private boolean depthFirstSearchRecursive(
VertexType vertex, VertexType fromVertex, PreWorkPostWorkHandler<VertexType> handler)
throws InvalidVertexException {
// TODO:Implementing non-recursive version
// int vertexId = vertex.getId();
vertex.setMark(true);
if (handler != null) if (handler.doPreWork(fromVertex, vertex)) return true;
dispatchEvent(new PreWorkEvent<VertexType, EdgeType>(fromVertex, vertex, graph));
EventUtils.algorithmStep(this, "visit: " + vertex.getId());
VertexType lastInDepthVertex = vertex;
for (VertexType i : graph) {
if (graph.isEdge(vertex, i)) {
if (!i.getMark()) {
lastInDepthVertex = i;
if (depthFirstSearchRecursive(i, vertex, handler)) return true;
}
}
}
dispatchEvent(new PostWorkEvent<VertexType, EdgeType>(lastInDepthVertex, vertex, graph));
EventUtils.algorithmStep(this, "leave: " + vertex.getId());
if (handler != null) if (handler.doPostWork(lastInDepthVertex, vertex)) return true;
return false;
}
/**
* Runs Depth First Search (DFS) algorithm on the graph starting from vertex <I>vertexId</I>. A
* reference to a PreWorkPostWorkHandler is supplied that contains implementation of pre-work and
* post-work operations that depends on the application of DFS.
*
* @param vertex Index of the starting vertex of the traversal.
* @param handler A reference to a PreWorkPostWorkHandler that contains implementation of pre-work
* and post-work operations that depends on the application of DFS.
* @param resetMarks If the search should reset vertex visit marks.
* @return Whether the traversal has stopped at the middle by the handler.
*/
public boolean doSearch(
VertexType vertex, PreWorkPostWorkHandler<VertexType> handler, boolean resetMarks)
throws InvalidVertexException, InvalidGraphException {
if (graph == null) throw new InvalidGraphException("Graph object is null.");
if (resetMarks) for (VertexType v : graph) v.setMark(false);
return depthFirstSearchRecursive(vertex, vertex, handler);
}
