Resolve "Sliding window n fixed frames"

Closes #391 (closed)

include/core/tree_manager/tree_manager_sliding_window.h

@@ -16,19 +16,21 @@ struct ParamsTreeManagerSlidingWindow : public ParamsTreeManagerBase
             ParamsTreeManagerBase(_unique_name, _server)
         {
             n_frames                    = _server.getParam<unsigned int>(prefix + "/n_frames");
-            fix_first_frame             = _server.getParam<bool>        (prefix + "/fix_first_frame");
+            n_fix_first_frames          = _server.getParam<unsigned int>(prefix + "/n_fix_first_frames");
             viral_remove_empty_parent   = _server.getParam<bool>        (prefix + "/viral_remove_empty_parent");
+            if (n_frames <= n_fix_first_frames)
+                throw std::runtime_error("TreeManagerSlidingWindow: Wrong parameter value. 'n_fix_first_frames' should be lower than 'n_frames'!");
         }
         std::string print() const override
         {
             return  ParamsTreeManagerBase::print()                                            + "\n"
                         + "n_frames: "                  + std::to_string(n_frames)                  + "\n"
-                        + "fix_first_frame: "           + std::to_string(fix_first_frame)           + "\n"
+                        + "fix_first_frame: "           + std::to_string(n_fix_first_frames)        + "\n"
                         + "viral_remove_empty_parent: " + std::to_string(viral_remove_empty_parent) + "\n";
         }
 
         unsigned int n_frames;
-        bool fix_first_frame;
+        unsigned int n_fix_first_frames;
         bool viral_remove_empty_parent;
 };