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
  25 struct SnappedConstraints {
  26     std::list<Inkscape::SnappedPoint> points;
  27     std::list<Inkscape::SnappedLineSegment> lines;
  28     std::list<Inkscape::SnappedLine> grid_lines;
  29     std::list<Inkscape::SnappedLine> guide_lines;
  30     std::list<Inkscape::SnappedCurve> curves;
  31 };
  32
  33 struct SPNamedView;
  34 struct SPItem;
  35
  36 namespace Inkscape
  37 {
  38
  39 /// Parent for classes that can snap points to something
  40 class Snapper
  41 {
  42 public:
  43     Snapper() {}
  44     Snapper(SPNamedView const *nv, ::NR::Coord const d);
  45     virtual ~Snapper() {}
  46
  47     /// Point types to snap.
  48     typedef int PointType;
  49     static const PointType SNAPPOINT_NODE;
  50     static const PointType SNAPPOINT_BBOX;
  51     static const PointType SNAPPOINT_GUIDE;
  52
  53     void setSnapFrom(PointType t, bool s);
  54     bool getSnapFrom(PointType t) const;
  55
  56     void setSnapperTolerance(NR::Coord t);
  57     NR::Coord getSnapperTolerance() const; //returns the tolerance of the snapper in screen pixels (i.e. independent of zoom)
  58     bool getSnapperAlwaysSnap() const; //if true, then the snapper will always snap, regardless of its tolerance
  59
  60     /**
  61     *  \return true if this Snapper will snap at least one kind of point.
  62     */
  63     virtual bool ThisSnapperMightSnap() const {return (_snap_enabled && _snap_from != 0);} // will likely be overridden by derived classes
  64
  65     void setEnabled(bool s);
  66     bool getEnabled() const {return _snap_enabled;}
  67
  68     virtual void freeSnap(SnappedConstraints &/*sc*/,
  69                           PointType const &/*t*/,
  70                           NR::Point const &/*p*/,
  71                           bool const &/*first_point*/,
  72                           boost::optional<NR::Rect> const &/*bbox_to_snap*/,
  73                           std::vector<SPItem const *> const */*it*/,
  74                           std::vector<NR::Point> */*unselected_nodes*/) const {};
  75
  76     class ConstraintLine
  77     {
  78     public:
  79         ConstraintLine(NR::Point const &d) : _has_point(false), _direction(d) {}
  80         ConstraintLine(NR::Point const &p, NR::Point const &d) : _has_point(true), _point(p), _direction(d) {}
  81
  82         bool hasPoint() const {
  83             return _has_point;
  84         }
  85
  86         NR::Point getPoint() const {
  87             return _point;
  88         }
  89
  90         NR::Point getDirection() const {
  91             return _direction;
  92         }
  93
  94         void setPoint(NR::Point const &p) {
  95             _point = p;
  96             _has_point = true;
  97         }
  98
  99     private:
 100
 101         bool _has_point;
 102         NR::Point _point;
 103         NR::Point _direction;
 104     };
 105
 106     virtual void constrainedSnap(SnappedConstraints &/*sc*/,
 107                                  PointType const &/*t*/,
 108                                  NR::Point const &/*p*/,
 109                                  bool const &/*first_point*/,
 110                                  boost::optional<NR::Rect> const &/*bbox_to_snap*/,
 111                                  ConstraintLine const &/*c*/,
 112                                  std::vector<SPItem const *> const */*it*/) const {};
 113
 114 protected:
 115     SPNamedView const *_named_view;
 116     int _snap_from; ///< bitmap of point types that we will snap from
 117     bool _snap_enabled; ///< true if this snapper is enabled, otherwise false
 118
 119 private:
 120     NR::Coord _snapper_tolerance;   ///< snap tolerance in desktop coordinates
 121                                     // must be private to enforce the usage of getTolerance(), which retrieves
 122                                     // the tolerance in screen pixels (making it zoom independent)
 123
 124 };
 125
 126 }
 127
 128 #endif /* !SEEN_SNAPPER_H */
 129
 130 /*
 131   Local Variables:
 132   mode:c++
 133   c-file-style:"stroustrup"
 134   c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
 135   indent-tabs-mode:nil
 136   fill-column:99
 137   End:
 138 */
 139 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :