| // 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_center.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 MouseRegion.onExit |
| // |
| //*************************************************************************** |
| //* ▼▼▼▼▼▼▼▼ description ▼▼▼▼▼▼▼▼ (do not modify or remove section marker) |
| |
| // The following example shows a widget that hides its content one second |
| // after being hovered, and also exposes the enter and exit callbacks. |
| // Because the widget conditionally creates the `MouseRegion`, and leaks the |
| // hover state, it needs to take the restriction into consideration. In this |
| // case, since it has access to the event that triggers the disappearance of |
| // the `MouseRegion`, it simply trigger the exit callback during that event |
| // as well. |
| |
| //* ▲▲▲▲▲▲▲▲ 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 Center( |
| child: MyStatefulWidget(), |
| ), |
| ), |
| ); |
| } |
| } |
| |
| //***************************************************************************** |
| //* ▼▼▼▼▼▼▼▼ code-preamble ▼▼▼▼▼▼▼▼ (do not modify or remove section marker) |
| |
| // A region that hides its content one second after being hovered. |
| class MyTimedButton extends StatefulWidget { |
| const MyTimedButton( |
| {Key? key, required this.onEnterButton, required this.onExitButton}) |
| : super(key: key); |
| |
| final VoidCallback onEnterButton; |
| final VoidCallback onExitButton; |
| |
| @override |
| State<MyTimedButton> createState() => _MyTimedButton(); |
| } |
| |
| class _MyTimedButton extends State<MyTimedButton> { |
| bool regionIsHidden = false; |
| bool hovered = false; |
| |
| Future<void> startCountdown() async { |
| await Future<void>.delayed(const Duration(seconds: 1)); |
| hideButton(); |
| } |
| |
| void hideButton() { |
| setState(() { |
| regionIsHidden = true; |
| }); |
| // This statement is necessary. |
| if (hovered) { |
| widget.onExitButton(); |
| } |
| } |
| |
| @override |
| Widget build(BuildContext context) { |
| return SizedBox( |
| width: 100, |
| height: 100, |
| child: MouseRegion( |
| child: regionIsHidden |
| ? null |
| : MouseRegion( |
| onEnter: (_) { |
| widget.onEnterButton(); |
| setState(() { |
| hovered = true; |
| }); |
| startCountdown(); |
| }, |
| onExit: (_) { |
| setState(() { |
| hovered = false; |
| }); |
| widget.onExitButton(); |
| }, |
| child: Container(color: Colors.red), |
| ), |
| ), |
| ); |
| } |
| } |
| |
| //* ▲▲▲▲▲▲▲▲ code-preamble ▲▲▲▲▲▲▲▲ (do not modify or remove section marker) |
| //***************************************************************************** |
| |
| /// 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) |
| |
| Key key = UniqueKey(); |
| bool hovering = false; |
| |
| @override |
| Widget build(BuildContext context) { |
| return Column( |
| children: <Widget>[ |
| ElevatedButton( |
| onPressed: () { |
| setState(() { |
| key = UniqueKey(); |
| }); |
| }, |
| child: const Text('Refresh'), |
| ), |
| if (hovering) const Text('Hovering'), |
| if (!hovering) const Text('Not hovering'), |
| MyTimedButton( |
| key: key, |
| onEnterButton: () { |
| setState(() { |
| hovering = true; |
| }); |
| }, |
| onExitButton: () { |
| setState(() { |
| hovering = false; |
| }); |
| }, |
| ), |
| ], |
| ); |
| } |
| |
| //* ▲▲▲▲▲▲▲▲ code ▲▲▲▲▲▲▲▲ (do not modify or remove section marker) |
| //******************************************************************** |
| |
| } |