Edge (yFiles-for-JavaFX-Complete-3.0 API)

java.lang.Object
- com.yworks.yfiles.algorithms.GraphObject
- - com.yworks.yfiles.algorithms.Edge

```
public class Edge
extends GraphObject
```
Represents an edge, i.e., a directed connection between two nodes (represented by instances of class Node) in the directed graph data type Graph.

The directed stems from the fact that an edge has a distinct source node and a distinct target node. Using pair notation, an edge would be written as (<source node>, <target node>).

Most notably, an edge provides access to its source node (Source) and its target node (Target). Note that an edge can have the same node as its source and target. Such an edge is then called "self-loop" and method SelfLoop yields true.

Important: Class Graph is the single authority for any structural changes to the graph data type. Specifically, this means that there is no way to create or delete a node or an edge without using an actual Graph instance.

Constructor Summary

Constructors
Modifier	Constructor and Description
`protected`	`Edge(Graph g, Node v, Edge e1, Node w, Edge e2, GraphElementInsertion d1, GraphElementInsertion d2)` Creates a new edge that belongs to the given graph.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`Edge`	`createCopy(Graph g, Node v, Node w)` Creates a copy of this edge that will be inserted into the given graph connecting the given source and target nodes.
`Graph`	`getGraph()` Gets the graph this edge belongs to.
`int`	`index()` Gets the index of this edge within its graph G.
`boolean`	`isSelfLoop()` Gets `true` if and only if this edge is a self-loop.
`Edge`	`nextInEdge()` Gets the successor of this edge in the list of incoming edges at its target node.
`Edge`	`nextOutEdge()` Gets the successor of this edge in the list of outgoing edges at its source node.
`protected void`	`onReinsert()` Callback method that is invoked from a graph just before this edge will be reinserted into that graph.
`Node`	`opposite(Node v)` Returns the node at the opposite edge end with respect to the given node.
`Edge`	`prevInEdge()` Gets the predecessor of this edge in the list of incoming edges at its target node.
`Edge`	`prevOutEdge()` Gets the predecessor of this edge in the list of outgoing edges at its source node.
`Node`	`source()` Gets the source node connected to this edge.
`Node`	`target()` Gets the target node connected to this edge.
`String`	`toString()` Returns a String representation of this edge.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Constructor Detail
  - Edge
```
protected Edge(Graph g,
               Node v,
               Edge e1,
               Node w,
               Edge e2,
               GraphElementInsertion d1,
               GraphElementInsertion d2)
```
    Creates a new edge that belongs to the given graph.
    The new edge e has source node v and target node w.
    
    Edge e is inserted in such a way that an iteration over the edges at node v returns e
    - after e1, if d1 == AFTER
    - before e1, if d1 == BEFORE,
    and an iteration over the edges at w returns e
    - after e2, if d2 == AFTER
    - before e2, if d2 == BEFORE.
    Precondition:
    Edge e1 must have source node v and edge e2 must have target node w.
    
    Parameters:
    
    v - The source node of the edge.
    
    e1 - An edge with source node v.
    
    w - The target node of the edge.
    
    e2 - An edge with target node w.
    
    d1 - One of the object insertion specifiers GraphElementInsertion.BEFORE or GraphElementInsertion.AFTER.
    
    d2 - One of the object insertion specifiers GraphElementInsertion.BEFORE or GraphElementInsertion.AFTER.
- Method Detail
  - createCopy
```
public Edge createCopy(Graph g,
                       Node v,
                       Node w)
```
    Creates a copy of this edge that will be inserted into the given graph connecting the given source and target nodes.
    
    Parameters:
    
    g - The graph the created edge will belong to.
    
    v - The source node of the created edge.
    
    w - The target node of the created edge.
    
    Returns:
    
    The newly created Edge object.
  - getGraph
```
public final Graph getGraph()
```
    Gets the graph this edge belongs to.
    If the edge does not belong to a graph, because it was removed or hidden from it, this method returns null.
    
    Returns:
    
    The Graph.
  - index
```
public final int index()
```
    Gets the index of this edge within its graph G.
    Edge indices represent the ordering of standard edge iteration on G. The value of an index is >= 0 and < G.edgeCount().
    
    Note that indices are subject to change whenever the sequence of edges in a graph is modified by either removing, hiding, reinserting, or unhiding an edge, or by explicitly changing its position in the sequence.
    
    Precondition:
    This edge must belong to some graph.
    
    Returns:
    
    The Index.
    
    See Also:
    
    Graph.removeEdge(Edge), Graph.hide(Edge), Graph.reInsertEdge(Edge), Graph.unhide(Edge), Graph.moveToFirst(Edge), Graph.moveToLast(Edge)
  - isSelfLoop
```
public final boolean isSelfLoop()
```
    Gets true if and only if this edge is a self-loop.
    An edge is called a self-loop, if it is adjacent to only one node, i.e., source node and target node are the same.
    
    Returns:
    
    The SelfLoop.
  - nextInEdge
```
public final Edge nextInEdge()
```
    Gets the successor of this edge in the list of incoming edges at its target node.
    If this edge is the last incoming edge at its target node, then null is returned.
    
    Precondition:
    This edge must belong to some graph.
    
    Returns:
    
    The NextInEdge.
    
    See Also:
    
    prevInEdge(), nextOutEdge()
  - nextOutEdge
```
public final Edge nextOutEdge()
```
    Gets the successor of this edge in the list of outgoing edges at its source node.
    If this edge is the last outgoing edge at its source node, then null is returned.
    
    Precondition:
    This edge must belong to some graph.
    
    Returns:
    
    The NextOutEdge.
    
    See Also:
    
    prevOutEdge(), nextInEdge()
  - onReinsert
```
protected void onReinsert()
```
    Callback method that is invoked from a graph just before this edge will be reinserted into that graph.
  - opposite
```
public final Node opposite(Node v)
```
    Returns the node at the opposite edge end with respect to the given node.
    Note that self-loops have the same node at both edge ends.
    
    Precondition:
    The given node must be either the edge's source node or target node.
  - prevInEdge
```
public final Edge prevInEdge()
```
    Gets the predecessor of this edge in the list of incoming edges at its target node.
    If this edge is the first incoming edge at its target node, then null is returned.
    
    Precondition:
    This edge must belong to some graph.
    
    Returns:
    
    The PrevInEdge.
    
    See Also:
    
    nextInEdge(), prevOutEdge()
  - prevOutEdge
```
public final Edge prevOutEdge()
```
    Gets the predecessor of this edge in the list of outgoing edges at its source node.
    If this edge is the first outgoing edge at its source node, then null is returned.
    
    Precondition:
    This edge must belong to some graph.
    
    Returns:
    
    The PrevOutEdge.
    
    See Also:
    
    nextOutEdge(), prevInEdge()
  - source
```
public final Node source()
```
    Gets the source node connected to this edge.
    
    Returns:
    
    The Source.
    
    See Also:
    
    target()
  - target
```
public final Node target()
```
    Gets the target node connected to this edge.
    
    Returns:
    
    The Target.
    
    See Also:
    
    source()
  - toString
```
public String toString()
```
    Returns a String representation of this edge.
    
    Overrides:
    
    toString in class Object

Class Edge

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

Edge

Method Detail

createCopy

getGraph

index

isSelfLoop

nextInEdge

nextOutEdge

onReinsert

opposite

prevInEdge

prevOutEdge

source

target

toString