inkscape/src/snap-candidate.h

#ifndef SEEN_SNAP_CANDIDATE_H
#define SEEN_SNAP_CANDIDATE_H

/**
 * @file
 * Some utility classes to store various kinds of snap candidates.
 */
/*
 * Authors:
 *   Diederik van Lierop <mail@diedenrezi.nl>
 *
 * Copyright (C) 2010 - 2012 Authors
 *
 * Released under GNU GPL, read the file 'COPYING' for more information
 */

#include <2geom/point.h>
#include <2geom/rect.h>
#include <cstdio>

#include "snap-enums.h"

class SPItem; // forward declaration

namespace Inkscape {

/// Class to store data for points which are snap candidates, either as a source or as a target
class SnapCandidatePoint
{
public:
    SnapCandidatePoint() {}; // only needed / used for resizing() of a vector in seltrans.cpp; do not use uninitialized instances!

    SnapCandidatePoint(Geom::Point const &point, Inkscape::SnapSourceType const source, long const source_num, Inkscape::SnapTargetType const target, Geom::OptRect const &bbox)
        : _point(point),
        _source_type(source),
        _target_type(target),
        _source_num(source_num),
        _target_bbox(bbox),
        _dist()
    {
    };

    SnapCandidatePoint(Geom::Point const &point, Inkscape::SnapSourceType const source, Inkscape::SnapTargetType const target)
        : _point(point),
        _source_type(source),
        _target_type(target),
        _target_bbox(Geom::OptRect()),
        _dist()
    {
        _source_num = -1;
    }

    SnapCandidatePoint(Geom::Point const &point, Inkscape::SnapSourceType const source)
        : _point(point),
        _source_type(source),
        _target_type(Inkscape::SNAPTARGET_UNDEFINED),
        _source_num(-1),
        _target_bbox(Geom::OptRect()),
        _dist()
    {
    };

    inline Geom::Point const & getPoint() const {return _point;}
    inline Inkscape::SnapSourceType getSourceType() const {return _source_type;}
    inline Inkscape::SnapTargetType getTargetType() const {return _target_type;}
    bool isSingleHandle() const {return (_source_type == SNAPSOURCE_NODE_HANDLE || _source_type == SNAPSOURCE_OTHER_HANDLE) && _source_num == -1;}

    inline long getSourceNum() const {return _source_num;}
    void setSourceNum(long num) {_source_num = num;}

    void setDistance(Geom::Coord dist) {_dist = dist;}
    Geom::Coord getDistance() { return _dist;}

    void addOrigin(Geom::Point pt) { _origins_and_vectors.push_back(std::make_pair(pt, false)); }
    void addVector(Geom::Point v) { _origins_and_vectors.push_back(std::make_pair(v, true)); }
    std::vector<std::pair<Geom::Point, bool> > const & getOriginsAndVectors() const {return _origins_and_vectors;}

    bool operator <(const SnapCandidatePoint &other) const { return _dist < other._dist; } // Needed for sorting the SnapCandidatePoints
    inline Geom::OptRect const getTargetBBox() const {return _target_bbox;}

private:
    // Coordinates of the point
    Geom::Point _point;
    // For perpendicular or tangential snapping of a ROTATING line we need to know its (stationary) starting point.
    // In case of editing with the node tool, a node can be connected to two lines simultaneously, in which case we
    // need to consider two starting points; Therefore a vector containing multiple starting points is used here. However,
    // for perpendicular or tangential snapping of a TRANSLATING line we need to know its direction vector instead. This
    // vector will be stored in the same way as the starting point is, i.e. as a Geom::Point. A boolean is paired to this
    // point, which is true for vectors but false for origins
    std::vector<std::pair<Geom::Point, bool> > _origins_and_vectors;

    // If this SnapCandidatePoint is a snap source, then _source_type must be defined. If it
    // is a snap target, then _target_type must be defined. If it's yet unknown whether it will
    // be a source or target, then both may be defined
    Inkscape::SnapSourceType _source_type;
    Inkscape::SnapTargetType _target_type;

    //Sequence number of the source point within the set of points that is to be snapped.
    // - Starts counting at zero, but only if there might be more points following (e.g. in the selector tool)
    // - Minus one (-1) if we're sure that we have only a single point
    long _source_num;

    // If this is a target and it belongs to a bounding box, e.g. when the target type is
    // SNAPTARGET_BBOX_EDGE_MIDPOINT, then _target_bbox stores the relevant bounding box
    Geom::OptRect _target_bbox;

    // For finding the snap candidate closest to the mouse pointer
    Geom::Coord _dist;
};

class SnapCandidateItem
{
public:
    SnapCandidateItem(SPItem* item, bool clip_or_mask, Geom::Affine additional_affine)
        : item(item), clip_or_mask(clip_or_mask), additional_affine(additional_affine) {}
    ~SnapCandidateItem() {};

    SPItem* item;        // An item that is to be considered for snapping to
    bool clip_or_mask;    // If true, then item refers to a clipping path or a mask

    /* To find out the absolute position of a clipping path or mask, we not only need to know
     * the transformation of the clipping path or mask itself, but also the transformation of
     * the object to which the clip or mask is being applied; that transformation is stored here
     */
    Geom::Affine additional_affine;
}
;

class SnapCandidatePath
{

public:
    SnapCandidatePath(Geom::PathVector* path, SnapTargetType target, Geom::OptRect bbox, bool edited = false)
        : path_vector(path), target_type(target), target_bbox(bbox), currently_being_edited(edited) {};
    ~SnapCandidatePath() {};

    Geom::PathVector* path_vector;
    SnapTargetType target_type;
    Geom::OptRect target_bbox;
    bool currently_being_edited; // true for the path that's currently being edited in the node tool (if any)

};
} // end of namespace Inkscape
#endif /* !SEEN_SNAP_CANDIDATE_H */