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"
19 #include "libnr/nr-maybe.h"
21 #include "snapped-point.h"
22 #include "snapped-line.h"
24 struct SnappedConstraints {
25 std::list<Inkscape::SnappedPoint> points;
26 std::list<Inkscape::SnappedLineSegment> lines;
27 std::list<Inkscape::SnappedLine> grid_lines;
28 std::list<Inkscape::SnappedLine> guide_lines;
29 };
31 struct SPNamedView;
32 struct SPItem;
34 namespace Inkscape
35 {
37 /// Parent for classes that can snap points to something
38 class Snapper
39 {
40 public:
41 Snapper() {}
42 Snapper(SPNamedView const *nv, ::NR::Coord const d);
43 virtual ~Snapper() {}
45 /// Point types to snap.
46 typedef int PointType;
47 static const PointType SNAPPOINT_NODE;
48 static const PointType SNAPPOINT_BBOX;
49 static const PointType SNAPPOINT_GUIDE;
51 void setSnapFrom(PointType t, bool s);
52 bool getSnapFrom(PointType t) const;
54 void setSnapperTolerance(NR::Coord t);
55 NR::Coord getSnapperTolerance() const; //returns the tolerance of the snapper in screen pixels (i.e. independent of zoom)
56 bool getSnapperAlwaysSnap() const; //if true, then the snapper will always snap, regardless of its tolerance
58 /**
59 * \return true if this Snapper will snap at least one kind of point.
60 */
61 virtual bool ThisSnapperMightSnap() const {return (_snap_enabled && _snap_from != 0);} // will likely be overridden by derived classes
63 void setEnabled(bool s);
64 bool getEnabled() const {return _snap_enabled;}
66 void freeSnap(SnappedConstraints &sc,
67 PointType const &t,
68 NR::Point const &p,
69 bool const &first_point,
70 std::vector<NR::Point> &points_to_snap,
71 SPItem const *it) const;
73 void freeSnap(SnappedConstraints &sc,
74 PointType const &t,
75 NR::Point const &p,
76 bool const &first_point,
77 std::vector<NR::Point> &points_to_snap,
78 std::list<SPItem const *> const &it,
79 std::vector<NR::Point> *unselected_nodes) const;
81 class ConstraintLine
82 {
83 public:
84 ConstraintLine(NR::Point const &d) : _has_point(false), _direction(d) {}
85 ConstraintLine(NR::Point const &p, NR::Point const &d) : _has_point(true), _point(p), _direction(d) {}
87 bool hasPoint() const {
88 return _has_point;
89 }
91 NR::Point getPoint() const {
92 return _point;
93 }
95 NR::Point getDirection() const {
96 return _direction;
97 }
99 private:
101 bool _has_point;
102 NR::Point _point;
103 NR::Point _direction;
104 };
106 void constrainedSnap(SnappedConstraints &sc,
107 PointType const &t,
108 NR::Point const &p,
109 bool const &first_point,
110 std::vector<NR::Point> &points_to_snap,
111 ConstraintLine const &c,
112 SPItem const *it) const;
114 void constrainedSnap(SnappedConstraints &sc,
115 PointType const &t,
116 NR::Point const &p,
117 bool const &first_point,
118 std::vector<NR::Point> &points_to_snap,
119 ConstraintLine const &c,
120 std::list<SPItem const *> const &it) const;
122 protected:
123 SPNamedView const *_named_view;
124 int _snap_from; ///< bitmap of point types that we will snap from
125 bool _snap_enabled; ///< true if this snapper is enabled, otherwise false
127 private:
128 NR::Coord _snapper_tolerance; ///< snap tolerance in desktop coordinates
129 // must be private to enforce the usage of getTolerance(), which retrieves
130 // the tolerance in screen pixels (making it zoom independent)
133 /**
134 * Try to snap a point to whatever this snapper is interested in. Any
135 * snap that occurs will be to the nearest "interesting" thing (e.g. a
136 * grid or guide line)
137 *
138 * \param p Point to snap (desktop coordinates).
139 * \param it Items that should not be snapped to.
140 * \return Snapped point.
141 */
142 virtual void _doFreeSnap(SnappedConstraints &sc,
143 PointType const &t,
144 NR::Point const &p,
145 bool const &first_point,
146 std::vector<NR::Point> &points_to_snap,
147 std::list<SPItem const *> const &it,
148 std::vector<NR::Point> *unselected_nodes) const = 0;
150 /**
151 * Try to snap a point to whatever this snapper is interested in, where
152 * the snap point is constrained to lie along a specified vector from the
153 * original point.
154 *
155 * \param p Point to snap (desktop coordinates).
156 * \param c Vector to constrain the snap to.
157 * \param it Items that should not be snapped to.
158 * \return Snapped point.
159 */
160 virtual void _doConstrainedSnap(SnappedConstraints &sc,
161 PointType const &t,
162 NR::Point const &p,
163 bool const &first_point,
164 std::vector<NR::Point> &points_to_snap,
165 ConstraintLine const &c,
166 std::list<SPItem const *> const &it) const = 0;
167 };
169 }
171 #endif /* !SEEN_SNAPPER_H */
173 /*
174 Local Variables:
175 mode:c++
176 c-file-style:"stroustrup"
177 c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
178 indent-tabs-mode:nil
179 fill-column:99
180 End:
181 */
182 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :