Suppress change preset to SLA if we have multi-part object

src/slic3r/GUI/GUI_ObjectList.cpp

@@ -1536,5 +1536,18 @@ void ObjectList::last_volume_is_deleted(const int obj_idx)
     volume->config.set_key_value("extruder", new ConfigOptionInt(0));
 }
 
+bool ObjectList::has_multi_part_objects()
+{
+    if (!m_objects_model->IsEmpty()) {
+        wxDataViewItemArray items;
+        m_objects_model->GetChildren(wxDataViewItem(0), items);
+
+        for (auto& item : items)
+            if (m_objects_model->GetItemByType(item, itVolume))
+                return true;
+    }
+    return false;
+}
+
 } //namespace GUI
 } //namespace Slic3r 

src/slic3r/GUI/GUI_ObjectList.hpp

@@ -166,6 +166,7 @@ public:
     void change_part_type();
 
     void last_volume_is_deleted(const int obj_idx);
+    bool has_multi_part_objects();
 };
 
 

src/slic3r/GUI/Tab.cpp

@@ -28,6 +28,7 @@
 #include <wx/wupdlock.h>
 
 #include "GUI_App.hpp"
+#include "GUI_ObjectList.hpp"
 
 namespace Slic3r {
 namespace GUI {
@@ -2368,6 +2369,9 @@ void Tab::select_preset(std::string preset_name)
 		const Preset 		&new_printer_preset     = *m_presets->find_preset(preset_name, true);
 		PrinterTechnology    old_printer_technology = m_presets->get_edited_preset().printer_technology();
 		PrinterTechnology    new_printer_technology = new_printer_preset.printer_technology();
+        if (new_printer_technology == ptSLA && old_printer_technology == ptFFF && !may_switch_to_SLA_preset())
+            canceled = true;
+        else {
             struct PresetUpdate {
                 Preset::Type         tab_type;
                 PresetCollection 	*presets;
@@ -2390,15 +2394,14 @@ void Tab::select_preset(std::string preset_name)
             if (!canceled) {
                 for (PresetUpdate &pu : updates) {
                     // The preset will be switched to a different, compatible preset, or the '-- default --'.
-                if (pu.technology == new_printer_technology) {
+                    if (pu.technology == new_printer_technology)
-// 				    m_reload_dependent_tabs.emplace_back(pu.name);
                         m_dependent_tabs.emplace_back(pu.tab_type);
-				}
                     if (pu.old_preset_dirty)
                         pu.presets->discard_current_changes();
                 }
             }
         }
+	}
 	if (canceled) {
 		update_tab_ui();
 		// Trigger the on_presets_changed event so that we also restore the previous value in the plater selector,
@@ -2457,6 +2460,21 @@ bool Tab::may_discard_current_dirty_preset(PresetCollection* presets /*= nullptr
 	return confirm->ShowModal() == wxID_YES;
 }
 
+// If we are switching from the FFF-preset to the SLA, we should to control the printed objects if they have a part(s).
+// Because of we can't to print the multi-part objects with SLA technology.
+bool Tab::may_switch_to_SLA_preset()
+{
+    if (wxGetApp().obj_list()->has_multi_part_objects())
+    {
+        show_info( parent(), 
+                    _(L("It's impossible to print multi-part object(s) with SLA technology.")) + 
+                    _(L("\n\nPlease check your object list before preset changing.")),
+                    _(L("Attention!")) );
+        return false;
+    }
+    return true;
+}
+
 void Tab::OnTreeSelChange(wxTreeEvent& event)
 {
 	if (m_disable_tree_sel_changed_event) return;

src/slic3r/GUI/Tab.hpp

@@ -222,6 +222,7 @@ public:
 	void        update_page_tree_visibility();
 	void		select_preset(std::string preset_name = "");
 	bool		may_discard_current_dirty_preset(PresetCollection* presets = nullptr, const std::string& new_printer_name = "");
+    bool        may_switch_to_SLA_preset();
 	wxSizer*	compatible_printers_widget(wxWindow* parent, wxCheckBox** checkbox, wxButton** btn);
 
 	void		load_key_value(const std::string& opt_key, const boost::any& value, bool saved_value = false);