inkscape/src/object-snapper.h

	object-snapper.h revision 6fc0952fcafd54a656fdc8257ebb44bad58af163
#ifndef SEEN_OBJECT_SNAPPER_H
#define SEEN_OBJECT_SNAPPER_H

/**
 *  \file object-snapper.h
 *  \brief Snapping things to objects.
 *
 * Authors:
 *   Carl Hetherington <inkscape@carlh.net>
 *   Diederik van Lierop <mail@diedenrezi.nl>
 *
 * Copyright (C) 2005 - 2008 Authors
 *
 * Released under GNU GPL, read the file 'COPYING' for more information
 */

#include "snapper.h"
#include "sp-path.h"
#include "splivarot.h"


struct SPNamedView;
struct SPItem;
struct SPObject;

namespace Inkscape
{

class SnapCandidate

{
public:
    SnapCandidate(SPItem* item, bool clip_or_mask, NR::Matrix _additional_affine);
    ~SnapCandidate();

    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
     */
    NR::Matrix additional_affine;
};

class ObjectSnapper : public Snapper
{

public:
    ObjectSnapper(SPNamedView const *nv, NR::Coord const d);
    ~ObjectSnapper();

    enum DimensionToSnap {
        GUIDE_TRANSL_SNAP_X, // For snapping a vertical guide (normal in the X-direction) to objects,
        GUIDE_TRANSL_SNAP_Y, // For snapping a horizontal guide (normal in the Y-direction) to objects
        ANGLED_GUIDE_TRANSL_SNAP, // For snapping an angled guide, while translating it accross the desktop
        ANGLED_GUIDE_ROT_SNAP, // For snapping an angled guide, while rotating it around some pivot point
        TRANSL_SNAP_XY}; // All other cases; for snapping to objects, other than guides

    void setSnapToItemNode(bool s) {_snap_to_itemnode = s;}
    bool getSnapToItemNode() const {return _snap_to_itemnode;}
    void setSnapToItemPath(bool s) {_snap_to_itempath = s;}
    bool getSnapToItemPath() const {return _snap_to_itempath;}
    void setSnapToBBoxNode(bool s) {_snap_to_bboxnode = s;}
    bool getSnapToBBoxNode() const {return _snap_to_bboxnode;}
    void setSnapToBBoxPath(bool s) {_snap_to_bboxpath = s;}
    bool getSnapToBBoxPath() const {return _snap_to_bboxpath;}
    void setSnapToPageBorder(bool s) {_snap_to_page_border = s;}
    bool getSnapToPageBorder() const {return _snap_to_page_border;}
    void setIncludeItemCenter(bool s) {_include_item_center = s;}
    bool getIncludeItemCenter() const {return _include_item_center;}
    void setStrictSnapping(bool enabled) {_strict_snapping = enabled;}
    void guideSnap(SnappedConstraints &sc,
                 NR::Point const &p,
                 NR::Point const &guide_normal) const;

    bool ThisSnapperMightSnap() const;
    bool GuidesMightSnap() const;

    void freeSnap(SnappedConstraints &sc,
                      Inkscape::Snapper::PointType const &t,
                      NR::Point const &p,
                      bool const &first_point,
                      NR::Maybe<NR::Rect> const &bbox_to_snap,
                      std::vector<SPItem const *> const *it,
                      std::vector<NR::Point> *unselected_nodes) const;

    void constrainedSnap(SnappedConstraints &sc,
                      Inkscape::Snapper::PointType const &t,
                      NR::Point const &p,
                      bool const &first_point,
                      NR::Maybe<NR::Rect> const &bbox_to_snap,
                      ConstraintLine const &c,
                      std::vector<SPItem const *> const *it) const;

private:
    //store some lists of candidates, points and paths, so we don't have to rebuild them for each point we want to snap
    std::vector<SnapCandidate> *_candidates;
    std::vector<NR::Point> *_points_to_snap_to;
    std::vector<NArtBpath*> *_bpaths_to_snap_to;
    std::vector<Path*> *_paths_to_snap_to;

    void _findCandidates(SPObject* parent,
                       std::vector<SPItem const *> const *it,
                       bool const &first_point,
                       NR::Rect const &bbox_to_snap,
                       DimensionToSnap snap_dim,
                       bool const _clip_or_mask,
                       NR::Matrix const additional_affine) const;

    void _snapNodes(SnappedConstraints &sc,
                      Inkscape::Snapper::PointType const &t,
                      NR::Point const &p,
                      bool const &first_point,
                      std::vector<NR::Point> *unselected_nodes) const;

    void _snapTranslatingGuideToNodes(SnappedConstraints &sc,
                     Inkscape::Snapper::PointType const &t,
                     NR::Point const &p,
                     NR::Point const &guide_normal) const;

    void _collectNodes(Inkscape::Snapper::PointType const &t,
                  bool const &first_point) const;

    void _snapPaths(SnappedConstraints &sc,
                      Inkscape::Snapper::PointType const &t,
                      NR::Point const &p,
                      bool const &first_point,
                      std::vector<NR::Point> *unselected_nodes,
                      SPPath const *selected_path,
                      NArtBpath const *border_bpath) const;

    void _snapPathsConstrained(SnappedConstraints &sc,
                 Inkscape::Snapper::PointType const &t,
                 NR::Point const &p,
                 bool const &first_point,
                 ConstraintLine const &c) const;

    bool isUnselectedNode(NR::Point const &point, std::vector<NR::Point> const *unselected_nodes) const;

    void _collectPaths(Inkscape::Snapper::PointType const &t,
                  bool const &first_point,
                  NArtBpath const *border_bpath = NULL) const;

    void _clear_paths() const;
    NArtBpath const* _getBorderBPath() const;

    bool _snap_to_itemnode;
    bool _snap_to_itempath;
    bool _snap_to_bboxnode;
    bool _snap_to_bboxpath;
    bool _snap_to_page_border;

    //If enabled, then bbox corners will only snap to bboxes,
    //and nodes will only snap to nodes and paths. We will not
    //snap bbox corners to nodes, or nodes to bboxes.
    //(snapping to grids and guides is not affected by this)
    bool _strict_snapping;
    bool _include_item_center;
};

}

#endif