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 * Diederik van Lierop <mail@diedenrezi.nl>
11 *
12 * Released under GNU GPL, read the file 'COPYING' for more information.
13 */
15 #include <map>
16 #include <list>
17 #include "libnr/nr-coord.h"
18 #include "libnr/nr-point.h"
20 #include "snapped-point.h"
21 #include "snapped-line.h"
23 struct SnappedConstraints {
24 std::list<Inkscape::SnappedPoint> points;
25 std::list<Inkscape::SnappedLineSegment> lines;
26 std::list<Inkscape::SnappedLine> grid_lines;
27 std::list<Inkscape::SnappedLine> guide_lines;
28 };
30 struct SPNamedView;
31 struct SPItem;
33 namespace Inkscape
34 {
36 /// Parent for classes that can snap points to something
37 class Snapper
38 {
39 public:
40 Snapper() {}
41 Snapper(SPNamedView const *nv, ::NR::Coord const d);
42 virtual ~Snapper() {}
44 /// Point types to snap.
45 typedef int PointType;
46 static const PointType SNAPPOINT_NODE;
47 static const PointType SNAPPOINT_BBOX;
48 static const PointType SNAPPOINT_GUIDE;
50 void setSnapFrom(PointType t, bool s);
51 bool getSnapFrom(PointType t) const;
53 void setSnapperTolerance(NR::Coord t);
54 NR::Coord getSnapperTolerance() const; //returns the tolerance of the snapper in screen pixels (i.e. independent of zoom)
55 bool getSnapperAlwaysSnap() const; //if true, then the snapper will always snap, regardless of its tolerance
57 /**
58 * \return true if this Snapper will snap at least one kind of point.
59 */
60 virtual bool ThisSnapperMightSnap() const {return (_snap_enabled && _snap_from != 0);} // will likely be overridden by derived classes
62 void setEnabled(bool s);
63 bool getEnabled() const {return _snap_enabled;}
65 void freeSnap(SnappedConstraints &sc,
66 PointType const &t,
67 NR::Point const &p,
68 bool const &first_point,
69 std::vector<NR::Point> &points_to_snap,
70 SPItem const *it) const;
72 void freeSnap(SnappedConstraints &sc,
73 PointType const &t,
74 NR::Point const &p,
75 bool const &first_point,
76 std::vector<NR::Point> &points_to_snap,
77 std::list<SPItem const *> const &it) const;
79 class ConstraintLine
80 {
81 public:
82 ConstraintLine(NR::Point const &d) : _has_point(false), _direction(d) {}
83 ConstraintLine(NR::Point const &p, NR::Point const &d) : _has_point(true), _point(p), _direction(d) {}
85 bool hasPoint() const {
86 return _has_point;
87 }
89 NR::Point getPoint() const {
90 return _point;
91 }
93 NR::Point getDirection() const {
94 return _direction;
95 }
97 private:
99 bool _has_point;
100 NR::Point _point;
101 NR::Point _direction;
102 };
104 void constrainedSnap(SnappedConstraints &sc,
105 PointType const &t,
106 NR::Point const &p,
107 bool const &first_point,
108 std::vector<NR::Point> &points_to_snap,
109 ConstraintLine const &c,
110 SPItem const *it) const;
112 void constrainedSnap(SnappedConstraints &sc,
113 PointType const &t,
114 NR::Point const &p,
115 bool const &first_point,
116 std::vector<NR::Point> &points_to_snap,
117 ConstraintLine const &c,
118 std::list<SPItem const *> const &it) const;
120 protected:
121 SPNamedView const *_named_view;
122 int _snap_from; ///< bitmap of point types that we will snap from
123 bool _snap_enabled; ///< true if this snapper is enabled, otherwise false
125 private:
126 NR::Coord _snapper_tolerance; ///< snap tolerance in desktop coordinates
127 // must be private to enforce the usage of getTolerance(), which retrieves
128 // the tolerance in screen pixels (making it zoom independent)
131 /**
132 * Try to snap a point to whatever this snapper is interested in. Any
133 * snap that occurs will be to the nearest "interesting" thing (e.g. a
134 * grid or guide line)
135 *
136 * \param p Point to snap (desktop coordinates).
137 * \param it Items that should not be snapped to.
138 * \return Snapped point.
139 */
140 virtual void _doFreeSnap(SnappedConstraints &sc,
141 PointType const &t,
142 NR::Point const &p,
143 bool const &first_point,
144 std::vector<NR::Point> &points_to_snap,
145 std::list<SPItem const *> const &it) const = 0;
147 /**
148 * Try to snap a point to whatever this snapper is interested in, where
149 * the snap point is constrained to lie along a specified vector from the
150 * original point.
151 *
152 * \param p Point to snap (desktop coordinates).
153 * \param c Vector to constrain the snap to.
154 * \param it Items that should not be snapped to.
155 * \return Snapped point.
156 */
157 virtual void _doConstrainedSnap(SnappedConstraints &sc,
158 PointType const &t,
159 NR::Point const &p,
160 bool const &first_point,
161 std::vector<NR::Point> &points_to_snap,
162 ConstraintLine const &c,
163 std::list<SPItem const *> const &it) const = 0;
164 };
166 }
168 #endif /* !SEEN_SNAPPER_H */
170 /*
171 Local Variables:
172 mode:c++
173 c-file-style:"stroustrup"
174 c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
175 indent-tabs-mode:nil
176 fill-column:99
177 End:
178 */
179 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :