Add code to expose text direction of cell

Signed-off-by: Christoph Auer <cau@zurich.ibm.com>

docling/backend/docling_parse_v2_backend.py

@@ -11,7 +11,7 @@ from PIL import Image, ImageDraw
 from pypdfium2 import PdfPage
 
 from docling.backend.pdf_backend import PdfDocumentBackend, PdfPageBackend
-from docling.datamodel.base_models import Cell, Size
+from docling.datamodel.base_models import Cell, Size, TextDirection
 
 if TYPE_CHECKING:
     from docling.datamodel.document import InputDocument
@@ -97,6 +97,7 @@ class DoclingParseV2PageBackend(PdfPageBackend):
             y0 = cell_data[cells_header.index("y0")]
             x1 = cell_data[cells_header.index("x1")]
             y1 = cell_data[cells_header.index("y1")]
+            ltr = cell_data[cells_header.index("left_to_right")]
 
             if x1 < x0:
                 x0, x1 = x1, x0
@@ -116,6 +117,11 @@ class DoclingParseV2PageBackend(PdfPageBackend):
                         t=y1 * page_size.height / parser_height,
                         coord_origin=CoordOrigin.BOTTOMLEFT,
                     ).to_top_left_origin(page_size.height),
+                    text_direction=(
+                        TextDirection.LEFT_TO_RIGHT
+                        if ltr
+                        else TextDirection.RIGHT_TO_LEFT
+                    ),
                 )
             )
             cell_counter += 1

docling/datamodel/base_models.py

@@ -120,10 +120,16 @@ class ErrorItem(BaseModel):
     error_message: str
 
 
+class TextDirection(str, Enum):
+    LEFT_TO_RIGHT = "left_to_right"
+    RIGHT_TO_LEFT = "right_to_left"
+
+
 class Cell(BaseModel):
     id: int
     text: str
     bbox: BoundingBox
+    text_direction: TextDirection = TextDirection.LEFT_TO_RIGHT
 
 
 class OcrCell(Cell):

docling/models/ds_glm_model.py

@@ -264,6 +264,7 @@ class GlmModel:
             glm_doc = self.model.apply_on_doc(ds_doc_dict)
 
             docling_doc: DoclingDocument = to_docling_document(glm_doc)  # Experimental
+            1 == 1
 
         # DEBUG code:
         def draw_clusters_and_cells(ds_document, page_no, show: bool = False):

docling/models/page_assemble_model.py

@@ -11,6 +11,7 @@ from docling.datamodel.base_models import (
     Page,
     PageElement,
     Table,
+    TextDirection,
     TextElement,
 )
 from docling.datamodel.document import ConversionResult
@@ -75,12 +76,23 @@ class PageAssembleModel(BasePageModel):
                     for cluster in page.predictions.layout.clusters:
                         # _log.info("Cluster label seen:", cluster.label)
                         if cluster.label in LayoutModel.TEXT_ELEM_LABELS:
+                            textlines = []
+
+                            dominant_text_direction = TextDirection.LEFT_TO_RIGHT
+
+                            # Naive code: dominant text direction == direction of first cell.
+                            for cell in cluster.cells:
+                                dominant_text_direction = cell.text_direction
+                                break
+
+                            for cell in cluster.cells:
+                                text = cell.text.replace("\x02", "-").strip()
+                                if text:
+                                    # if dominant_text_direction == TextDirection.RIGHT_TO_LEFT:
+                                    #    textlines.insert(0, text)  # Prepend RTL text
+                                    # else:
+                                    textlines.append(text)  # Append LTR text
 
-                            textlines = [
-                                cell.text.replace("\x02", "-").strip()
-                                for cell in cluster.cells
-                                if len(cell.text.strip()) > 0
-                            ]
                             text = self.sanitize_text(textlines)
                             text_el = TextElement(
                                 label=cluster.label,

docs/examples/batch_convert.py

@@ -49,6 +49,8 @@ def export_documents(
                 with (output_dir / f"{doc_filename}.md").open("w") as fp:
                     fp.write(conv_res.document.export_to_markdown())
 
+                conv_res.document.save_as_html(output_dir / f"{doc_filename}.html")
+
                 # Export Docling document format to text:
                 with (output_dir / f"{doc_filename}.txt").open("w") as fp:
                     fp.write(conv_res.document.export_to_markdown(strict_text=True))
@@ -103,10 +105,13 @@ def main():
     logging.basicConfig(level=logging.INFO)
 
     input_doc_paths = [
-        Path("./tests/data/2206.01062.pdf"),
-        Path("./tests/data/2203.01017v2.pdf"),
-        Path("./tests/data/2305.03393v1.pdf"),
-        Path("./tests/data/redp5110_sampled.pdf"),
+        Path("./tests/data/pdf/right_to_left_01.pdf"),
+        Path("./tests/data/pdf/right_to_left_02.pdf"),
+        Path("./tests/data/pdf/right_to_left_03.pdf"),
+        Path("./tests/data/pdf/2206.01062.pdf"),
+        Path("./tests/data/pdf/2203.01017v2.pdf"),
+        Path("./tests/data/pdf/2305.03393v1.pdf"),
+        Path("./tests/data/pdf/redp5110_sampled.pdf"),
     ]
 
     # buf = BytesIO(Path("./test/data/2206.01062.pdf").open("rb").read())

tests/test_backend_docling_parse_v2.py

@@ -26,6 +26,17 @@ def _get_backend(pdf_doc):
     return doc_backend
 
 
+def test_cell_ordering():
+    pdf_doc = Path("tests/data/pdf/right_to_left_01.pdf")
+    doc_backend = _get_backend(pdf_doc)
+
+    for page_index in range(0, doc_backend.page_count()):
+        page_backend: DoclingParseV2PageBackend = doc_backend.load_page(page_index)
+        cells = list(page_backend.get_text_cells())
+
+        1 == 1
+
+
 def test_text_cell_counts():
     pdf_doc = Path("./tests/data/pdf/redp5110_sampled.pdf")