make cell wall statuses public

cell.py

@@ -1,3 +1,4 @@
+from typing import Dict
 from graphics import Window, Point, Line
 
 
@@ -17,6 +18,11 @@ class Cell:
     A Cell represents a grid on the maze.
     """
 
+    TOP_WALL = 0
+    BOTTOM_WALL = 1
+    LEFT_WALL = 2
+    RIGHT_WALL = 4
+
     def __init__(
             self,
             x1: int, y1: int,
@@ -39,10 +45,12 @@ class Cell:
         left_wall = Line(Point(x1, y1), Point(x1, y2))
         right_wall = Line(Point(x2, y1), Point(x2, y2))
 
-        self._top_wall = CellWall(top_wall)
+        self._walls: Dict[int, CellWall] = {
-        self._bottom_wall = CellWall(bottom_wall)
+            Cell.TOP_WALL: CellWall(top_wall),
-        self._left_wall = CellWall(left_wall)
+            Cell.BOTTOM_WALL: CellWall(bottom_wall),
-        self._right_wall = CellWall(right_wall)
+            Cell.LEFT_WALL: CellWall(left_wall),
+            Cell.RIGHT_WALL: CellWall(right_wall),
+        }
 
         # Calculate the cell's central point
         centre_x = x1 + ((x2 - x1) / 2)
@@ -64,10 +72,10 @@ class Cell:
         """
         configure_walls configures the existence of the Cell's walls.
         """
-        self._top_wall.exists = top
+        self._walls[Cell.TOP_WALL].exists = top
-        self._bottom_wall.exists = bottom
+        self._walls[Cell.BOTTOM_WALL].exists = bottom
-        self._left_wall.exists = left
+        self._walls[Cell.LEFT_WALL].exists = left
-        self._right_wall.exists = right
+        self._walls[Cell.RIGHT_WALL].exists = right
 
     def centre(self) -> Point:
         """
@@ -75,6 +83,11 @@ class Cell:
         """
         return self._centre
 
+    def wall_exists(self, wall: int) -> bool:
+        if wall not in self._walls:
+            raise Exception("received invalid cell wall")
+        return self._walls[wall].exists
+
     #def break_walls_r(self, i: int, j: int) -> None:
     #    self.visited = True
     #    while True:
@@ -89,47 +102,47 @@ class Cell:
         if not self._window:
             return
 
-        if self._top_wall.exists:
+        if self.wall_exists(Cell.TOP_WALL):
             self._window.draw_line(
-                self._top_wall.line,
+                self._walls[Cell.TOP_WALL].line,
                 fill_colour=self._window.cell_grid_colour,
             )
         else:
             self._window.draw_line(
-                self._top_wall.line,
+                self._walls[Cell.TOP_WALL].line,
                 fill_colour=self._window.background_colour,
             )
 
-        if self._bottom_wall.exists:
+        if self.wall_exists(Cell.BOTTOM_WALL):
             self._window.draw_line(
-                self._bottom_wall.line,
+                self._walls[Cell.BOTTOM_WALL].line,
                 fill_colour=self._window.cell_grid_colour,
             )
         else:
             self._window.draw_line(
-                self._bottom_wall.line,
+                self._walls[Cell.BOTTOM_WALL].line,
                 fill_colour=self._window.background_colour,
             )
 
-        if self._left_wall.exists:
+        if self.wall_exists(Cell.LEFT_WALL):
             self._window.draw_line(
-                self._left_wall.line,
+                self._walls[Cell.LEFT_WALL].line,
                 fill_colour=self._window.cell_grid_colour,
             )
         else:
             self._window.draw_line(
-                self._left_wall.line,
+                self._walls[Cell.LEFT_WALL].line,
                 fill_colour=self._window.background_colour,
             )
 
-        if self._right_wall.exists:
+        if self.wall_exists(Cell.RIGHT_WALL):
             self._window.draw_line(
-                self._right_wall.line,
+                self._walls[Cell.RIGHT_WALL].line,
                 fill_colour=self._window.cell_grid_colour,
             )
         else:
             self._window.draw_line(
-                self._right_wall.line,
+                self._walls[Cell.RIGHT_WALL].line,
                 fill_colour=self._window.background_colour,
             )
 
@@ -150,11 +163,11 @@ class Cell:
 
 class CellInvalidError(Exception):
     """
-    CellInvalidError is returned when the program tries to create a Cell whose
+    CellInvalidError is raised when the program tries to create a Cell whose
     values are invalid. The values are invalid when x2 is smaller than x1
     and/or y2 is smaller than y1. When creating a Cell the x and y values
-    should always represent the top left and the bottom right of the cell's
+    should always represent the top left and the bottom right corners of
-    walls (i.e. x1 < x2 and y1 < y2).
+    the cell (i.e. x1 < x2 and y1 < y2).
     """
 
     def __init__(self, x1: int, y1: int, x2: int, y2: int, *args):
@@ -170,7 +183,7 @@ class CellInvalidError(Exception):
 
 class CellTooSmallError(Exception):
     """
-    CellTooSmallError is returned when the program tries to create a Cell
+    CellTooSmallError is raised when the program tries to create a Cell
     which is too small to correctly draw it's central point.
     """