blob: e6e9035d508b5ff273283e4287f7ef682a75416f [file] [log] [blame]
// 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:collection/collection.dart' show lowerBound;
import 'package:flutter/material.dart';
import 'package:flutter/semantics.dart';
import '../../gallery/demo.dart';
enum LeaveBehindDemoAction {
reset,
horizontalSwipe,
leftSwipe,
rightSwipe,
confirmDismiss,
}
class LeaveBehindItem implements Comparable<LeaveBehindItem> {
LeaveBehindItem({ this.index, this.name, this.subject, this.body });
LeaveBehindItem.from(LeaveBehindItem item)
: index = item.index, name = item.name, subject = item.subject, body = item.body;
final int? index;
final String? name;
final String? subject;
final String? body;
@override
int compareTo(LeaveBehindItem other) => index!.compareTo(other.index!);
}
class LeaveBehindDemo extends StatefulWidget {
const LeaveBehindDemo({ super.key });
static const String routeName = '/material/leave-behind';
@override
LeaveBehindDemoState createState() => LeaveBehindDemoState();
}
class LeaveBehindDemoState extends State<LeaveBehindDemo> {
DismissDirection _dismissDirection = DismissDirection.horizontal;
bool _confirmDismiss = true;
late List<LeaveBehindItem> leaveBehindItems;
void initListItems() {
leaveBehindItems = List<LeaveBehindItem>.generate(16, (int index) {
return LeaveBehindItem(
index: index,
name: 'Item $index Sender',
subject: 'Subject: $index',
body: "[$index] first line of the message's body...",
);
});
}
@override
void initState() {
super.initState();
initListItems();
}
void handleDemoAction(LeaveBehindDemoAction action) {
setState(() {
switch (action) {
case LeaveBehindDemoAction.reset:
initListItems();
break;
case LeaveBehindDemoAction.horizontalSwipe:
_dismissDirection = DismissDirection.horizontal;
break;
case LeaveBehindDemoAction.leftSwipe:
_dismissDirection = DismissDirection.endToStart;
break;
case LeaveBehindDemoAction.rightSwipe:
_dismissDirection = DismissDirection.startToEnd;
break;
case LeaveBehindDemoAction.confirmDismiss:
_confirmDismiss = !_confirmDismiss;
break;
}
});
}
void handleUndo(LeaveBehindItem item) {
final int insertionIndex = lowerBound(leaveBehindItems, item);
setState(() {
leaveBehindItems.insert(insertionIndex, item);
});
}
void _handleArchive(LeaveBehindItem item) {
setState(() {
leaveBehindItems.remove(item);
});
ScaffoldMessenger.of(context).showSnackBar(SnackBar(
content: Text('You archived item ${item.index}'),
action: SnackBarAction(
label: 'UNDO',
onPressed: () { handleUndo(item); },
),
));
}
void _handleDelete(LeaveBehindItem item) {
setState(() {
leaveBehindItems.remove(item);
});
ScaffoldMessenger.of(context).showSnackBar(SnackBar(
content: Text('You deleted item ${item.index}'),
action: SnackBarAction(
label: 'UNDO',
onPressed: () { handleUndo(item); },
),
));
}
@override
Widget build(BuildContext context) {
Widget body;
if (leaveBehindItems.isEmpty) {
body = Center(
child: ElevatedButton(
onPressed: () => handleDemoAction(LeaveBehindDemoAction.reset),
child: const Text('Reset the list'),
),
);
} else {
body = Scrollbar(
child: ListView(
primary: true,
children: leaveBehindItems.map<Widget>((LeaveBehindItem item) {
return _LeaveBehindListItem(
confirmDismiss: _confirmDismiss,
item: item,
onArchive: _handleArchive,
onDelete: _handleDelete,
dismissDirection: _dismissDirection,
);
}).toList(),
),
);
}
return Scaffold(
appBar: AppBar(
title: const Text('Swipe to dismiss'),
actions: <Widget>[
MaterialDemoDocumentationButton(LeaveBehindDemo.routeName),
PopupMenuButton<LeaveBehindDemoAction>(
onSelected: handleDemoAction,
itemBuilder: (BuildContext context) => <PopupMenuEntry<LeaveBehindDemoAction>>[
const PopupMenuItem<LeaveBehindDemoAction>(
value: LeaveBehindDemoAction.reset,
child: Text('Reset the list'),
),
const PopupMenuDivider(),
CheckedPopupMenuItem<LeaveBehindDemoAction>(
value: LeaveBehindDemoAction.horizontalSwipe,
checked: _dismissDirection == DismissDirection.horizontal,
child: const Text('Horizontal swipe'),
),
CheckedPopupMenuItem<LeaveBehindDemoAction>(
value: LeaveBehindDemoAction.leftSwipe,
checked: _dismissDirection == DismissDirection.endToStart,
child: const Text('Only swipe left'),
),
CheckedPopupMenuItem<LeaveBehindDemoAction>(
value: LeaveBehindDemoAction.rightSwipe,
checked: _dismissDirection == DismissDirection.startToEnd,
child: const Text('Only swipe right'),
),
CheckedPopupMenuItem<LeaveBehindDemoAction>(
value: LeaveBehindDemoAction.confirmDismiss,
checked: _confirmDismiss,
child: const Text('Confirm dismiss'),
),
],
),
],
),
body: body,
);
}
}
class _LeaveBehindListItem extends StatelessWidget {
const _LeaveBehindListItem({
required this.item,
required this.onArchive,
required this.onDelete,
required this.dismissDirection,
required this.confirmDismiss,
});
final LeaveBehindItem item;
final DismissDirection dismissDirection;
final void Function(LeaveBehindItem) onArchive;
final void Function(LeaveBehindItem) onDelete;
final bool confirmDismiss;
void _handleArchive() {
onArchive(item);
}
void _handleDelete() {
onDelete(item);
}
@override
Widget build(BuildContext context) {
final ThemeData theme = Theme.of(context);
return Semantics(
customSemanticsActions: <CustomSemanticsAction, VoidCallback>{
const CustomSemanticsAction(label: 'Archive'): _handleArchive,
const CustomSemanticsAction(label: 'Delete'): _handleDelete,
},
child: Dismissible(
key: ObjectKey(item),
direction: dismissDirection,
onDismissed: (DismissDirection direction) {
if (direction == DismissDirection.endToStart) {
_handleArchive();
} else {
_handleDelete();
}
},
confirmDismiss: !confirmDismiss ? null : (DismissDirection dismissDirection) async {
switch(dismissDirection) {
case DismissDirection.endToStart:
return await _showConfirmationDialog(context, 'archive') ?? false;
case DismissDirection.startToEnd:
return await _showConfirmationDialog(context, 'delete') ?? false;
case DismissDirection.horizontal:
case DismissDirection.vertical:
case DismissDirection.up:
case DismissDirection.down:
case DismissDirection.none:
assert(false);
}
return false;
},
background: Container(
color: theme.primaryColor,
child: const Center(
child: ListTile(
leading: Icon(Icons.delete, color: Colors.white, size: 36.0),
),
),
),
secondaryBackground: Container(
color: theme.primaryColor,
child: const Center(
child: ListTile(
trailing: Icon(Icons.archive, color: Colors.white, size: 36.0),
),
),
),
child: Container(
decoration: BoxDecoration(
color: theme.canvasColor,
border: Border(bottom: BorderSide(color: theme.dividerColor)),
),
child: ListTile(
title: Text(item.name!),
subtitle: Text('${item.subject}\n${item.body}'),
isThreeLine: true,
),
),
),
);
}
Future<bool?> _showConfirmationDialog(BuildContext context, String action) {
return showDialog<bool>(
context: context,
builder: (BuildContext context) {
return AlertDialog(
title: Text('Do you want to $action this item?'),
actions: <Widget>[
TextButton(
child: const Text('Yes'),
onPressed: () {
Navigator.pop(context, true); // showDialog() returns true
},
),
TextButton(
child: const Text('No'),
onPressed: () {
Navigator.pop(context, false); // showDialog() returns false
},
),
],
);
},
);
}
}