fix thumbnail generator for iOS and open document when file clicked

src/app_dialogs.cpp

@@ -192,22 +192,8 @@ void App::dialog_browse()
 
         dialog->btn_ok->on_click = [this, dialog](Node*)
         {
-            canvas->reset_camera();
-            layers->clear();
-            doc_name = dialog->selected_name;
-            canvas->m_canvas->project_open(dialog->selected_path, [this] {
-                // on complete
-                async_start();
-                title_update();
-                for (auto& i : canvas->m_canvas->m_order)
-                {
-                    auto* l = layers->add_layer(canvas->m_canvas->m_layers[i].m_name.c_str());
-                    l->m_opacity->m_value.x = canvas->m_canvas->m_layers[i].m_opacity;
-                }
-                async_end();
-            });
+            open_document(dialog->selected_path);
             dialog->destroy();
-            ActionManager::clear();
         };
         async_end();
     };