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// Copyright 2016 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/animation.dart';
import 'package:flutter/widgets.dart';
import 'colors.dart';
import 'icon.dart';
import 'list_item.dart';
import 'material_list.dart';
import 'theme.dart';
import 'theme_data.dart';
const Duration _kExpand = const Duration(milliseconds: 200);
class TwoLevelListItem extends StatelessComponent {
TwoLevelListItem({
Key key,
this.left,
this.center,
this.right,
this.onTap,
this.onLongPress
}) : super(key: key) {
assert(center != null);
}
final Widget left;
final Widget center;
final Widget right;
final GestureTapCallback onTap;
final GestureLongPressCallback onLongPress;
Widget build(BuildContext context) {
final TwoLevelList parentList = context.ancestorWidgetOfExactType(TwoLevelList);
assert(parentList != null);
return new SizedBox(
height: kListItemExtent[parentList.type],
child: new ListItem(
left: left,
center: center,
right: right,
onTap: onTap,
onLongPress: onLongPress
)
);
}
}
class TwoLevelSublist extends StatefulComponent {
TwoLevelSublist({ Key key, this.left, this.center, this.children }) : super(key: key);
final Widget left;
final Widget center;
final List<Widget> children;
_TwoLevelSublistState createState() => new _TwoLevelSublistState();
}
class _TwoLevelSublistState extends State<TwoLevelSublist> {
AnimationController _controller;
CurvedAnimation _easeOutAnimation;
CurvedAnimation _easeInAnimation;
ColorTween _borderColor;
ColorTween _headerColor;
ColorTween _iconColor;
Animation<double> _iconTurns;
bool _isExpanded = false;
void initState() {
super.initState();
_controller = new AnimationController(duration: _kExpand);
_easeOutAnimation = new CurvedAnimation(parent: _controller, curve: Curves.easeOut);
_easeInAnimation = new CurvedAnimation(parent: _controller, curve: Curves.easeIn);
_borderColor = new ColorTween(begin: Colors.transparent);
_headerColor = new ColorTween();
_iconColor = new ColorTween();
_iconTurns = new Tween<double>(begin: 0.0, end: 0.5).animate(_easeInAnimation);
_isExpanded = PageStorage.of(context)?.readState(context) ?? false;
if (_isExpanded)
_controller.value = 1.0;
}
void _handleOnTap() {
setState(() {
_isExpanded = !_isExpanded;
if (_isExpanded)
_controller.forward();
else
_controller.reverse();
PageStorage.of(context)?.writeState(context, _isExpanded);
});
}
Widget buildList(BuildContext context, Widget child) {
return new Container(
decoration: new BoxDecoration(
border: new Border(
top: new BorderSide(color: _borderColor.evaluate(_easeOutAnimation)),
bottom: new BorderSide(color: _borderColor.evaluate(_easeOutAnimation))
)
),
child: new Column(
children: <Widget>[
new TwoLevelListItem(
onTap: _handleOnTap,
left: config.left,
center: new DefaultTextStyle(
style: Theme.of(context).text.body1.copyWith(color: _headerColor.evaluate(_easeInAnimation)),
child: config.center
),
right: new RotationTransition(
turns: _iconTurns,
child: new Icon(
icon: 'navigation/expand_more',
color: _iconColor.evaluate(_easeInAnimation)
)
)
),
new ClipRect(
child: new Align(
heightFactor: _easeInAnimation.value,
child: new Column(children: config.children)
)
)
]
)
);
}
Widget build(BuildContext context) {
final ThemeData theme = Theme.of(context);
_borderColor.end = theme.dividerColor;
_headerColor
..begin = theme.text.body1.color
..end = theme.accentColor;
_iconColor
..begin = theme.unselectedColor
..end = theme.accentColor;
return new AnimatedBuilder(
animation: _controller.view,
builder: buildList
);
}
}
class TwoLevelList extends StatelessComponent {
TwoLevelList({ Key key, this.items, this.type: MaterialListType.twoLine }) : super(key: key);
final List<Widget> items;
final MaterialListType type;
Widget build(BuildContext context) => new Block(children: items);
}