feat: add the Cell class

Add the Cell class to represent a grid in the maze. Each 'Cell' can
be configured to specify which walls exists for it.

graphics.py

@@ -75,7 +75,7 @@ class Window:
         while self.__is_running:
             self.redraw()
 
-    def draw_line(self, line: Line, fill_colour: str):
+    def draw_line(self, line: Line, fill_colour: str = "black"):
         """
         draw_line draws a line on the canvas.
         """
@@ -86,3 +86,41 @@ class Window:
         close sets the window to close.
         """
         self.__is_running = False
+
+
+class Cell:
+    """
+    A Cell represents a grid on the maze.
+    """
+
+    def __init__(
+            self,
+            x1: int, y1: int,
+            x2: int, y2: int,
+            window: Window
+    ):
+        self.__top_wall_exists = True
+        self.__bottom_wall_exists = True
+        self.__left_wall_exists = True
+        self.__right_wall_exists = True
+        self.__top_wall = Line(Point(x1, y1), Point(x2, y1))
+        self.__bottom_wall = Line(Point(x1, y2), Point(x2, y2))
+        self.__left_wall = Line(Point(x1, y1), Point(x1, y2))
+        self.__right_wall = Line(Point(x2, y1), Point(x2, y2))
+        self.__window = window
+
+    def set_walls(self, top: bool, bottom: bool, left: bool, right: bool):
+        self.__top_wall_exists = top
+        self.__bottom_wall_exists = bottom
+        self.__left_wall_exists = left
+        self.__right_wall_exists = right
+
+    def draw(self):
+        if self.__top_wall_exists:
+            self.__window.draw_line(self.__top_wall)
+        if self.__bottom_wall_exists:
+            self.__window.draw_line(self.__bottom_wall)
+        if self.__left_wall_exists:
+            self.__window.draw_line(self.__left_wall)
+        if self.__right_wall_exists:
+            self.__window.draw_line(self.__right_wall)

main.py

@@ -1,14 +1,23 @@
-from graphics import Window, Line, Point
+from graphics import Window, Cell
 
 
 def main():
     window = Window(800, 800)
-    line_1 = Line(Point(10, 50), Point(100, 70))
-    line_2 = Line(Point(300, 145), Point(456, 200))
-    line_3 = Line(Point(20, 498), Point(50, 600))
-    window.draw_line(line_1, "black")
-    window.draw_line(line_2, "red")
-    window.draw_line(line_3, "black")
+
+    # Draw all walls
+    cell_1 = Cell(10, 30, 100, 100, window)
+    cell_1.draw()
+
+    # Draw vertical walls only
+    cell_2 = Cell(300, 50, 400, 100, window)
+    cell_2.set_walls(False, False, True, True)
+    cell_2.draw()
+
+    # Draw horizontal walls only
+    cell_3 = Cell(200, 400, 500, 600, window)
+    cell_3.set_walls(True, True, False, False)
+    cell_3.draw()
+
     window.wait_for_close()