src/snapper.h

   1 #ifndef SEEN_SNAPPER_H
   2 #define SEEN_SNAPPER_H
   3
   4 /**
   5  *    \file src/snapper.h
   6  *    \brief Snapper class.
   7  *
   8  *    Authors:
   9  *      Carl Hetherington <inkscape@carlh.net>
  10  *      Diederik van Lierop <mail@diedenrezi.nl>
  11  *
  12  *    Released under GNU GPL, read the file 'COPYING' for more information.
  13  */
  14
  15 #include <map>
  16 #include <list>
  17 #include "libnr/nr-coord.h"
  18 #include "libnr/nr-point.h"
  19 #include <boost/optional.hpp>
  20
  21 #include "snapped-point.h"
  22 #include "snapped-line.h"
  23 #include "snapped-curve.h"
  24 #include "snap-preferences.h"
  25
  26 struct SnappedConstraints {
  27     std::list<Inkscape::SnappedPoint> points;
  28     std::list<Inkscape::SnappedLineSegment> lines;
  29     std::list<Inkscape::SnappedLine> grid_lines;
  30     std::list<Inkscape::SnappedLine> guide_lines;
  31     std::list<Inkscape::SnappedCurve> curves;
  32 };
  33
  34 class SnapManager;
  35 struct SPItem;
  36
  37 namespace Inkscape
  38 {
  39
  40 /// Parent for classes that can snap points to something
  41 class Snapper
  42 {
  43 public:
  44         Snapper() {}
  45         Snapper(SnapManager *sm, ::Geom::Coord const t);
  46         virtual ~Snapper() {}
  47
  48     void setSnapperTolerance(Geom::Coord t);
  49     Geom::Coord getSnapperTolerance() const; //returns the tolerance of the snapper in screen pixels (i.e. independent of zoom)
  50     bool getSnapperAlwaysSnap() const; //if true, then the snapper will always snap, regardless of its tolerance
  51
  52     /**
  53     *  \return true if this Snapper will snap at least one kind of point.
  54     */
  55     //virtual bool ThisSnapperMightSnap() const;
  56     virtual bool ThisSnapperMightSnap() const {return _snap_enabled;} // will likely be overridden by derived classes
  57
  58     void setEnabled(bool s);
  59     bool getEnabled() const {return _snap_enabled;}
  60
  61     virtual void freeSnap(SnappedConstraints &/*sc*/,
  62                           SnapPreferences::PointType const &/*t*/,
  63                           Geom::Point const &/*p*/,
  64                           bool const &/*first_point*/,
  65                           Geom::OptRect const &/*bbox_to_snap*/,
  66                           std::vector<SPItem const *> const */*it*/,
  67                           std::vector<Geom::Point> */*unselected_nodes*/) const {};
  68
  69     class ConstraintLine
  70     {
  71     public:
  72         ConstraintLine(Geom::Point const &d) : _has_point(false), _direction(d) {}
  73         ConstraintLine(Geom::Point const &p, Geom::Point const &d) : _has_point(true), _point(p), _direction(d) {}
  74
  75         bool hasPoint() const {
  76             return _has_point;
  77         }
  78
  79         Geom::Point getPoint() const {
  80             return _point;
  81         }
  82
  83         Geom::Point getDirection() const {
  84             return _direction;
  85         }
  86
  87         void setPoint(Geom::Point const &p) {
  88             _point = p;
  89             _has_point = true;
  90         }
  91
  92     private:
  93
  94         bool _has_point;
  95         Geom::Point _point;
  96         Geom::Point _direction;
  97     };
  98
  99     virtual void constrainedSnap(SnappedConstraints &/*sc*/,
 100                                                          SnapPreferences::PointType const &/*t*/,
 101                                  Geom::Point const &/*p*/,
 102                                  bool const &/*first_point*/,
 103                                  Geom::OptRect const &/*bbox_to_snap*/,
 104                                  ConstraintLine const &/*c*/,
 105                                  std::vector<SPItem const *> const */*it*/) const {};
 106
 107 protected:
 108         SnapManager *_snapmanager;
 109
 110         bool _snap_enabled; ///< true if this snapper is enabled, otherwise false
 111
 112 private:
 113         Geom::Coord _snapper_tolerance;   ///< snap tolerance in desktop coordinates
 114                                     // must be private to enforce the usage of getTolerance(), which retrieves
 115                                     // the tolerance in screen pixels (making it zoom independent)
 116 };
 117
 118 }
 119
 120 #endif /* !SEEN_SNAPPER_H */
 121
 122 /*
 123   Local Variables:
 124   mode:c++
 125   c-file-style:"stroustrup"
 126   c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
 127   indent-tabs-mode:nil
 128   fill-column:99
 129   End:
 130 */
 131 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :