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"
19 #include "snapped-point.h"
20 #include "snapped-line.h"
22 struct SnappedConstraints {
23 std::list<Inkscape::SnappedPoint> points;
24 std::list<Inkscape::SnappedLineSegment> lines;
25 std::list<Inkscape::SnappedLine> grid_lines;
26 std::list<Inkscape::SnappedLine> guide_lines;
27 };
29 struct SPNamedView;
30 struct SPItem;
32 namespace Inkscape
33 {
35 /// Parent for classes that can snap points to something
36 class Snapper
37 {
38 public:
39 Snapper() {}
40 Snapper(SPNamedView const *nv, ::NR::Coord const d);
41 virtual ~Snapper() {}
43 /// Point types to snap.
44 typedef int PointType;
45 static const PointType SNAPPOINT_NODE;
46 static const PointType SNAPPOINT_BBOX;
47 static const PointType SNAPPOINT_GUIDE;
49 void setSnapFrom(PointType t, bool s);
50 void setDistance(::NR::Coord d);
52 bool getSnapFrom(PointType t) const;
53 ::NR::Coord getDistance() const;
55 /**
56 * \return true if this Snapper will snap at least one kind of point.
57 */
58 virtual bool ThisSnapperMightSnap() const {return (_enabled && _snap_from != 0);} // will likely be overridden by derived classes
60 void setEnabled(bool s);
62 void freeSnap(SnappedConstraints &sc,
63 PointType const &t,
64 NR::Point const &p,
65 bool const &first_point,
66 std::vector<NR::Point> &points_to_snap,
67 SPItem const *it) const;
69 void freeSnap(SnappedConstraints &sc,
70 PointType const &t,
71 NR::Point const &p,
72 bool const &first_point,
73 std::vector<NR::Point> &points_to_snap,
74 std::list<SPItem const *> const &it) const;
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) {}
82 bool hasPoint() const {
83 return _has_point;
84 }
86 NR::Point getPoint() const {
87 return _point;
88 }
90 NR::Point getDirection() const {
91 return _direction;
92 }
94 private:
96 bool _has_point;
97 NR::Point _point;
98 NR::Point _direction;
99 };
101 void constrainedSnap(SnappedConstraints &sc,
102 PointType const &t,
103 NR::Point const &p,
104 bool const &first_point,
105 std::vector<NR::Point> &points_to_snap,
106 ConstraintLine const &c,
107 SPItem const *it) const;
109 void constrainedSnap(SnappedConstraints &sc,
110 PointType const &t,
111 NR::Point const &p,
112 bool const &first_point,
113 std::vector<NR::Point> &points_to_snap,
114 ConstraintLine const &c,
115 std::list<SPItem const *> const &it) const;
117 protected:
118 SPNamedView const *_named_view;
119 int _snap_from; ///< bitmap of point types that we will snap from
120 bool _enabled; ///< true if this snapper is enabled, otherwise false
122 private:
124 /**
125 * Try to snap a point to whatever this snapper is interested in. Any
126 * snap that occurs will be to the nearest "interesting" thing (e.g. a
127 * grid or guide line)
128 *
129 * \param p Point to snap (desktop coordinates).
130 * \param it Items that should not be snapped to.
131 * \return Snapped point.
132 */
133 virtual void _doFreeSnap(SnappedConstraints &sc,
134 PointType const &t,
135 NR::Point const &p,
136 bool const &first_point,
137 std::vector<NR::Point> &points_to_snap,
138 std::list<SPItem const *> const &it) const = 0;
140 /**
141 * Try to snap a point to whatever this snapper is interested in, where
142 * the snap point is constrained to lie along a specified vector from the
143 * original point.
144 *
145 * \param p Point to snap (desktop coordinates).
146 * \param c Vector to constrain the snap to.
147 * \param it Items that should not be snapped to.
148 * \return Snapped point.
149 */
150 virtual void _doConstrainedSnap(SnappedConstraints &sc,
151 PointType const &t,
152 NR::Point const &p,
153 bool const &first_point,
154 std::vector<NR::Point> &points_to_snap,
155 ConstraintLine const &c,
156 std::list<SPItem const *> const &it) const = 0;
158 NR::Coord _distance; ///< snap distance (desktop coordinates)
159 };
161 }
163 #endif /* !SEEN_SNAPPER_H */
165 /*
166 Local Variables:
167 mode:c++
168 c-file-style:"stroustrup"
169 c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
170 indent-tabs-mode:nil
171 fill-column:99
172 End:
173 */
174 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :