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 SNAP_POINT;
37 static const PointType BBOX_POINT;
39 typedef std::pair<PointType, NR::Point> PointWithType;
41 void setSnapTo(PointType t, bool s);
42 void setDistance(::NR::Coord d);
44 bool getSnapTo(PointType t) const;
45 ::NR::Coord getDistance() const;
47 bool willSnapSomething() const;
49 SnappedPoint freeSnap(PointType t,
50 NR::Point const &p,
51 SPItem const *it) const;
53 SnappedPoint freeSnap(PointType t,
54 NR::Point const &p,
55 std::list<SPItem const *> const &it) const;
57 class ConstraintLine
58 {
59 public:
60 ConstraintLine(NR::Point const &d) : _has_point(false), _direction(d) {}
61 ConstraintLine(NR::Point const &p, NR::Point const &d) : _has_point(true), _point(p), _direction(d) {}
63 bool hasPoint() const {
64 return _has_point;
65 }
67 NR::Point getPoint() const {
68 return _point;
69 }
71 NR::Point getDirection() const {
72 return _direction;
73 }
75 private:
77 bool _has_point;
78 NR::Point _point;
79 NR::Point _direction;
80 };
82 SnappedPoint constrainedSnap(PointType t,
83 NR::Point const &p,
84 ConstraintLine const &c,
85 SPItem const *it) const;
87 SnappedPoint constrainedSnap(PointType t,
88 NR::Point const &p,
89 ConstraintLine const &c,
90 std::list<SPItem const *> const &it) const;
91 protected:
92 SPNamedView const *_named_view;
94 private:
96 /**
97 * Try to snap a point to whatever this snapper is interested in. Any
98 * snap that occurs will be to the nearest "interesting" thing (e.g. a
99 * grid or guide line)
100 *
101 * \param p Point to snap (desktop coordinates).
102 * \param it Items that should not be snapped to.
103 * \return Snapped point.
104 */
105 virtual SnappedPoint _doFreeSnap(NR::Point const &p,
106 std::list<SPItem const *> const &it) const = 0;
108 /**
109 * Try to snap a point to whatever this snapper is interested in, where
110 * the snap point is constrained to lie along a specified vector from the
111 * original point.
112 *
113 * \param p Point to snap (desktop coordinates).
114 * \param c Vector to constrain the snap to.
115 * \param it Items that should not be snapped to.
116 * \return Snapped point.
117 */
118 virtual SnappedPoint _doConstrainedSnap(NR::Point const &p,
119 ConstraintLine const &c,
120 std::list<SPItem const *> const &it) const = 0;
122 ::NR::Coord _distance; ///< snap distance (desktop coordinates)
123 int _snap_to; ///< bitmap of point types that we will snap to
124 };
126 }
128 #endif /* !SEEN_SNAPPER_H */
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 :