Refactoring

Pull base class for page partioner out of page partioner and add random
page partioner derived class.

test/fixtures/page_generation/page.py

@@ -380,7 +380,7 @@ def blank_page(texture, texture_fn) -> np.ndarray:
     """Creates a blank page with a given orientation and dpi."""
     page = random_flip(texture)
     page = texture_fn(page)
-    page_partitioner = PagePartitioner()
+    page_partitioner = RandomPagePartitioner()
     boxes = page_partitioner(page)
     content_generator = ContentGenerator()
     boxes = content_generator(boxes)
@@ -1170,7 +1170,7 @@ def paste_contents(page, contents: Iterable[ContentRectangle]):
     return page
 
 
-class PagePartitioner:
+class PagePartitioner(abc.ABC):
     def __init__(self):
         self.left_margin_percentage = 0.05
         self.right_margin_percentage = 0.05
@@ -1195,6 +1195,21 @@ class PagePartitioner:
         # boxes = list(boxes)
         return boxes
 
+    @abc.abstractmethod
+    def generate_content_boxes(self, box: Rectangle, depth=0):
+        raise NotImplementedError
+
+    def recurse(self, depth):
+        return random.random() <= self.recursion_probability(depth)
+
+    def recursion_probability(self, depth):
+        return self.initial_recursion_probability * (1 - self.recursion_probability_decay) ** depth
+
+
+class RandomPagePartitioner(PagePartitioner):
+    def __init__(self):
+        super().__init__()
+
     def generate_content_boxes(self, box: Rectangle, depth=0):
         if depth >= self.max_recursion_depth:
             yield box
@@ -1205,12 +1220,6 @@ class PagePartitioner:
             else:
                 yield child_boxes
 
-    def recurse(self, depth):
-        return random.random() <= self.recursion_probability(depth)
-
-    def recursion_probability(self, depth):
-        return self.initial_recursion_probability * (1 - self.recursion_probability_decay) ** depth
-
 
 def generate_random_child_boxes(box: Rectangle, margin_percentage) -> Tuple[Rectangle, Rectangle]:
     axis = random.choice(["x", "y"])