Use BuchheimWalkerConfiguration to show tree merge node has problem

[zhangxinagjunHJH]

I use BuchheimWalkerConfiguration like this, there are 2 branch and one merge node, it's OK

`graph.addEdge(node1, node2, paint: Paint()..color = Colors.red);
graph.addEdge(node2, node6);
graph.addEdge(node6, node5);

graph.addEdge(node2, node3);
graph.addEdge(node3, node4);
graph.addEdge(node4, node5);`

but if i change the order like this, it will show wrong connect line

`graph.addEdge(node1, node2, paint: Paint()..color = Colors.red);
graph.addEdge(node2, node3);
graph.addEdge(node3, node4);
graph.addEdge(node4, node5);

graph.addEdge(node2, node6);
graph.addEdge(node6, node5);`

[nabil6391]

Basically BuchheimWalker is for treelayouts only, if you want merged nodes, suggest you use Sugiyama

[zhangxinagjunHJH]

@nabil6391 Yes, I checked code both Sugiyama and FruchtermanReingoldAlgorithm, but i found they don't support change orientation to horizontal. can add this feature to them?

[nabil6391]

Hm that is correct, yes I would prefer to add them but do not think it can be done soon.

[zhangxinagjunHJH]

@nabil6391 OK, Thank you very much! I will continue to pay attention and wait.

[nabil6391]

Added support for different orientation in 0.6.5. Try it out. Closing for now.