reverted page transition, added main app bar transition, fixed regular app bar spacing

lib/widgets/aves_app.dart

@@ -126,7 +126,11 @@ class _AvesAppState extends State<AvesApp> with WidgetsBindingObserver {
                               // - `FadeUpwardsPageTransitionsBuilder` on Oreo / API 27 and below
                               // - `OpenUpwardsPageTransitionsBuilder` on Pie / API 28
                               // - `ZoomPageTransitionsBuilder` on Android 10 / API 29 and above (default in Flutter v3.0.0)
-                              ? const PageTransitionsTheme()
+                              ? const PageTransitionsTheme(
+                                  builders: {
+                                    TargetPlatform.android: FadeUpwardsPageTransitionsBuilder(),
+                                  },
+                                )
                               // strip page transitions used by `MaterialPageRoute`
                               : const DirectPageTransitionsTheme();
 

lib/widgets/common/identity/aves_app_bar.dart

@@ -13,6 +13,9 @@ class AvesAppBar extends StatelessWidget {
   final Widget? bottom;
   final Object? transitionKey;
 
+  static const leadingHeroTag = 'appbar-leading';
+  static const titleHeroTag = 'appbar-title';
+
   const AvesAppBar({
     super.key,
     required this.contentHeight,
@@ -49,9 +52,18 @@ class AvesAppBar extends StatelessWidget {
                         children: [
                           Padding(
                             padding: const EdgeInsets.symmetric(horizontal: 4),
+                            child: Hero(
+                              tag: leadingHeroTag,
+                              flightShuttleBuilder: _flightShuttleBuilder,
+                              transitionOnUserGestures: true,
                               child: leading,
                             ),
+                          ),
                           Expanded(
+                            child: Hero(
+                              tag: titleHeroTag,
+                              flightShuttleBuilder: _flightShuttleBuilder,
+                              transitionOnUserGestures: true,
                               child: AnimatedSwitcher(
                                 duration: context.read<DurationsData>().iconAnimation,
                                 child: Row(
@@ -63,6 +75,7 @@ class AvesAppBar extends StatelessWidget {
                                 ),
                               ),
                             ),
+                          ),
                         ],
                       ),
                     ),
@@ -77,6 +90,38 @@ class AvesAppBar extends StatelessWidget {
     );
   }
 
+  static Widget _flightShuttleBuilder(
+    BuildContext flightContext,
+    Animation<double> animation,
+    HeroFlightDirection direction,
+    BuildContext fromHero,
+    BuildContext toHero,
+  ) {
+    final pushing = direction == HeroFlightDirection.push;
+    Widget popBuilder(context, child) => Opacity(opacity: 1 - animation.value, child: child);
+    Widget pushBuilder(context, child) => Opacity(opacity: animation.value, child: child);
+    return Material(
+      type: MaterialType.transparency,
+      child: DefaultTextStyle(
+        style: DefaultTextStyle.of(toHero).style,
+        child: Stack(
+          children: [
+            AnimatedBuilder(
+              animation: animation,
+              builder: pushing ? popBuilder : pushBuilder,
+              child: fromHero.widget,
+            ),
+            AnimatedBuilder(
+              animation: animation,
+              builder: pushing ? pushBuilder : popBuilder,
+              child: toHero.widget,
+            ),
+          ],
+        ),
+      ),
+    );
+  }
+
   static double appBarHeightForContentHeight(double contentHeight) => AvesFloatingBar.margin.vertical + contentHeight;
 }
 

lib/widgets/search/search_page.dart

@@ -3,8 +3,10 @@ import 'dart:ui';
 import 'package:aves/theme/durations.dart';
 import 'package:aves/utils/debouncer.dart';
 import 'package:aves/widgets/common/extensions/build_context.dart';
+import 'package:aves/widgets/common/identity/aves_app_bar.dart';
 import 'package:aves/widgets/search/search_delegate.dart';
 import 'package:flutter/material.dart';
+import 'package:flutter/scheduler.dart';
 
 class SearchPage extends StatefulWidget {
   static const routeName = '/search';
@@ -51,7 +53,10 @@ class _SearchPageState extends State<SearchPage> {
       return;
     }
     widget.animation.removeStatusListener(_onAnimationStatusChanged);
+    Future.delayed(Durations.pageTransitionAnimation * timeDilation).then((_) {
+      if (!mounted) return;
       _focusNode.requestFocus();
+    });
   }
 
   @override
@@ -110,20 +115,28 @@ class _SearchPageState extends State<SearchPage> {
     }
     return Scaffold(
       appBar: AppBar(
-        leading: widget.delegate.buildLeading(context),
+        leading: Hero(
-        title: DefaultTextStyle.merge(
+          tag: AvesAppBar.leadingHeroTag,
+          transitionOnUserGestures: true,
+          child: Center(child: widget.delegate.buildLeading(context)),
+        ),
+        title: Hero(
+          tag: AvesAppBar.titleHeroTag,
+          transitionOnUserGestures: true,
+          child: DefaultTextStyle.merge(
             style: const TextStyle(fontFeatures: [FontFeature.disable('smcp')]),
             child: TextField(
               controller: widget.delegate.queryTextController,
               focusNode: _focusNode,
-            style: theme.textTheme.headline6,
-            textInputAction: TextInputAction.search,
-            onSubmitted: (_) => widget.delegate.showResults(context),
               decoration: InputDecoration(
                 border: InputBorder.none,
                 hintText: context.l10n.searchCollectionFieldHint,
                 hintStyle: theme.inputDecorationTheme.hintStyle,
               ),
+              textInputAction: TextInputAction.search,
+              style: theme.textTheme.headline6,
+              onSubmitted: (_) => widget.delegate.showResults(context),
+            ),
           ),
         ),
         actions: widget.delegate.buildActions(context),

lib/widgets/settings/settings_page.dart

@@ -96,7 +96,6 @@ class _SettingsPageState extends State<SettingsPage> with FeedbackMixin {
               ),
             ),
           ],
-          titleSpacing: 0,
         ),
         body: GestureAreaProtectorStack(
           child: SafeArea(

lib/widgets/viewer/info/info_app_bar.dart

@@ -74,7 +74,6 @@ class InfoAppBar extends StatelessWidget {
             ),
           ),
       ],
-      titleSpacing: 0,
       floating: true,
     );
   }