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     virtual Geom::Coord getSnapperTolerance() const = 0; //returns the tolerance of the snapper in screen pixels (i.e. independent of zoom)
  49     virtual bool getSnapperAlwaysSnap() const = 0; //if true, then the snapper will always snap, regardless of its tolerance
  50
  51     /**
  52     *  \return true if this Snapper will snap at least one kind of point.
  53     */
  54     virtual bool ThisSnapperMightSnap() const {return _snap_enabled;} // will likely be overridden by derived classes
  55
  56     void setEnabled(bool s); // This is only used for grids, for which snapping can be enabled individually
  57     bool getEnabled() const {return _snap_enabled;}
  58
  59     virtual void freeSnap(SnappedConstraints &/*sc*/,
  60                           SnapPreferences::PointType const &/*t*/,
  61                           Geom::Point const &/*p*/,
  62                           bool const &/*first_point*/,
  63                           Geom::OptRect const &/*bbox_to_snap*/,
  64                           std::vector<SPItem const *> const */*it*/,
  65                           std::vector<Geom::Point> */*unselected_nodes*/) const {};
  66
  67     class ConstraintLine
  68     {
  69     public:
  70         ConstraintLine(Geom::Point const &d) : _has_point(false), _direction(d) {}
  71         ConstraintLine(Geom::Point const &p, Geom::Point const &d) : _has_point(true), _point(p), _direction(d) {}
  72
  73         bool hasPoint() const {
  74             return _has_point;
  75         }
  76
  77         Geom::Point getPoint() const {
  78             return _point;
  79         }
  80
  81         Geom::Point getDirection() const {
  82             return _direction;
  83         }
  84
  85         void setPoint(Geom::Point const &p) {
  86             _point = p;
  87             _has_point = true;
  88         }
  89
  90     private:
  91
  92         bool _has_point;
  93         Geom::Point _point;
  94         Geom::Point _direction;
  95     };
  96
  97     virtual void constrainedSnap(SnappedConstraints &/*sc*/,
  98                                                          SnapPreferences::PointType const &/*t*/,
  99                                  Geom::Point const &/*p*/,
 100                                  bool const &/*first_point*/,
 101                                  Geom::OptRect const &/*bbox_to_snap*/,
 102                                  ConstraintLine const &/*c*/,
 103                                  std::vector<SPItem const *> const */*it*/) const {};
 104
 105 protected:
 106         SnapManager *_snapmanager;
 107
 108         bool _snap_enabled; ///< true if this snapper is enabled, otherwise false
 109                                                 // This is only used for grids, for which snapping can be enabled individually
 110 };
 111
 112 }
 113
 114 #endif /* !SEEN_SNAPPER_H */
 115
 116 /*
 117   Local Variables:
 118   mode:c++
 119   c-file-style:"stroustrup"
 120   c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
 121   indent-tabs-mode:nil
 122   fill-column:99
 123   End:
 124 */
 125 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :