.lang.Object
  y.layout.NodeHalo

public final class NodeHalo
extends java.lang.Object

A NodeHalo specifies a rectangular area around a specific node. A layout algorithm that supports NodeHalos, keeps this area clear of graph elements, except the node labels of this specific node and the adjacent segments of its edges. All minimum distances to this node, which are used in the layout calculation, e.g., minimum first segment length, will be extended by the halo size.

This class defines a key used for registering a DataProvider that provides NodeHalos for all nodes of the input graph. NodeHalo-aware layout algorithms like IncrementalHierarchicLayouter look for DataProviders registered with this key to retrieve NodeHalo information.

The following layouters support NodeHalos with different restrictions:

• IncrementalHierarchicLayouter
• OrthogonalLayouter
• CompactOrthogonalLayouter
• OrthogonalGroupLayouter
• DirectedOrthogonalLayouter
• GenericTreeLayouter
• TreeLayouter
• TabularLayouter
• SmartOrganicLayouter
  • if the scope is set to SmartOrganicLayouter.SCOPE_SUBSET, SmartOrganicLayouter.SCOPE_MAINLY_SUBSET or SmartOrganicLayouter.SCOPE_MAINLY_SUBSET_GEOMETRIC, there might be some overlapping nodes and NodeHalos
  • if node overlaps are allowed, NodeHalos may also overlap
  • edges do not consider NodeHalos
• MISLabelingAlgorithm
  • if there is not enough space, labels may overlap with NodeHalos
• EdgeRouter
  • other constraints (e.g. PortConstraints) with higher costs may cause edges to cross NodeHalos
• CircularLayouter
  • NodeHalo overlaps may occur if the internal BalloonLayouter allows overlaps
  • edges do not consider NodeHalos
• BalloonLayouter
  • NodeHalo overlaps may occur, if BalloonLayouter.setAllowOverlaps(boolean) is enabled
  • edges do not consider NodeHalos
• SelfLoopLayouter
  • if there is not enough space, self-loops may overlap with NodeHalos
• RadialLayouter
  • non-tree edges do not consider NodeHalos
• RecursiveGroupLayouter
• ComponentLayouter

Field Summary

double	bottom The NodeHalo size at the bottom side of the node.
double	left The NodeHalo size at the left side of the node.
static java.lang.Object	NODE_HALO_DPKEY A DataProvider key for assigning halos for the nodes
double	right The NodeHalo size at the right side of the node.
double	top The NodeHalo size at the top side of the node.
static NodeHalo	ZERO_HALO A constant holding a NodeHalo with zero size on each side.

Method Summary

static NodeHalo	create(double value) Creates a NodeHalo object with the specified value on each side of the node.
static NodeHalo	create(double top, double left, double bottom, double right) Creates a NodeHalo with the specified values.
boolean	equals(java.lang.Object o)
static NodeHalo	getHalo(LayoutGraph graph, Node node) Returns the NodeHalo associated with the given node.
static YRectangle	getHaloBox(LayoutGraph graph, Node node) Returns a YRectangle instance with the bounds of the given node including its NodeHalo.
static boolean	hasHalos(LayoutGraph graph) Checks whether or not the given graph contains NodeHalo information.
int	hashCode()

Methods inherited from class java.lang.Object

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

Field Detail

NODE_HALO_DPKEY

public static final java.lang.Object NODE_HALO_DPKEY

A DataProvider key for assigning halos for the nodes

ZERO_HALO

public static final NodeHalo ZERO_HALO

A constant holding a NodeHalo with zero size on each side.

top

public final double top

The NodeHalo size at the top side of the node.

left

public final double left

The NodeHalo size at the left side of the node.

bottom

public final double bottom

The NodeHalo size at the bottom side of the node.

right

public final double right

The NodeHalo size at the right side of the node.

Method Detail

create

public static NodeHalo create(double top,
                              double left,
                              double bottom,
                              double right)

Creates a NodeHalo with the specified values.

The values must not be negative, Double.NaN or Double.POSITIVE_INFINITY.

Parameters:

top - the NodeHalo size at the top side of the node

left - the NodeHalo size at the left side of the node

bottom - the NodeHalo size at the bottom side of the node

right - the NodeHalo size at the right side of the node

Returns:

the newly created NodeHalo

Throws:

java.lang.IllegalArgumentException - if one of the values is negative, Double.NaN or Double.POSITIVE_INFINITY

create

public static NodeHalo create(double value)

Creates a NodeHalo object with the specified value on each side of the node.

The value must not be negative, Double.NaN or Double.POSITIVE_INFINITY.

Parameters:

value - the halo size at each side of the node

Returns:

the newly created NodeHalo

Throws:

java.lang.IllegalArgumentException - if the value is negative, Double.NaN or Double.POSITIVE_INFINITY

hasHalos

public static boolean hasHalos(LayoutGraph graph)

Checks whether or not the given graph contains NodeHalo information.

This method looks for a DataProvider that has been registered with the given graph using NODE_HALO_DPKEY.

Parameters:

graph - the input graph

Returns:

true if a DataProvider has been registered with the according key, false otherwise

getHalo

public static NodeHalo getHalo(LayoutGraph graph,
                               Node node)

Returns the NodeHalo associated with the given node.

If no such NodeHalo is available, this method returns a ZERO_HALO.

Parameters:

graph - the graph containing the given node

node - the node whose NodeHalo will be determined

Returns:

the NodeHalo of the given node if available, otherwise a ZERO_HALO

getHaloBox

public static YRectangle getHaloBox(LayoutGraph graph,
                                    Node node)

Returns a YRectangle instance with the bounds of the given node including its NodeHalo.

This YRectangle is located at the position of the node.

If the node does not have a NodeHalo assigned, this box has the same size as the node.

Parameters:

graph - the graph containing the given node

node - the node whose NodeHalo will be determined

Returns:

a YRectangle instance with the bounds of the given node including its NodeHalo

equals

public boolean equals(java.lang.Object o)

Overrides:

equals in class java.lang.Object

hashCode

public int hashCode()

Overrides:

hashCode in class java.lang.Object