Merge pull request #1111 from ispyisail/feat/1070-rotate-whole-group

Rotate a selected group as one piece

sources/itemgroups.cpp

@@ -163,3 +163,34 @@ bool ItemGroups::completeSelection(QGraphicsScene *scene,
 	}
 	return changed;
 }
+
+/**
+	@return the group @a selected is exactly, whole -- every item in it
+	belongs to that group and every member of the group is in it -- or a null
+	uuid. Rotating such a selection turns the group as one piece rather than
+	each member in place (discussion #1070). A member picked out on its own
+	is not a whole group, and turns in place.
+	@param selected : the selected items that can be members (the caller
+	leaves out wires, which follow their symbols)
+*/
+QUuid ItemGroups::soleWholeGroup(const QList<QGraphicsItem *> &selected)
+{
+	if (selected.isEmpty() || !selected.first()->scene()) {
+		return QUuid();
+	}
+	const QUuid group = groupOf(selected.first());
+	if (group.isNull()) {
+		return QUuid();
+	}
+	for (QGraphicsItem *item : selected) {
+		if (groupOf(item) != group) {
+			return QUuid();
+		}
+	}
+	for (QGraphicsItem *item : selected.first()->scene()->items()) {
+		if (groupOf(item) == group && !item->isSelected()) {
+			return QUuid();
+		}
+	}
+	return group;
+}