HFlow Details

The hierarchical layout arranges vertices in horizontal layers. The orders of the vertices on the layers are chosen so that the number of crossings is kept as small as possible.

As HFlow applies to AddFlow diagrams, it can be viewed as an extension of AddFlow, an ActiveX component dedicated to the creation and the use of flowchart diagrams or graphs.

The following VB6 code is all you need to do to perform a hierarchical layout:

HFlow1.LayerDistance = 1000 ' Sets the distance between adjacent levels

HFlow1.VertexDistance = 1500 ' Sets the distance between adjacent vertices.

HFlow1.Orientation = North

HFlow1.LayerWidth = 0 ' No limitation in the number od vertices in a level

HFlow1.Layout AddFlow1 ' Perform the hierarchical layout

This code supposes that you have a form containing an AddFlow component and an HFlow component. You create the graph in the AddFlow component, using the AddFlow API, giving each vertex a random position or a (0,0) position. Then you apply the HFlow layout to this graph. And each vertex will be placed at a reasonable position.

If the AddFlow LogicalOnly property is true, then only the logical vertices of the AddFlow component are involved in this layout. This will allow you to apply the layout only to important vertices. For instance, you will be able to exclude a node just used to display a label by setting its Logical property to false.

Note that it is necessary to use AddFlow version 3.00 or higher to be able to use HFlow.

HFlow Main
AddFlow