mirror of
https://git.lyx.org/repos/lyx.git
synced 2024-09-22 07:57:22 +00:00
bf8f302b64
main advantage of what has been done here is that it would now be fairly easy to return ALL the paths connecting two nodes. In practice, this would mean that we could find ALL ways of converting one format (say, LaTeX) into another (say, PDF), and present these to the user for her perusal. git-svn-id: svn://svn.lyx.org/lyx/lyx-devel/trunk@31927 a592a061-630c-0410-9148-cb99ea01b6c8
111 lines
3.3 KiB
C++
111 lines
3.3 KiB
C++
// -*- C++ -*-
|
|
/**
|
|
* \file Graph.h
|
|
* This file is part of LyX, the document processor.
|
|
* Licence details can be found in the file COPYING.
|
|
*
|
|
* \author Dekel Tsur (original code)
|
|
* \author Richard Heck (re-implementation)
|
|
*
|
|
* Full author contact details are available in file CREDITS.
|
|
*/
|
|
|
|
#ifndef GRAPH_H
|
|
#define GRAPH_H
|
|
|
|
#include <list>
|
|
#include <queue>
|
|
#include <vector>
|
|
|
|
|
|
namespace lyx {
|
|
|
|
|
|
/// Represents a directed graph, possibly with multiple edges
|
|
/// connecting the vertices.
|
|
class Graph {
|
|
public:
|
|
Graph() : numedges_(0) {}
|
|
///
|
|
typedef std::vector<int> EdgePath;
|
|
/// \return a vector of the vertices from which "to" can be reached
|
|
std::vector<int> const getReachableTo(int to, bool clear_visited);
|
|
/// \return a vector of the vertices that can be reached from "from"
|
|
std::vector<int> const
|
|
getReachable(int from, bool only_viewable, bool clear_visited);
|
|
/// can "from" be reached from "to"?
|
|
bool isReachable(int from, int to);
|
|
/// find a path from "from" to "to". always returns one of the
|
|
/// shortest such paths.
|
|
EdgePath const getPath(int from, int to);
|
|
/// called repeatedly to build the graph
|
|
void addEdge(int from, int to);
|
|
/// reset the internal data structures
|
|
void init(int size);
|
|
|
|
private:
|
|
///
|
|
bool bfs_init(int, bool clear_visited = true);
|
|
/// clears the "marks" on the arrows. should be called
|
|
/// before any new marking begins.
|
|
void clearMarks();
|
|
/// used to recover a marked path
|
|
void getMarkedPath(int from, int to, EdgePath & path);
|
|
/// these represent the arrows connecting the nodes of the graph.
|
|
/// this is the basic representation of the graph: as a bunch of
|
|
/// arrows.
|
|
struct Arrow {
|
|
///
|
|
Arrow(int f, int t, int i):
|
|
from(f), to(t), id(i), marked(false) {}
|
|
/// the vertex at the tail of the arrow
|
|
int from;
|
|
/// the vertex at the head
|
|
int to;
|
|
/// an id for this arrow, e.g., for use in describing paths
|
|
/// through the graph
|
|
int id;
|
|
/// used for "marking" paths, i.e., constructing sub-graphs
|
|
/// without really doing so.
|
|
bool marked;
|
|
};
|
|
/// a container for the arrows
|
|
/// we use a list because we want pointers to the arrows,
|
|
/// and a vector might invalidate them
|
|
typedef std::list<Arrow> Arrows;
|
|
Arrows arrows_;
|
|
/// Represents a vertex of the graph. Note that we could recover
|
|
/// the in_arrows and out_arrows from the Arrows, so these are in
|
|
/// effect a kind of cache.
|
|
struct Vertex {
|
|
/// arrows that point at this one
|
|
std::vector<Arrow *> in_arrows;
|
|
/// arrows out from here
|
|
std::vector<Arrow *> out_arrows;
|
|
/// used in the search routines
|
|
bool visited;
|
|
};
|
|
/// a container for the vertices
|
|
/// the index into the vector functions as the identifier by which
|
|
/// these are referenced in the Arrow struct
|
|
/// the code making use of the Graph must keep track of the relation
|
|
/// between these indices and the objects they represent. (in the case
|
|
/// of Format, this is easy, since the Format objects already have ints
|
|
/// as identifiers.)
|
|
std::vector<Vertex> vertices_;
|
|
///
|
|
std::queue<int> Q_;
|
|
/// a counter that we use to assign id's to the arrows
|
|
/// FIXME This technique assumes a correspondence between the
|
|
/// ids of the arrows and ids associated with Converters that
|
|
/// seems kind of fragile. Perhaps a better solution would be
|
|
/// to pass the ids as we create the arrows.
|
|
int numedges_;
|
|
};
|
|
|
|
|
|
|
|
} // namespace lyx
|
|
|
|
#endif //GRAPH_H
|