Swim lane constraints (HL)

Swim lanes are rectangular areas orthogonal to the levels.

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

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

The minimum margin is the margin of the swim lane 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 swim lane border, and the east minimum margin is the minimum horizontal distance between the rightmost node of the swimlane and the right swim lane border.

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

A swim lane 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 swim lane, but side-by-side constraints of nodes of different swim lanes are ignored. You can specify relative position constraints between nodes of the same swim lane. You can also specify relative position constraints between one entire swim lane group and another swim lane group, which effectively orders the swim lanes. But relative position constraints are ignored if they would require breaking the swim lanes apart. The swim lane constraint dominates the specified position indices and the extremity constraints, that is, if a swim lane constraint is used, you cannot specify position indices or east/west extremity constraints for any node.