LaTeX: Add :confval:latex_theme_options to override theme options

CHANGES

@@ -20,6 +20,7 @@ Features added
 
 * LaTeX: Make the ``toplevel_sectioning`` setting optional in LaTeX theme
 * LaTeX: Allow to override papersize and pointsize from LaTeX themes
+* LaTeX: Add :confval:`latex_theme_options` to override theme options
 * #7410: Allow to suppress "circular toctree references detected" warnings using
   :confval:`suppress_warnings`
 * C, added scope control directives, :rst:dir:`c:namespace`,

doc/usage/configuration.rst

@@ -2119,6 +2119,13 @@ These options influence LaTeX output.
 
    .. versionadded:: 3.0
 
+.. confval:: latex_theme_options
+
+   A dictionary of options that influence the look and feel of the selected
+   theme.
+
+   .. versionadded:: 3.1
+
 .. confval:: latex_theme_path
 
    A list of paths that contain custom LaTeX themes as subdirectories.  Relative

sphinx/builders/latex/__init__.py

@@ -493,6 +493,14 @@ def validate_config_values(app: Sphinx, config: Config) -> None:
             config.latex_elements.pop(key)
 
 
+def validate_latex_theme_options(app: Sphinx, config: Config) -> None:
+    for key in list(config.latex_theme_options):
+        if key not in Theme.UPDATABLE_KEYS:
+            msg = __("Unknown theme option: latex_theme_options[%r], ignored.")
+            logger.warning(msg % (key,))
+            config.latex_theme_options.pop(key)
+
+
 def default_latex_engine(config: Config) -> str:
     """ Better default latex_engine settings for specific languages. """
     if config.language == 'ja':
@@ -539,6 +547,7 @@ def setup(app: Sphinx) -> Dict[str, Any]:
 
     app.add_builder(LaTeXBuilder)
     app.connect('config-inited', validate_config_values, priority=800)
+    app.connect('config-inited', validate_latex_theme_options, priority=800)
 
     app.add_config_value('latex_engine', default_latex_engine, None,
                          ENUM('pdflatex', 'xelatex', 'lualatex', 'platex', 'uplatex'))
@@ -555,6 +564,7 @@ def setup(app: Sphinx) -> Dict[str, Any]:
     app.add_config_value('latex_elements', {}, None)
     app.add_config_value('latex_additional_files', [], None)
     app.add_config_value('latex_theme', 'manual', None, [str])
+    app.add_config_value('latex_theme_options', {}, None)
     app.add_config_value('latex_theme_path', [], None, [list])
 
     app.add_config_value('latex_docclass', default_latex_docclass, None)

sphinx/builders/latex/theming.py

@@ -25,6 +25,7 @@ class Theme:
     """A set of LaTeX configurations."""
 
     LATEX_ELEMENTS_KEYS = ['papersize', 'pointsize']
+    UPDATABLE_KEYS = ['papersize', 'pointsize']
 
     def __init__(self, name: str) -> None:
         self.name = name
@@ -41,6 +42,11 @@ class Theme:
                 value = config.latex_elements[key]
                 setattr(self, key, value)
 
+        for key in self.UPDATABLE_KEYS:
+            if key in config.latex_theme_options:
+                value = config.latex_theme_options[key]
+                setattr(self, key, value)
+
 
 class BuiltInTheme(Theme):
     """A built-in LaTeX theme."""

tests/test_build_latex.py

@@ -235,6 +235,17 @@ def test_latex_theme_papersize(app, status, warning):
     assert r'\documentclass[b5paper,9pt,english]{sphinxbook}' in result
 
 
+@pytest.mark.sphinx('latex', testroot='latex-theme',
+                    confoverrides={'latex_theme_options': {'papersize': 'b5paper',
+                                                           'pointsize': '9pt'}})
+def test_latex_theme_options(app, status, warning):
+    app.builder.build_all()
+    result = (app.outdir / 'python.tex').read_text(encoding='utf8')
+    print(result)
+    assert r'\def\sphinxdocclass{book}' in result
+    assert r'\documentclass[b5paper,9pt,english]{sphinxbook}' in result
+
+
 @pytest.mark.sphinx('latex', testroot='basic', confoverrides={'language': 'zh'})
 def test_latex_additional_settings_for_language_code(app, status, warning):
     app.builder.build_all()