samples/material_3_demo/lib/main.dart

// Copyright 2021 The Flutter team. 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:convert';

import 'package:flutter/material.dart';
import 'package:web_startup_analyzer/web_startup_analyzer.dart';

import 'constants.dart';
import 'home.dart';

void main() async {
  var analyzer = WebStartupAnalyzer(additionalFrameCount: 10);
  debugPrint(json.encode(analyzer.startupTiming));
  analyzer.onFirstFrame.addListener(() {
    debugPrint(json.encode({'firstFrame': analyzer.onFirstFrame.value}));
  });
  analyzer.onFirstPaint.addListener(() {
    debugPrint(json.encode({
      'firstPaint': analyzer.onFirstPaint.value?.$1,
      'firstContentfulPaint': analyzer.onFirstPaint.value?.$2,
    }));
  });
  analyzer.onAdditionalFrames.addListener(() {
    debugPrint(json.encode({
      'additionalFrames': analyzer.onAdditionalFrames.value,
    }));
  });
  runApp(
    const App(),
  );
}

class App extends StatefulWidget {
  const App({super.key});

  @override
  State<App> createState() => _AppState();
}

class _AppState extends State<App> {
  bool useMaterial3 = true;
  ThemeMode themeMode = ThemeMode.system;
  ColorSeed colorSelected = ColorSeed.baseColor;
  ColorImageProvider imageSelected = ColorImageProvider.leaves;
  ColorScheme? imageColorScheme = const ColorScheme.light();
  ColorSelectionMethod colorSelectionMethod = ColorSelectionMethod.colorSeed;

  bool get useLightMode => switch (themeMode) {
        ThemeMode.system =>
          View.of(context).platformDispatcher.platformBrightness ==
              Brightness.light,
        ThemeMode.light => true,
        ThemeMode.dark => false
      };

  void handleBrightnessChange(bool useLightMode) {
    setState(() {
      themeMode = useLightMode ? ThemeMode.light : ThemeMode.dark;
    });
  }

  void handleMaterialVersionChange() {
    setState(() {
      useMaterial3 = !useMaterial3;
    });
  }

  void handleColorSelect(int value) {
    setState(() {
      colorSelectionMethod = ColorSelectionMethod.colorSeed;
      colorSelected = ColorSeed.values[value];
    });
  }

  void handleImageSelect(int value) {
    final String url = ColorImageProvider.values[value].url;
    ColorScheme.fromImageProvider(provider: NetworkImage(url))
        .then((newScheme) {
      setState(() {
        colorSelectionMethod = ColorSelectionMethod.image;
        imageSelected = ColorImageProvider.values[value];
        imageColorScheme = newScheme;
      });
    });
  }

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      debugShowCheckedModeBanner: false,
      title: 'Material 3',
      themeMode: themeMode,
      theme: ThemeData(
        colorSchemeSeed: colorSelectionMethod == ColorSelectionMethod.colorSeed
            ? colorSelected.color
            : null,
        colorScheme: colorSelectionMethod == ColorSelectionMethod.image
            ? imageColorScheme
            : null,
        useMaterial3: useMaterial3,
        brightness: Brightness.light,
      ),
      darkTheme: ThemeData(
        colorSchemeSeed: colorSelectionMethod == ColorSelectionMethod.colorSeed
            ? colorSelected.color
            : imageColorScheme!.primary,
        useMaterial3: useMaterial3,
        brightness: Brightness.dark,
      ),
      home: Home(
        useLightMode: useLightMode,
        useMaterial3: useMaterial3,
        colorSelected: colorSelected,
        imageSelected: imageSelected,
        handleBrightnessChange: handleBrightnessChange,
        handleMaterialVersionChange: handleMaterialVersionChange,
        handleColorSelect: handleColorSelect,
        handleImageSelect: handleImageSelect,
        colorSelectionMethod: colorSelectionMethod,
      ),
    );
  }
}