1 files changed, 21 insertions, 5 deletions

diff --git a/src/sp-item.cpp b/src/sp-item.cpp
index 0cacc86b1..428f9555e 100644
--- a/src/sp-item.cpp
+++ b/src/sp-item.cpp
@@ -228,18 +228,25 @@ void SPItem::setExplicitlyHidden(bool val) {
 }
 
 /**
- * Sets the transform_center_x and transform_center_y properties to retain the rotation centre
- */
+ * Sets the transform_center_x and transform_center_y properties to retain the rotation center
+*/
 void SPItem::setCenter(Geom::Point const &object_centre) {
     document->ensureUpToDate();
 
+    // Copied from DocumentProperties::onDocUnitChange()
+    gdouble viewscale_w = this->document->getWidth().value("px") / this->document->getRoot()->viewBox.width();
+    gdouble viewscale_h = this->document->getHeight().value("px")/ this->document->getRoot()->viewBox.height();
+    gdouble viewscale = std::min(viewscale_h, viewscale_w);
+
     // FIXME this is seriously wrong
     Geom::OptRect bbox = desktopGeometricBounds();
     if (bbox) {
-        transform_center_x = object_centre[Geom::X] - bbox->midpoint()[Geom::X];
+        // object centre is document coordinates (i.e. in pixels), so we need to consider the viewbox
+        // to translate to user units; transform_center_x/y is in user units
+        transform_center_x = (object_centre[Geom::X] - bbox->midpoint()[Geom::X])/viewscale;
         if (Geom::are_near(transform_center_x, 0)) // rounding error
             transform_center_x = 0;
-        transform_center_y = object_centre[Geom::Y] - bbox->midpoint()[Geom::Y];
+        transform_center_y = (object_centre[Geom::Y] - bbox->midpoint()[Geom::Y])/viewscale;
         if (Geom::are_near(transform_center_y, 0)) // rounding error
             transform_center_y = 0;
     }
@@ -255,16 +262,25 @@ bool SPItem::isCenterSet() const {
     return (transform_center_x != 0 || transform_center_y != 0);
 }
 
+// Get the item's transformation center in document coordinates (i.e. in pixels)
 Geom::Point SPItem::getCenter() const {
     document->ensureUpToDate();
 
+    // Copied from DocumentProperties::onDocUnitChange()
+    gdouble viewscale_w = this->document->getWidth().value("px") / this->document->getRoot()->viewBox.width();
+    gdouble viewscale_h = this->document->getHeight().value("px")/ this->document->getRoot()->viewBox.height();
+    gdouble viewscale = std::min(viewscale_h, viewscale_w);
+
     // FIXME this is seriously wrong
     Geom::OptRect bbox = desktopGeometricBounds();
     if (bbox) {
-        return bbox->midpoint() + Geom::Point (transform_center_x, transform_center_y);
+        // transform_center_x/y are stored in user units, so we have to take the viewbox into account to translate to document coordinates
+        return bbox->midpoint() + Geom::Point (transform_center_x*viewscale, transform_center_y*viewscale);
+
     } else {
         return Geom::Point(0, 0); // something's wrong!
     }
+
 }
 
 void