| // 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. |
| |
| // Template: dev/snippets/config/templates/stateful_widget_scaffold.tmpl |
| // |
| // Comment lines marked with "▼▼▼" and "▲▲▲" are used for authoring |
| // of samples, and may be ignored if you are just exploring the sample. |
| |
| // Flutter code sample for Draggable |
| // |
| //*************************************************************************** |
| //* ▼▼▼▼▼▼▼▼ description ▼▼▼▼▼▼▼▼ (do not modify or remove section marker) |
| |
| // The following example has a [Draggable] widget along with a [DragTarget] |
| // in a row demonstrating an incremented `acceptedData` integer value when |
| // you drag the element to the target. |
| |
| //* ▲▲▲▲▲▲▲▲ description ▲▲▲▲▲▲▲▲ (do not modify or remove section marker) |
| //*************************************************************************** |
| |
| import 'package:flutter/material.dart'; |
| |
| void main() => runApp(const MyApp()); |
| |
| /// This is the main application widget. |
| class MyApp extends StatelessWidget { |
| const MyApp({Key? key}) : super(key: key); |
| |
| static const String _title = 'Flutter Code Sample'; |
| |
| @override |
| Widget build(BuildContext context) { |
| return MaterialApp( |
| title: _title, |
| home: Scaffold( |
| appBar: AppBar(title: const Text(_title)), |
| body: const MyStatefulWidget(), |
| ), |
| ); |
| } |
| } |
| |
| /// This is the stateful widget that the main application instantiates. |
| class MyStatefulWidget extends StatefulWidget { |
| const MyStatefulWidget({Key? key}) : super(key: key); |
| |
| @override |
| State<MyStatefulWidget> createState() => _MyStatefulWidgetState(); |
| } |
| |
| /// This is the private State class that goes with MyStatefulWidget. |
| class _MyStatefulWidgetState extends State<MyStatefulWidget> { |
| //******************************************************************** |
| //* ▼▼▼▼▼▼▼▼ code ▼▼▼▼▼▼▼▼ (do not modify or remove section marker) |
| |
| int acceptedData = 0; |
| |
| @override |
| Widget build(BuildContext context) { |
| return Row( |
| mainAxisAlignment: MainAxisAlignment.spaceEvenly, |
| children: <Widget>[ |
| Draggable<int>( |
| // Data is the value this Draggable stores. |
| data: 10, |
| child: Container( |
| height: 100.0, |
| width: 100.0, |
| color: Colors.lightGreenAccent, |
| child: const Center( |
| child: Text('Draggable'), |
| ), |
| ), |
| feedback: Container( |
| color: Colors.deepOrange, |
| height: 100, |
| width: 100, |
| child: const Icon(Icons.directions_run), |
| ), |
| childWhenDragging: Container( |
| height: 100.0, |
| width: 100.0, |
| color: Colors.pinkAccent, |
| child: const Center( |
| child: Text('Child When Dragging'), |
| ), |
| ), |
| ), |
| DragTarget<int>( |
| builder: ( |
| BuildContext context, |
| List<dynamic> accepted, |
| List<dynamic> rejected, |
| ) { |
| return Container( |
| height: 100.0, |
| width: 100.0, |
| color: Colors.cyan, |
| child: Center( |
| child: Text('Value is updated to: $acceptedData'), |
| ), |
| ); |
| }, |
| onAccept: (int data) { |
| setState(() { |
| acceptedData += data; |
| }); |
| }, |
| ), |
| ], |
| ); |
| } |
| |
| //* ▲▲▲▲▲▲▲▲ code ▲▲▲▲▲▲▲▲ (do not modify or remove section marker) |
| //******************************************************************** |
| |
| } |