com.yworks.yfiles.layout

Class NodeHalo

java.lang.Object

com.yworks.yfiles.layout.NodeHalo

public final class NodeHalo
extends 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 IDataProvider that provides NodeHalos for all nodes of the input graph. NodeHalo-aware layout algorithms like HierarchicLayout look for IDataProviders registered with this key to retrieve NodeHalo information.

The following layouters support NodeHalos with different restrictions:

• HierarchicLayout
• OrthogonalLayout
• CompactOrthogonalLayout
• TreeLayout
• ClassicTreeLayout
• OrganicLayout
• GenericLabeling
• EdgeRouter
• CircularLayout
• BalloonLayout
• SelfLoopRouter
• RadialLayout
• RecursiveGroupLayout
• ComponentLayout

Field Summary

Fields

Modifier and Type	Field and Description
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 NodeDpKey<NodeHalo>	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

Modifier and Type	Method and Description
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(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

bottom

public final double bottom

The NodeHalo size at the bottom side of the node.

left

public final double left

The NodeHalo size at the left side of the node.

NODE_HALO_DPKEY

public static final NodeDpKey<NodeHalo> NODE_HALO_DPKEY

A DataProvider key for assigning halos for the nodes

right

public final double right

The NodeHalo size at the right side of the node.

top

public final double top

The NodeHalo size at the top side of the node.

ZERO_HALO

public static final NodeHalo ZERO_HALO

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

Method Detail

create

public static final 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.

Throws:

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

Parameters:

value - the halo size at each side of the node

Returns:

the newly created NodeHalo

create

public static final 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.

Throws:

IllegalArgumentException - if one of the values is 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

equals

public boolean equals(Object o)

Overrides:

equals in class Object

getHalo

public static final 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 final 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

hasHalos

public static final boolean hasHalos(LayoutGraph graph)

Checks whether or not the given graph contains NodeHalo information.

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

Parameters:

graph - the input graph

Returns:

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

hashCode

public int hashCode()

Overrides:

hashCode in class Object