com.github.gwtd3.api.layout

Class HierarchicalLayout<L,T,N extends HierarchicalLayout.Node<T>>

java.lang.Object

com.google.gwt.core.client.JavaScriptObject

com.github.gwtd3.api.layout.HierarchicalLayout<L,T,N>

Type Parameters:

L - the concrete subclass of layout

T - the type of datum in each node

N - the concrete subclass of node

Direct Known Subclasses:

Cluster, Tree

public abstract class HierarchicalLayout<L,T,N extends HierarchicalLayout.Node<T>>
extends com.google.gwt.core.client.JavaScriptObject

Base class for all hierarchical layouts.

You should use only concrete subclass of this one

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	HierarchicalLayout.Link<T> A link between two nodes in a HierarchicalLayout.
static class	HierarchicalLayout.Node<T> A node used in a HierarchicalLayout.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	HierarchicalLayout()

Method Summary

Modifier and Type	Method and Description
L	children(DatumFunction<List<T>> df) Sets the specified children accessor function.
Array<HierarchicalLayout.Link<T>>	links(Array<N> n) Given the specified array of nodes, such as those returned by nodes, returns an array of objects representing the from parent to child for each node.
Array<N>	nodes(T data) Runs the layout, returning the array of nodes associated with the specified root node.
L	sort(Comparator<N> comparator) Sets the sort order of sibling nodes for the layout using the specified comparator function.
L	sort(com.google.gwt.core.client.JavaScriptObject sortFunction) Sets the sort order of sibling nodes for the layout using the specified comparator function.
protected com.google.gwt.core.client.JavaScriptObject	toJSOComparator(Comparator<N> comparator) internal trampoline method
DatumFunction<Integer>	value() Returns the current value accessor which defaults to null, meaning that the value attribute is not computed.
L	value(DatumFunction<Integer> df) Sets the value accessor to the specified function.

Methods inherited from class com.google.gwt.core.client.JavaScriptObject

cast, createArray, createArray, createFunction, createObject, equals, hashCode, toSource, toString

Methods inherited from class java.lang.Object

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

Constructor Detail

HierarchicalLayout

protected HierarchicalLayout()

Method Detail

nodes

public final Array<N> nodes(T data)

Runs the layout, returning the array of nodes associated with the specified root node.

The input argument to layout is the root node of the hierarchy, and the output return value is an array representing the computed positions of all nodes. Several attributes are populated on each node:

• parent - the parent HierarchicalLayout.Node, or null for the root.
• children - the array of child nodes, or null for leaf nodes.
• depth - the depth of the node, starting at 0 for the root.
• x - the computed x-coordinate of the node position.
• y - the computed y-coordinate of the node position.

Although the layout has a size in x and y, this represents an arbitrary coordinate system; for example, you can treat x as a radius and y as an angle to produce a radial rather than Cartesian layout.

Parameters:

data - the root node of the hierarchy

Returns:

array of computed HierarchicalLayout.Nodes

links

public final Array<HierarchicalLayout.Link<T>> links(Array<N> n)

Given the specified array of nodes, such as those returned by nodes, returns an array of objects representing the from parent to child for each node. Leaf nodes will not have any links. Each link is an object with two attributes:

• source - the parent node (as described above).
• target - the child node.

This method is useful for retrieving a set of link descriptions suitable for display, often in conjunction with the Diagonal shape generator.

Parameters:

the - array of nodes, as returned by nodes(Object)

Returns:

array of HierarchicalLayout.Link connecting nodes

children

public final L children(DatumFunction<List<T>> df)

Sets the specified children accessor function. The default children accessor function assumes the input data is an object with a children array. The children accessor is first invoked for root node in the hierarchy. If the accessor returns null, then the node is assumed to be a leaf node at the layout traversal terminates. Otherwise, the accessor should return an array of data elements representing the child nodes.

Parameters:

df - a datum function describing how to compute children

Returns:

this layout for chaining

value

public final L value(DatumFunction<Integer> df)

Sets the value accessor to the specified function. The value accessor is invoked for each input data element, and must return a number representing the numeric value of the node.

For area-proportional layouts such as treemaps, this value is used to set the area of each node proportionally to the value; for other hierarchical layouts, the value has no effect on the layout.

Parameters:

df - a datum function describing how to access node values

Returns:

this layout for chaining

value

public final DatumFunction<Integer> value()

Returns the current value accessor which defaults to null, meaning that the value attribute is not computed.

Returns:

the current datum function registered for calculating node values

sort

public final L sort(Comparator<N> comparator)

Sets the sort order of sibling nodes for the layout using the specified comparator function.

The comparator function is invoked for pairs of nodes, being passed the input data for each node. The default comparator is null, which disables sorting and uses tree traversal order. Sorting by the node's name or key is common and can be done easily via sort(JavaScriptObject) using D3#ascending() or D3#descending().

Parameters:

comparator - the comparator to use or null to remove the sort

Returns:

this layout for chaining

sort

public final L sort(com.google.gwt.core.client.JavaScriptObject sortFunction)

Sets the sort order of sibling nodes for the layout using the specified comparator function.

The comparator function is invoked for pairs of nodes, being passed the input data for each node. The default comparator is null, which disables sorting and uses tree traversal order. Sorting by the node's name or key is common and can be done easily using D3#ascending() or D3#descending().

From Java, you may prefer use sort(Comparator).

Parameters:

sortFunction - the comparator to use or null to remove the sort

Returns:

this layout for chaining

toJSOComparator

protected final com.google.gwt.core.client.JavaScriptObject toJSOComparator(Comparator<N> comparator)

internal trampoline method

Parameters:

comparator -

Returns: