Inheritance (Mixin) - Introduction to Dart

main.dart

import "package:flutter/material.dart";

void main() {
  //new instance of class
  MyNewClass myNewClass = new MyNewClass();
  var anotherInstance = new MyNewClass();
  print(myNewClass.runtimeType);
  anotherInstance.sayHello();

  Shape rectangle1 = new Rectangle(20, 30);
  print(rectangle1.runtimeType);
  print(rectangle1.perimeter());
  rectangle1.showPerimeter();

  Shape square1 = new Square(35);
  print(square1.runtimeType);
  print(square1.perimeter());
  square1.showPerimeter();

  Rectangle(20, 20).showPerimeter();
  Square(20).showPerimeter();

  Circle circle1 = Circle(radius: 66);
  circle1.showPerimeter();
  print(circle1.diameter);
  circle1.showDiameter();

  //Shape shape = new Shape(1, 2);

  Square square2 = Square(10);
  square2.showSides();

  Rectangle rectangle2 = new Rectangle(10, 25);
  rectangle2.showSides();

  showQuadSides(square2);
  showQuadSides(square1 as Square);
  showShapePerimeter(square2);
  showCircleDiameter(circle1);
}

class MyNewClass {
  void sayHello() {
    print("hello");
  }
}

class Rectangle extends Shape with Quadrilateral {
  Rectangle(int length, int breadth) : super(length, breadth) {
    sides = 2;
  }
  void showPerimeter() {
    print(
        "The perimeter of rectangle with length $length and breadth $breadth is ${perimeter()}");
  }
}

class Square extends Shape with Quadrilateral {
  Square(int size) : super(size, size);
  void showPerimeter() {
    print("The perimeter of square with size $length is ${perimeter()}");
  }
}

class Circle extends Shape {
  Circle({@required int radius}) : super(radius, radius);
  @override
  int perimeter() {
    return (2 * length * 3.14).toInt();
  }

  int get diameter {
    return length * 2;
  }

  void showDiameter() {
    print("the diameter of the circle is $diameter");
  }

  void showPerimeter() {
    print("The perimeter of circle with radius $length is ${perimeter()}");
  }
}

abstract class Shape {
  int length;
  int breadth;
  Shape(this.length, this.breadth);

  int perimeter() {
    return 2 * (length + breadth);
  }

  void showPerimeter();

  //add area
}

mixin Quadrilateral {
  int sides = 4;
  void showSides() {
    print(
        "This Quadrilateral is a ${this.runtimeType} with $sides equal sides ");
  }
}

void showQuadSides(Quadrilateral quad) {
  quad.showSides();
}

void showShapePerimeter(Shape shape) {
  shape.showPerimeter();
}

void showCircleDiameter(Circle circle) {
  circle.showDiameter();
}
//add 3DShape