#ifndef SEEN_SNAPPER_H

#define SEEN_SNAPPER_H

#include <map>

#include <list>

#include "libnr/nr-coord.h"

#include "libnr/nr-point.h"

#include <boost/optional.hpp>

#include "snapped-point.h"

#include "snapped-line.h"

#include "snapped-curve.h"

#include "snap-preferences.h"

struct SnappedConstraints {

std::list<Inkscape::SnappedPoint> points;

std::list<Inkscape::SnappedLineSegment> lines;

std::list<Inkscape::SnappedLine> grid_lines;

std::list<Inkscape::SnappedLine> guide_lines;

std::list<Inkscape::SnappedCurve> curves;

};

class SnapManager;

struct SPItem;

namespace Inkscape

{

class Snapper

{

public:

Snapper() {}

Snapper(SnapManager *sm, ::Geom::Coord const t);

virtual ~Snapper() {}

virtual Geom::Coord getSnapperTolerance() const = 0; //returns the tolerance of the snapper in screen pixels (i.e. independent of zoom)

virtual bool getSnapperAlwaysSnap() const = 0; //if true, then the snapper will always snap, regardless of its tolerance

/**

virtual bool ThisSnapperMightSnap() const {return _snap_enabled;} // will likely be overridden by derived classes

void setEnabled(bool s); // This is only used for grids, for which snapping can be enabled individually

bool getEnabled() const {return _snap_enabled;}

virtual void freeSnap(SnappedConstraints &/*sc*/,

SnapPreferences::PointType const &/*t*/,

Geom::Point const &/*p*/,

SnapSourceType const &/*source_type*/,

bool const &/*first_point*/,

Geom::OptRect const &/*bbox_to_snap*/,

std::vector<SPItem const *> const */*it*/,

std::vector<std::pair<Geom::Point, int> > */*unselected_nodes*/) const {};

class ConstraintLine

{

public:

ConstraintLine(Geom::Point const &d) : _has_point(false), _direction(d) {}

ConstraintLine(Geom::Point const &p, Geom::Point const &d) : _has_point(true), _point(p), _direction(d) {}

bool hasPoint() const {

return _has_point;

}

Geom::Point getPoint() const {

return _point;

}

Geom::Point getDirection() const {

return _direction;

}

void setPoint(Geom::Point const &p) {

_point = p;

_has_point = true;

}

private:

bool _has_point;

Geom::Point _point;

Geom::Point _direction;

};

virtual void constrainedSnap(SnappedConstraints &/*sc*/,

SnapPreferences::PointType const &/*t*/,

Geom::Point const &/*p*/,

SnapSourceType const &/*source_type*/,

bool const &/*first_point*/,

Geom::OptRect const &/*bbox_to_snap*/,

ConstraintLine const &/*c*/,

std::vector<SPItem const *> const */*it*/) const {};

protected:

SnapManager *_snapmanager;

bool _snap_enabled; ///< true if this snapper is enabled, otherwise false

// This is only used for grids, for which snapping can be enabled individually

};

}

#endif /* !SEEN_SNAPPER_H */