Force auto arrangement when loading an object on an empty printbed (XL printers only)

src/slic3r/GUI/GUI_ObjectList.cpp

@@ -1840,6 +1840,7 @@ void ObjectList::load_mesh_object(
     const TextConfiguration *text_config /* = nullptr*/,
     const Transform3d *      transformation /* = nullptr*/)
 {   
+    PlaterAfterLoadAutoArrange plater_after_load_auto_arrange;
     // Add mesh to model as a new object
     Model& model = wxGetApp().plater()->model();
 

src/slic3r/GUI/Plater.cpp

@@ -2440,6 +2440,8 @@ std::vector<size_t> Plater::priv::load_files(const std::vector<fs::path>& input_
 
     auto *nozzle_dmrs = config->opt<ConfigOptionFloats>("nozzle_diameter");
 
+    PlaterAfterLoadAutoArrange plater_after_load_auto_arrange;
+
     bool one_by_one = input_files.size() == 1 || printer_technology == ptSLA || nozzle_dmrs->values.size() <= 1;
     if (! one_by_one) {
         for (const auto &path : input_files) {
@@ -2699,6 +2701,9 @@ std::vector<size_t> Plater::priv::load_files(const std::vector<fs::path>& input_
                     new_model->add_object(*model_object);
                 }
             }
+
+            if (is_project_file)
+                plater_after_load_auto_arrange.disable();
         }
     }
 
@@ -7588,4 +7593,18 @@ SuppressBackgroundProcessingUpdate::~SuppressBackgroundProcessingUpdate()
     wxGetApp().plater()->schedule_background_process(m_was_scheduled);
 }
 
+PlaterAfterLoadAutoArrange::PlaterAfterLoadAutoArrange()
+{
+    Plater* plater = wxGetApp().plater();
+    m_enabled = plater->model().objects.empty() &&
+                plater->printer_technology() == ptFFF &&
+                plater->fff_print().config().printer_model.value == "XL";
+}
+
+PlaterAfterLoadAutoArrange::~PlaterAfterLoadAutoArrange()
+{
+    if (m_enabled)
+        wxGetApp().plater()->arrange();
+}
+
 }}    // namespace Slic3r::GUI

src/slic3r/GUI/Plater.hpp

@@ -507,6 +507,16 @@ private:
     bool m_was_scheduled;
 };
 
+class PlaterAfterLoadAutoArrange
+{
+    bool m_enabled{ false };
+
+public:
+    PlaterAfterLoadAutoArrange();
+    ~PlaterAfterLoadAutoArrange();
+    void disable() { m_enabled = false; }
+};
+
 } // namespace GUI
 } // namespace Slic3r