1 files changed, 135 insertions, 0 deletions
diff --git a/sphinx/builders/latex/theming.py b/sphinx/builders/latex/theming.py
new file mode 100644
index 0000000..21b49e8
--- /dev/null
+++ b/sphinx/builders/latex/theming.py
@@ -0,0 +1,135 @@
+"""Theming support for LaTeX builder."""
+
+from __future__ import annotations
+
+import configparser
+from os import path
+from typing import TYPE_CHECKING
+
+from sphinx.errors import ThemeError
+from sphinx.locale import __
+from sphinx.util import logging
+
+if TYPE_CHECKING:
+    from sphinx.application import Sphinx
+    from sphinx.config import Config
+
+logger = logging.getLogger(__name__)
+
+
+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
+        self.docclass = name
+        self.wrapperclass = name
+        self.papersize = 'letterpaper'
+        self.pointsize = '10pt'
+        self.toplevel_sectioning = 'chapter'
+
+    def update(self, config: Config) -> None:
+        """Override theme settings by user's configuration."""
+        for key in self.LATEX_ELEMENTS_KEYS:
+            if config.latex_elements.get(key):
+                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."""
+
+    def __init__(self, name: str, config: Config) -> None:
+        super().__init__(name)
+
+        if name == 'howto':
+            self.docclass = config.latex_docclass.get('howto', 'article')
+        else:
+            self.docclass = config.latex_docclass.get('manual', 'report')
+
+        if name in ('manual', 'howto'):
+            self.wrapperclass = 'sphinx' + name
+        else:
+            self.wrapperclass = name
+
+        # we assume LaTeX class provides \chapter command except in case
+        # of non-Japanese 'howto' case
+        if name == 'howto' and not self.docclass.startswith('j'):
+            self.toplevel_sectioning = 'section'
+        else:
+            self.toplevel_sectioning = 'chapter'
+
+
+class UserTheme(Theme):
+    """A user defined LaTeX theme."""
+
+    REQUIRED_CONFIG_KEYS = ['docclass', 'wrapperclass']
+    OPTIONAL_CONFIG_KEYS = ['papersize', 'pointsize', 'toplevel_sectioning']
+
+    def __init__(self, name: str, filename: str) -> None:
+        super().__init__(name)
+        self.config = configparser.RawConfigParser()
+        self.config.read(path.join(filename), encoding='utf-8')
+
+        for key in self.REQUIRED_CONFIG_KEYS:
+            try:
+                value = self.config.get('theme', key)
+                setattr(self, key, value)
+            except configparser.NoSectionError as exc:
+                raise ThemeError(__('%r doesn\'t have "theme" setting') %
+                                 filename) from exc
+            except configparser.NoOptionError as exc:
+                raise ThemeError(__('%r doesn\'t have "%s" setting') %
+                                 (filename, exc.args[0])) from exc
+
+        for key in self.OPTIONAL_CONFIG_KEYS:
+            try:
+                value = self.config.get('theme', key)
+                setattr(self, key, value)
+            except configparser.NoOptionError:
+                pass
+
+
+class ThemeFactory:
+    """A factory class for LaTeX Themes."""
+
+    def __init__(self, app: Sphinx) -> None:
+        self.themes: dict[str, Theme] = {}
+        self.theme_paths = [path.join(app.srcdir, p) for p in app.config.latex_theme_path]
+        self.config = app.config
+        self.load_builtin_themes(app.config)
+
+    def load_builtin_themes(self, config: Config) -> None:
+        """Load built-in themes."""
+        self.themes['manual'] = BuiltInTheme('manual', config)
+        self.themes['howto'] = BuiltInTheme('howto', config)
+
+    def get(self, name: str) -> Theme:
+        """Get a theme for given *name*."""
+        if name in self.themes:
+            theme = self.themes[name]
+        else:
+            theme = self.find_user_theme(name) or Theme(name)
+
+        theme.update(self.config)
+        return theme
+
+    def find_user_theme(self, name: str) -> Theme | None:
+        """Find a theme named as *name* from latex_theme_path."""
+        for theme_path in self.theme_paths:
+            config_path = path.join(theme_path, name, 'theme.conf')
+            if path.isfile(config_path):
+                try:
+                    return UserTheme(name, config_path)
+                except ThemeError as exc:
+                    logger.warning(exc)
+
+        return None