1) When pasting, use an offset that is a multiple of the grid pitch (got lost during a previous round of refactoring)

2) Refactor some of the pasting code

(bzr r6580)

5 files changed, 118 insertions, 40 deletions

diff --git a/src/display/canvas-axonomgrid.h b/src/display/canvas-axonomgrid.h
index 668c59649..564d266a6 100644
--- a/src/display/canvas-axonomgrid.h
+++ b/src/display/canvas-axonomgrid.h
@@ -41,18 +41,13 @@ public:
     void readRepr();
     void onReprAttrChanged (Inkscape::XML::Node * repr, const gchar *key, const gchar *oldval, const gchar *newval, bool is_interactive);
 
-    SPUnit const* gridunit;
-
-    NR::Point origin;     /**< Origin of the grid */
     double lengthy;       /**< The lengths of the primary y-axis */
     double angle_deg[3];  /**< Angle of each axis (note that angle[2] == 0) */
     double angle_rad[3];  /**< Angle of each axis (note that angle[2] == 0) */
     double tan_angle[3];  /**< tan(angle[.]) */
-    guint32 color;        /**< Color for normal lines */
-    guint32 empcolor;     /**< Color for emphasis lines */
-    gint empspacing;      /**< Spacing between emphasis lines */
+    
     bool scaled;          /**< Whether the grid is in scaled mode */
-
+    
     NR::Point ow;         /**< Transformed origin by the affine for the zoom */
     double lyw;           /**< Transformed length y by the affine for the zoom */
     double lxw_x;
diff --git a/src/display/canvas-grid.h b/src/display/canvas-grid.h
index a9e317534..5d674bb2d 100644
--- a/src/display/canvas-grid.h
+++ b/src/display/canvas-grid.h
@@ -89,6 +89,13 @@ public:
 
     Gtk::Widget * newWidget();
 
+    NR::Point origin;     /**< Origin of the grid */
+    guint32 color;        /**< Color for normal lines */
+    guint32 empcolor;     /**< Color for emphasis lines */
+    gint empspacing;      /**< Spacing between emphasis lines */
+    
+    SPUnit const* gridunit;
+    
     Inkscape::XML::Node * repr;
     SPDocument *doc;
 
@@ -130,12 +137,6 @@ public:
     void readRepr();
     void onReprAttrChanged (Inkscape::XML::Node * repr, const gchar *key, const gchar *oldval, const gchar *newval, bool is_interactive);
 
-    NR::Point origin;
-    guint32 color;
-    guint32 empcolor;
-    gint  empspacing;
-    SPUnit const* gridunit;
-
     NR::Point spacing; /**< Spacing between elements of the grid */
     bool scaled[2];    /**< Whether the grid is in scaled mode, which can
                             be different in the X or Y direction, hense two
diff --git a/src/snap.cpp b/src/snap.cpp
index 68f4c8465..46b9ecad2 100644
--- a/src/snap.cpp
+++ b/src/snap.cpp
@@ -232,6 +232,60 @@ Inkscape::SnappedPoint SnapManager::freeSnap(Inkscape::Snapper::PointType point_
     return findBestSnap(p, sc, false);
 }
 
+// When pasting, we would like to snap to the grid. Problem is that we don't know which nodes were
+// aligned to the grid at the time of copying, so we don't know which nodes to snap. If we'd snap an
+// unaligned node to the grid, previously aligned nodes would become unaligned. That's undesirable.
+// Instead we will make sure that the offset between the source and the copy is a multiple of the grid
+// pitch. If the source was aligned, then the copy will therefore also be aligned
+// PS: Wether we really find a multiple also depends on the snapping range!
+Geom::Point SnapManager::multipleOfGridPitch(Geom::Point const &t) const
+{
+    if (!_snap_enabled_globally) 
+        return t;
+    
+    //FIXME: this code should actually do this: add new grid snappers that are active for this desktop. now it just adds all gridsnappers
+    SPDesktop* desktop = SP_ACTIVE_DESKTOP;
+    
+    if (desktop && desktop->gridsEnabled()) {
+        bool success = false;
+        NR::Point nearest_multiple; 
+        NR::Coord nearest_distance = NR_HUGE;
+        
+        // It will snap to the grid for which we find the closest snap. This might be a different
+        // grid than to which the objects were initially aligned. I don't see an easy way to fix 
+        // this, so when using multiple grids one can get unexpected results 
+        
+        // Cannot use getGridSnappers() because we need both the grids AND their snappers
+        // Therefor we iterate through all grids manually        
+        for (GSList const *l = _named_view->grids; l != NULL; l = l->next) {
+            Inkscape::CanvasGrid *grid = (Inkscape::CanvasGrid*) l->data;
+            const Inkscape::Snapper* snapper = grid->snapper; 
+            if (snapper && snapper->ThisSnapperMightSnap()) {
+                // To find the nearest multiple of the grid pitch for a given translation t, we 
+                // will use the grid snapper. Simply snapping the value t to the grid will do, but
+                // only if the origin of the grid is at (0,0). If it's not then compensate for this
+                // in the translation t
+                NR::Point const t_offset = from_2geom(t) + grid->origin;
+                SnappedConstraints sc;    
+                // Only the first three parameters are being used for grid snappers
+                snapper->freeSnap(sc, Inkscape::Snapper::SNAPPOINT_NODE, t_offset, TRUE, boost::optional<NR::Rect>(), NULL, NULL);
+                // Find the best snap for this grid, including intersections of the grid-lines
+                Inkscape::SnappedPoint s = findBestSnap(t_offset, sc, false);
+                if (s.getSnapped() && (s.getDistance() < nearest_distance)) {
+                    success = true;
+                    nearest_multiple = s.getPoint() - grid->origin;
+                    nearest_distance = s.getDistance();
+                }
+            }
+        }
+        
+        if (success) 
+            return to_2geom(nearest_multiple);
+    }
+    
+    return t;
+}
+
 /**
  *  Try to snap a point to any interested snappers.  A snap will only occur along
  *  a line described by a Inkscape::Snapper::ConstraintLine.
diff --git a/src/snap.h b/src/snap.h
index 966d2a543..981e91ecd 100644
--- a/src/snap.h
+++ b/src/snap.h
@@ -62,6 +62,8 @@ public:
                                     bool first_point = true,
                                     boost::optional<NR::Rect> const &bbox_to_snap = boost::optional<NR::Rect>() ) 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 occured; otherwise p is untouched
     void constrainedSnapReturnByRef(Inkscape::Snapper::PointType point_type,
diff --git a/src/ui/clipboard.cpp b/src/ui/clipboard.cpp
index 013882327..e7f2d82ee 100644
--- a/src/ui/clipboard.cpp
+++ b/src/ui/clipboard.cpp
@@ -78,6 +78,8 @@
 #include "unit-constants.h"
 #include "helper/png-write.h"
 #include "svg/svg-color.h"
+#include "sp-namedview.h"
+#include "snap.h"
 
 /// @brief Made up mimetype to represent Gdk::Pixbuf clipboard contents
 #define CLIPBOARD_GDK_PIXBUF_TARGET "image/x-gdk-pixbuf"
@@ -753,36 +755,60 @@ void ClipboardManagerImpl::_pasteDocument(SPDocument *clipdoc, bool in_place)
         Inkscape::XML::Node *obj_copy = _copyNode(obj, target_xmldoc, target_parent);
         pasted_objects = g_slist_prepend(pasted_objects, (gpointer) obj_copy);
     }
-
+    
+    /* The pasted objects are at the origin of the document coordinates (i.e. the upper left corner
+     * of the bounding box of the pasted selection is aligned to the upper left page corner).
+     * Now we will move the pasted objects to where we want them to be, which is either at the
+     * original position ("in place") or at the location of the mouse pointer (optionaly with snapping
+     * to the grid)
+     */ 
+
+    Geom::Point rel_pos_original, rel_pos_mouse;
+    
+    // Calculate the relative location of the original objects
+    Inkscape::XML::Node *clipnode = sp_repr_lookup_name(root, "inkscape:clipboard", 1);
+    if (clipnode) {
+        Geom::Point min, max;
+        // Get two bounding box corners of the data in the clipboard (still in it's original position)
+        sp_repr_get_point(clipnode, "min", &min); //In desktop coordinates
+        sp_repr_get_point(clipnode, "max", &max);        
+        // Calculate the upper-left page corner in desktop coordinates (where the pasted objects are located)
+        Geom::Point ul_page_corner = desktop->doc2dt(Geom::Point(0,0)); 
+        // Calculate the upper-left bbox corner of the original objects
+        Geom::Point ul_sel_corner = Geom::Point(min[Geom::X], max[Geom::Y]);
+        // Now calculate how far we would have to move the pasted objects to get them
+        // at the location of the original
+        rel_pos_original = ul_sel_corner - ul_page_corner; // in desktop coordinates
+    }
+    
+    // Calculate the relative location of the mouse pointer
     Inkscape::Selection *selection = sp_desktop_selection(desktop);
-    selection->setReprList(pasted_objects);
-
-    // move the selection to the right position
-    if(in_place)
-    {
-        Inkscape::XML::Node *clipnode = sp_repr_lookup_name(root, "inkscape:clipboard", 1);
-        if (clipnode) {
-            Geom::Point min, max;
-            sp_repr_get_point(clipnode, "min", &min);
-            sp_repr_get_point(clipnode, "max", &max);
-
-            // this formula was discovered empyrically
-            min[Geom::Y] += ((max[Geom::Y] - min[Geom::Y]) - sp_document_height(target_document));
-            sp_selection_move_relative(selection, Geom::Point(min));
-        }
+    selection->setReprList(pasted_objects);         // Change the selection to the freshly pasted objects
+    sp_document_ensure_up_to_date(target_document); // What does this do?
+    
+    boost::optional<NR::Rect> sel_bbox = selection->bounds(); //In desktop coordinates
+    // PS: We could also have used the min/max corners calculated above, because we know that
+    // after pasting the upper left corner of the selection will be aligend to the corresponding page corner
+    // Using the boundingbox of the selection is more foolproof though
+        if (sel_bbox) {
+        Geom::Point pos_mouse = to_2geom(desktop->point()); //Location of mouse pointer in desktop coordinates
+        // Now calculate how far we would have to move the pasted objects to get their
+        // midpoint at the location of the mouse pointer
+        rel_pos_mouse = pos_mouse - to_2geom(sel_bbox->midpoint());
     }
-    // copied from former sp_selection_paste in selection-chemistry.cpp
-    else {
-        sp_document_ensure_up_to_date(target_document);
-        boost::optional<NR::Rect> sel_size = selection->bounds();
-
-        Geom::Point m( desktop->point() );
-        if (sel_size) {
-            m -= sel_size->midpoint();
-        }
-        sp_selection_move_relative(selection, m);
+    
+    // Determine which offset we need to apply to the pasted objects
+    Geom::Point offset;
+    if (in_place) { // Align the pasted objects with their originals
+        offset = rel_pos_original;        
+    } else { // Stick to the grid if snapping is enabled, otherwise paste at mouse position;
+        SnapManager &m = desktop->namedview->snap_manager;
+        m.setup(NULL, NULL); //Don't display snapindicator
+        offset = rel_pos_original + m.multipleOfGridPitch(rel_pos_mouse - rel_pos_original); 
     }
-
+    
+    // Apply the offset to the pasted objects
+    sp_selection_move_relative(selection, offset);
     g_slist_free(pasted_objects);
 }