[img]http://www.yuangchi.com/offtopic/ss4.gif[/img]
The image above shows a simple chart. The 'Start' node was added first, then the numbered in order.

After each node was added the code called
[code]
procedure tFlowChartHelper.layout;
var
t : Treelayout;
begin
t := CreateComObject(CLASS_TreeLayout) as Treelayout;
t.NodeSpacing := CLayoutNodeSpacing;
t.LevelSpacing := CLayoutLevelSpacing;
t.ArrowAnchoring := ancKeep;
t.type_ := tltCentralized;
t.ArrowStyle := tlaPerpendicular3;
fcx.ArrangeDiagram(t);
fcx.RouteAllArrows;
fcx.FitDocToObjects(CLayoutMargin);
end;
[/code]

I've set up the fcx.RoutingOptions with this ...

[code]
const
CLayoutGridSize = 16;
CLayoutLevelSpacing = 60;
CLayoutMargin = 20;
CLayoutNodeSpacing = 48;
CLayoutTurnCost = 255;
ClayoutCrossingCost = 255;
CLayoutNodeVicinityCost = 0;
CLayoutLengthCost = 255;

...

fcx.RoutingOptions.CrossingCost := CLayoutCrossingCost;
fcx.RoutingOptions.TurnCost := CLayoutTurnCost;
fcx.RoutingOptions.LengthCost := CLayoutLengthCost;
fcx.RoutingOptions.NodeVicinityCost := CLayoutNodeVicinityCost;

[/code]

It doesn't seem to matter [i]what[/i] I do to the RoutingOptions values, I just can't get it to do something sensible like move the boxes to the correct side of the decision node.

I'd appreciate any suggestions.

TVM

OK Stoyan, thanks.

I guess that's gust something I'm going to have to document for my users.

That said, I wonder if there's not something I should expect from TreeLayout wrt placing of the nodes, before Routing does it's thing?

TreeLayout was designed to arrange trees. It does not know a thing about the logical meaning of the links, and whether you want to place some nodes on the left and other nodes on the right. It just places the nodes in the order in which they an be accessed through the OutgoingArrows of the parent node. So the only way for you to control the order of child nodes is to use the same order for links in the parent's OutgoingArrows collection. You either create the links in that order, or use the OugoingArrows.ChangeIndex method. E.g. to make TreeLayout place the Yes node on the right of the No node, the Yes link should come after the No link in the OugoingArrows collection.

I hope that helps,
Stoyan

Actually this is the only layout class that provides you with some control over the order of child nodes 8) It's not that hard though - if you let your users draw links, use the OutgoingArrows.ChangeIndex method to specify in what order you'd like the child nodes to appear before calling ArrangeDiagram. If you create the diagrams entirely from code, just call CreateArrow in the correct order.

Stoyan