Groundwork to snap to intersections, e.g. intersections of gridlines with guidelines, and of objects with other objects. The snappers used to return only SnappedPoints, but now also SnappedLines and SnappedInfiniteLines can be returned. SnappedPaths will be implemented later.

(bzr r4016)

1 files changed, 32 insertions, 22 deletions

diff --git a/src/object-snapper.cpp b/src/object-snapper.cpp
index 53f04f8c4..10f75e5c4 100644
--- a/src/object-snapper.cpp
+++ b/src/object-snapper.cpp
@@ -113,16 +113,13 @@ void Inkscape::ObjectSnapper::_findCandidates(SPObject* r,
 }
 
 
-void Inkscape::ObjectSnapper::_snapNodes(Inkscape::Snapper::PointType const &t,
+bool Inkscape::ObjectSnapper::_snapNodes(Inkscape::Snapper::PointType const &t,
 										 Inkscape::SnappedPoint &s,
                                          NR::Point const &p,
                                          bool const &first_point,
                                          DimensionToSnap const snap_dim) const
 {
-    /* FIXME: this seems like a hack.  Perhaps Snappers should be
-    ** in SPDesktop rather than SPNamedView?
-    */
-    SPDesktop const *desktop = SP_ACTIVE_DESKTOP;
+    bool success = false;
     
     // Determine the type of bounding box we should snap to
     SPItem::BBoxType bbox_type = SPItem::GEOMETRIC_BBOX; 
@@ -194,16 +191,20 @@ void Inkscape::ObjectSnapper::_snapNodes(Inkscape::Snapper::PointType const &t,
         
         if (dist < getDistance() && dist < s.getDistance()) {
             s = SnappedPoint(snapped_point, dist);
+            success = true;
         }       
     }
+    
+    return success;
 }
 
 
-void Inkscape::ObjectSnapper::_snapPaths(Inkscape::Snapper::PointType const &t,
+bool Inkscape::ObjectSnapper::_snapPaths(Inkscape::Snapper::PointType const &t,
 										 Inkscape::SnappedPoint &s,
                                          NR::Point const &p,
                                          bool const &first_point) const
 {
+    bool success = false;
     /* FIXME: this seems like a hack.  Perhaps Snappers should be
     ** in SPDesktop rather than SPNamedView?
     */
@@ -314,21 +315,25 @@ void Inkscape::ObjectSnapper::_snapPaths(Inkscape::Snapper::PointType const &t,
 	            NR::Coord const dist = NR::L2(o_dt - p);
 	            if (dist < getDistance() && dist < s.getDistance()) {
 	                s = SnappedPoint(o_dt, dist);
+	                success = true;
 	            }
 	        }
         }        
     }
+    
+    return success;
 }
 
 
-Inkscape::SnappedPoint Inkscape::ObjectSnapper::_doFreeSnap(Inkscape::Snapper::PointType const &t,
-															NR::Point const &p,
-															bool const &first_point,
-                                             				std::vector<NR::Point> &points_to_snap,
-                                                            std::list<SPItem const *> const &it) const
+void Inkscape::ObjectSnapper::_doFreeSnap(SnappedConstraints &sc,
+											Inkscape::Snapper::PointType const &t,
+											NR::Point const &p,
+											bool const &first_point,
+	                         				std::vector<NR::Point> &points_to_snap,
+	                                        std::list<SPItem const *> const &it) const
 {
     if ( NULL == _named_view ) {
-        return SnappedPoint(p, NR_HUGE);
+        return;
     }
 
     /* Get a list of all the SPItems that we will try to snap to */
@@ -337,30 +342,35 @@ Inkscape::SnappedPoint Inkscape::ObjectSnapper::_doFreeSnap(Inkscape::Snapper::P
 	}
 
 	SnappedPoint s(p, NR_HUGE);
+	bool snapped_to_node = false;
+	bool snapped_to_path = false;
 
     if (_snap_to_itemnode || _snap_to_bboxnode) {
-        _snapNodes(t, s, p, first_point, SNAP_XY);
+        snapped_to_node = _snapNodes(t, s, p, first_point, SNAP_XY);
     }
     if (_snap_to_itempath || _snap_to_bboxpath) {
-        _snapPaths(t, s, p, first_point);
+        snapped_to_path = _snapPaths(t, s, p, first_point);
     }
 
-    return s;
+    if (snapped_to_node || snapped_to_path) {
+    	sc.points.push_back(s);
+    }
 }
 
 
 
-Inkscape::SnappedPoint Inkscape::ObjectSnapper::_doConstrainedSnap(Inkscape::Snapper::PointType const &t,
-																   NR::Point const &p,
-																   bool const &first_point,
-                                             					   std::vector<NR::Point> &points_to_snap,
-                                                                   ConstraintLine const &c,
-                                                                   std::list<SPItem const *> const &it) const
+void Inkscape::ObjectSnapper::_doConstrainedSnap(SnappedConstraints &sc,
+												   Inkscape::Snapper::PointType const &t,
+												   NR::Point const &p,
+												   bool const &first_point,
+				             					   std::vector<NR::Point> &points_to_snap,
+				                                   ConstraintLine const &c,
+				                                   std::list<SPItem const *> const &it) const
 {
     /* FIXME: this needs implementing properly; I think we have to do the
     ** intersection of c with the objects.
     */
-    return _doFreeSnap(t, p, first_point, points_to_snap, it);
+    _doFreeSnap(sc, t, p, first_point, points_to_snap, it);
 }