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// Copyright 2014 The Flutter Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
import 'package:flutter/material.dart';
import '../../gallery/demo.dart';
// Each TabBarView contains a _Page and for each _Page there is a list
// of _CardData objects. Each _CardData object is displayed by a _CardItem.
const String _kGalleryAssetsPackage = 'flutter_gallery_assets';
class _Page {
_Page({ this.label });
final String? label;
String get id => label!.characters.first;
@override
String toString() => '$runtimeType("$label")';
}
class _CardData {
const _CardData({ this.title, this.imageAsset, this.imageAssetPackage });
final String? title;
final String? imageAsset;
final String? imageAssetPackage;
}
final Map<_Page, List<_CardData>> _allPages = <_Page, List<_CardData>>{
_Page(label: 'HOME'): <_CardData>[
const _CardData(
title: 'Flatwear',
imageAsset: 'products/flatwear.png',
imageAssetPackage: _kGalleryAssetsPackage,
),
const _CardData(
title: 'Pine Table',
imageAsset: 'products/table.png',
imageAssetPackage: _kGalleryAssetsPackage,
),
const _CardData(
title: 'Blue Cup',
imageAsset: 'products/cup.png',
imageAssetPackage: _kGalleryAssetsPackage,
),
const _CardData(
title: 'Tea Set',
imageAsset: 'products/teaset.png',
imageAssetPackage: _kGalleryAssetsPackage,
),
const _CardData(
title: 'Desk Set',
imageAsset: 'products/deskset.png',
imageAssetPackage: _kGalleryAssetsPackage,
),
const _CardData(
title: 'Blue Linen Napkins',
imageAsset: 'products/napkins.png',
imageAssetPackage: _kGalleryAssetsPackage,
),
const _CardData(
title: 'Planters',
imageAsset: 'products/planters.png',
imageAssetPackage: _kGalleryAssetsPackage,
),
const _CardData(
title: 'Kitchen Quattro',
imageAsset: 'products/kitchen_quattro.png',
imageAssetPackage: _kGalleryAssetsPackage,
),
const _CardData(
title: 'Platter',
imageAsset: 'products/platter.png',
imageAssetPackage: _kGalleryAssetsPackage,
),
],
_Page(label: 'APPAREL'): <_CardData>[
const _CardData(
title: 'Cloud-White Dress',
imageAsset: 'products/dress.png',
imageAssetPackage: _kGalleryAssetsPackage,
),
const _CardData(
title: 'Ginger Scarf',
imageAsset: 'products/scarf.png',
imageAssetPackage: _kGalleryAssetsPackage,
),
const _CardData(
title: 'Blush Sweats',
imageAsset: 'products/sweats.png',
imageAssetPackage: _kGalleryAssetsPackage,
),
],
};
class _CardDataItem extends StatelessWidget {
const _CardDataItem({ this.page, this.data });
static const double height = 272.0;
final _Page? page;
final _CardData? data;
@override
Widget build(BuildContext context) {
return Card(
child: Padding(
padding: const EdgeInsets.all(16.0),
child: Column(
crossAxisAlignment: CrossAxisAlignment.stretch,
children: <Widget>[
Align(
alignment: page!.id == 'H'
? Alignment.centerLeft
: Alignment.centerRight,
child: CircleAvatar(child: Text(page!.id)),
),
SizedBox(
width: 144.0,
height: 144.0,
child: Image.asset(
data!.imageAsset!,
package: data!.imageAssetPackage,
fit: BoxFit.contain,
),
),
Center(
child: Text(
data!.title!,
style: Theme.of(context).textTheme.headline6,
),
),
],
),
),
);
}
}
class TabsDemo extends StatelessWidget {
const TabsDemo({Key? key}) : super(key: key);
static const String routeName = '/material/tabs';
@override
Widget build(BuildContext context) {
return DefaultTabController(
length: _allPages.length,
child: Scaffold(
body: NestedScrollView(
headerSliverBuilder: (BuildContext context, bool innerBoxIsScrolled) {
return <Widget>[
SliverOverlapAbsorber(
handle: NestedScrollView.sliverOverlapAbsorberHandleFor(context),
sliver: SliverAppBar(
title: const Text('Tabs and scrolling'),
actions: <Widget>[MaterialDemoDocumentationButton(routeName)],
pinned: true,
expandedHeight: 150.0,
forceElevated: innerBoxIsScrolled,
bottom: TabBar(
tabs: _allPages.keys.map<Widget>(
(_Page page) => Tab(text: page.label),
).toList(),
),
),
),
];
},
body: TabBarView(
children: _allPages.keys.map<Widget>((_Page page) {
return SafeArea(
top: false,
bottom: false,
child: Builder(
builder: (BuildContext context) {
return CustomScrollView(
key: PageStorageKey<_Page>(page),
slivers: <Widget>[
SliverOverlapInjector(
handle: NestedScrollView.sliverOverlapAbsorberHandleFor(context),
),
SliverPadding(
padding: const EdgeInsets.symmetric(
vertical: 8.0,
horizontal: 16.0,
),
sliver: SliverFixedExtentList(
itemExtent: _CardDataItem.height,
delegate: SliverChildBuilderDelegate(
(BuildContext context, int index) {
final _CardData data = _allPages[page]![index];
return Padding(
padding: const EdgeInsets.symmetric(
vertical: 8.0,
),
child: _CardDataItem(
page: page,
data: data,
),
);
},
childCount: _allPages[page]!.length,
),
),
),
],
);
},
),
);
}).toList(),
),
),
),
);
}
}