@Override
	public void keyTyped(KeyEvent e) {
		switch (e.getKeyChar()) {
		case 's':
		case 'S':
			getScreen().shoot(propulsion);
			break;
		case 'w':
		case 'W':
			getScreen().selectNextWeapon();
			break;
		case '+':
			propulsion = Math.min(MAX_PROPULSION, propulsion + PROPULSION_STEP);
			break;
		case '-':
			propulsion = Math.max(MIN_PROPULSION, propulsion - PROPULSION_STEP);
			break;
		}
	}