- I
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Remarks
Layout Style
The edge paths of multi-edges consist of parallel segments. At the end points, the edges can either still be parallel or joined in one point.
Concept
ParallelEdgeRouter performs four basic steps:
- For each set of multi-edges between the same endpoints, the algorithm removes all edges but one from the input graph (the remaining edge is called the leading edge).
- Invoke the coreLayout on the graph without multi-edges.
- Reinsert all previously removed multi-edges.
- Route the multi-edges such that their path is parallel to that of the associated leading edge.
Features
ParallelEdgeRouter can either be used as a ILayoutStage wrapping an ILayoutAlgorithm which cannot handle multi-edges. Then it will hide the multi-edges from this coreLayout and take over the routing of them.
If no coreLayout is specified, ParallelEdgeRouter can work alone. It will route only the multi-edges and keep the remaining graph unchanged. Note that, since the multi-edges' paths are parallel to the path of the associated leading edge, the leading edge should always have a suitable route before calling the ParallelEdgeRouter.
The edges this stage routed can be obtained from routedMultiEdgesResult. Multi-edges that were hidden during the core layout and then routed by this stage are marked. Leading edges are not marked. This may be convenient if multi-edges require further consideration, e.g., to place labels their labels (the core layout could not do that because they were hidden).
Multi-edges can either be all edges between the same two nodes, ignoring the direction, or edges are only considered to be multi-edges if they share the same source node and target node. Hence, they share the same direction.
To make sure that the ports of all multi-edges are on the end nodes, the first and last segments can be joined. However, these segments won't be parallel.
There are two ways to define the distance between two parallel edges. First, an absolute distance can be defined. Parallel segments will keep this distance. Second, the distance can be determined relative to the node bounds. Depending on the size of the nodes and the number of parallel edges between them, the distance between parallel edges is adjusted. This will keep the edges straight in most cases.
It is possible to select custom leading edges. All edges that are multi-edges of the selected edges will be temporarily removed.
Default Values of Properties
| Name | Default | Description |
|---|---|---|
| adaptiveEdgeDistances | true | The distances between multi-edges are adjusted to the nodes' bounds. |
| adjustLeadingEdge | true | The leading edge is adjusted for more symmetric results. |
| coreLayout | null | |
| directedMode | false | All edges that connect the same pair of nodes are considered parallel, ignoring their directions. |
| edgeDistance | 10 | |
| joinEnds | false | Multi-edges have only parallel segments. |
See Also
Developer's Guide
Members
Constructors
Creates a new ParallelEdgeRouter instance with an optional coreLayout.
Properties
The absolute distance needs to be non-negative.
The distance from the end point to the first parallel segment in the resulting layout is the sum of this absolute distance and the length of the first segment multiplied by the relativeJoinEndDistanceFactor.
Property Value
Throws
- Exception ({ name: 'ArgumentError' })
- if the specified distance is negative
Default Value
Sample Graphs
20See Also
Property Value
true if the distances are determined according to the nodes' bounds, false otherwiseDefault Value
Sample Graphs
falseSee Also
API
- edgeDistance
Property Value
true if the leading edge is adjusted, false otherwiseDefault Value
Sample Graphs
falseGets or sets the core ILayoutAlgorithm that is wrapped by this stage.
Property Value
Default Value
Defined in
LayoutStageBase.coreLayoutIn directed mode, only edges that share the same source and target node will be routed in parallel. Edges that connect to the same nodes but in different directions won't be considered parallel.
In undirected mode, all edges connecting the same pair of nodes will be routed in parallel.
Property Value
true if the direction of multi-edges must be the same, false otherwiseDefault Value
Sample Graphs
falseProperty Value
Throws
- Exception ({ name: 'ArgumentError' })
- if the specified distance is less than
0
Default Value
Sample Graphs
10See Also
Gets or sets a value that determines whether this stage should do anything but execute the coreLayout.
By default, when constructed, stages should be enabled. Users may disable a stage's functionality by setting this property to false.
Stages that can guarantee that the graph will not change can choose to not even execute the coreLayout when disabled.
Defined in
LayoutStageBase.enabledProperty Value
true if edges are joined at the ends, false otherwiseDefault Value
Sample Graphs
falseSee Also
The length is relative to the corresponding original segment's length. It needs to have a value in the interval [0,1].
The distance from the end point to the first parallel segment in the resulting layout is the sum of the absoluteJoinEndDistance and the length of the first segment multiplied by this relative distance factor.
Property Value
Throws
- Exception ({ name: 'ArgumentError' })
- if the specified relative distance is less than
0or greater than1
Default Value
Sample Graphs
0.1See Also
Methods
Implementation of the ILayoutAlgorithm interface and main entry point for the layout calculation.
Parameters
- graph: LayoutGraph
- The graph to apply the layout to.
Defined in
LayoutStageBase.applyLayoutDelegates the arrangement of nodes and edges to the coreLayout and routes the multi-edges.
Routes all the multi-edges.
The layout for each multi-edge follows the layout of the leading edge which was not removed from the coreLayout.
This method is called when the coreLayout is finished. It may be overridden to introduce a custom routing for multi-edges.
Parameters
- graph: LayoutGraph
- the graph after the core layout
- parallelEdges: IMapper<LayoutEdge, YList<LayoutEdge>>
- the IMapper<K, V> that provides all multi-edges for each leading edge, or
nullif there are none