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 /**
48 * \return true if this Snapper will snap at least one kind of point.
49 */
50 virtual bool ThisSnapperMightSnap() const {return (_enabled && _snap_to != 0);} // will likely be overridden by derived classes
53 void setEnabled(bool s);
55 SnappedPoint freeSnap(PointType t,
56 NR::Point const &p,
57 SPItem const *it) const;
59 SnappedPoint freeSnap(PointType t,
60 NR::Point const &p,
61 std::list<SPItem const *> const &it) const;
63 class ConstraintLine
64 {
65 public:
66 ConstraintLine(NR::Point const &d) : _has_point(false), _direction(d) {}
67 ConstraintLine(NR::Point const &p, NR::Point const &d) : _has_point(true), _point(p), _direction(d) {}
69 bool hasPoint() const {
70 return _has_point;
71 }
73 NR::Point getPoint() const {
74 return _point;
75 }
77 NR::Point getDirection() const {
78 return _direction;
79 }
81 private:
83 bool _has_point;
84 NR::Point _point;
85 NR::Point _direction;
86 };
88 SnappedPoint constrainedSnap(PointType t,
89 NR::Point const &p,
90 ConstraintLine const &c,
91 SPItem const *it) const;
93 SnappedPoint constrainedSnap(PointType t,
94 NR::Point const &p,
95 ConstraintLine const &c,
96 std::list<SPItem const *> const &it) const;
97 protected:
98 SPNamedView const *_named_view;
99 int _snap_to; ///< bitmap of point types that we will snap to
100 bool _enabled; ///< true if this snapper is enabled, otherwise false
102 private:
104 /**
105 * Try to snap a point to whatever this snapper is interested in. Any
106 * snap that occurs will be to the nearest "interesting" thing (e.g. a
107 * grid or guide line)
108 *
109 * \param p Point to snap (desktop coordinates).
110 * \param it Items that should not be snapped to.
111 * \return Snapped point.
112 */
113 virtual SnappedPoint _doFreeSnap(NR::Point const &p,
114 std::list<SPItem const *> const &it) const = 0;
116 /**
117 * Try to snap a point to whatever this snapper is interested in, where
118 * the snap point is constrained to lie along a specified vector from the
119 * original point.
120 *
121 * \param p Point to snap (desktop coordinates).
122 * \param c Vector to constrain the snap to.
123 * \param it Items that should not be snapped to.
124 * \return Snapped point.
125 */
126 virtual SnappedPoint _doConstrainedSnap(NR::Point const &p,
127 ConstraintLine const &c,
128 std::list<SPItem const *> const &it) const = 0;
130 ::NR::Coord _distance; ///< snap distance (desktop coordinates)
131 };
133 }
135 #endif /* !SEEN_SNAPPER_H */
137 /*
138 Local Variables:
139 mode:c++
140 c-file-style:"stroustrup"
141 c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
142 indent-tabs-mode:nil
143 fill-column:99
144 End:
145 */
146 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :