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,
78 std::vector<NR::Point> *unselected_nodes) const;
80 class ConstraintLine
81 {
82 public:
83 ConstraintLine(NR::Point const &d) : _has_point(false), _direction(d) {}
84 ConstraintLine(NR::Point const &p, NR::Point const &d) : _has_point(true), _point(p), _direction(d) {}
86 bool hasPoint() const {
87 return _has_point;
88 }
90 NR::Point getPoint() const {
91 return _point;
92 }
94 NR::Point getDirection() const {
95 return _direction;
96 }
98 private:
100 bool _has_point;
101 NR::Point _point;
102 NR::Point _direction;
103 };
105 void constrainedSnap(SnappedConstraints &sc,
106 PointType const &t,
107 NR::Point const &p,
108 bool const &first_point,
109 std::vector<NR::Point> &points_to_snap,
110 ConstraintLine const &c,
111 SPItem const *it) const;
113 void constrainedSnap(SnappedConstraints &sc,
114 PointType const &t,
115 NR::Point const &p,
116 bool const &first_point,
117 std::vector<NR::Point> &points_to_snap,
118 ConstraintLine const &c,
119 std::list<SPItem const *> const &it) const;
121 protected:
122 SPNamedView const *_named_view;
123 int _snap_from; ///< bitmap of point types that we will snap from
124 bool _snap_enabled; ///< true if this snapper is enabled, otherwise false
126 private:
127 NR::Coord _snapper_tolerance; ///< snap tolerance in desktop coordinates
128 // must be private to enforce the usage of getTolerance(), which retrieves
129 // the tolerance in screen pixels (making it zoom independent)
132 /**
133 * Try to snap a point to whatever this snapper is interested in. Any
134 * snap that occurs will be to the nearest "interesting" thing (e.g. a
135 * grid or guide line)
136 *
137 * \param p Point to snap (desktop coordinates).
138 * \param it Items that should not be snapped to.
139 * \return Snapped point.
140 */
141 virtual void _doFreeSnap(SnappedConstraints &sc,
142 PointType const &t,
143 NR::Point const &p,
144 bool const &first_point,
145 std::vector<NR::Point> &points_to_snap,
146 std::list<SPItem const *> const &it,
147 std::vector<NR::Point> *unselected_nodes) const = 0;
149 /**
150 * Try to snap a point to whatever this snapper is interested in, where
151 * the snap point is constrained to lie along a specified vector from the
152 * original point.
153 *
154 * \param p Point to snap (desktop coordinates).
155 * \param c Vector to constrain the snap to.
156 * \param it Items that should not be snapped to.
157 * \return Snapped point.
158 */
159 virtual void _doConstrainedSnap(SnappedConstraints &sc,
160 PointType const &t,
161 NR::Point const &p,
162 bool const &first_point,
163 std::vector<NR::Point> &points_to_snap,
164 ConstraintLine const &c,
165 std::list<SPItem const *> const &it) const = 0;
166 };
168 }
170 #endif /* !SEEN_SNAPPER_H */
172 /*
173 Local Variables:
174 mode:c++
175 c-file-style:"stroustrup"
176 c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
177 indent-tabs-mode:nil
178 fill-column:99
179 End:
180 */
181 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :