improve Dyn/Topic DraggableScrollableSheet

Signed-off-by: dom <githubaccount56556@proton.me>

lib/common/widgets/flutter/draggable_scrollable_sheet.dart

@@ -2,27 +2,15 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// ignore_for_file: uri_does_not_exist_in_doc_import, depend_on_referenced_packages
-
-/// @docImport 'package:flutter/material.dart';
-/// @docImport 'package:flutter_test/flutter_test.dart';
-///
-/// @docImport 'primary_scroll_controller.dart';
-/// @docImport 'scroll_configuration.dart';
-/// @docImport 'scroll_view.dart';
-/// @docImport 'scrollable.dart';
-/// @docImport 'single_child_scroll_view.dart';
-/// @docImport 'viewport.dart';
-library;
-
 import 'dart:math' as math;
 
-import 'package:PiliPlus/common/widgets/flutter/layout_builder.dart';
 import 'package:collection/collection.dart';
 import 'package:flutter/foundation.dart';
 import 'package:flutter/gestures.dart';
-import 'package:flutter/material.dart'
-    hide DraggableScrollableSheet, LayoutBuilder;
+import 'package:flutter/material.dart' hide DraggableScrollableSheet;
+
+part 'package:PiliPlus/common/widgets/draggable_sheet/dyn.dart';
+part 'package:PiliPlus/common/widgets/draggable_sheet/topic.dart';
 
 /// Controls a [DraggableScrollableSheet].
 ///
@@ -730,9 +718,7 @@ class _DraggableScrollableSheetState extends State<DraggableScrollableSheet> {
 ///    [_DraggableScrollableSheetScrollController] as the primary controller for
 ///    descendants.
 class _DraggableScrollableSheetScrollController extends ScrollController {
-  _DraggableScrollableSheetScrollController({
-    required this.extent,
-  });
+  _DraggableScrollableSheetScrollController({required this.extent});
 
   _DraggableSheetExtent extent;
   VoidCallback? onPositionDetached;
@@ -807,6 +793,7 @@ class _DraggableScrollableSheetScrollPosition
     required super.context,
     super.oldPosition,
     required this.getExtent,
+    super.initialPixels,
   });
 
   VoidCallback? _dragCancelCallback;
@@ -817,8 +804,6 @@ class _DraggableScrollableSheetScrollPosition
 
   _DraggableSheetExtent get extent => getExtent();
 
-  bool _isAtTop = true;
-
   @override
   void absorb(ScrollPosition other) {
     super.absorb(other);
@@ -846,9 +831,7 @@ class _DraggableScrollableSheetScrollPosition
 
   @override
   void applyUserOffset(double delta) {
-    if (!_isAtTop) {
-      super.applyUserOffset(delta);
-    } else if (!listShouldScroll &&
+    if (!listShouldScroll &&
         (!(extent.isAtMin || extent.isAtMax) ||
             (extent.isAtMin && delta < 0) ||
             (extent.isAtMax && delta > 0))) {
@@ -883,10 +866,6 @@ class _DraggableScrollableSheetScrollPosition
 
   @override
   void goBallistic(double velocity) {
-    if (!_isAtTop) {
-      super.goBallistic(velocity);
-      return;
-    }
     if ((velocity == 0.0 && !_shouldSnap()) ||
         (velocity < 0.0 && listShouldScroll) ||
         (velocity > 0.0 && extent.isAtMax)) {
@@ -964,71 +943,12 @@ class _DraggableScrollableSheetScrollPosition
 
   @override
   Drag drag(DragStartDetails details, VoidCallback dragCancelCallback) {
-    _isAtTop = pixels == 0;
     // Save this so we can call it later if we have to [goBallistic] on our own.
     _dragCancelCallback = dragCancelCallback;
     return super.drag(details, dragCancelCallback);
   }
 }
 
-/// A widget that can notify a descendent [DraggableScrollableSheet] that it
-/// should reset its position to the initial state.
-///
-/// The [Scaffold] uses this widget to notify a persistent bottom sheet that
-/// the user has tapped back if the sheet has started to cover more of the body
-/// than when at its initial position. This is important for users of assistive
-/// technology, where dragging may be difficult to communicate.
-///
-/// This is just a wrapper on top of [DraggableScrollableController]. It is
-/// primarily useful for controlling a sheet in a part of the widget tree that
-/// the current code does not control (e.g. library code trying to affect a sheet
-/// in library users' code). Generally, it's easier to control the sheet
-/// directly by creating a controller and passing the controller to the sheet in
-/// its constructor (see [DraggableScrollableSheet.controller]).
-class DraggableScrollableActuator extends StatefulWidget {
-  /// Creates a widget that can notify descendent [DraggableScrollableSheet]s
-  /// to reset to their initial position.
-  ///
-  /// The [child] parameter is required.
-  const DraggableScrollableActuator({super.key, required this.child});
-
-  /// This child's [DraggableScrollableSheet] descendant will be reset when the
-  /// [reset] method is applied to a context that includes it.
-  final Widget child;
-
-  /// Notifies any descendant [DraggableScrollableSheet] that it should reset
-  /// to its initial position.
-  ///
-  /// Returns `true` if a [DraggableScrollableActuator] is available and
-  /// some [DraggableScrollableSheet] is listening for updates, `false`
-  /// otherwise.
-  static bool reset(BuildContext context) {
-    final _InheritedResetNotifier? notifier = context
-        .dependOnInheritedWidgetOfExactType<_InheritedResetNotifier>();
-    return notifier?._sendReset() ?? false;
-  }
-
-  @override
-  State<DraggableScrollableActuator> createState() =>
-      _DraggableScrollableActuatorState();
-}
-
-class _DraggableScrollableActuatorState
-    extends State<DraggableScrollableActuator> {
-  final _ResetNotifier _notifier = _ResetNotifier();
-
-  @override
-  Widget build(BuildContext context) {
-    return _InheritedResetNotifier(notifier: _notifier, child: widget.child);
-  }
-
-  @override
-  void dispose() {
-    _notifier.dispose();
-    super.dispose();
-  }
-}
-
 /// A [ChangeNotifier] to use with [_InheritedResetNotifier] to notify
 /// descendants that they should reset to initial state.
 class _ResetNotifier extends ChangeNotifier {