| // 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 'dart:html' as html; |
| |
| import 'package:flutter/material.dart'; |
| |
| void main() => runApp(const MyApp()); |
| |
| class MyApp extends StatelessWidget { |
| const MyApp({super.key}); |
| |
| // This widget is the root of your application. |
| @override |
| Widget build(BuildContext context) { |
| return MaterialApp( |
| title: 'Flutter Scroll Wheel Test', |
| theme: ThemeData( |
| primarySwatch: Colors.blue, |
| fontFamily: 'RobotoMono', |
| visualDensity: VisualDensity.adaptivePlatformDensity, |
| ), |
| home: const MyHomePage(title: 'Flutter Scroll Wheel Test'), |
| ); |
| } |
| } |
| |
| class MyHomePage extends StatefulWidget { |
| const MyHomePage({super.key, required this.title}); |
| |
| final String title; |
| |
| @override |
| State createState() => _MyHomePageState(); |
| } |
| |
| class _MyHomePageState extends State<MyHomePage> { |
| @override |
| Widget build(BuildContext context) { |
| return Scaffold( |
| appBar: AppBar( |
| title: Text(widget.title), |
| ), |
| body: ListView.builder( |
| itemCount: 1000, |
| itemBuilder: (BuildContext context, int index) => Padding( |
| padding: const EdgeInsets.all(20), |
| child: Container( |
| height: 100, |
| color: Colors.lightBlue, |
| child: Center( |
| child: Text('Item $index'), |
| ), |
| ), |
| ), |
| ), |
| floatingActionButton: FloatingActionButton.extended( |
| key: const Key('scroll-button'), |
| onPressed: () { |
| const int centerX = 100; //html.window.innerWidth ~/ 2; |
| const int centerY = 100; //html.window.innerHeight ~/ 2; |
| dispatchMouseWheelEvent(centerX, centerY, DeltaMode.kLine, 0, 1); |
| dispatchMouseWheelEvent(centerX, centerY, DeltaMode.kLine, 0, 1); |
| dispatchMouseWheelEvent(centerX, centerY, DeltaMode.kLine, 0, 1); |
| dispatchMouseWheelEvent(centerX, centerY, DeltaMode.kLine, 0, 1); |
| dispatchMouseWheelEvent(centerX, centerY, DeltaMode.kLine, 0, 1); |
| }, |
| label: const Text('Scroll'), |
| icon: const Icon(Icons.thumb_up), |
| ), |
| ); |
| } |
| } |
| |
| abstract class DeltaMode { |
| static const int kPixel = 0x00; |
| static const int kLine = 0x01; |
| static const int kPage = 0x02; |
| } |
| |
| void dispatchMouseWheelEvent(int mouseX, int mouseY, |
| int deltaMode, double deltaX, double deltaY) { |
| final html.EventTarget target = html.document.elementFromPoint(mouseX, mouseY)!; |
| |
| target.dispatchEvent(html.MouseEvent('mouseover', |
| screenX: mouseX, |
| screenY: mouseY, |
| clientX: mouseX, |
| clientY: mouseY, |
| )); |
| |
| target.dispatchEvent(html.MouseEvent('mousemove', |
| screenX: mouseX, |
| screenY: mouseY, |
| clientX: mouseX, |
| clientY: mouseY, |
| )); |
| |
| target.dispatchEvent(html.WheelEvent('wheel', |
| screenX: mouseX, |
| screenY: mouseY, |
| clientX: mouseX, |
| clientY: mouseY, |
| deltaMode: deltaMode, |
| deltaX : deltaX, |
| deltaY : deltaY, |
| )); |
| } |