Initial commit

docling/backend/abstract_backend.py

@@ -0,0 +1,55 @@
+from abc import ABC, abstractmethod
+from io import BytesIO
+from pathlib import Path
+from typing import Any, Iterable, Optional, Union
+
+from PIL import Image
+
+
+class PdfPageBackend(ABC):
+    def __init__(self, page_obj: Any) -> object:
+        pass
+
+    @abstractmethod
+    def get_text_in_rect(self, bbox: "BoundingBox") -> str:
+        pass
+
+    @abstractmethod
+    def get_text_cells(self) -> Iterable["Cell"]:
+        pass
+
+    @abstractmethod
+    def get_page_image(
+        self, scale: int = 1, cropbox: Optional["BoundingBox"] = None
+    ) -> Image.Image:
+        pass
+
+    @abstractmethod
+    def get_size(self) -> "PageSize":
+        pass
+
+    @abstractmethod
+    def unload(self):
+        pass
+
+
+class PdfDocumentBackend(ABC):
+    @abstractmethod
+    def __init__(self, path_or_stream: Iterable[Union[BytesIO, Path]]):
+        pass
+
+    @abstractmethod
+    def load_page(self, page_no: int) -> PdfPageBackend:
+        pass
+
+    @abstractmethod
+    def page_count(self) -> int:
+        pass
+
+    @abstractmethod
+    def is_valid(self) -> bool:
+        pass
+
+    @abstractmethod
+    def unload(self):
+        pass