Added some fabs

lib/common/extensions/scroll_controller_extensions.dart

@@ -0,0 +1,27 @@
+import 'package:flutter/widgets.dart';
+import 'package:flutter/rendering.dart';
+
+extension ScrollControllerExtensions on ScrollController {
+  void handleScrollForFab(AnimationController hideFabController) {
+    print(position.userScrollDirection);
+    print(position.pixels);
+    print(position.atEdge);
+    switch (position.userScrollDirection) {
+      case ScrollDirection.idle:
+        break;
+      case ScrollDirection.forward:
+        hideFabController.forward();
+        break;
+      case ScrollDirection.reverse:
+        hideFabController.reverse();
+        break;
+    }
+
+    if (position.pixels == 0 && position.atEdge) {
+      //User is at the top, so lets hide the fab
+      hideFabController.reverse();
+    }
+  }
+
+  void goToTheTop() => animateTo(0, duration: const Duration(milliseconds: 500), curve: Curves.easeInOut);
+}

lib/ui/pages/artifacts_page.dart

@@ -12,6 +12,7 @@ import '../widgets/artifacts/artifact_info_card.dart';
 import '../widgets/common/loading.dart';
 import '../widgets/common/sliver_nothing_found.dart';
 import '../widgets/common/sliver_page_filter.dart';
+import '../widgets/common/sliver_scaffold_with_fab.dart';
 
 class ArtifactsPage extends StatefulWidget {
   @override
@@ -31,7 +32,7 @@ class _ArtifactsPageState extends State<ArtifactsPage> with AutomaticKeepAliveCl
       builder: (context, state) {
         return state.map(
           loading: (_) => const Loading(),
-          loaded: (state) => CustomScrollView(
+          loaded: (state) => SliverScaffoldWithFab(
             slivers: [
               SliverPageFilter(
                 search: state.search,

lib/ui/pages/character_page.dart

@@ -1,21 +1,57 @@
 import 'package:flutter/material.dart';
 
+import '../../common/extensions/scroll_controller_extensions.dart';
 import '../widgets/characters/character_detail.dart';
+import '../widgets/common/app_fab.dart';
 
-class CharacterPage extends StatelessWidget {
+class CharacterPage extends StatefulWidget {
   const CharacterPage({Key key}) : super(key: key);
 
+  @override
+  _CharacterPageState createState() => _CharacterPageState();
+}
+
+class _CharacterPageState extends State<CharacterPage> with SingleTickerProviderStateMixin {
+  ScrollController _scrollController;
+  AnimationController _hideFabAnimController;
+
+  @override
+  void initState() {
+    super.initState();
+
+    _scrollController = ScrollController();
+    _hideFabAnimController = AnimationController(
+      vsync: this,
+      duration: kThemeAnimationDuration,
+      value: 0, // initially not visible
+    );
+    _scrollController.addListener(() => _scrollController.handleScrollForFab(_hideFabAnimController));
+  }
+
   @override
   Widget build(BuildContext context) {
     return Scaffold(
       body: SafeArea(
         child: SingleChildScrollView(
-            child: Stack(
-          fit: StackFit.passthrough,
-          clipBehavior: Clip.none,
-          children: const [CharacterDetailTop(), CharacterDetailBottom()],
-        )),
+          controller: _scrollController,
+          child: Stack(
+            fit: StackFit.passthrough,
+            clipBehavior: Clip.none,
+            children: const [CharacterDetailTop(), CharacterDetailBottom()],
+          ),
+        ),
+      ),
+      floatingActionButton: AppFab(
+        hideFabAnimController: _hideFabAnimController,
+        scrollController: _scrollController,
       ),
     );
   }
+
+  @override
+  void dispose() {
+    _scrollController.dispose();
+    _hideFabAnimController.dispose();
+    super.dispose();
+  }
 }

lib/ui/pages/characters_page.dart

@@ -11,6 +11,7 @@ import '../widgets/characters/character_card.dart';
 import '../widgets/common/loading.dart';
 import '../widgets/common/sliver_nothing_found.dart';
 import '../widgets/common/sliver_page_filter.dart';
+import '../widgets/common/sliver_scaffold_with_fab.dart';
 
 class CharactersPage extends StatefulWidget {
   @override
@@ -30,7 +31,7 @@ class _CharactersPageState extends State<CharactersPage> with AutomaticKeepAlive
       builder: (context, state) {
         return state.map(
           loading: (_) => const Loading(),
-          loaded: (state) => CustomScrollView(
+          loaded: (state) => SliverScaffoldWithFab(
             slivers: [
               SliverPageFilter(
                 search: state.search,

lib/ui/pages/weapons_page.dart

@@ -10,6 +10,7 @@ import '../../models/weapons/weapon_card_model.dart';
 import '../widgets/common/loading.dart';
 import '../widgets/common/sliver_nothing_found.dart';
 import '../widgets/common/sliver_page_filter.dart';
+import '../widgets/common/sliver_scaffold_with_fab.dart';
 import '../widgets/weapons/weapon_bottom_sheet.dart';
 import '../widgets/weapons/weapon_card.dart';
 
@@ -30,7 +31,7 @@ class _WeaponsPageState extends State<WeaponsPage> with AutomaticKeepAliveClient
       builder: (context, state) {
         return state.map(
           loading: (_) => const Loading(),
-          loaded: (state) => CustomScrollView(
+          loaded: (state) => SliverScaffoldWithFab(
             slivers: [
               SliverPageFilter(
                 search: state.search,

lib/ui/widgets/common/app_fab.dart

@@ -0,0 +1,31 @@
+import 'package:flutter/material.dart';
+
+import '../../../common/extensions/scroll_controller_extensions.dart';
+
+class AppFab extends StatelessWidget {
+  final ScrollController scrollController;
+  final AnimationController hideFabAnimController;
+
+  const AppFab({
+    Key key,
+    @required this.scrollController,
+    @required this.hideFabAnimController,
+  }) : super(key: key);
+
+  @override
+  Widget build(BuildContext context) {
+    return FadeTransition(
+      opacity: hideFabAnimController,
+      child: ScaleTransition(
+        scale: hideFabAnimController,
+        child: FloatingActionButton(
+          backgroundColor: Theme.of(context).primaryColor,
+          mini: true,
+          onPressed: () => scrollController.goToTheTop(),
+          heroTag: null,
+          child: const Icon(Icons.arrow_upward),
+        ),
+      ),
+    );
+  }
+}

lib/ui/widgets/common/sliver_scaffold_with_fab.dart

@@ -0,0 +1,55 @@
+import 'package:flutter/material.dart';
+
+import '../../../common/extensions/scroll_controller_extensions.dart';
+import 'app_fab.dart';
+
+class SliverScaffoldWithFab extends StatefulWidget {
+  final List<Widget> slivers;
+
+  const SliverScaffoldWithFab({
+    Key key,
+    @required this.slivers,
+  }) : super(key: key);
+
+  @override
+  _SliverScaffoldWithFabState createState() => _SliverScaffoldWithFabState();
+}
+
+class _SliverScaffoldWithFabState extends State<SliverScaffoldWithFab> with SingleTickerProviderStateMixin {
+  ScrollController _scrollController;
+  AnimationController _hideFabAnimController;
+
+  @override
+  void initState() {
+    super.initState();
+
+    _scrollController = ScrollController();
+    _hideFabAnimController = AnimationController(
+      vsync: this,
+      duration: kThemeAnimationDuration,
+      value: 0, // initially not visible
+    );
+    _scrollController.addListener(() => _scrollController.handleScrollForFab(_hideFabAnimController));
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return Scaffold(
+      body: CustomScrollView(
+        controller: _scrollController,
+        slivers: widget.slivers,
+      ),
+      floatingActionButton: AppFab(
+        hideFabAnimController: _hideFabAnimController,
+        scrollController: _scrollController,
+      ),
+    );
+  }
+
+  @override
+  void dispose() {
+    _scrollController.dispose();
+    _hideFabAnimController.dispose();
+    super.dispose();
+  }
+}