Package	com.yworks.yfiles.layout.tree
Class	public class TreeReductionStage
Inheritance	TreeReductionStage AbstractLayoutStage YObject Object

This stage can be used to layout non-tree structures with a tree layout algorithm. First this stage transforms a graph into a tree or forest by removing some edges. Then it invokes the core layout algorithm on the reduced graph. Finally, it reinserts the hidden non-tree edges to the graph again and optionally routes these edges.

Typical usage:

 TreeLayouter tl = new TreeLayouter(); TreeReductionStage trs = new TreeReductionStage(); trs.setNonTreeEdgeRouter(new OrganicEdgeRouter()); trs.setNonTreeEdgeSelectionKey(OrganicEdgeRouter.ROUTE_EDGE_DPKEY); tl.appendStage(trs); new BufferedLayouter(tl).doLayout(graph); tl.removeStage(trs); 

Note that if there are edges between group nodes, the com.yworks.yfiles.layout.tree.TreeLayouter may throw a com.yworks.yfiles.base.InvalidGraphStructureException -Exception. Such exceptions can be prevented by temporarily removing those edges.

Note that this layout stage is also able to handle multi-parent structures, i.e., structures of multiple nodes that share the same predecessors as well as the same successors. More precisely, if the specified core layout can handle multi-parent structures (see com.yworks.yfiles.layout.tree.GenericTreeLayouter.multiParentAllowed) and option multiParentAllowed is enabled, this stage does not hide such structures (i.e., the multi-parents are passed to the core layouter).

See also

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