Inline utility methods

docs/devel/changelog_staging.md

@@ -7,3 +7,4 @@
 - Disruption: Two components of `PdfDocument` have been removed to clean up the code (without a major release, due to their insignificance):
   - Removal of `update_rendering_input()`. Callers are expected to save and re-open the document on their if they wish that changes take effect with the multi-page renderer.
   - The multipage renderer does not implicitly read byte buffers into memory anymore. Callers are expected to take an explicit decision by providing a different input in the first place.
+- Docs: The changelog page now selectively includes an entry for the next release that may be shown on `latest` builds.

src/pypdfium2/_helpers/document.py

@@ -35,44 +35,6 @@
 logger = logging.getLogger(__name__)
 
 
-def _open_pdf(input_data, password=None):
-
-    if isinstance(password, str):
-        password = password.encode("utf-8")
-
-    ld_data = None
-    if isinstance(input_data, str):
-        pdf = pdfium.FPDF_LoadDocument(input_data.encode("utf-8"), password)
-    elif isinstance(input_data, bytes):
-        pdf = pdfium.FPDF_LoadMemDocument64(input_data, len(input_data), password)
-        ld_data = DataHolder(input_data)
-    elif is_input_buffer(input_data):
-        fileaccess, ld_data = get_fileaccess(input_data)
-        pdf = pdfium.FPDF_LoadCustomDocument(fileaccess, password)
-    else:
-        raise TypeError("Invalid input type '%s'" % type(input_data).__name__)
-
-    if pdfium.FPDF_GetPageCount(pdf) < 1:
-        err_code = pdfium.FPDF_GetLastError()
-        pdfium_msg = ErrorToStr.get(err_code, "Error code %s" % err_code)
-        raise PdfiumError("Loading the document failed (PDFium: %s)" % pdfium_msg)
-
-    return pdf, ld_data
-
-
-class _writer_class:
-
-    def __init__(self, buffer):
-        self.buffer = buffer
-        if not callable( getattr(self.buffer, "write", None) ):
-            raise ValueError("Output buffer must implement the write() method.")
-
-    def __call__(self, _, data, size):
-        block = ctypes.cast(data, ctypes.POINTER(ctypes.c_ubyte * size))
-        self.buffer.write(block.contents)
-        return 1
-
-
 class PdfDocument (BitmapConvAliases):
     """
     Document helper class.
@@ -608,6 +570,44 @@ def render_to(
         assert len(page_indices) == i
 
 
+def _open_pdf(input_data, password=None):
+
+    if isinstance(password, str):
+        password = password.encode("utf-8")
+
+    ld_data = None
+    if isinstance(input_data, str):
+        pdf = pdfium.FPDF_LoadDocument(input_data.encode("utf-8"), password)
+    elif isinstance(input_data, bytes):
+        pdf = pdfium.FPDF_LoadMemDocument64(input_data, len(input_data), password)
+        ld_data = DataHolder(input_data)
+    elif is_input_buffer(input_data):
+        fileaccess, ld_data = get_fileaccess(input_data)
+        pdf = pdfium.FPDF_LoadCustomDocument(fileaccess, password)
+    else:
+        raise TypeError("Invalid input type '%s'" % type(input_data).__name__)
+
+    if pdfium.FPDF_GetPageCount(pdf) < 1:
+        err_code = pdfium.FPDF_GetLastError()
+        pdfium_msg = ErrorToStr.get(err_code, "Error code %s" % err_code)
+        raise PdfiumError("Loading the document failed (PDFium: %s)" % pdfium_msg)
+
+    return pdf, ld_data
+
+
+class _writer_class:
+
+    def __init__(self, buffer):
+        self.buffer = buffer
+        if not callable( getattr(self.buffer, "write", None) ):
+            raise ValueError("Output buffer must implement the write() method.")
+
+    def __call__(self, _, data, size):
+        block = ctypes.cast(data, ctypes.POINTER(ctypes.c_ubyte * size))
+        self.buffer.write(block.contents)
+        return 1
+
+
 class PdfXObject:
     """
     XObject helper class.

src/pypdfium2/_helpers/page.py

@@ -8,10 +8,6 @@
 import logging
 from ctypes import c_float
 import pypdfium2._pypdfium as pdfium
-from pypdfium2._helpers._utils import (
-    validate_colours,
-    auto_bitmap_format,
-)
 from pypdfium2._helpers.misc import (
     OptimiseMode,
     PdfiumError,
@@ -488,10 +484,12 @@ def render_base(
             Image size is given in pixels as a tuple of width and height.
         """
 
-        validate_colours(fill_colour, colour_scheme)
+        _validate_colours(fill_colour)
+        if colour_scheme is not None:
+            _validate_colours(*colour_scheme.colours.values())
 
         if force_bitmap_format in (None, pdfium.FPDFBitmap_Unknown):
-            cl_pdfium = auto_bitmap_format(fill_colour, greyscale, prefer_bgrx)
+            cl_pdfium = _auto_bitmap_format(fill_colour, greyscale, prefer_bgrx)
         else:
             cl_pdfium = force_bitmap_format
 
@@ -589,6 +587,26 @@ def render_base(
         return buffer, cl_string, (width, height)
 
 
+def _validate_colours(*colours):
+    for col in colours:
+        if len(col) != 4:
+            raise ValueError("Colour must consist of exactly 4 values.")
+        if not all(0 <= c <= 255 for c in col):
+            raise ValueError("Colour value exceeds boundaries.")
+
+
+def _auto_bitmap_format(fill_colour, greyscale, prefer_bgrx):
+    # no need to take alpha values of colour_scheme into account (drawings are additive)
+    if (fill_colour[3] < 255):
+        return pdfium.FPDFBitmap_BGRA
+    elif greyscale:
+        return pdfium.FPDFBitmap_Gray
+    elif prefer_bgrx:
+        return pdfium.FPDFBitmap_BGRx
+    else:
+        return pdfium.FPDFBitmap_BGR
+
+
 class ColourScheme:
     """
     Rendering colour scheme.