Reapply "hide systembar when preview"

This reverts commit d6bce6aa63.

lib/common/widgets/image_viewer/gallery_viewer.dart

@@ -25,10 +25,13 @@ import 'package:PiliPlus/common/widgets/image_viewer/image.dart';
 import 'package:PiliPlus/common/widgets/image_viewer/loading_indicator.dart';
 import 'package:PiliPlus/common/widgets/image_viewer/viewer.dart';
 import 'package:PiliPlus/common/widgets/scroll_physics.dart';
+import 'package:PiliPlus/main.dart' show tmpPadding;
 import 'package:PiliPlus/models/common/image_preview_type.dart';
+import 'package:PiliPlus/plugin/pl_player/utils/fullscreen.dart';
 import 'package:PiliPlus/utils/extension/num_ext.dart';
 import 'package:PiliPlus/utils/extension/string_ext.dart';
 import 'package:PiliPlus/utils/image_utils.dart';
+import 'package:PiliPlus/utils/max_screen_size.dart';
 import 'package:PiliPlus/utils/page_utils.dart';
 import 'package:PiliPlus/utils/platform_utils.dart';
 import 'package:PiliPlus/utils/storage_pref.dart';
@@ -76,6 +79,7 @@ class _GalleryViewerState extends State<GalleryViewer>
   late final int _quality;
   late final RxInt _currIndex;
   GlobalKey? _key;
+  EdgeInsets? _padding;
 
   late bool _hasInit = false;
   Player? _player;
@@ -170,6 +174,45 @@ class _GalleryViewerState extends State<GalleryViewer>
     );
   }
 
+  late final bool _hideSystemBar;
+
+  void _initHideSystemBar() {
+    if (Platform.isAndroid) {
+      if (showSystemBar_) {
+        final view = WidgetsBinding.instance.platformDispatcher.views.first;
+        final size = view.physicalSize / view.devicePixelRatio;
+        _hideSystemBar = !MaxScreenSize.isWindowMode(
+          width: size.width,
+          height: size.height,
+        );
+      } else {
+        _hideSystemBar = false;
+      }
+    } else if (Platform.isIOS) {
+      _hideSystemBar = showSystemBar_;
+    } else {
+      _hideSystemBar = false;
+    }
+  }
+
+  @override
+  void didChangeDependencies() {
+    super.didChangeDependencies();
+    if (_padding == null) {
+      final padding = MediaQuery.viewPaddingOf(context);
+      _padding = padding;
+      _initHideSystemBar();
+      if (_hideSystemBar) {
+        tmpPadding = padding;
+        hideSystemBar()!.whenComplete(
+          () => WidgetsBinding.instance.addPostFrameCallback(
+            (_) => tmpPadding = null,
+          ),
+        );
+      }
+    }
+  }
+
   Matrix4 _onTransform(double val) {
     final scale = val.lerp(1.0, 0.25);
 
@@ -259,6 +302,9 @@ class _GalleryViewerState extends State<GalleryViewer>
     }
     Future.delayed(const Duration(milliseconds: 200), _currIndex.close);
     super.dispose();
+    if (_hideSystemBar) {
+      showSystemBar();
+    }
   }
 
   void _onPointerDown(PointerDownEvent event) {
@@ -311,9 +357,7 @@ class _GalleryViewerState extends State<GalleryViewer>
     right: 0,
     child: IgnorePointer(
       child: Container(
-        padding:
-            MediaQuery.viewPaddingOf(context) +
-            const EdgeInsets.fromLTRB(12, 8, 20, 8),
+        padding: _padding! + const EdgeInsets.fromLTRB(12, 8, 20, 8),
         decoration: BoxDecoration(
           gradient: LinearGradient(
             begin: Alignment.topCenter,