feat: allow dragging anywhere to dismiss search sheet

lib/models/discoverable_feature.dart

@@ -7,31 +7,38 @@ enum DiscoverableFeature {
   settingsShortcutOnItemScreen(
     featureId: 'settings_shortcut_on_item_screen',
     title: 'Go to Settings',
-    description: '''You can now go to settings page directly from a thread.''',
+    description: '''Tap to adjust thread appearance in Settings.''',
   ),
   login(
     featureId: 'log_in',
     title: 'Log in for more',
     description:
-        '''Log in using your Hacker News account to check out stories and comments you have posted in the past, and get in-app notification when there is new reply to your comments or stories.''',
+        '''Log in with your Hacker News account to view your past stories and comments and receive in-app notifications when someone replies to them.''',
   ),
   pinToTop(
     featureId: 'pin_to_top',
     title: 'Pin a Story',
-    description:
-        '''Pin this story to the top of your home screen so that you can come back later.''',
+    description: '''Pin this story to the top of your home screen.''',
   ),
   jumpUpButton(
     featureId: 'jump_up_button_with_long_press',
     title: 'Shortcut',
-    description:
-        '''Tapping on this button will take you to the previous root level comment.\n\nLong press on it to jump to the very beginning of this thread.''',
+    description: '''
+Tap this button to go to the previous root-level comment.
+
+Long press to jump to the beginning of the thread.
+
+Drag to move the button around.''',
   ),
   jumpDownButton(
     featureId: 'jump_down_button_with_long_press',
     title: 'Shortcut',
-    description:
-        '''Tapping on this button will take you to the next root level comment.\n\nLong press on it to jump to the end of this thread.''',
+    description: '''
+Tap this button to go to the next root-level comment.
+
+Long press to jump to the end of the thread.
+
+Drag to move the button around.''',
   ),
   searchInThread(
     featureId: 'search_in_thread',

lib/screens/item/widgets/more_popup_menu.dart

@@ -274,17 +274,21 @@ class MorePopupMenu extends StatelessWidget {
       isScrollControlled: true,
       showDragHandle: true,
       builder: (BuildContext context) {
-        return BlocProvider<SearchCubit>(
-          create: (_) =>
-              SearchCubit()..addFilter(PostedByFilter(author: item.by)),
-          child: SizedBox(
-            height: MediaQuery.of(context).size.height - Dimens.pt120,
-            child: const Column(
-              children: <Widget>[
-                Expanded(child: SearchScreen(isInBottomSheet: true)),
-              ],
-            ),
-          ),
+        return DraggableScrollableSheet(
+          expand: false,
+          initialChildSize: 0.9,
+          maxChildSize: 0.9,
+          minChildSize: 0.7,
+          builder: (BuildContext context, ScrollController scrollController) {
+            return BlocProvider<SearchCubit>(
+              create: (_) =>
+                  SearchCubit()..addFilter(PostedByFilter(author: item.by)),
+              child: SearchScreen(
+                isInBottomSheet: true,
+                scrollController: scrollController,
+              ),
+            );
+          },
         );
       },
     );

lib/screens/item/widgets/time_machine_dialog.dart

@@ -58,6 +58,7 @@ class TimeMachineDialog extends StatelessWidget {
                   Expanded(
                     child: ListView(
                       controller: scrollController,
+                      physics: const ClampingScrollPhysics(),
                       children: <Widget>[
                         switch (rootItem) {
                           Story() => StoryTile(

lib/screens/search/search_screen.dart

@@ -14,20 +14,28 @@ import 'package:pull_to_refresh/pull_to_refresh.dart';
 import 'package:scrolls_to_top/scrolls_to_top.dart';
 
 class SearchScreen extends StatefulWidget {
-  const SearchScreen({super.key, this.isInBottomSheet = false});
+  const SearchScreen({
+    super.key,
+    this.isInBottomSheet = false,
+    this.scrollController,
+  }) : assert(
+         !isInBottomSheet || scrollController != null,
+         '''ScrollController should be assigned when search screen is presented inside a sheet.''',
+       );
 
   /// If user is viewing [SearchScreen] in bottom sheet,
   /// we navigate to [ItemScreen] directly instead of injecting the
   /// item into [SplitViewCubit].
   final bool isInBottomSheet;
+  final ScrollController? scrollController;
 
   @override
   _SearchScreenState createState() => _SearchScreenState();
 }
 
 class _SearchScreenState extends State<SearchScreen> with ItemActionMixin {
   final RefreshController refreshController = RefreshController();
-  final ScrollController scrollController = ScrollController();
+  late final ScrollController scrollController;
   final FocusNode focusNode = FocusNode();
   final Debouncer debouncer = Debouncer(delay: AppDurations.oneSecond);
 
@@ -36,13 +44,22 @@ class _SearchScreenState extends State<SearchScreen> with ItemActionMixin {
   @override
   void initState() {
     super.initState();
+    scrollController = widget.scrollController ?? ScrollController();
     scrollController.addListener(onScroll);
   }
 
   @override
   void dispose() {
+    scrollController.removeListener(onScroll);
+
+    /// Do not dispose the scroll controller if it is being passed in from
+    /// the builder func of draggable scrollable sheet. It will be disposed
+    /// by the sheet.
+    if (!widget.isInBottomSheet) {
+      scrollController.dispose();
+    }
+
     refreshController.dispose();
-    scrollController.dispose();
     focusNode
       ..unfocus()
       ..dispose();
@@ -71,6 +88,7 @@ class _SearchScreenState extends State<SearchScreen> with ItemActionMixin {
               children: <Widget>[
                 Expanded(
                   child: SmartRefresher(
+                    physics: const ClampingScrollPhysics(),
                     scrollController: scrollController,
                     enablePullDown: false,
                     enablePullUp: true,
@@ -108,7 +126,7 @@ class _SearchScreenState extends State<SearchScreen> with ItemActionMixin {
                     child: ListView(
                       physics: state.results.isEmpty
                           ? const NeverScrollableScrollPhysics()
-                          : null,
+                          : const ClampingScrollPhysics(),
                       children: <Widget>[
                         Column(
                           children: <Widget>[

lib/screens/widgets/onboarding_view.dart

@@ -48,18 +48,17 @@ class _OnboardingViewState extends State<OnboardingView> {
                 children: const <Widget>[
                   _PageViewChild(
                     path: Constants.commentTileRightSlidePath,
-                    description:
-                        '''Swipe right to leave a comment, vote, and more.''',
+                    description: '''Swipe right to reply, vote, and more.''',
                   ),
                   _PageViewChild(
                     path: Constants.commentTileLeftSlidePath,
                     description:
-                        '''Swipe left to view all the ancestor comments.''',
+                        '''Swipe left to view all ancestor comments.''',
                   ),
                   _PageViewChild(
                     path: Constants.commentTileTopTapPath,
                     description:
-                        '''Tap on anywhere inside a comment tile to collapse. Long press any link to copy.''',
+                        '''Tap anywhere on a comment to collapse it. Long press any link to copy it.''',
                   ),
                 ],
               ),

lib/services/dialog_proxy.dart

@@ -41,16 +41,20 @@ abstract final class DialogProxy {
       isScrollControlled: true,
       showDragHandle: true,
       builder: (BuildContext context) {
-        return BlocProvider<SearchCubit>(
-          create: (_) => SearchCubit()..search(text),
-          child: SizedBox(
-            height: MediaQuery.of(context).size.height - Dimens.pt120,
-            child: const Column(
-              children: <Widget>[
-                Expanded(child: SearchScreen(isInBottomSheet: true)),
-              ],
-            ),
-          ),
+        return DraggableScrollableSheet(
+          expand: false,
+          initialChildSize: 0.9,
+          maxChildSize: 0.9,
+          minChildSize: 0.7,
+          builder: (BuildContext context, ScrollController scrollController) {
+            return BlocProvider<SearchCubit>(
+              create: (_) => SearchCubit()..search(text),
+              child: SearchScreen(
+                isInBottomSheet: true,
+                scrollController: scrollController,
+              ),
+            );
+          },
         );
       },
     );
@@ -72,7 +76,7 @@ abstract final class DialogProxy {
           expand: false,
           initialChildSize: 0.9,
           maxChildSize: 0.9,
-          minChildSize: 0.85,
+          minChildSize: 0.7,
           builder: (BuildContext context, ScrollController scrollController) {
             return TimeMachineDialog(
               comment: comment,