JGo Autolayout customization

JGo
1
I use JGoLayeredDigraphAutoLayout.performLayout()
and would like to know if can customize the outcome in some ways.
1. Before auto layout
After auto layout
Customization desired: I would like to keep the connector lines straight. They seem to bend if one node has a multi line label and the adjoining one doesn't.
2. Before auto layout
After auto layout
Customization desired: The 2 assign nodes should be vertically equidistant from the multi-port switch node.
3. After auto layout, the entire workflow of nodes seems to move to the right on the canvas, leaving extra space on the left. How can I prevent that?
4. Is there any way to set a wrapping width on the auto layout algorithm?
2

The problem is that the layered-digraph autolayout is operating on the centers of the nodes, not the centers of the icons, as you would prefer for your particular application.

The following code modifies Flower.java, of the Flower example.
It customizes the JGoNetworkNode’s idea of what the center of the node is.

[code] static class CustomNetwork extends JGoNetwork {
public CustomNetwork(JGoObjectSimpleCollection coll) {
super(coll);
}
public JGoNetworkNode createNetworkNode() {
return new CustomNetworkNode();
}
}

static class CustomNetworkNode extends JGoNetworkNode {
public void setJGoObject(JGoObject obj) {
super.setJGoObject(obj);
if (obj instanceof SimpleNode) {
SimpleNode sn = (SimpleNode)obj;
Point center = sn.getIcon().getSpotLocation(JGoObject.Center);
setCenter(center);
}
}
public void commitPosition() {
SimpleNode sn = (SimpleNode)getJGoObject();
int x = getCenter().x; // - sn.getWidth()/2; // + sn.getIcon().getWidth()/2;
int y = getCenter().y; // - sn.getHeight()/2; // + sn.getIcon().getHeight()/2;
sn.getIcon().setSpotLocation(JGoObject.Center, x, y);
}
}

void layerAction() {
ProcessDocument doc = getCurrentView().getDoc();
doc.startTransaction();
JGoLayeredDigraphAutoLayout l = new JGoLayeredDigraphAutoLayout(doc, new CustomNetwork(doc),
30, 30, JGoLayeredDigraphAutoLayout.LD_DIRECTION_RIGHT,
JGoLayeredDigraphAutoLayout.LD_CYCLEREMOVE_DFS,
JGoLayeredDigraphAutoLayout.LD_LAYERING_OPTIMALLINKLENGTH,
JGoLayeredDigraphAutoLayout.LD_INITIALIZE_DFSOUT, 4,
JGoLayeredDigraphAutoLayout.LD_AGGRESSIVE_FALSE);
l.performLayout();

// minimize the size of the document
Rectangle b = doc.computeBounds();
doc.setDocumentTopLeft(b.getLocation());
doc.setDocumentSize(b.getSize());

// scroll the view to show the top-left corner of the laid-out diagram
getCurrentView().setIncludingNegativeCoords(true);  // could do this when initializing the JGoView
getCurrentView().setViewPosition(doc.getDocumentTopLeft());
// or show a particular area of the diagram by calling JGoView.scrollRectToVisible

doc.endTransaction("LayeredDigraph Layout");

}[/code]
So I believe this handles the straight-line cases, like your #1. But it won’t help when there are multiple paths, each with different height nodes.

For #2, I don’t know if that can be improved as long as the node have different heights and you still want to vertically center the icons rather than the whole nodes.

For #3, the above code sizes the document and scrolls the view to show the top left corner of the document.

For #4, no there isn’t such a property. I suggest doing the normal layout and then moving subsections of the graph programmatically.

3

For 1, I use JGoNode and not JGoNetworkNode. Is there a way to center a JGoNode?

Thanks.
4

As you can see from the documentation, JGoNetworkNode does not extend JGoNode. JGoNetworkNode is just a data structure used by JGoLayout and JGoNetwork to represent JGoNodes internally before and during the layout. JGoLayout operates on a JGoNetwork, not directly on a JGoDocument.