This application is a simple Fifteen Game.

The "board" is made from 16 buttons. The "empty space" is a white button with no text.

The pieces that player can move are buttons with text from 1->15.

When a player clicks a button, we check:

• All it's neighbours on 4 directions: North, South, East and West.
• On a matrix those positions would be:
  • x + (1,0)
  • x - (0,1)
  • y + (1,0)
  • y - (0,1)
• We ignore those who go out of bounds ( bigger than matrix size or negative values )
• If we find a neighbour that has no text this is our empty button, and the current button will switch places with it.

All buttons positions are saved in a List so we can check if they are in order. If the list is sorted, the game is over.