/**
* Split the given graph into its connected components.
*
* @param graph an input graph.
* @return a list of components that can be processed one by one.
*/
public List<FGraph> split(final FGraph graph) {
Boolean separate = graph.getProperty(LayoutOptions.SEPARATE_CC);
if (separate == null || separate.booleanValue()) {
boolean[] visited = new boolean[graph.getNodes().size()];
List<FEdge>[] incidence = buildIncidenceLists(graph);
// perform DFS starting on each node, collecting connected components
List<FGraph> components = new LinkedList<FGraph>();
for (FNode node : graph.getNodes()) {
FGraph comp = dfs(node, null, visited, incidence);
if (comp != null) {
comp.copyProperties(graph);
components.add(comp);
}
}
// redistribute identifier numbers to each component
if (components.size() > 1) {
for (FGraph comp : components) {
int id = 0;
for (FNode node : comp.getNodes()) {
node.id = id++;
}
}
}
return components;
}
return Lists.newArrayList(graph);
}
/**
* Pack the given components into a single graph.
*
* @param components a list of components.
* @return a single graph that contains all components.
*/
public FGraph recombine(final List<FGraph> components) {
if (components.size() == 1) {
return components.get(0);
} else if (components.size() <= 0) {
return new FGraph();
}
// assign priorities and sizes
for (FGraph graph : components) {
int priority = 0;
double minx = Integer.MAX_VALUE,
miny = Integer.MAX_VALUE,
maxx = Integer.MIN_VALUE,
maxy = Integer.MIN_VALUE;
for (FNode node : graph.getNodes()) {
Integer p = node.getProperty(LayoutOptions.PRIORITY);
if (p != null) {
priority += p;
}
minx = Math.min(minx, node.getPosition().x);
miny = Math.min(miny, node.getPosition().y);
maxx = Math.max(maxx, node.getPosition().x + node.getSize().x);
maxy = Math.max(maxy, node.getPosition().y + node.getSize().y);
}
graph.setProperty(Properties.PRIORITY, priority);
graph.setProperty(Properties.BB_UPLEFT, new KVector(minx, miny));
graph.setProperty(Properties.BB_LOWRIGHT, new KVector(maxx, maxy));
}
// sort the components by their priority and size
Collections.sort(
components,
new Comparator<FGraph>() {
public int compare(final FGraph graph1, final FGraph graph2) {
int prio =
graph2.getProperty(Properties.PRIORITY) - graph1.getProperty(Properties.PRIORITY);
if (prio == 0) {
KVector size1 =
graph1
.getProperty(Properties.BB_LOWRIGHT)
.clone()
.sub(graph1.getProperty(Properties.BB_UPLEFT));
KVector size2 =
graph2
.getProperty(Properties.BB_LOWRIGHT)
.clone()
.sub(graph2.getProperty(Properties.BB_UPLEFT));
return Double.compare(size1.x * size1.y, size2.x * size2.y);
}
return prio;
}
});
FGraph result = new FGraph();
result.copyProperties(components.get(0));
// determine the maximal row width by the maximal box width and the total area
double maxRowWidth = 0.0f;
double totalArea = 0.0f;
for (FGraph graph : components) {
KVector size =
graph
.getProperty(Properties.BB_LOWRIGHT)
.clone()
.sub(graph.getProperty(Properties.BB_UPLEFT));
maxRowWidth = Math.max(maxRowWidth, size.x);
totalArea += size.x * size.y;
}
maxRowWidth =
Math.max(
maxRowWidth,
(float) Math.sqrt(totalArea) * result.getProperty(Properties.ASPECT_RATIO));
double spacing = result.getProperty(Properties.SPACING).doubleValue();
// place nodes iteratively into rows
double xpos = 0, ypos = 0, highestBox = 0, broadestRow = spacing;
for (FGraph graph : components) {
KVector size =
graph
.getProperty(Properties.BB_LOWRIGHT)
.clone()
.sub(graph.getProperty(Properties.BB_UPLEFT));
if (xpos + size.x > maxRowWidth) {
// place the graph into the next row
xpos = 0;
ypos += highestBox + spacing;
highestBox = 0;
}
moveGraph(result, graph, xpos, ypos);
broadestRow = Math.max(broadestRow, xpos + size.x);
highestBox = Math.max(highestBox, size.y);
xpos += size.x + spacing;
}
return result;
}