Class HierarchicalBCEngine

  • All Implemented Interfaces:
    GraphConstants, LayoutEngine

    public class HierarchicalBCEngine
    extends java.lang.Object
    implements GraphConstants, LayoutEngine
    This class lays out the vertices of a graph in a hierarchy of vertical levels, with a number of nodes in each level. The number of levels is the depth of the deepest child reachable from some parent at level 0. It implements a layout technique as described by K. Sugiyama, S. Tagawa, and M. Toda. in "Methods for visual understanding of hierarchical systems", IEEE Transactions on Systems, Man and Cybernetics, SMC-11(2):109-125, Feb. 1981.

    There have been a few modifications made, however. The crossings function is changed as it was non-linear in time complexity. Furthermore, we don't have any interconnection matrices for each level, instead we just have one big interconnection matrix for the whole graph and a int[][] array which stores the vertices present in each level.

    Version:
    $Revision: 10503 $ - 24 Apr 2003 - Initial version (Ashraf M. Kibriya)
    Author:
    Ashraf M. Kibriya (amk14@cs.waikato.ac.nz)
    • Constructor Detail

      • HierarchicalBCEngine

        public HierarchicalBCEngine​(FastVector nodes,
                                    FastVector edges,
                                    int nodeWidth,
                                    int nodeHeight)
        Constructor - takes in FastVectors of nodes and edges, and the initial width and height of a node
      • HierarchicalBCEngine

        public HierarchicalBCEngine​(FastVector nodes,
                                    FastVector edges,
                                    int nodeWidth,
                                    int nodeHeight,
                                    boolean edgeConcentration)
        Constructor - takes in FastVectors of nodes and edges, the initial width and height of a node, and a boolean value to indicate if the edges should be concentrated.
        Parameters:
        nodes - - FastVector containing all the nodes
        edges - - FastVector containing all the edges
        nodeWidth - - A node's allowed width
        nodeHeight - - A node's allowed height
        edgeConcentration - - True: if want to concentrate edges, False: otherwise
      • HierarchicalBCEngine

        public HierarchicalBCEngine()
        SimpleConstructor If we want to instantiate the class first, and if information for nodes and edges is not available. However, we would have to manually provide all the information later on by calling setNodesEdges and setNodeSize methods
    • Method Detail

      • getControlPanel

        public javax.swing.JPanel getControlPanel()
        This method returns a handle to the extra controls panel, so that the visualizing class can add it to some of it's own gui panel.
        Specified by:
        getControlPanel in interface LayoutEngine
      • getProgressBar

        public javax.swing.JProgressBar getProgressBar()
        Returns a handle to the progressBar of this LayoutEngine.
        Specified by:
        getProgressBar in interface LayoutEngine
      • setNodesEdges

        public void setNodesEdges​(FastVector nodes,
                                  FastVector edges)
        Sets the nodes and edges for this LayoutEngine. Must be used if the class created by simple HierarchicalBCEngine() constructor.
        Specified by:
        setNodesEdges in interface LayoutEngine
        Parameters:
        nodes - - FastVector containing all the nodes
        edges - - FastVector containing all the edges
      • setNodeSize

        public void setNodeSize​(int nodeWidth,
                                int nodeHeight)
        Sets the size of a node. This method must be used if the class created by simple HierarchicalBCEngine() constructor.
        Specified by:
        setNodeSize in interface LayoutEngine
        Parameters:
        nodeWidth - - A node's allowed width
        nodeHeight - - A node's allowed height
      • layoutGraph

        public void layoutGraph()
        This method does a complete layout of the graph which includes removing cycles, assigning levels to nodes, reducing edge crossings and laying out the vertices horizontally for better visibility. The removing of cycles and assignment of levels is only performed if hasn't been performed earlier or if some layout option has been changed and it is necessary to do so. It is necessary to do so, if the user selects/deselects edge concentration or topdown/bottomup options.

        The layout is performed in a separate thread and the progress bar of the class is updated for each of the steps as the process continues.

        Specified by:
        layoutGraph in interface LayoutEngine
      • phaseIU

        public void phaseIU​(int lindex,
                            int[][] levels)
        See Sugiyama et al. 1981 (full reference give at top) lindex is the index of the level we want to process. In this method we'll sort the vertices at the level lindex according to their DOWN-barycenters (or row barycenters).
      • phaseIID

        public void phaseIID​(int lindex,
                             int[][] levels)
        See Sugiyama et al. 1981 (full reference give at top)
      • phaseIIU

        public void phaseIIU​(int lindex,
                             int[][] levels)
        See Sugiyama et al. 1981 (full reference give at top)