Support the PyMuPDF-Layout Feature

Author: JorjMcKie

src/__init__.py

@@ -28,7 +28,7 @@
 import zipfile
 
 from . import extra
-
+import importlib.util
 
 # Set up g_out_log and g_out_message from environment variables.
 #
@@ -333,6 +333,37 @@ def __init__(self):
 
 _globals = _Globals()
 
+_get_layout: typing.Optional[typing.Callable] = None
+
+# global switch ensuring that the recommendation message is shown at most once
+_recommend_layout = True  # must be referred to as "global" everywhere
+
+
+def no_recommend_layout():
+    """For users who never want to see the layout recommendation."""
+    global _recommend_layout
+    _recommend_layout = False
+
+
+def _warn_layout_once():
+    """Check if we should recommend installing the layout package."""
+    msg="""Consider using the pymupdf_layout package for a greatly improved page layout analysis."""
+
+    global _recommend_layout
+    if (
+        1
+        and _recommend_layout  # still True?
+        and _get_layout is None  # no layout function stored here
+
+        # client did not globally disable the recommendation
+        and os.getenv("PYMUPDF_SUGGEST_LAYOUT_ANALYZER") != "0"
+
+        # layout is not available in this Python
+        and not importlib.util.find_spec("pymupdf.layout")
+    ):
+        print(msg)
+        _recommend_layout = False  # never show the message again
+
 
 # Optionally use MuPDF via cppyy bindings; experimental and not tested recently
 # as of 2023-01-20 11:51:40
@@ -9952,7 +9983,7 @@ def _get_resource_properties(self):
         return rc
 
     def _get_textpage(self, clip=None, flags=0, matrix=None):
-        if g_use_extra:
+        if 1 or g_use_extra:
             ll_tpage = extra.page_get_textpage(self.this, clip, flags, matrix)
             tpage = mupdf.FzStextPage(ll_tpage)
             return tpage
@@ -10781,6 +10812,20 @@ def clip_to_rect(self, rect):
         pclip = JM_rect_from_py(clip)
         mupdf.pdf_clip_page(pdfpage, pclip)
 
+    def get_layout(self):
+        """Try to access layout information."""
+
+        if self.layout_information is not None:
+            # layout information already present
+            return
+
+        if not _get_layout:
+            # no layout information available
+            return
+
+        layout_info = _get_layout(self)
+        self.layout_information = layout_info
+
     @property
     def artbox(self):
         """The ArtBox"""
@@ -11432,7 +11477,7 @@ def get_cdrawings(self, extended=None, callback=None, method=None):
         assert isinstance(page, mupdf.FzPage), f'{self.this=}'
         clips = True if extended else False
         prect = mupdf.fz_bound_page(page)
-        if g_use_extra:
+        if 1 or g_use_extra:
             rc = extra.get_cdrawings(page, extended, callback, method)
         else:
             rc = list()
@@ -12157,7 +12202,7 @@ def get_texttrace(self):
             self.set_rotation(0)
         page = self.this
         rc = []
-        if g_use_extra:
+        if 1 or g_use_extra:
             dev = extra.JM_new_texttrace_device(rc)
         else:
             dev = JM_new_texttrace_device(rc)
@@ -13206,6 +13251,9 @@ def xref(self):
 
     rect = property(bound, doc="page rectangle")
 
+    # any result of layout analysis is stored here
+    layout_information = None
+
 
 class Pixmap:
 
@@ -16391,7 +16439,7 @@ def _textpage_dict(self, raw=False):
 
     def extractBLOCKS(self):
         """Return a list with text block information."""
-        if g_use_extra:
+        if 1 or g_use_extra:
             return extra.extractBLOCKS(self.this)
         block_n = -1
         this_tpage = self.this
@@ -16587,7 +16635,7 @@ def extractTextbox(self, rect):
 
     def extractWORDS(self, delimiters=None):
         """Return a list with text word information."""
-        if g_use_extra:
+        if 1 or g_use_extra:
             return extra.extractWORDS(self.this, delimiters)
         buflen = 0
         last_char_rtl = 0
@@ -18969,7 +19017,7 @@ def JM_color_FromSequence(color):
 
 
 def JM_color_count( pm, clip):
-    if g_use_extra:
+    if 1 or g_use_extra:
         return extra.ll_JM_color_count(pm.m_internal, clip)
 
     rc = dict()
@@ -20469,7 +20517,7 @@ def JM_make_annot_DA(annot, ncol, col, fontname, fontsize):
 
 
 def JM_make_spanlist(line_dict, line, raw, buff, tp_rect):
-    if g_use_extra:
+    if 1 or g_use_extra:
         return extra.JM_make_spanlist(line_dict, line, raw, buff, tp_rect)
     char_list = None
     span_list = []
@@ -20682,7 +20730,7 @@ def JM_make_image_block(block, block_dict):
 
 
 def JM_make_text_block(block, block_dict, raw, buff, tp_rect):
-    if g_use_extra:
+    if 1 or g_use_extra:
         return extra.JM_make_text_block(block.m_internal, block_dict, raw, buff.m_internal, tp_rect.m_internal)
     line_list = []
     block_rect = mupdf.FzRect(mupdf.FzRect.Fixed_EMPTY)
@@ -20705,7 +20753,7 @@ def JM_make_text_block(block, block_dict, raw, buff, tp_rect):
 
 
 def JM_make_textpage_dict(tp, page_dict, raw):
-    if g_use_extra:
+    if 1 or g_use_extra:
         return extra.JM_make_textpage_dict(tp.m_internal, page_dict, raw)
     text_buffer = mupdf.fz_new_buffer(128)
     block_list = []
@@ -21356,7 +21404,7 @@ def JM_rotate_page_matrix(page):
 
 
 def JM_search_stext_page(page, needle):
-    if g_use_extra:
+    if 1 or g_use_extra:
         return extra.JM_search_stext_page(page.m_internal, needle)
 
     rect = mupdf.FzRect(page.m_internal.mediabox)