private void initialize(final LGraph graph) {
layeredGraph = graph;
int layerCount = graph.getLayers().size();
bestNodeOrder = new LNode[layerCount][];
currentNodeOrder = new LNode[layerCount][];
originalNodeOrder = new LNode[layerCount][];
ListIterator<Layer> layerIter = graph.getLayers().listIterator();
while (layerIter.hasNext()) {
Layer layer = layerIter.next();
int layerNodeCount = layer.getNodes().size();
assert layerNodeCount > 0;
int layerIndex = layerIter.previousIndex();
bestNodeOrder[layerIndex] = new LNode[layerNodeCount];
currentNodeOrder[layerIndex] = new LNode[layerNodeCount];
originalNodeOrder[layerIndex] = new LNode[layerNodeCount];
ListIterator<LNode> nodeIter = layer.getNodes().listIterator();
int id = 0;
while (nodeIter.hasNext()) {
LNode node = nodeIter.next();
node.id = id++;
currentNodeOrder[layerIndex][nodeIter.previousIndex()] = node;
bestNodeOrder[layerIndex][nodeIter.previousIndex()] = node;
originalNodeOrder[layerIndex][nodeIter.previousIndex()] = node;
}
}
crossingCounter = new AllCrossingsCounter(currentNodeOrder);
if (greedySwitchType.useHyperedgeCounter()) {
crossingCounter.useHyperedgeCounter();
}
}
private void setAsGraph(final LNode[][] nodeOrder) {
ListIterator<Layer> layerIter = layeredGraph.getLayers().listIterator();
while (layerIter.hasNext()) {
Layer layer = layerIter.next();
LNode[] nodes = nodeOrder[layerIter.previousIndex()];
ListIterator<LNode> nodeIter = layer.getNodes().listIterator();
while (nodeIter.hasNext()) {
nodeIter.next();
nodeIter.set(nodes[nodeIter.previousIndex()]);
}
}
}
/**
* Merge regions by testing whether they would overlap after applying the deflection.
*
* @param layeredGraph the layered graph
* @return true if any two regions have been merged
*/
private boolean mergeRegions(final LGraph layeredGraph) {
boolean changed = false;
double threshold = OVERLAP_DETECT * spacings.nodeSpacing * spacings.inLayerSpacingFactor;
for (Layer layer : layeredGraph) {
Iterator<LNode> nodeIter = layer.getNodes().iterator();
// Get the first node
LNode node1 = nodeIter.next();
LinearSegment region1 = linearSegments[node1.id].region();
// While there are still nodes following the current node
while (nodeIter.hasNext()) {
// Test whether nodes have different regions
LNode node2 = nodeIter.next();
LinearSegment region2 = linearSegments[node2.id].region();
if (region1 != region2) {
// Calculate how much space is allowed between the nodes
double spacing = spacings.getVerticalSpacing(node1, node2);
double node1Extent =
node1.getPosition().y
+ node1.getSize().y
+ node1.getMargin().bottom
+ region1.deflection
+ spacing;
double node2Extent = node2.getPosition().y - node2.getMargin().top + region2.deflection;
// Test if the nodes are overlapping
if (node1Extent > node2Extent + threshold) {
// Merge the first region under the second top level segment
int weightSum = region1.weight + region2.weight;
assert weightSum > 0;
region2.deflection =
(region2.weight * region2.deflection + region1.weight * region1.deflection)
/ weightSum;
region2.weight = weightSum;
region1.refSegment = region2;
changed = true;
}
}
node1 = node2;
region1 = region2;
}
}
return changed;
}
/**
* Creates an unbalanced placement for the sorted linear segments.
*
* @param layeredGraph the layered graph to create an unbalanced placement for.
*/
private void createUnbalancedPlacement(final LGraph layeredGraph) {
// How many nodes are currently placed in each layer
int[] nodeCount = new int[layeredGraph.getLayers().size()];
// The type of the node most recently placed in a given layer
NodeType[] recentNodeType = new NodeType[layeredGraph.getLayers().size()];
// Iterate through the linear segments (in proper order!) and place them
for (LinearSegment segment : linearSegments) {
// Determine the uppermost placement for the linear segment
double uppermostPlace = 0.0f;
for (LNode node : segment.nodes) {
NodeType nodeType = node.getType();
int layerIndex = node.getLayer().getIndex();
nodeCount[layerIndex]++;
// Calculate how much space to leave between the linear segment and the last
// node of the given layer
float spacing = spacings.edgeEdgeSpacing * spacings.inLayerSpacingFactor;
if (nodeCount[layerIndex] > 0) {
if (recentNodeType[layerIndex] != null) {
spacing = spacings.getVerticalSpacing(recentNodeType[layerIndex], nodeType);
}
}
uppermostPlace = Math.max(uppermostPlace, node.getLayer().getSize().y + spacing);
}
// Apply the uppermost placement to all elements
for (LNode node : segment.nodes) {
// Set the node position
node.getPosition().y = uppermostPlace + node.getMargin().top;
// Adjust layer size
Layer layer = node.getLayer();
layer.getSize().y =
uppermostPlace + node.getMargin().top + node.getSize().y + node.getMargin().bottom;
recentNodeType[layer.getIndex()] = node.getType();
}
}
}
/**
* Fills the dependency graph with dependencies. If a dependency would introduce a cycle, the
* offending linear segment is split into two linear segments.
*
* @param layeredGraph the layered graph.
* @param segmentList the list of segments. Updated to include the newly created linear segments.
* @param outgoingList the lists of outgoing dependencies for each segment. This essentially
* encodes the edges of the dependency graph.
* @param incomingCountList the number of incoming dependencies for each segment.
*/
private void createDependencyGraphEdges(
final LGraph layeredGraph,
final List<LinearSegment> segmentList,
final List<List<LinearSegment>> outgoingList,
final List<Integer> incomingCountList) {
/*
* There's some <scaryVoice> faaaancy </scaryVoice> stuff going on here. Basically, we go
* through all the layers, from left to right. In each layer, we go through all the nodes.
* For each node, we retrieve the linear segment it's part of and add a dependency to the
* next node's linear segment. So far so good.
*
* This works perfectly fine as long as we assume that the relative order of linear segments
* doesn't change from one layer to the next. However, since the introduction of north /
* south port dummies, it can. We now have to avoid creating cycles in the dependency graph.
* This is done by remembering the indices of each linear segment in the previous layer.
* When we encounter a segment x, we check if there is a segment y that came before x in the
* previous layer. (that would introduce a cycle) If that's the case, we split x at the
* current layer, resulting in two segments, x1 and x2, x2 starting at the current layer.
* Now, we proceed as usual, adding a dependency from x2 to y. But we have avoided a cycle
* because y does not depend on x2, but on x1.
*/
int nextLinearSegmentID = segmentList.size();
int layerIndex = 0;
for (Layer layer : layeredGraph) {
List<LNode> nodes = layer.getNodes();
if (nodes.isEmpty()) {
// Ignore empty layers
continue;
}
Iterator<LNode> nodeIter = nodes.iterator();
int indexInLayer = 0;
// We carry the previous node with us for dependency management
LNode previousNode = null;
// Get the layer's first node
LNode currentNode = nodeIter.next();
LinearSegment currentSegment = null;
while (currentNode != null) {
// Get the current node's segment
currentSegment = segmentList.get(currentNode.id);
/*
* Check if we have a cycle. That's the case if the following holds: - The current
* segment appeared in the previous layer as well. - In the previous layer, we find
* a segment after the current segment that appears before the current segment in
* the current layer.
*/
if (currentSegment.indexInLastLayer >= 0) {
LinearSegment cycleSegment = null;
Iterator<LNode> cycleNodesIter = layer.getNodes().listIterator(indexInLayer + 1);
while (cycleNodesIter.hasNext()) {
LNode cycleNode = cycleNodesIter.next();
cycleSegment = segmentList.get(cycleNode.id);
if (cycleSegment.lastLayer == currentSegment.lastLayer
&& cycleSegment.indexInLastLayer < currentSegment.indexInLastLayer) {
break;
} else {
cycleSegment = null;
}
}
// If we have found a cycle segment, we need to split the current linear segment
if (cycleSegment != null) {
// Update the current segment before it's split
if (previousNode != null) {
incomingCountList.set(currentNode.id, incomingCountList.get(currentNode.id) - 1);
outgoingList.get(previousNode.id).remove(currentSegment);
}
currentSegment = currentSegment.split(currentNode, nextLinearSegmentID++);
segmentList.add(currentSegment);
outgoingList.add(new ArrayList<LinearSegment>());
if (previousNode != null) {
outgoingList.get(previousNode.id).add(currentSegment);
incomingCountList.add(1);
} else {
incomingCountList.add(0);
}
}
}
// Now add a dependency to the next node, if any
LNode nextNode = null;
if (nodeIter.hasNext()) {
nextNode = nodeIter.next();
LinearSegment nextSegment = segmentList.get(nextNode.id);
outgoingList.get(currentNode.id).add(nextSegment);
incomingCountList.set(nextNode.id, incomingCountList.get(nextNode.id) + 1);
}
// Update segment's layer information
currentSegment.lastLayer = layerIndex;
currentSegment.indexInLastLayer = indexInLayer++;
// Cycle nodes
previousNode = currentNode;
currentNode = nextNode;
}
layerIndex++;
}
// Write debug output graph
if (layeredGraph.getProperty(LayoutOptions.DEBUG_MODE)) {
DebugUtil.writeDebugGraph(layeredGraph, segmentList, outgoingList);
}
}