#130 opt.

lib/data/res/build_data.dart

@@ -2,8 +2,8 @@
 
 class BuildData {
   static const String name = "ServerBox";
-  static const int build = 461;
+  static const int build = 471;
   static const String engine = "3.10.6";
-  static const String buildAt = "2023-08-11 11:41:48.137847";
+  static const String buildAt = "2023-08-13 22:48:32.724672";
   static const int modifications = 6;
 }

lib/data/res/ui.dart

@@ -22,6 +22,8 @@ final appIcon = Image.asset('assets/app_icon.png');
 const roundRectCardPadding = EdgeInsets.symmetric(horizontal: 17, vertical: 13);
 
 /// SizedBox
+
+const placeholder = SizedBox();
 const height13 = SizedBox(height: 13);
 const width13 = SizedBox(width: 13);
 const width7 = SizedBox(width: 7);

lib/view/page/docker.dart

@@ -1,6 +1,5 @@
 import 'package:flutter/material.dart';
 import 'package:flutter_gen/gen_l10n/l10n.dart';
-import 'package:nil/nil.dart';
 import 'package:provider/provider.dart';
 import 'package:toolbox/core/extension/navigator.dart';
 import 'package:toolbox/core/route.dart';
@@ -337,7 +336,7 @@ class _DockerManagePageState extends State<DockerManagePage> {
   }
 
   Widget _buildLoading() {
-    if (_docker.runLog == null) return nil;
+    if (_docker.runLog == null) return placeholder;
     return Padding(
       padding: const EdgeInsets.all(17),
       child: Column(

lib/view/page/full_screen.dart

@@ -6,7 +6,6 @@ import 'package:circle_chart/circle_chart.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter_gen/gen_l10n/l10n.dart';
 import 'package:get_it/get_it.dart';
-import 'package:nil/nil.dart';
 import 'package:provider/provider.dart';
 import 'package:toolbox/core/route.dart';
 import 'package:toolbox/data/model/server/disk.dart';
@@ -148,7 +147,7 @@ class _FullScreenPageState extends State<FullScreenPage> with AfterLayoutMixin {
           final id = pro.serverOrder[idx];
           final s = pro.servers[id];
           if (s == null) {
-            return nil;
+            return Center(child: Text(_s.noClient));
           }
           return _buildRealServerCard(s.status, s.state, s.spi);
         },

lib/view/page/pkg.dart

@@ -1,6 +1,5 @@
 import 'package:flutter/material.dart';
 import 'package:flutter_gen/gen_l10n/l10n.dart';
-import 'package:nil/nil.dart';
 import 'package:provider/provider.dart';
 import 'package:toolbox/core/extension/navigator.dart';
 import 'package:toolbox/view/widget/input_field.dart';
@@ -132,9 +131,9 @@ class _PkgManagePageState extends State<PkgManagePage>
     return _textController.text.trim();
   }
 
-  Widget _buildFAB(PkgProvider pkg) {
+  Widget? _buildFAB(PkgProvider pkg) {
     if (pkg.upgradeable?.isEmpty ?? true) {
-      return nil;
+      return null;
     }
     return FloatingActionButton(
       onPressed: () {

lib/view/page/private_key/edit.dart

@@ -5,7 +5,6 @@ import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter/services.dart';
 import 'package:flutter_gen/gen_l10n/l10n.dart';
-import 'package:nil/nil.dart';
 import 'package:toolbox/core/extension/navigator.dart';
 import 'package:toolbox/core/extension/numx.dart';
 import 'package:toolbox/core/utils/misc.dart';
@@ -43,7 +42,7 @@ class _PrivateKeyEditPageState extends State<PrivateKeyEditPage>
   late PrivateKeyProvider _provider;
   late S _s;
 
-  Widget _loading = nil;
+  Widget? _loading;
 
   @override
   void initState() {
@@ -124,7 +123,7 @@ class _PrivateKeyEditPageState extends State<PrivateKeyEditPage>
           rethrow;
         } finally {
           setState(() {
-            _loading = nil;
+            _loading = null;
           });
         }
         context.pop();
@@ -196,7 +195,7 @@ class _PrivateKeyEditPageState extends State<PrivateKeyEditPage>
           icon: Icons.password,
         ),
         SizedBox(height: MediaQuery.of(context).size.height * 0.1),
-        _loading
+        _loading ?? placeholder,
       ],
     );
   }

lib/view/page/private_key/list.dart

@@ -24,7 +24,8 @@ class PrivateKeysListPage extends StatefulWidget {
   _PrivateKeyListState createState() => _PrivateKeyListState();
 }
 
-class _PrivateKeyListState extends State<PrivateKeysListPage> with AfterLayoutMixin {
+class _PrivateKeyListState extends State<PrivateKeysListPage>
+    with AfterLayoutMixin {
   late S _s;
 
   @override
@@ -115,7 +116,7 @@ class _PrivateKeyListState extends State<PrivateKeysListPage> with AfterLayoutMi
       );
     }
   }
-  
+
   @override
   FutureOr<void> afterFirstLayout(BuildContext context) {
     autoAddSystemPriavteKey();

lib/view/page/server/detail.dart

@@ -1,6 +1,5 @@
 import 'package:flutter/material.dart';
 import 'package:flutter_gen/gen_l10n/l10n.dart';
-import 'package:nil/nil.dart';
 import 'package:provider/provider.dart';
 import 'package:toolbox/core/extension/order.dart';
 import 'package:toolbox/data/model/server/cpu.dart';
@@ -249,7 +248,7 @@ class _ServerDetailPageState extends State<ServerDetailPage>
   }
 
   Widget _buildSwapView(ServerStatus ss) {
-    if (ss.swap.total == 0) return nil;
+    if (ss.swap.total == 0) return placeholder;
     final used = ss.swap.usedPercent * 100;
     final cached = ss.swap.cached / ss.swap.total * 100;
     return RoundRectCard(
@@ -408,7 +407,7 @@ class _ServerDetailPageState extends State<ServerDetailPage>
   Widget _buildTemperature(ServerStatus ss) {
     final temps = ss.temps;
     if (temps.isEmpty) {
-      return nil;
+      return placeholder;
     }
     final List<Widget> children = [
       const Row(

lib/view/page/server/tab.dart

@@ -5,7 +5,6 @@ import 'package:circle_chart/circle_chart.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter_gen/gen_l10n/l10n.dart';
 import 'package:get_it/get_it.dart';
-import 'package:nil/nil.dart';
 import 'package:provider/provider.dart';
 import 'package:toolbox/core/extension/order.dart';
 import 'package:toolbox/data/model/app/net_view.dart';
@@ -121,6 +120,7 @@ class _ServerPageState extends State<ServerPage>
               initTag: _tag,
               all: _s.all,
             ),
+            footer: const SizedBox(height: 77),
             padding: const EdgeInsets.fromLTRB(7, 10, 7, 7),
             onReorder: (oldIndex, newIndex) => setState(() {
               pro.serverOrder.moveByItem(
@@ -145,7 +145,7 @@ class _ServerPageState extends State<ServerPage>
 
   Widget _buildEachServerCard(Server? si) {
     if (si == null) {
-      return nil;
+      return placeholder;
     }
     return GestureDetector(
       key: Key(si.spi.id + (_tag ?? '')),
@@ -491,7 +491,7 @@ class _ServerPageState extends State<ServerPage>
 
   Future<void> gotoSSH(ServerPrivateInfo spi) async {
     // as a `Mobile first` app -> handle mobile first
-    // 
+    //
     // run built-in ssh on macOS due to incompatibility
     if (!isDesktop || isMacOS) {
       AppRoute(SSHPage(spi: spi), 'ssh page').go(context);

lib/view/widget/tag/switcher.dart

@@ -1,5 +1,5 @@
 import 'package:flutter/material.dart';
-import 'package:nil/nil.dart';
+import 'package:toolbox/data/res/ui.dart';
 import 'package:toolbox/view/widget/fade_in.dart';
 import 'package:toolbox/view/widget/tag/view.dart';
 
@@ -21,7 +21,7 @@ class TagSwitcher extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
-    if (tags.isEmpty) return nil;
+    if (tags.isEmpty) return placeholder;
     final items = <String?>[null, ...tags];
     return Container(
       height: 37,