workaround: PageView reload

flutter/lib/desktop/widgets/tabbar_widget.dart

@@ -327,14 +327,32 @@ class DesktopTab extends StatelessWidget {
         ));
   }
 
+  List<Widget> _tabWidgets = [];
   Widget _buildPageView() {
     return _buildBlock(
         child: Obx(() => PageView(
             controller: state.value.pageController,
             physics: NeverScrollableScrollPhysics(),
-            children: state.value.tabs
+            children: () {
-                .map((tab) => tab.page)
+              /// to-do refactor, separate connection state and UI state for remote session.
-                .toList(growable: false))));
+              /// [workaround] PageView children need an immutable list, after it has been passed into PageView
+              final tabLen = state.value.tabs.length;
+              if (tabLen == _tabWidgets.length) {
+                return _tabWidgets;
+              } else if (_tabWidgets.isNotEmpty &&
+                  tabLen == _tabWidgets.length + 1) {
+                /// On add. Use the previous list(pointer) to prevent item's state init twice.
+                /// *[_tabWidgets.isNotEmpty] means TabsWindow(remote_tab_page or file_manager_tab_page) opened before, but was hidden. In this case, we have to reload, otherwise the child can't be built.
+                _tabWidgets.add(state.value.tabs.last.page);
+                return _tabWidgets;
+              } else {
+                /// On remove or change. Use new list(pointer) to reload list children so that items loading order is normal.
+                /// the Widgets in list must enable [AutomaticKeepAliveClientMixin]
+                final newList = state.value.tabs.map((v) => v.page).toList();
+                _tabWidgets = newList;
+                return newList;
+              }
+            }())));
   }
 
   /// Check whether to show ListView
@@ -765,7 +783,8 @@ class _ListView extends StatelessWidget {
                   tabBuilder: tabBuilder,
                   tabMenuBuilder: tabMenuBuilder,
                   maxLabelWidth: maxLabelWidth,
-                  selectedTabBackgroundColor: selectedTabBackgroundColor ?? MyTheme.tabbar(context).selectedTabBackgroundColor,
+                  selectedTabBackgroundColor: selectedTabBackgroundColor ??
+                      MyTheme.tabbar(context).selectedTabBackgroundColor,
                   unSelectedTabBackgroundColor: unSelectedTabBackgroundColor,
                 );
               }).toList()));
@@ -1119,7 +1138,8 @@ class TabbarTheme extends ThemeExtension<TabbarTheme> {
       dividerColor: dividerColor ?? this.dividerColor,
       hoverColor: hoverColor ?? this.hoverColor,
       closeHoverColor: closeHoverColor ?? this.closeHoverColor,
-      selectedTabBackgroundColor: selectedTabBackgroundColor ?? this.selectedTabBackgroundColor,
+      selectedTabBackgroundColor:
+          selectedTabBackgroundColor ?? this.selectedTabBackgroundColor,
     );
   }
 
@@ -1145,7 +1165,8 @@ class TabbarTheme extends ThemeExtension<TabbarTheme> {
       dividerColor: Color.lerp(dividerColor, other.dividerColor, t),
       hoverColor: Color.lerp(hoverColor, other.hoverColor, t),
       closeHoverColor: Color.lerp(closeHoverColor, other.closeHoverColor, t),
-      selectedTabBackgroundColor: Color.lerp(selectedTabBackgroundColor, other.selectedTabBackgroundColor, t),
+      selectedTabBackgroundColor: Color.lerp(
+          selectedTabBackgroundColor, other.selectedTabBackgroundColor, t),
     );
   }
 

flutter/lib/models/model.dart

@@ -17,7 +17,6 @@ import 'package:flutter_hbb/models/server_model.dart';
 import 'package:flutter_hbb/models/user_model.dart';
 import 'package:flutter_hbb/models/state_model.dart';
 import 'package:flutter_hbb/common/shared_state.dart';
-import 'package:flutter_hbb/utils/multi_window_manager.dart';
 import 'package:tuple/tuple.dart';
 import 'package:image/image.dart' as img2;
 import 'package:flutter_custom_cursor/cursor_manager.dart';
@@ -25,7 +24,6 @@ import 'package:flutter_svg/flutter_svg.dart';
 import 'package:get/get.dart';
 
 import '../common.dart';
-import '../common/shared_state.dart';
 import '../utils/image.dart' as img;
 import '../mobile/widgets/dialog.dart';
 import 'input_model.dart';
@@ -1348,13 +1346,13 @@ class FFI {
           canvasModel.y, canvasModel.scale, ffiModel.pi.currentDisplay);
     }
     bind.sessionClose(id: id);
-    id = '';
     imageModel.update(null);
     cursorModel.clear();
     ffiModel.clear();
     canvasModel.clear();
     inputModel.resetModifiers();
     debugPrint('model $id closed');
+    id = '';
   }
 
   void setMethodCallHandler(FMethod callback) {