Swimlane constraints (HL)

Swimlanes are rectangular areas orthogonal to the levels.

You can use swimlanes if the nodes are partitioned into groups, to indicate which nodes belong to a certain group. The nodes in the same swimlane are placed so that it is possible to draw a surrounding rectangle around them. Swimlanes allow you to organize the graph in a table-like manner. For example, you can have a workflow diagram where nodes represent actions; the swimlanes could then represent the departments that perform these actions. Each node can belong to only one swimlane.

SwimLaneConstraint {
  group: { node1, node2, node3 }
  relativeSize: -1.0
  positionIndex: -1
  eastMinMargin: 0.0
  westMinMargin: 0.0
}

layout.addConstraint(new IlvSwimLaneConstraint(new IlvNodeGroup(nodeVector)));

public IlvSwimLaneConstraint(IlvNodeGroup group,
                             float relativeSize,
                             int positionIndex,
                             float westMinMargin,
                             float eastMinMargin)

The relative size indicates how large this swimlane is compared to the other swimlanes. Assume that the flow direction is towards the bottom. In this case, the relative size indicates the width of the swimlane. All swimlanes with the same relative size have the same width. A swimlane with a relative size that is twice the value of another swimlane will have twice the width of the other swimlane. The actual number of this parameter does not matter, only how large the value is compared to the other swimlanes. If you do not want to restrict the size of the swimlane, set the value to 0. In this case, the width of the swimlane is independent of the other swimlanes.

The minimum margin is the margin of the swimlane in absolute coordinates. If the flow direction is towards the bottom, then the west minimum margin is the minimum horizontal distance between the leftmost node of the swimlane and the left swimlane border, and the east minimum margin is the minimum horizontal distance between the rightmost node of the swimlane and the right swimlane border.

The position index indicates the order of the swimlanes. Just as nodes have position indexes, the swimlanes are placed sequentially at relative positions numbered from 0 to n. In a top-down layout, the swimlane with position 0 is the leftmost swimlane, and the swimlanes with higher position indexes are placed farther to the right. If the swimlanes have the position index -1, the layout algorithm determines the appropriate position automatically.

A swimlane constraint is always evaluated, even if the incremental mode is enabled. The constraint has a higher priority than the relative position constraint and the side-by-side constraint. You can specify side-by-side constraints for a group of nodes that belong to the same swimlane, but side-by-side constraints of nodes of different swimlanes are ignored. You can specify relative position constraints between nodes of the same swimlane. You can also specify relative position constraints between one entire swimlane group and another swimlane group, which effectively orders the swimlanes. But relative position constraints are ignored if they would require breaking the swimlanes apart. The swimlane constraint dominates the specified position indexes and the extremity constraints, that is, if a swimlane constraint is used, you cannot specify position indexes or east/west extremity constraints for any node.