Save the transform matrix of group items to SVG

Solves issue where items (other than strokes) that had been grouped then
moved (and/or rotated) lost their new position after saving and loading
the document.

src/adaptors/UBSvgSubsetAdaptor.cpp

@@ -938,6 +938,8 @@ UBGraphicsGroupContainerItem* UBSvgSubsetAdaptor::UBSvgSubsetReader::readGroup()
     if(mStrokesList.contains(id))
         shouldSkipSubElements = true;
 
+    QStringRef svgTransform = mXmlReader.attributes().value("transform");
+
     mXmlReader.readNext();
     while (!mXmlReader.atEnd())
     {
@@ -981,6 +983,12 @@ UBGraphicsGroupContainerItem* UBSvgSubsetAdaptor::UBSvgSubsetReader::readGroup()
             group->destroy(false);
         }
     }
+
+    if (!svgTransform.isNull()) {
+        QMatrix itemMatrix = fromSvgTransform(svgTransform.toString());
+        group->setMatrix(itemMatrix);
+    }
+
     return group;
 }
 
@@ -1346,6 +1354,10 @@ bool UBSvgSubsetAdaptor::UBSvgSubsetWriter::persistScene(UBDocumentProxy* proxy,
                 if(curElement.hasAttribute("locked")){
                     mXmlWriter.writeAttribute(UBSettings::uniboardDocumentNamespaceUri,"locked",curElement.attribute("locked"));
                 }
+
+                if (curElement.hasAttribute("transform"))
+                    mXmlWriter.writeAttribute("transform", curElement.attribute("transform"));
+
                 QDomElement curSubElement = curElement.firstChildElement();
                 while (!curSubElement.isNull()) {
                     if (curSubElement.hasAttribute(aId)) {
@@ -1391,6 +1403,8 @@ void UBSvgSubsetAdaptor::UBSvgSubsetWriter::persistGroupToDom(QGraphicsItem *gro
             else
                 curGroupElement.setAttribute("locked", xmlFalse);
         }
+
+        curGroupElement.setAttribute("transform", toSvgTransform(groupItem->sceneMatrix()));
         curParent->appendChild(curGroupElement);
         foreach (QGraphicsItem *item, groupItem->childItems()) {
             QUuid tmpUuid = UBGraphicsScene::getPersonalUuid(item);