support sorting by a single property

results.cpp

@@ -21,17 +21,26 @@
 
 using namespace realm;
 
-Results::Results(SharedRealm &r, ObjectSchema &o, Query q) :
+Results::Results(SharedRealm &r, ObjectSchema &o, Query q, SortOrder s) :
     realm(r), object_schema(o), backing_query(q), table_view(backing_query.find_all())
 {
+    setSort(std::move(s));
 }
 
-size_t Results::size() {
+size_t Results::size()
+{
     verify_attached();
     return table_view.size();
 }
 
-Row Results::get(std::size_t row_ndx) {
+void Results::setSort(SortOrder s)
+{
+    sort_order = std::make_unique<SortOrder>(std::move(s));
+    table_view.sort(sort_order->columnIndices, sort_order->ascending);
+}
+
+Row Results::get(std::size_t row_ndx)
+{
     verify_attached();
     if (row_ndx >= table_view.size()) {
         throw std::range_error(std::string("Index ") + std::to_string(row_ndx) + " is outside of range 0..." +
@@ -40,7 +49,8 @@ Row Results::get(std::size_t row_ndx) {
     return table_view.get(row_ndx);
 }
 
-void Results::verify_attached() {
+void Results::verify_attached()
+{
     if (!table_view.is_attached()) {
         throw std::runtime_error("Tableview is not attached");
     }

results.hpp

@@ -23,8 +23,19 @@
 #import <realm/table_view.hpp>
 
 namespace realm {
+    struct SortOrder {
+        std::vector<size_t> columnIndices;
+        std::vector<bool> ascending;
+
+        explicit operator bool() const {
+            return !columnIndices.empty();
+        }
+    };
+
+    static SortOrder s_defaultSort = {{}, {}};
+
     struct Results {
-        Results(SharedRealm &r, ObjectSchema &o, Query q);
+        Results(SharedRealm &r, ObjectSchema &o, Query q, SortOrder s = s_defaultSort);
         size_t size();
         Row get(std::size_t row_ndx);
         void verify_attached();
@@ -33,6 +44,9 @@ namespace realm {
         ObjectSchema &object_schema;
         Query backing_query;
         TableView table_view;
+        std::unique_ptr<SortOrder> sort_order;
+
+        void setSort(SortOrder s);
     };
 }