Added "Restore window position on start" option to the "Preferences > General"

+ added crash detection for the cases, when PrusaSlicer is started from secondary display

Possible fix for part of:
 #2939 - PrusaSlic3r freezing at startup (Win 10)
and
 #5573 - PrusaSlicer won't launch on secondary monitor. Nahimic?

src/libslic3r/AppConfig.cpp

@@ -175,6 +175,9 @@ void AppConfig::set_defaults()
     if (get("show_splash_screen").empty())
         set("show_splash_screen", "1");
 
+    if (get("restore_win_position").empty())
+        set("restore_win_position", "1");       // allowed values - "1", "0", "crashed_at_..."
+
     if (get("show_hints").empty())
         set("show_hints", "1");
 

src/slic3r/GUI/GUI_App.cpp

@@ -1143,15 +1143,25 @@ bool GUI_App::on_init_inner()
         // Detect position (display) to show the splash screen
         // Now this position is equal to the mainframe position
         wxPoint splashscreen_pos = wxDefaultPosition;
-        if (app_config->has("window_mainframe")) {
+        bool default_splashscreen_pos = true;
+        if (app_config->has("window_mainframe") && app_config->get("restore_win_position") == "1") {
             auto metrics = WindowMetrics::deserialize(app_config->get("window_mainframe"));
-            if (metrics)
+            default_splashscreen_pos = metrics == boost::none;
+            if (!default_splashscreen_pos)
                 splashscreen_pos = metrics->get_rect().GetPosition();
         }
 
+        if (!default_splashscreen_pos)
+            // workaround for crash related to the positioning of the window on secondary monitor
+            get_app_config()->set("restore_win_position", "crashed_at_splashscreen_pos");
+
         // create splash screen with updated bmp
         scrn = new SplashScreen(bmp.IsOk() ? bmp : create_scaled_bitmap("PrusaSlicer", nullptr, 400), 
                                 wxSPLASH_CENTRE_ON_SCREEN | wxSPLASH_TIMEOUT, 4000, splashscreen_pos);
+
+        if (!default_splashscreen_pos)
+            // revert "restore_win_position" value if application wasn't crashed
+            get_app_config()->set("restore_win_position", "1");
 #ifndef __linux__
         wxYield();
 #endif
@@ -1308,6 +1318,23 @@ bool GUI_App::on_init_inner()
     });
 
     m_initialized = true;
+
+    if (const std::string& crash_reason = app_config->get("restore_win_position");
+        crash_reason._Starts_with("crashed"))
+    {
+        MessageDialog dialog(mainframe,
+            format_wxstr(_L("PrusaSlicer was crashed during a previous start due to \"%1%\".\n"
+               "PrusaSlicer works in save mode now.\n"
+               "To avoid a next application crash you have to disable\n"
+               "\"%2%\" in \"Preferences\""), from_u8(crash_reason), _L("Restore window position on start"))
+                + "\n\n" +
+            format_wxstr(_L("Do you want to disable \"%1%\"?"), _L("Restore window position on start")),
+            _L("Start PrusaSlicer in save mode"),
+            wxICON_QUESTION | wxYES_NO);
+        if (dialog.ShowModal() == wxID_YES)
+            app_config->set("restore_win_position", "0");
+    }
+
     return true;
 }
 
@@ -2937,8 +2964,22 @@ void GUI_App::window_pos_restore(wxTopLevelWindow* window, const std::string &na
     }
 
     const wxRect& rect = metrics->get_rect();
+
+    if (app_config->get("restore_win_position") == "1") {
+        // workaround for crash related to the positioning of the window on secondary monitor
+        app_config->set("restore_win_position", (boost::format("crashed_at_%1%_pos") % name).str());
         window->SetPosition(rect.GetPosition());
+
+        // workaround for crash related to the positioning of the window on secondary monitor
+        app_config->set("restore_win_position", (boost::format("crashed_at_%1%_size") % name).str());
         window->SetSize(rect.GetSize());
+
+        // revert "restore_win_position" value if application wasn't crashed
+        app_config->set("restore_win_position", "1");
+    }
+    else
+        window->CenterOnScreen();
+
     window->Maximize(metrics->get_maximized());
 }
 

src/slic3r/GUI/Preferences.cpp

@@ -284,6 +284,13 @@ void PreferencesDialog::build(size_t selected_tab)
 	option = Option(def, "show_splash_screen");
 	m_optgroup_general->append_single_option_line(option);
 
+	def.label = L("Restore window position on start");
+	def.type = coBool;
+	def.tooltip = L("If enabled, PrusaSlicer will be open at the position it was closed");
+	def.set_default_value(new ConfigOptionBool{ app_config->get("restore_win_position") == "1" });
+	option = Option(def, "restore_win_position");
+	m_optgroup_general->append_single_option_line(option);
+
     // Clear Undo / Redo stack on new project
 	def.label = L("Clear Undo / Redo stack on new project");
 	def.type = coBool;