JGraphX - Autolayout edges only

Question

Is there anyway i can a run auto-layout on graph edges only? I have a lot of fixed vertexes that i do not want to move/rearrange, but i do want to fix edges that overlap my cell/vertexes. Is there any way to do this?

Answer 1

The layouts, namely mxIGraphLayout implementations, concern themselves with visible cells only, and they access those via the mxGraph object API. So the proper solution is to subclass mxGraph and override the isCellVisible(Object cell) method according to your needs. This way you'd create an alternate view of your graph.

Of course, you can also change the actual cell visibility in the model (graph.getModel().setVisible(cell, false)) and restore it back after the layout execution. But that seems like a hack.

Alternatively you could subclass the layout class itself and override these methods:

public boolean isVertexMovable(Object vertex)
{
    return graph.isCellMovable(vertex);
}

public boolean isVertexIgnored(Object vertex)
{
    return !graph.getModel().isVertex(vertex)
            || !graph.isCellVisible(vertex);
}

public boolean isEdgeIgnored(Object edge)
{
    mxIGraphModel model = graph.getModel();

    return !model.isEdge(edge) || !graph.isCellVisible(edge)
            || model.getTerminal(edge, true) == null
            || model.getTerminal(edge, false) == null;
}