smarter groups

copienator/commands/annotating_by_label.py

@@ -275,15 +275,7 @@ def _existing_group_state(
 
 def split_batches(rendered):
     batches = []
-    current = []
-    current_height = 0
-
-    def flush() -> None:
-        nonlocal current, current_height
-        if current:
-            batches.append(current)
-            current = []
-            current_height = 0
+    heights = []
 
     index = 0
     while index < len(rendered):
@@ -302,15 +294,17 @@ def split_batches(rendered):
                 f"maximum group height is {MAX_HEIGHT_PX} px."
             )
 
-        # Consider the student's complete block before adding its first image.
-        # Otherwise later images from that same student could overflow the batch.
-        if current and current_height + student_height > MAX_HEIGHT_PX:
-            flush()
-        current.extend(student_items)
-        current_height += student_height
+        # Reuse space in earlier groups, keeping each student's block intact.
+        for batch_index, height in enumerate(heights):
+            if height + student_height <= MAX_HEIGHT_PX:
+                batches[batch_index].extend(student_items)
+                heights[batch_index] += student_height
+                break
+        else:
+            batches.append(list(student_items))
+            heights.append(student_height)
         index = end
 
-    flush()
     return batches