so i have to do a project, which is to make a simple galaga/ space invaders clone, i managed to get the thing working using just the main class(1 tab <<<noob =/) but now i would like to break it off into classes and i am having some issues with moving the ship(a triangle), every time the movment key the ship keeps moving in that direction instead of moving in steps.

here is the main class 

2. //SIZE
3. int width = 400;
4. int height = width;
5. 
   
6. //SHIP CENTER COORDINATES + OBEJECT
7. int shipCenterX = 200;
8. int shipCenterY = 380;
9. ship shipA;
10. 
    
11. //INITIALIZE GAME
12. void setup()
13. {
14.   size(width, height);
15.   shipA = new ship(shipCenterX, shipCenterY, width, height);
16. }
17. 
    
18. 
    
19. //DRAW GAME
20. void draw()
21. {
22.   background(0);
23.   shipA.keyPressed();
24.   shipA.drawShip();
25.   
26. }

and here is the ship class 

2. class ship
3. { 
4.   int x, y, w, h;
5.   
6.   ship(int x, int y, int w, int h)
7.   {
8.     this.x = x;
9.     this.y = y;
10.     this.w = w;
11.     this.h = h;
12.   }
13.   
14.   void drawShip()
15.   {
16.     fill(255);
17.     triangle(x - 10, y + 10, x, y, x + 10, y + 10);
18.   }
19.   
20.   //TRIANFGLE MOVEMENT
21.   void keyPressed()
22.   {
23.     if (key == CODED)
24.     {
25.       switch(keyCode)
26.        {
27.         case LEFT:
28.         x -= 3;
29.         if (x < 0)
30.         {
31.          x = width;
32.         } 
33.         break;
34.         //
35.         case RIGHT:
36.         x += 3;
37.         if (x > width)
38.         {
39.           x = 0;
40.         }
41.         break;
42.         //
43.         //case UP:
44.          //shoot = true;
45.          //break;
46.      }
47.     }
48.   }
49. }
50.   
51.   
52.    
53.