/**
* 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();
}
}
}
/**
* Post-process the balanced placement by moving linear segments where obvious improvements can be
* made.
*
* @param layeredGraph the layered graph
*/
private void postProcess(final LGraph layeredGraph) {
// process each linear segment independently
for (LinearSegment segment : linearSegments) {
double minRoomAbove = Integer.MAX_VALUE, minRoomBelow = Integer.MAX_VALUE;
for (LNode node : segment.nodes) {
double roomAbove, roomBelow;
int index = node.getIndex();
// determine the amount by which the linear segment can be moved up without overlap
if (index > 0) {
LNode neighbor = node.getLayer().getNodes().get(index - 1);
float spacing = spacings.getVerticalSpacing(node, neighbor);
roomAbove =
node.getPosition().y
- node.getMargin().top
- (neighbor.getPosition().y
+ neighbor.getSize().y
+ neighbor.getMargin().bottom
+ spacing);
} else {
roomAbove = node.getPosition().y - node.getMargin().top;
}
minRoomAbove = Math.min(roomAbove, minRoomAbove);
// determine the amount by which the linear segment can be moved down without
// overlap
if (index < node.getLayer().getNodes().size() - 1) {
LNode neighbor = node.getLayer().getNodes().get(index + 1);
float spacing = spacings.getVerticalSpacing(node, neighbor);
roomBelow =
neighbor.getPosition().y
- neighbor.getMargin().top
- (node.getPosition().y + node.getSize().y + node.getMargin().bottom + spacing);
} else {
roomBelow = 2 * node.getPosition().y;
}
minRoomBelow = Math.min(roomBelow, minRoomBelow);
}
double minDisplacement = Integer.MAX_VALUE;
boolean foundPlace = false;
// determine the minimal displacement that would make one incoming edge straight
LNode firstNode = segment.nodes.get(0);
for (LPort target : firstNode.getPorts()) {
double pos = firstNode.getPosition().y + target.getPosition().y + target.getAnchor().y;
for (LEdge edge : target.getIncomingEdges()) {
LPort source = edge.getSource();
double d =
source.getNode().getPosition().y
+ source.getPosition().y
+ source.getAnchor().y
- pos;
if (Math.abs(d) < Math.abs(minDisplacement)
&& Math.abs(d) < (d < 0 ? minRoomAbove : minRoomBelow)) {
minDisplacement = d;
foundPlace = true;
}
}
}
// determine the minimal displacement that would make one outgoing edge straight
LNode lastNode = segment.nodes.get(segment.nodes.size() - 1);
for (LPort source : lastNode.getPorts()) {
double pos = lastNode.getPosition().y + source.getPosition().y + source.getAnchor().y;
for (LEdge edge : source.getOutgoingEdges()) {
LPort target = edge.getTarget();
double d =
target.getNode().getPosition().y
+ target.getPosition().y
+ target.getAnchor().y
- pos;
if (Math.abs(d) < Math.abs(minDisplacement)
&& Math.abs(d) < (d < 0 ? minRoomAbove : minRoomBelow)) {
minDisplacement = d;
foundPlace = true;
}
}
}
// if such a displacement could be found, apply it to the whole linear segment
if (foundPlace && minDisplacement != 0) {
for (LNode node : segment.nodes) {
node.getPosition().y += minDisplacement;
}
}
}
}