snap.h revision 70d31ae8a7a27e57cfcdc921ea0d2f47c92442a4
425N/A/**
425N/A * \file snap.h
1356N/A * \brief Per-desktop object that handles snapping queries
425N/A *//*
1356N/A * Authors:
425N/A * Lauris Kaplinski <lauris@kaplinski.com>
425N/A * Frank Felfe <innerspace@iname.com>
919N/A * Carl Hetherington <inkscape@carlh.net>
919N/A * Diederik van Lierop <mail@diedenrezi.nl>
919N/A *
919N/A * Copyright (C) 2006-2007 Johan Engelen <johan@shouraizou.nl>
919N/A * Copyright (C) 2000-2002 Lauris Kaplinski
919N/A * Copyright (C) 2000-2009 Authors
919N/A *
919N/A * Released under GNU GPL, read the file 'COPYING' for more information
919N/A */
919N/A
919N/A#ifndef SEEN_SNAP_H
919N/A#define SEEN_SNAP_H
919N/A
919N/A#include <vector>
919N/A#include "guide-snapper.h"
919N/A#include "object-snapper.h"
919N/A#include "snap-preferences.h"
425N/A
425N/A/* Guides */
425N/Aenum SPGuideDragType { // used both here and in desktop-events.cpp
425N/A SP_DRAG_TRANSLATE,
493N/A SP_DRAG_ROTATE,
425N/A SP_DRAG_MOVE_ORIGIN,
970N/A SP_DRAG_NONE
970N/A};
970N/A
970N/Aclass SPNamedView;
1356N/A
1356N/A/// Class to coordinate snapping operations
1356N/A/**
425N/A * The SnapManager class handles most (if not all) of the interfacing of the snapping mechanisms
1068N/A * with the other parts of the code base. It stores the references to the various types of snappers
425N/A * for grid, guides and objects, and it stores most of the snapping preferences. Besides that
911N/A * it provides methods to setup the snapping environment (e.g. keeps a list of the items to ignore
1068N/A * when looking for snap target candidates, and toggling of the snap indicator), and it provides
1068N/A * many different methods for snapping queries (free snapping vs. constrained snapping,
911N/A * returning the result by reference or through a return statement, etc.)
425N/A *
425N/A * Each SPNamedView has one of these. It offers methods to snap points to whatever
425N/A * snappers are defined (e.g. grid, guides etc.). It also allows callers to snap
425N/A * points which have undergone some transformation (e.g. translation, scaling etc.)
425N/A *
493N/A * \par How snapping is implemented in Inkscape
425N/A * \par
970N/A * The snapping system consists of two key elements. The first one is the snap manager
970N/A * (this class), which keeps some data about objects in the document and answers queries
970N/A * of the type "given this point and type of transformation, what is the best place
425N/A * to snap to?".
970N/A *
970N/A * The second is in event-context.cpp and implements the snapping timeout. Whenever a motion
970N/A * events happens over the canvas, it stores it for later use and initiates a timeout.
970N/A * This timeout is discarded whenever a new motion event occurs. When the timeout expires,
970N/A * a global flag in SnapManager, accessed via getSnapPostponedGlobally(), is set to true
970N/A * and the stored event is replayed, but this time with snapping enabled. This way you can
970N/A * write snapping code directly in your control point's dragged handler as if there was
* no timeout.
*/
class SnapManager
{
public:
enum Transformation {
TRANSLATION,
SCALE,
STRETCH,
SKEW
};
SnapManager(SPNamedView const *v);
typedef std::list<const Inkscape::Snapper*> SnapperList;
bool someSnapperMightSnap() const;
bool gridSnapperMightSnap() const;
void setup(SPDesktop const *desktop,
bool snapindicator = true,
SPItem const *item_to_ignore = NULL,
std::vector<std::pair<Geom::Point, int> > *unselected_nodes = NULL,
SPGuide *guide_to_ignore = NULL);
void setup(SPDesktop const *desktop,
bool snapindicator,
std::vector<SPItem const *> const &items_to_ignore,
std::vector<std::pair<Geom::Point, int> > *unselected_nodes = NULL,
SPGuide *guide_to_ignore = NULL);
void setupIgnoreSelection(SPDesktop const *desktop,
bool snapindicator = true,
std::vector<std::pair<Geom::Point, int> > *unselected_nodes = NULL,
SPGuide *guide_to_ignore = NULL);
// freeSnapReturnByRef() is preferred over freeSnap(), because it only returns a
// point if snapping has occurred (by overwriting p); otherwise p is untouched
void freeSnapReturnByRef(Inkscape::SnapPreferences::PointType point_type,
Geom::Point &p,
Inkscape::SnapSourceType const source_type,
bool first_point = true,
Geom::OptRect const &bbox_to_snap = Geom::OptRect()) const;
Inkscape::SnappedPoint freeSnap(Inkscape::SnapPreferences::PointType point_type,
Geom::Point const &p,
Inkscape::SnapSourceType const &source_type,
bool first_point = true,
Geom::OptRect const &bbox_to_snap = Geom::OptRect() ) const;
Geom::Point multipleOfGridPitch(Geom::Point const &t) const;
// constrainedSnapReturnByRef() is preferred over constrainedSnap(), because it only returns a
// point, by overwriting p, if snapping has occurred; otherwise p is untouched
void constrainedSnapReturnByRef(Inkscape::SnapPreferences::PointType point_type,
Geom::Point &p,
Inkscape::SnapSourceType const source_type,
Inkscape::Snapper::ConstraintLine const &constraint,
bool first_point = true,
Geom::OptRect const &bbox_to_snap = Geom::OptRect()) const;
Inkscape::SnappedPoint constrainedSnap(Inkscape::SnapPreferences::PointType point_type,
Geom::Point const &p,
Inkscape::SnapSourceType const &source_type,
Inkscape::Snapper::ConstraintLine const &constraint,
bool first_point = true,
Geom::OptRect const &bbox_to_snap = Geom::OptRect()) const;
void guideFreeSnap(Geom::Point &p, Geom::Point const &guide_normal, SPGuideDragType drag_type) const;
void guideConstrainedSnap(Geom::Point &p, SPGuide const &guideline) const;
Inkscape::SnappedPoint freeSnapTranslation(Inkscape::SnapPreferences::PointType point_type,
std::vector<std::pair<Geom::Point, int> > const &p,
Geom::Point const &pointer,
Geom::Point const &tr) const;
Inkscape::SnappedPoint constrainedSnapTranslation(Inkscape::SnapPreferences::PointType point_type,
std::vector<std::pair<Geom::Point, int> > const &p,
Geom::Point const &pointer,
Inkscape::Snapper::ConstraintLine const &constraint,
Geom::Point const &tr) const;
Inkscape::SnappedPoint freeSnapScale(Inkscape::SnapPreferences::PointType point_type,
std::vector<std::pair<Geom::Point, int> > const &p,
Geom::Point const &pointer,
Geom::Scale const &s,
Geom::Point const &o) const;
Inkscape::SnappedPoint constrainedSnapScale(Inkscape::SnapPreferences::PointType point_type,
std::vector<std::pair<Geom::Point, int> > const &p,
Geom::Point const &pointer,
Geom::Scale const &s,
Geom::Point const &o) const;
Inkscape::SnappedPoint constrainedSnapStretch(Inkscape::SnapPreferences::PointType point_type,
std::vector<std::pair<Geom::Point, int> > const &p,
Geom::Point const &pointer,
Geom::Coord const &s,
Geom::Point const &o,
Geom::Dim2 d,
bool uniform) const;
Inkscape::SnappedPoint constrainedSnapSkew(Inkscape::SnapPreferences::PointType point_type,
std::vector<std::pair<Geom::Point, int> > const &p,
Geom::Point const &pointer,
Inkscape::Snapper::ConstraintLine const &constraint,
Geom::Point const &s, // s[0] = skew factor, s[1] = scale factor
Geom::Point const &o,
Geom::Dim2 d) const;
Inkscape::GuideSnapper guide; ///< guide snapper
Inkscape::ObjectSnapper object; ///< snapper to other objects
Inkscape::SnapPreferences snapprefs;
SnapperList getSnappers() const;
SnapperList getGridSnappers() const;
SPDesktop const *getDesktop() const {return _desktop;}
SPNamedView const *getNamedView() const {return _named_view;}
SPDocument *getDocument() const;
SPGuide const *getGuideToIgnore() const {return _guide_to_ignore;}
bool getSnapIndicator() const {return _snapindicator;}
protected:
SPNamedView const *_named_view;
private:
std::vector<SPItem const *> _items_to_ignore; ///< Items that should not be snapped to, for example the items that are currently being dragged. Set using the setup() method
SPGuide *_guide_to_ignore; ///< A guide that should not be snapped to, e.g. the guide that is currently being dragged
SPDesktop const *_desktop;
bool _snapindicator; ///< When true, an indicator will be drawn at the position that was being snapped to
std::vector<std::pair<Geom::Point, int> > *_unselected_nodes; ///< Nodes of the path that is currently being edited and which have not been selected and which will therefore be stationary. Only these nodes will be considered for snapping to. Of each unselected node both the position (Geom::Point) and the type (Inkscape::SnapTargetType) will be stored
//TODO: Make _unselected_nodes type safe; in the line above int is used for Inkscape::SnapTargetType, but if I remember
//correctly then in other cases the int is being used for Inkscape::SnapSourceType, or for both. How to make
//this type safe?
Inkscape::SnappedPoint _snapTransformed(Inkscape::SnapPreferences::PointType type,
std::vector<std::pair<Geom::Point, int> > const &points,
Geom::Point const &pointer,
bool constrained,
Inkscape::Snapper::ConstraintLine const &constraint,
Transformation transformation_type,
Geom::Point const &transformation,
Geom::Point const &origin,
Geom::Dim2 dim,
bool uniform) const;
Geom::Point _transformPoint(std::pair<Geom::Point, int> const &p,
Transformation const transformation_type,
Geom::Point const &transformation,
Geom::Point const &origin,
Geom::Dim2 const dim,
bool const uniform) const;
void _displaySnapsource(Inkscape::SnapPreferences::PointType point_type, std::pair<Geom::Point, int> const &p) const;
Inkscape::SnappedPoint findBestSnap(Geom::Point const &p, Inkscape::SnapSourceType const source_type, SnappedConstraints &sc, bool constrained, bool noCurves = false) const;
};
#endif /* !SEEN_SNAP_H */
/*
Local Variables:
mode:c++
c-file-style:"stroustrup"
c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
indent-tabs-mode:nil
fill-column:99
End:
*/
// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :