1) Fix moving by an integer multiple of the grid spacing (<alt>-dragging in the selector tool)

2) Allow constrained translation for 1) (with <ctrl>)
3) Fix snapping to the grid when pasting
4) Show snap indicators for all of the above
5) Implement snap delay mechanism for 1) and 2)

(bzr r9113)

7 files changed, 38 insertions, 15 deletions

diff --git a/src/display/snap-indicator.cpp b/src/display/snap-indicator.cpp
index 25b5090c1..1e4ca12a8 100644
--- a/src/display/snap-indicator.cpp
+++ b/src/display/snap-indicator.cpp
@@ -208,6 +208,9 @@ SnapIndicator::set_new_snaptarget(Inkscape::SnappedPoint const &p, bool pre_snap
             case SNAPSOURCE_TEXT_BASELINE:
                 source_name = _("Text baseline");
                 break;
+            case SNAPSOURCE_GRID_PITCH:
+                source_name = _("Multiple of grid spacing");
+                break;
             default:
                 g_warning("Snap source has not yet been defined!");
                 break;
@@ -247,7 +250,12 @@ SnapIndicator::set_new_snaptarget(Inkscape::SnappedPoint const &p, bool pre_snap
         _snaptarget_is_presnap = pre_snap;
 
         // Display the tooltip, which reveals the type of snap source and the type of snap target
-        gchar *tooltip_str = g_strconcat(source_name, _(" to "), target_name, NULL);
+        gchar *tooltip_str = NULL;
+        if (p.getSource() != SNAPSOURCE_GRID_PITCH) {
+            tooltip_str = g_strconcat(source_name, _(" to "), target_name, NULL);
+        } else {
+            tooltip_str = g_strdup(source_name);
+        }
         Geom::Point tooltip_pos = p.getPoint() + _desktop->w2d(Geom::Point(15, -15));
 
         SPCanvasItem *canvas_tooltip = sp_canvastext_new(sp_desktop_tempgroup(_desktop), _desktop, tooltip_pos, tooltip_str);
diff --git a/src/seltrans.cpp b/src/seltrans.cpp
index 1c601b3ea..7a08e0a7e 100644
--- a/src/seltrans.cpp
+++ b/src/seltrans.cpp
@@ -1439,13 +1439,17 @@ void Inkscape::SelTrans::moveTo(Geom::Point const &xy, guint state)
 
     if (alt) {
 
-        /* Alt pressed means keep offset: snap the moved distance to the grid.
-        ** FIXME: this will snap to more than just the grid, nowadays.
-        */
+        // Alt pressed means: move only by integer multiples of the grid spacing
 
+        if (control) { // ... if also constrained to the orthogonal axes
+            if (fabs(dxy[Geom::X]) > fabs(dxy[Geom::Y])) {
+                dxy[Geom::Y] = 0;
+            } else {
+                dxy[Geom::X] = 0;
+            }
+        }
         m.setup(_desktop, true, _items_const);
-        m.freeSnapReturnByRef(dxy, Inkscape::SNAPSOURCE_UNDEFINED);
-
+        dxy = m.multipleOfGridPitch(dxy, _point);
     } else if (shift) {
         if (control) { // shift & control: constrained movement without snapping
             if (fabs(dxy[Geom::X]) > fabs(dxy[Geom::Y])) {
diff --git a/src/snap-enums.h b/src/snap-enums.h
index 3d03711e3..cf09ba45b 100644
--- a/src/snap-enums.h
+++ b/src/snap-enums.h
@@ -75,7 +75,8 @@ enum SnapSourceType {
     SNAPSOURCE_GUIDE,
     SNAPSOURCE_GUIDE_ORIGIN,
     SNAPSOURCE_TEXT_BASELINE,
-    SNAPSOURCE_OTHER_HANDLE // eg. the handle of a gradient of a connector (ie not being tied to a stroke)
+    SNAPSOURCE_OTHER_HANDLE, // eg. the handle of a gradient of a connector (ie not being tied to a stroke)
+    SNAPSOURCE_GRID_PITCH, // eg. when pasting or alt-dragging in the selector tool; not realy a snap source
 };
 
 }
diff --git a/src/snap.cpp b/src/snap.cpp
index 53832994f..0df58080e 100644
--- a/src/snap.cpp
+++ b/src/snap.cpp
@@ -249,15 +249,16 @@ void SnapManager::preSnap(Inkscape::SnapCandidatePoint const &p)
  * \return Offset vector after snapping to the closest multiple of a grid pitch
  */
 
-Geom::Point SnapManager::multipleOfGridPitch(Geom::Point const &t) const
+Geom::Point SnapManager::multipleOfGridPitch(Geom::Point const &t, Geom::Point const &origin)
 {
-    if (!snapprefs.getSnapEnabledGlobally()) // No need to check for snapprefs.getSnapPostponedGlobally() here
+    if (!snapprefs.getSnapEnabledGlobally() || snapprefs.getSnapPostponedGlobally())
         return t;
 
     if (_desktop && _desktop->gridsEnabled()) {
         bool success = false;
         Geom::Point nearest_multiple;
         Geom::Coord nearest_distance = NR_HUGE;
+        Inkscape::SnappedPoint bestSnappedPoint(t);
 
         // 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
@@ -276,21 +277,28 @@ Geom::Point SnapManager::multipleOfGridPitch(Geom::Point const &t) const
                 Geom::Point const t_offset = t + grid->origin;
                 SnappedConstraints sc;
                 // Only the first three parameters are being used for grid snappers
-                snapper->freeSnap(sc, Inkscape::SnapCandidatePoint(t_offset, Inkscape::SNAPSOURCE_UNDEFINED),Geom::OptRect(), NULL, NULL);
+                snapper->freeSnap(sc, Inkscape::SnapCandidatePoint(t_offset, Inkscape::SNAPSOURCE_GRID_PITCH),Geom::OptRect(), NULL, NULL);
                 // Find the best snap for this grid, including intersections of the grid-lines
-                Inkscape::SnappedPoint s = findBestSnap(Inkscape::SnapCandidatePoint(t_offset, Inkscape::SNAPSOURCE_UNDEFINED), sc, false);
+                bool old_val = _snapindicator;
+                _snapindicator = false;
+                Inkscape::SnappedPoint s = findBestSnap(Inkscape::SnapCandidatePoint(t_offset, Inkscape::SNAPSOURCE_GRID_PITCH), sc, false);
+                _snapindicator = old_val;
                 if (s.getSnapped() && (s.getSnapDistance() < nearest_distance)) {
                     // use getSnapDistance() instead of getWeightedDistance() here because the pointer's position
                     // doesn't tell us anything about which node to snap
                     success = true;
                     nearest_multiple = s.getPoint() - to_2geom(grid->origin);
                     nearest_distance = s.getSnapDistance();
+                    bestSnappedPoint = s;
                 }
             }
         }
 
-        if (success)
+        if (success) {
+            bestSnappedPoint.setPoint(origin + nearest_multiple);
+            _desktop->snapindicator->set_new_snaptarget(bestSnappedPoint);
             return nearest_multiple;
+        }
     }
 
     return t;
diff --git a/src/snap.h b/src/snap.h
index 613550376..24f62ec6f 100644
--- a/src/snap.h
+++ b/src/snap.h
@@ -107,7 +107,7 @@ public:
 
     void preSnap(Inkscape::SnapCandidatePoint const &p);
 
-    Geom::Point multipleOfGridPitch(Geom::Point const &t) const;
+    Geom::Point multipleOfGridPitch(Geom::Point const &t, Geom::Point const &origin);
 
     // constrainedSnapReturnByRef() is preferred over constrainedSnap(), because it only returns a
     // point, by overwriting p, if snapping has occurred; otherwise p is untouched
diff --git a/src/snapped-point.h b/src/snapped-point.h
index 33230e212..10d36f57e 100644
--- a/src/snapped-point.h
+++ b/src/snapped-point.h
@@ -57,6 +57,7 @@ public:
      * determine itself which point is most appropriate
      */
     Geom::Point getPoint() const {return _point;}
+    void setPoint(Geom::Point const &p) {_point = p;}
 
     bool getAtIntersection() const {return _at_intersection;}
     bool getFullyConstrained() const {return _fully_constrained;}
diff --git a/src/ui/clipboard.cpp b/src/ui/clipboard.cpp
index af0ec0129..f213160f4 100644
--- a/src/ui/clipboard.cpp
+++ b/src/ui/clipboard.cpp
@@ -822,11 +822,12 @@ void ClipboardManagerImpl::_pasteDocument(SPDocument *clipdoc, bool in_place)
 
         if (!in_place) {
             SnapManager &m = desktop->namedview->snap_manager;
-            m.setup(desktop, false); // Don't display the snapindicator
+            m.setup(desktop);
+            sp_event_context_discard_delayed_snap_event(desktop->event_context);
 
             // get offset from mouse pointer to bbox center, snap to grid if enabled
             Geom::Point mouse_offset = desktop->point() - sel_bbox->midpoint();
-            offset = m.multipleOfGridPitch(mouse_offset - offset) + offset;
+            offset = m.multipleOfGridPitch(mouse_offset - offset, sel_bbox->midpoint() + offset) + offset;
         }
 
         sp_selection_move_relative(selection, offset);