CLASS SHAPE

gistfile1.txt

/*
OOP 

- incapsulare

 Ascunderea datelor interne si controlul accesului la ele prin metode publice.

 Campurile: #id, #color, #x, #y, #borderWidth # visibile sunt declarate cu #, adica sunt private, 

 nu pot fi accesate direct din afara clasei. Shape.#x ar da eroare

Accesul la ele se face prin metode publice controlate
getId()
getColor()
move(dx,dy)
show() / hide()

Datele sunt protejate

- Mostenire
- abstractizare

Expunere doar ceea ce este NECESAR , ascunzi datele de implementare

metoda computeArea() din Shape este un exemplu de abstractizare

clasa Shape defineste CE trebuie sa faca o forma (sa calculeze aria) , dar nu CUM - asta ramane la latitudinea fiecare clase derivate

Este o abstractizare a conceptului de forma geometrica , fara a specifica detalii concrete de calcul

De asemnea displayInfo abstractizeaza afisearea informatiilor - utilizatorul clasei apeleaza o singura metoda, fara sa stie ce campuri interne sunt afisare 

sau cum sunt formatate

- polimorfism

*/
//clasa de baza
class Shape {

      #id;
      #color;
      #x;
      #y;
      #borderWidth;
      #visible;      

      constructor(id, color, x, y, borderWidth = 1) {

      	  this.#id = id;
      	  this.#color = color;
      	  this.#x = x;
      	  this.#y = y;
      	  this.#borderWidth = borderWidth;
      	  this.#visible = true;          

      }


      //getters 
      getId() {
      	return this.#id
      }

      getColor() {
      	return this.#color
      }

      getPosition() {

      	return {
      		 x: this.#x,
      		 y: this.#y
      	};
      }

      move(dx, dy) {
      	this.#x += dx
      	this.#y += dy
      }

      hide() {
      	this.#visible = false;
      }

      show() {
      	this.#visible = true;
      }

      computeArea() {

      	throw new Error("computeArea() trebuie implementata")
      }

      displayInfo() {

      	 console.log(`ID: ${this.getId()} Color: ${this.#color} Position: ( ${this.#x}, ${this.#y} ) Border: ${this.#borderWidth}px Visible: ${this.#visible}`)  

      }
}


//mostenire OOP
//clasa derivata sau Subclasa
class Circle extends Shape {

      #radius;

      constructor(id, color, x, y, borderWidth, radius) {

                 super(id, color, x, y, borderWidth);

                 this.#radius = radius;
      }

      computeArea() {

             return Math.PI * this.#radius ** 2;
      }

      getRadius() {

      	return this.#radius;
      }

}


class Rectangle extends Shape {

      #width;
      #height;

      constructor(id, color, x, y, borderWidth, width, height) {


      	   super(id, color, x, y, borderWidth);

      	   this.#width = width
      	   this.#height = height
      }  

      computeArea() {

      	  return this.#width * this.#height;
      }

}


class Triangle extends Shape {


	 #base;
	 #height;

	 constructor(id, color, x, y, borderWidth, base, height) {

	 	  super(id, color, x, y, borderWidth);

	 	  this.#base = base;

	 	  this.#height = height;

	 }

	 computeArea() {

	 	return (this.#base * this.#height) / 2;
	 }
}



//CREAREA OBIECTELOR

const circle = new Circle(

"C1",
"red",
10,
20,
2,
5
);

const rectangle = new Rectangle(
	 "R1",
	 "blue",
	 30,
	 50,
	 1,
	 10,
	 5
)

const triangle = new Triangle(

    "T1",
    "green",
    50,
    60,
    3,
    8,
    5
)

//Polimorfismul in action

const shapes = [ circle, rectangle, triangle ]

for(const shape of shapes) {

	  console.log(`${shape.getId()} AREA = ${shape.computeArea()}`) //apel polimorfic

	  shape.displayInfo() //apel polimorfic
}

/*
Desi shapes contine obiecte de diferite tipuri (Circle , Rectangle, Triangle) codul apeleaza ACEEASI METODA

computeArea() de fiecare data, dar fiecare obiect executa PROPRIA IMPLEMENTARE


Circle.computeArea() =====>>>> pi * r * r
Rectangle.computeArea() =====>> width * height
Triangle.computeArea() =====> (base * height) / 2

Acesta este polimorfis; interfata comuna cu acelasi nume, comportament diferit in functie de tipul real al obiectul la 

RUNTIME


incapsulare: #private campurile plus metode getter, move, hide, show

Abstractizare computeArea() definit ca abstract in Shape

Mostenire Circle, REctangle si Triangle extends Shape

Polimorfism : Bucla for care apeleaza computeArea polimorfic
*/