flutterdevrelgists

class Bicycle {
  int cadence;
  int speed;
  int gear;
  
  Bicycle(this.cadence, this.speed, this.gear);
  
  @override
  String toString() => 'Bicycle: $speed mph';
}

flutterdevrelgists

import 'dart:math';

abstract class Shape {
  num get area;
}

class Circle implements Shape {
  final num radius;
  Circle(this.radius);
  @override

flutterdevrelgists

import 'dart:math';

abstract class Shape {
  factory Shape(String type) {
    if (type == 'circle') return Circle(2);
    if (type == 'square') return Square(2);
    // To trigger exception, don't implement a check for 'triangle'.
    throw 'Can\'t create $type.';
  }
  num get area;

flutterdevrelgists

import 'dart:math';

abstract class Shape {
  num get area;
}

class Circle implements Shape {
  final num radius;
  Circle(this.radius);
  @override

flutterdevrelgists

import 'dart:math';

abstract class Shape {
  factory Shape(String type) {
    if (type == 'circle') return Circle(2);
    if (type == 'square') return Square(2);
    throw 'Can\'t create $type.';
  }
  num get area;
}

flutterdevrelgists

import 'dart:math';

abstract class Shape {
  factory Shape(String type) {
    if (type == 'circle') return Circle(2);
    if (type == 'square') return Square(2);
    throw 'Can\'t create $type.';
  }
  num get area;
}

flutterdevrelgists

// 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:flutter/material.dart';

void main() => runApp(const AnimatedBuilderExample());

/// This widget listens for changes in the focus state of the subtree defined by
/// its [child] widget, changing the border and color of the container it is in

flutterdevrelgists

// 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.

/// Flutter code sample for [LayoutBuilder].

import 'package:flutter/material.dart';

void main() => runApp(const LayoutBuilderExample());

flutterdevrelgists

// 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:flutter/material.dart';

void main() {
  runApp(const MainApp());
}

flutterdevrelgists

import 'package:flutter/material.dart';

void main() {
  runApp(const MyApp());
}

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  @override