Decouple tqdm from progressbar setup

src/ocrmypdf/_exec/ghostscript.py

@@ -18,7 +18,6 @@ from subprocess import PIPE, CalledProcessError
 from typing import Optional, cast
 
 from PIL import Image
-from tqdm import tqdm
 
 from ocrmypdf.exceptions import MissingDependencyError, SubprocessOutputError
 from ocrmypdf.helpers import Resolution
@@ -144,21 +143,26 @@ class GhostscriptFollower:
     re_process = re.compile(r"Processing pages \d+ through (\d+).")
     re_page = re.compile(r"Page (\d+)")
 
-    def __init__(self):
+    def __init__(self, progressbar_class):
         self.count = 0
-        self.tqdm = None
+        self.progressbar_class = progressbar_class
+        self.progressbar = None
 
     def __call__(self, line):
-        if not self.tqdm:
+        if not self.progressbar_class:
+            return
+        if not self.progressbar:
             m = self.re_process.match(line.strip())
             if m:
                 self.count = int(m.group(1))
-                self.tqdm = tqdm(total=self.count, desc="Ghostscript", unit='page')
+                self.progressbar = self.progressbar_class(
+                    total=self.count, desc="PDF/A conversion", unit='page'
+                )
                 return
         else:
             m = self.re_page.match(line.strip())
             if m:
-                self.tqdm.update()
+                self.progressbar.update()
 
 
 def generate_pdfa(
@@ -167,6 +171,7 @@ def generate_pdfa(
     compression: str,
     pdf_version: str = '1.5',
     pdfa_part: str = '2',
+    progressbar_class=None,
 ):
     # Ghostscript's compression is all or nothing. We can either force all images
     # to JPEG, force all to Flate/PNG, or let it decide how to encode the images.
@@ -240,7 +245,7 @@ def generate_pdfa(
                 text=True,
                 encoding='utf-8',
                 errors='replace',
-                callback=GhostscriptFollower(),
+                callback=GhostscriptFollower(progressbar_class),
             )
     except CalledProcessError as e:
         # Ghostscript does not change return code when it fails to create

src/ocrmypdf/_pipeline.py

@@ -19,6 +19,7 @@ import img2pdf
 import pikepdf
 from pikepdf.models.metadata import encode_pdf_date
 from PIL import Image, ImageColor, ImageDraw
+from tqdm import tqdm
 
 from ocrmypdf import leptonica
 from ocrmypdf._exec import unpaper
@@ -709,6 +710,7 @@ def convert_to_pdfa(input_pdf: Path, input_ps_stub: Path, context: PdfContext):
         output_file=output_file,
         compression=options.pdfa_image_compression,
         pdfa_part=options.output_type[-1],  # is pdfa-1, pdfa-2, or pdfa-3
+        progressbar_class=tqdm if options.progress_bar else None,
     )
 
     return output_file

src/ocrmypdf/builtin_plugins/ghostscript.py

@@ -79,12 +79,21 @@ def rasterize_pdf_page(
 
 
 @hookimpl
-def generate_pdfa(pdf_pages, pdfmark, output_file, compression, pdf_version, pdfa_part):
+def generate_pdfa(
+    pdf_pages,
+    pdfmark,
+    output_file,
+    compression,
+    pdf_version,
+    pdfa_part,
+    progressbar_class,
+):
     ghostscript.generate_pdfa(
         pdf_pages=[*pdf_pages, pdfmark],
         output_file=output_file,
         compression=compression,
         pdf_version=pdf_version,
         pdfa_part=pdfa_part,
+        progressbar_class=progressbar_class,
     )
     return output_file

src/ocrmypdf/pluginspec.py

@@ -59,7 +59,7 @@ def check_options(options: Namespace) -> None:
     Note:
         This hook will be called from the main process, and may modify global state
         before child worker processes are forked.
-	"""
+    """
 
 
 @hookspec
@@ -280,6 +280,7 @@ def generate_pdfa(
     compression: str,
     pdf_version: str,
     pdfa_part: str,
+    progressbar_class,
 ) -> Path:
     """Generate a PDF/A.
 
@@ -302,10 +303,21 @@ def generate_pdfa(
             At its own discretion, the PDF/A generator may raise the version,
             but should not lower it.
         pdfa_part: The desired PDF/A compliance level, such as ``'2B'``.
+        progressbar_class: The class of a progress bar with a tqdm-like API. An
+            instance of this class will be initialized when PDF/A conversion
+            begins, using
+            ``instance = progressbar_class(total: int, desc: str, unit:str)``,
+            defining the number of work units, a user-visible description,
+            and the name of the work units ("page"). Then ``instance.update()``
+            will be called when a work unit is completed. If ``None``, no
+            progress information is reported.
 
     Returns:
         Path: If successful, the hook should return ``output_file``.
 
     Note:
         This is a :ref:`firstresult hook<firstresult>`.
+
+    See also:
+        https://github.com/tqdm/tqdm
     """

tests/plugins/gs_feature_elision.py

@@ -45,5 +45,6 @@ def generate_pdfa(pdf_pages, pdfmark, output_file, compression, pdf_version, pdf
             compression=compression,
             pdf_version=pdf_version,
             pdfa_part=pdfa_part,
+            progressbar_class=None,
         )
         return output_file

tests/plugins/gs_pdfa_failure.py

@@ -47,5 +47,6 @@ def generate_pdfa(pdf_pages, pdfmark, output_file, compression, pdf_version, pdf
             compression=compression,
             pdf_version=pdf_version,
             pdfa_part=pdfa_part,
+            progressbar_class=None,
         )
         return output_file

tests/plugins/gs_render_failure.py

@@ -42,5 +42,6 @@ def generate_pdfa(pdf_pages, pdfmark, output_file, compression, pdf_version, pdf
             compression=compression,
             pdf_version=pdf_version,
             pdfa_part=pdfa_part,
+            progressbar_class=None,
         )
         return output_file