flutter/examples/material_gallery/lib/demo/tabs_fab_demo.dart
2016-02-09 10:09:54 -08:00

114 lines
3.5 KiB
Dart

// Copyright 2015 The Chromium 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';
class _Page {
_Page({ this.label, this.colors, this.icon });
final String label;
final Map<int, Color> colors;
final String icon;
TabLabel get tabLabel => new TabLabel(text: label.toUpperCase());
Color get labelColor => colors != null ? colors[300] : Colors.grey[300];
bool get fabDefined => colors != null && icon != null;
Color get fabColor => colors[400];
Icon get fabIcon => new Icon(icon: icon);
Key get fabKey => new ValueKey<Color>(fabColor);
}
const String _explanatoryText =
"When the Scaffold's floating action button changes, the new button fades and "
"turns into view. In this demo, changing tabs can cause the app to be rebuilt "
"with a FloatingActionButton that the Scaffold distinguishes from the others "
"by its key.";
class TabsFabDemo extends StatefulComponent {
_TabsFabDemoState createState() => new _TabsFabDemoState();
}
class _TabsFabDemoState extends State<TabsFabDemo> {
final GlobalKey scaffoldKey = new GlobalKey();
final List<_Page> pages = <_Page>[
new _Page(label: 'Blue', colors: Colors.indigo, icon: 'content/add'),
new _Page(label: 'Too', colors: Colors.indigo, icon: 'content/add'),
new _Page(label: 'Eco', colors: Colors.green, icon: 'content/create'),
new _Page(label: 'No'),
new _Page(label: 'Teal', colors: Colors.teal, icon: 'content/add'),
new _Page(label: 'Red', colors: Colors.red, icon: 'content/create')
];
_Page selectedPage;
void initState() {
super.initState();
selectedPage = pages[0];
}
void _handleTabSelection(_Page page) {
setState(() {
selectedPage = page;
});
}
void _showExplanatoryText() {
scaffoldKey.currentState.showBottomSheet((BuildContext context) {
return new Container(
decoration: new BoxDecoration(
border: new Border(top: new BorderSide(color: Theme.of(context).dividerColor))
),
child: new Padding(
padding: const EdgeDims.all(32.0),
child: new Text(_explanatoryText, style: Theme.of(context).text.subhead)
)
);
});
}
Widget buildTabView(_Page page) {
return new Builder(
builder: (BuildContext context) {
final TextStyle textStyle = new TextStyle(
color: page.labelColor,
fontSize: 32.0,
textAlign: TextAlign.center
);
return new Container(
key: new ValueKey<String>(page.label),
padding: const EdgeDims.TRBL(48.0, 48.0, 96.0, 48.0),
child: new Card(
child: new Center(
child: new Text(page.label, style: textStyle)
)
)
);
}
);
}
Widget build(BuildContext context) {
return new TabBarSelection<_Page>(
values: pages,
onChanged: _handleTabSelection,
child: new Scaffold(
key: scaffoldKey,
toolBar: new ToolBar(
center: new Text("FAB per Tab"),
tabBar: new TabBar<_Page>(
labels: new Map.fromIterable(pages, value: (_Page page) => page.tabLabel)
)
),
floatingActionButton: !selectedPage.fabDefined ? null : new FloatingActionButton(
key: selectedPage.fabKey,
backgroundColor: selectedPage.fabColor,
child: selectedPage.fabIcon,
onPressed: _showExplanatoryText
),
body: new TabBarView(children: pages.map(buildTabView).toList())
)
);
}
}