/*
* Copyright (c) 2005-2012, JGraph Ltd
*/
package com.mxgraph.layout.hierarchical.model;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.HashSet;
import java.util.Hashtable;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.LinkedHashSet;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.Set;
import com.mxgraph.layout.hierarchical.mxHierarchicalLayout;
import com.mxgraph.view.mxGraph;
/**
* Internal model of a hierarchical graph. This model stores nodes and edges
* equivalent to the real graph nodes and edges, but also stores the rank of the
* cells, the order within the ranks and the new candidate locations of cells.
* The internal model also reverses edge direction were appropriate , ignores
* self-loop and groups parallels together under one edge object.
*/
public class mxGraphHierarchyModel
{
/**
* Stores the largest rank number allocated
*/
public int maxRank;
/**
* Map from graph vertices to internal model nodes
*/
protected Map<Object, mxGraphHierarchyNode> vertexMapper = null;
/**
* Map from graph edges to internal model edges
*/
protected Map<Object, mxGraphHierarchyEdge> edgeMapper = null;
/**
* Mapping from rank number to actual rank
*/
public Map<Integer, mxGraphHierarchyRank> ranks = null;
/**
* Store of roots of this hierarchy model, these are real graph cells, not
* internal cells
*/
public List<Object> roots;
/**
* The parent cell whose children are being laid out
*/
public Object parent = null;
/**
* Count of the number of times the ancestor dfs has been used
*/
protected int dfsCount = 0;
/** High value to start source layering scan rank value from */
private final int SOURCESCANSTARTRANK = 100000000;
/**
* Creates an internal ordered graph model using the vertices passed in. If
* there are any, leftward edge need to be inverted in the internal model
*
* @param layout
* the enclosing layout object
* @param vertices
* the vertices for this hierarchy
*/
public mxGraphHierarchyModel(mxHierarchicalLayout layout,
Object[] vertices, List<Object> roots, Object parent)
{
mxGraph graph = layout.getGraph();
this.roots = roots;
this.parent = parent;
if (vertices == null)
{
vertices = graph.getChildVertices(parent);
}
// map of cells to internal cell needed for second run through
// to setup the sink of edges correctly. Guess size by number
// of edges is roughly same as number of vertices.
vertexMapper = new Hashtable<Object, mxGraphHierarchyNode>(
vertices.length);
edgeMapper = new Hashtable<Object, mxGraphHierarchyEdge>(
vertices.length);
maxRank = SOURCESCANSTARTRANK;
mxGraphHierarchyNode[] internalVertices = new mxGraphHierarchyNode[vertices.length];
createInternalCells(layout, vertices, internalVertices);
// Go through edges set their sink values. Also check the
// ordering if and invert edges if necessary
for (int i = 0; i < vertices.length; i++)
{
Collection<mxGraphHierarchyEdge> edges = internalVertices[i].connectsAsSource;
Iterator<mxGraphHierarchyEdge> iter = edges.iterator();
while (iter.hasNext())
{
mxGraphHierarchyEdge internalEdge = iter.next();
Collection<Object> realEdges = internalEdge.edges;
Iterator<Object> iter2 = realEdges.iterator();
// Only need to process the first real edge, since
// all the edges connect to the same other vertex
if (iter2.hasNext())
{
Object realEdge = iter2.next();
Object targetCell = graph.getView().getVisibleTerminal(
realEdge, false);
mxGraphHierarchyNode internalTargetCell = vertexMapper
.get(targetCell);
if (internalVertices[i] == internalTargetCell)
{
// The real edge is reversed relative to the internal edge
targetCell = graph.getView().getVisibleTerminal(
realEdge, true);
internalTargetCell = vertexMapper.get(targetCell);
}
if (internalTargetCell != null
&& internalVertices[i] != internalTargetCell)
{
internalEdge.target = internalTargetCell;
if (internalTargetCell.connectsAsTarget.size() == 0)
{
internalTargetCell.connectsAsTarget = new LinkedHashSet<mxGraphHierarchyEdge>(
4);
}
internalTargetCell.connectsAsTarget.add(internalEdge);
}
}
}
// Use the temp variable in the internal nodes to mark this
// internal vertex as having been visited.
internalVertices[i].temp[0] = 1;
}
}
/**
* Creates all edges in the internal model
*
* @param layout
* reference to the layout algorithm
* @param vertices
* the vertices whom are to have an internal representation
* created
* @param internalVertices
* the blank internal vertices to have their information filled
* in using the real vertices
*/
protected void createInternalCells(mxHierarchicalLayout layout,
Object[] vertices, mxGraphHierarchyNode[] internalVertices)
{
mxGraph graph = layout.getGraph();
// Create internal edges
for (int i = 0; i < vertices.length; i++)
{
internalVertices[i] = new mxGraphHierarchyNode(vertices[i]);
vertexMapper.put(vertices[i], internalVertices[i]);
// If the layout is deterministic, order the cells
Object[] conns = layout.getEdges(vertices[i]);
List<Object> outgoingCells = Arrays.asList(graph.getOpposites(
conns, vertices[i]));
internalVertices[i].connectsAsSource = new LinkedHashSet<mxGraphHierarchyEdge>(
outgoingCells.size());
// Create internal edges, but don't do any rank assignment yet
// First use the information from the greedy cycle remover to
// invert the leftward edges internally
Iterator<Object> iter = outgoingCells.iterator();
while (iter.hasNext())
{
// Don't add self-loops
Object cell = iter.next();
if (cell != vertices[i] && graph.getModel().isVertex(cell)
&& !layout.isVertexIgnored(cell))
{
// We process all edge between this source and its targets
// If there are edges going both ways, we need to collect
// them all into one internal edges to avoid looping problems
// later. We assume this direction (source -> target) is the
// natural direction if at least half the edges are going in
// that direction.
// The check below for edgeMapper.get(edges[0]) == null is
// in case we've processed this the other way around
// (target -> source) and the number of edges in each direction
// are the same. All the graph edges will have been assigned to
// an internal edge going the other way, so we don't want to
// process them again
Object[] undirectEdges = graph.getEdgesBetween(vertices[i],
cell, false);
Object[] directedEdges = graph.getEdgesBetween(vertices[i],
cell, true);
if (undirectEdges != null
&& undirectEdges.length > 0
&& (edgeMapper.get(undirectEdges[0]) == null)
&& (directedEdges.length * 2 >= undirectEdges.length))
{
ArrayList<Object> listEdges = new ArrayList<Object>(
undirectEdges.length);
for (int j = 0; j < undirectEdges.length; j++)
{
listEdges.add(undirectEdges[j]);
}
mxGraphHierarchyEdge internalEdge = new mxGraphHierarchyEdge(
listEdges);
Iterator<Object> iter2 = listEdges.iterator();
while (iter2.hasNext())
{
Object edge = iter2.next();
edgeMapper.put(edge, internalEdge);
// Resets all point on the edge and disables the edge style
// without deleting it from the cell style
graph.resetEdge(edge);
if (layout.isDisableEdgeStyle())
{
layout.setEdgeStyleEnabled(edge, false);
layout.setOrthogonalEdge(edge, true);
}
}
internalEdge.source = internalVertices[i];
internalVertices[i].connectsAsSource.add(internalEdge);
}
}
}
// Ensure temp variable is cleared from any previous use
internalVertices[i].temp[0] = 0;
}
}
/**
* Basic determination of minimum layer ranking by working from from sources
* or sinks and working through each node in the relevant edge direction.
* Starting at the sinks is basically a longest path layering algorithm.
*/
public void initialRank()
{
Collection<mxGraphHierarchyNode> internalNodes = vertexMapper.values();
LinkedList<mxGraphHierarchyNode> startNodes = new LinkedList<mxGraphHierarchyNode>();
if (roots != null)
{
Iterator<Object> iter = roots.iterator();
while (iter.hasNext())
{
mxGraphHierarchyNode internalNode = vertexMapper.get(iter
.next());
if (internalNode != null)
{
startNodes.add(internalNode);
}
}
}
Iterator<mxGraphHierarchyNode> iter = internalNodes.iterator();
while (iter.hasNext())
{
mxGraphHierarchyNode internalNode = iter.next();
// Mark the node as not having had a layer assigned
internalNode.temp[0] = -1;
}
List<mxGraphHierarchyNode> startNodesCopy = new ArrayList<mxGraphHierarchyNode>(
startNodes);
while (!startNodes.isEmpty())
{
mxGraphHierarchyNode internalNode = startNodes.getFirst();
Collection<mxGraphHierarchyEdge> layerDeterminingEdges;
Collection<mxGraphHierarchyEdge> edgesToBeMarked;
layerDeterminingEdges = internalNode.connectsAsTarget;
edgesToBeMarked = internalNode.connectsAsSource;
// flag to keep track of whether or not all layer determining
// edges have been scanned
boolean allEdgesScanned = true;
// Work out the layer of this node from the layer determining
// edges
Iterator<mxGraphHierarchyEdge> iter2 = layerDeterminingEdges
.iterator();
// The minimum layer number of any node connected by one of
// the layer determining edges variable. If we are starting
// from sources, need to start at some huge value and
// normalise down afterwards
int minimumLayer = SOURCESCANSTARTRANK;
while (allEdgesScanned && iter2.hasNext())
{
mxGraphHierarchyEdge internalEdge = iter2.next();
if (internalEdge.temp[0] == 5270620)
{
// This edge has been scanned, get the layer of the
// node on the other end
mxGraphHierarchyNode otherNode = internalEdge.source;
minimumLayer = Math.min(minimumLayer,
otherNode.temp[0] - 1);
}
else
{
allEdgesScanned = false;
}
}
// If all edge have been scanned, assign the layer, mark all
// edges in the other direction and remove from the nodes list
if (allEdgesScanned)
{
internalNode.temp[0] = minimumLayer;
maxRank = Math.min(maxRank, minimumLayer);
if (edgesToBeMarked != null)
{
Iterator<mxGraphHierarchyEdge> iter3 = edgesToBeMarked
.iterator();
while (iter3.hasNext())
{
mxGraphHierarchyEdge internalEdge = iter3.next();
// Assign unique stamp ( y/m/d/h )
internalEdge.temp[0] = 5270620;
// Add node on other end of edge to LinkedList of
// nodes to be analysed
mxGraphHierarchyNode otherNode = internalEdge.target;
// Only add node if it hasn't been assigned a layer
if (otherNode.temp[0] == -1)
{
startNodes.addLast(otherNode);
// Mark this other node as neither being
// unassigned nor assigned so it isn't
// added to this list again, but it's
// layer isn't used in any calculation.
otherNode.temp[0] = -2;
}
}
}
startNodes.removeFirst();
}
else
{
// Not all the edges have been scanned, get to the back of
// the class and put the dunces cap on
Object removedCell = startNodes.removeFirst();
startNodes.addLast(internalNode);
if (removedCell == internalNode && startNodes.size() == 1)
{
// This is an error condition, we can't get out of
// this loop. It could happen for more than one node
// but that's a lot harder to detect. Log the error
// TODO make log comment
break;
}
}
}
// Normalize the ranks down from their large starting value to place
// at least 1 sink on layer 0
iter = internalNodes.iterator();
while (iter.hasNext())
{
mxGraphHierarchyNode internalNode = iter.next();
// Mark the node as not having had a layer assigned
internalNode.temp[0] -= maxRank;
}
// Tighten the roots as far as possible
for (int i = 0; i < startNodesCopy.size(); i++)
{
mxGraphHierarchyNode internalNode = startNodesCopy.get(i);
int currentMaxLayer = 0;
Iterator<mxGraphHierarchyEdge> iter2 = internalNode.connectsAsSource
.iterator();
while (iter2.hasNext())
{
mxGraphHierarchyEdge internalEdge = iter2.next();
mxGraphHierarchyNode otherNode = internalEdge.target;
internalNode.temp[0] = Math.max(currentMaxLayer,
otherNode.temp[0] + 1);
currentMaxLayer = internalNode.temp[0];
}
}
// Reset the maxRank to that which would be expected for a from-sink
// scan
maxRank = SOURCESCANSTARTRANK - maxRank;
}
/**
* Fixes the layer assignments to the values stored in the nodes. Also needs
* to create dummy nodes for edges that cross layers.
*/
public void fixRanks()
{
final mxGraphHierarchyRank[] rankList = new mxGraphHierarchyRank[maxRank + 1];
ranks = new LinkedHashMap<Integer, mxGraphHierarchyRank>(maxRank + 1);
for (int i = 0; i < maxRank + 1; i++)
{
rankList[i] = new mxGraphHierarchyRank();
ranks.put(new Integer(i), rankList[i]);
}
// Perform a DFS to obtain an initial ordering for each rank.
// Without doing this you would end up having to process
// crossings for a standard tree.
mxGraphHierarchyNode[] rootsArray = null;
if (roots != null)
{
Object[] oldRootsArray = roots.toArray();
rootsArray = new mxGraphHierarchyNode[oldRootsArray.length];
for (int i = 0; i < oldRootsArray.length; i++)
{
Object node = oldRootsArray[i];
mxGraphHierarchyNode internalNode = vertexMapper.get(node);
rootsArray[i] = internalNode;
}
}
visit(new mxGraphHierarchyModel.CellVisitor()
{
public void visit(mxGraphHierarchyNode parent,
mxGraphHierarchyNode cell,
mxGraphHierarchyEdge connectingEdge, int layer, int seen)
{
mxGraphHierarchyNode node = cell;
if (seen == 0 && node.maxRank < 0 && node.minRank < 0)
{
rankList[node.temp[0]].add(cell);
node.maxRank = node.temp[0];
node.minRank = node.temp[0];
// Set temp[0] to the nodes position in the rank
node.temp[0] = rankList[node.maxRank].size() - 1;
}
if (parent != null && connectingEdge != null)
{
int parentToCellRankDifference = (parent).maxRank
- node.maxRank;
if (parentToCellRankDifference > 1)
{
// There are ranks in between the parent and current cell
mxGraphHierarchyEdge edge = connectingEdge;
edge.maxRank = (parent).maxRank;
edge.minRank = (cell).maxRank;
edge.temp = new int[parentToCellRankDifference - 1];
edge.x = new double[parentToCellRankDifference - 1];
edge.y = new double[parentToCellRankDifference - 1];
for (int i = edge.minRank + 1; i < edge.maxRank; i++)
{
// The connecting edge must be added to the
// appropriate ranks
rankList[i].add(edge);
edge.setGeneralPurposeVariable(i,
rankList[i].size() - 1);
}
}
}
}
}, rootsArray, false, null);
}
/**
* A depth first search through the internal hierarchy model
*
* @param visitor
* the visitor pattern to be called for each node
* @param trackAncestors
* whether or not the search is to keep track all nodes directly
* above this one in the search path
*/
public void visit(CellVisitor visitor, mxGraphHierarchyNode[] dfsRoots,
boolean trackAncestors, Set<mxGraphHierarchyNode> seenNodes)
{
// Run dfs through on all roots
if (dfsRoots != null)
{
for (int i = 0; i < dfsRoots.length; i++)
{
mxGraphHierarchyNode internalNode = dfsRoots[i];
if (internalNode != null)
{
if (seenNodes == null)
{
seenNodes = new HashSet<mxGraphHierarchyNode>();
}
if (trackAncestors)
{
// Set up hash code for root
internalNode.hashCode = new int[2];
internalNode.hashCode[0] = dfsCount;
internalNode.hashCode[1] = i;
dfs(null, internalNode, null, visitor, seenNodes,
internalNode.hashCode, i, 0);
}
else
{
dfs(null, internalNode, null, visitor, seenNodes, 0);
}
}
}
dfsCount++;
}
}
/**
* Performs a depth first search on the internal hierarchy model
*
* @param parent
* the parent internal node of the current internal node
* @param root
* the current internal node
* @param connectingEdge
* the internal edge connecting the internal node and the parent
* internal node, if any
* @param visitor
* the visitor pattern to be called for each node
* @param seen
* a set of all nodes seen by this dfs a set of all of the
* ancestor node of the current node
* @param layer
* the layer on the dfs tree ( not the same as the model ranks )
*/
public void dfs(mxGraphHierarchyNode parent, mxGraphHierarchyNode root,
mxGraphHierarchyEdge connectingEdge, CellVisitor visitor,
Set<mxGraphHierarchyNode> seen, int layer)
{
if (root != null)
{
if (!seen.contains(root))
{
visitor.visit(parent, root, connectingEdge, layer, 0);
seen.add(root);
// Copy the connects as source list so that visitors
// can change the original for edge direction inversions
final Object[] outgoingEdges = root.connectsAsSource.toArray();
for (int i = 0; i < outgoingEdges.length; i++)
{
mxGraphHierarchyEdge internalEdge = (mxGraphHierarchyEdge) outgoingEdges[i];
mxGraphHierarchyNode targetNode = internalEdge.target;
// Root check is O(|roots|)
dfs(root, targetNode, internalEdge, visitor, seen,
layer + 1);
}
}
else
{
// Use the int field to indicate this node has been seen
visitor.visit(parent, root, connectingEdge, layer, 1);
}
}
}
/**
* Performs a depth first search on the internal hierarchy model. This dfs
* extends the default version by keeping track of cells ancestors, but it
* should be only used when necessary because of it can be computationally
* intensive for deep searches.
*
* @param parent
* the parent internal node of the current internal node
* @param root
* the current internal node
* @param connectingEdge
* the internal edge connecting the internal node and the parent
* internal node, if any
* @param visitor
* the visitor pattern to be called for each node
* @param seen
* a set of all nodes seen by this dfs
* @param ancestors
* the parent hash code
* @param childHash
* the new hash code for this node
* @param layer
* the layer on the dfs tree ( not the same as the model ranks )
*/
public void dfs(mxGraphHierarchyNode parent, mxGraphHierarchyNode root,
mxGraphHierarchyEdge connectingEdge, CellVisitor visitor,
Set<mxGraphHierarchyNode> seen, int[] ancestors, int childHash,
int layer)
{
// Explanation of custom hash set. Previously, the ancestors variable
// was passed through the dfs as a HashSet. The ancestors were copied
// into a new HashSet and when the new child was processed it was also
// added to the set. If the current node was in its ancestor list it
// meant there is a cycle in the graph and this information is passed
// to the visitor.visit() in the seen parameter. The HashSet clone was
// very expensive on CPU so a custom hash was developed using primitive
// types. temp[] couldn't be used so hashCode[] was added to each node.
// Each new child adds another int to the array, copying the prefix
// from its parent. Child of the same parent add different ints (the
// limit is therefore 2^32 children per parent...). If a node has a
// child with the hashCode already set then the child code is compared
// to the same portion of the current nodes array. If they match there
// is a loop.
// Note that the basic mechanism would only allow for 1 use of this
// functionality, so the root nodes have two ints. The second int is
// incremented through each node root and the first is incremented
// through each run of the dfs algorithm (therefore the dfs is not
// thread safe). The hash code of each node is set if not already set,
// or if the first int does not match that of the current run.
if (root != null)
{
if (parent != null)
{
// Form this nodes hash code if necessary, that is, if the
// hashCode variable has not been initialized or if the
// start of the parent hash code does not equal the start of
// this nodes hash code, indicating the code was set on a
// previous run of this dfs.
if (root.hashCode == null
|| root.hashCode[0] != parent.hashCode[0])
{
int hashCodeLength = parent.hashCode.length + 1;
root.hashCode = new int[hashCodeLength];
System.arraycopy(parent.hashCode, 0, root.hashCode, 0,
parent.hashCode.length);
root.hashCode[hashCodeLength - 1] = childHash;
}
}
if (!seen.contains(root))
{
visitor.visit(parent, root, connectingEdge, layer, 0);
seen.add(root);
// Copy the connects as source list so that visitors
// can change the original for edge direction inversions
final Object[] outgoingEdges = root.connectsAsSource.toArray();
for (int i = 0; i < outgoingEdges.length; i++)
{
mxGraphHierarchyEdge internalEdge = (mxGraphHierarchyEdge) outgoingEdges[i];
mxGraphHierarchyNode targetNode = internalEdge.target;
// Root check is O(|roots|)
dfs(root, targetNode, internalEdge, visitor, seen,
root.hashCode, i, layer + 1);
}
}
else
{
// Use the int field to indicate this node has been seen
visitor.visit(parent, root, connectingEdge, layer, 1);
}
}
}
/**
* Defines the interface that visitors use to perform operations upon the
* graph information during depth first search (dfs) or other tree-traversal
* strategies implemented by subclassers.
*/
public interface CellVisitor
{
/**
* The method within which the visitor will perform operations upon the
* graph model
*
* @param parent
* the parent cell the current cell
* @param cell
* the current cell visited
* @param connectingEdge
* the edge that led the last cell visited to this cell
* @param layer
* the current layer of the tree
* @param seen
* an int indicating whether this cell has been seen
* previously
*/
public void visit(mxGraphHierarchyNode parent,
mxGraphHierarchyNode cell, mxGraphHierarchyEdge connectingEdge,
int layer, int seen);
}
/**
* @return Returns the vertexMapping.
*/
public Map<Object, mxGraphHierarchyNode> getVertexMapper()
{
if (vertexMapper == null)
{
vertexMapper = new Hashtable<Object, mxGraphHierarchyNode>();
}
return vertexMapper;
}
/**
* @param vertexMapping
* The vertexMapping to set.
*/
public void setVertexMapper(Map<Object, mxGraphHierarchyNode> vertexMapping)
{
this.vertexMapper = vertexMapping;
}
/**
* @return Returns the edgeMapper.
*/
public Map<Object, mxGraphHierarchyEdge> getEdgeMapper()
{
return edgeMapper;
}
/**
* @param edgeMapper
* The edgeMapper to set.
*/
public void setEdgeMapper(Map<Object, mxGraphHierarchyEdge> edgeMapper)
{
this.edgeMapper = edgeMapper;
}
/**
* @return Returns the dfsCount.
*/
public int getDfsCount()
{
return dfsCount;
}
/**
* @param dfsCount
* The dfsCount to set.
*/
public void setDfsCount(int dfsCount)
{
this.dfsCount = dfsCount;
}
}