private boolean isWalkable(FieldState state) {
		if (mode == Mode.EDITOR) {
			if (state == FieldState.EMPTY || state == FieldState.GOAL
					|| state == FieldState.DIAMOND || state == FieldState.PLAYER) {
				return true;
			}
		} else if (mode == Mode.GAME) {
			if (state == FieldState.EMPTY || state == FieldState.GOAL) {
				return true;
			}
		}
		return false;
	}