1 #ifndef SEEN_SNAPPER_H
2 #define SEEN_SNAPPER_H
4 /**
5 * \file src/snapper.h
6 * \brief Snapper class.
7 *
8 * Authors:
9 * Carl Hetherington <inkscape@carlh.net>
10 *
11 * Released under GNU GPL, read the file 'COPYING' for more information.
12 */
14 #include <map>
15 #include <list>
16 #include "libnr/nr-coord.h"
17 #include "libnr/nr-point.h"
18 #include "snapped-point.h"
20 struct SPNamedView;
21 struct SPItem;
23 namespace Inkscape
24 {
26 /// Parent for classes that can snap points to something
27 class Snapper
28 {
29 public:
30 Snapper() {}
31 Snapper(SPNamedView const *nv, ::NR::Coord const d);
32 virtual ~Snapper() {}
34 /// Point types to snap.
35 typedef int PointType;
36 static const PointType SNAPPOINT_NODE;
37 static const PointType SNAPPOINT_BBOX;
38 static const PointType SNAPPOINT_GUIDE;
40 void setSnapFrom(PointType t, bool s);
41 void setDistance(::NR::Coord d);
43 bool getSnapFrom(PointType t) const;
44 ::NR::Coord getDistance() const;
46 /**
47 * \return true if this Snapper will snap at least one kind of point.
48 */
49 virtual bool ThisSnapperMightSnap() const {return (_enabled && _snap_from != 0);} // will likely be overridden by derived classes
51 void setEnabled(bool s);
53 SnappedPoint freeSnap(PointType const &t,
54 NR::Point const &p,
55 bool const &first_point,
56 std::vector<NR::Point> &points_to_snap,
57 SPItem const *it) const;
59 SnappedPoint freeSnap(PointType const &t,
60 NR::Point const &p,
61 bool const &first_point,
62 std::vector<NR::Point> &points_to_snap,
63 std::list<SPItem const *> const &it) const;
65 class ConstraintLine
66 {
67 public:
68 ConstraintLine(NR::Point const &d) : _has_point(false), _direction(d) {}
69 ConstraintLine(NR::Point const &p, NR::Point const &d) : _has_point(true), _point(p), _direction(d) {}
71 bool hasPoint() const {
72 return _has_point;
73 }
75 NR::Point getPoint() const {
76 return _point;
77 }
79 NR::Point getDirection() const {
80 return _direction;
81 }
83 private:
85 bool _has_point;
86 NR::Point _point;
87 NR::Point _direction;
88 };
90 SnappedPoint constrainedSnap(PointType const &t,
91 NR::Point const &p,
92 bool const &first_point,
93 std::vector<NR::Point> &points_to_snap,
94 ConstraintLine const &c,
95 SPItem const *it) const;
97 SnappedPoint constrainedSnap(PointType const &t,
98 NR::Point const &p,
99 bool const &first_point,
100 std::vector<NR::Point> &points_to_snap,
101 ConstraintLine const &c,
102 std::list<SPItem const *> const &it) const;
103 protected:
104 SPNamedView const *_named_view;
105 int _snap_from; ///< bitmap of point types that we will snap from
106 bool _enabled; ///< true if this snapper is enabled, otherwise false
108 private:
110 /**
111 * Try to snap a point to whatever this snapper is interested in. Any
112 * snap that occurs will be to the nearest "interesting" thing (e.g. a
113 * grid or guide line)
114 *
115 * \param p Point to snap (desktop coordinates).
116 * \param it Items that should not be snapped to.
117 * \return Snapped point.
118 */
119 virtual SnappedPoint _doFreeSnap(PointType const &t,
120 NR::Point const &p,
121 bool const &first_point,
122 std::vector<NR::Point> &points_to_snap,
123 std::list<SPItem const *> const &it) const = 0;
125 /**
126 * Try to snap a point to whatever this snapper is interested in, where
127 * the snap point is constrained to lie along a specified vector from the
128 * original point.
129 *
130 * \param p Point to snap (desktop coordinates).
131 * \param c Vector to constrain the snap to.
132 * \param it Items that should not be snapped to.
133 * \return Snapped point.
134 */
135 virtual SnappedPoint _doConstrainedSnap(PointType const &t,
136 NR::Point const &p,
137 bool const &first_point,
138 std::vector<NR::Point> &points_to_snap,
139 ConstraintLine const &c,
140 std::list<SPItem const *> const &it) const = 0;
142 ::NR::Coord _distance; ///< snap distance (desktop coordinates)
143 };
145 }
147 #endif /* !SEEN_SNAPPER_H */
149 /*
150 Local Variables:
151 mode:c++
152 c-file-style:"stroustrup"
153 c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
154 indent-tabs-mode:nil
155 fill-column:99
156 End:
157 */
158 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :