Support LaTeX Theming; a set of document class settings (refs: #6672)

CHANGES

@@ -42,6 +42,7 @@ Deprecated
 * ``sphinx.testing.path.Path.text()``
 * ``sphinx.testing.path.Path.bytes()``
 * ``sphinx.util.inspect.getargspec()``
+* ``sphinx.writers.latex.LaTeXWriter.format_docclass()``
 
 Features added
 --------------
@@ -68,6 +69,7 @@ Features added
   ``no-scaled-link`` class
 * #7144: Add CSS class indicating its domain for each desc node
 * #7211: latex: Use babel for Chinese document when using XeLaTeX
+* #6672: LaTeX: Support LaTeX Theming (experimental)
 * #7005: LaTeX: Add LaTeX styling macro for :rst:role:`kbd` role
 * #7220: genindex: Show "main" index entries at first
 * #7103: linkcheck: writes all links to ``output.json``

doc/extdev/deprecated.rst

@@ -61,6 +61,11 @@ The following is a list of deprecated interfaces.
      - 5.0
      - ``inspect.getargspec()``
 
+   * - ``sphinx.writers.latex.LaTeXWriter.format_docclass()``
+     - 3.0
+     - 5.0
+     - LaTeX Themes
+
    * - ``decode`` argument of ``sphinx.pycode.ModuleAnalyzer()``
      - 2.4
      - 4.0

sphinx/builders/latex/__init__.py

@@ -21,6 +21,7 @@ from sphinx import package_dir, addnodes, highlighting
 from sphinx.application import Sphinx
 from sphinx.builders import Builder
 from sphinx.builders.latex.constants import ADDITIONAL_SETTINGS, DEFAULT_SETTINGS
+from sphinx.builders.latex.theming import Theme, ThemeFactory
 from sphinx.builders.latex.util import ExtBabel
 from sphinx.config import Config, ENUM
 from sphinx.deprecation import RemovedInSphinx40Warning
@@ -126,6 +127,7 @@ class LaTeXBuilder(Builder):
         self.context = {}           # type: Dict[str, Any]
         self.docnames = []          # type: Iterable[str]
         self.document_data = []     # type: List[Tuple[str, str, str, str, str, bool]]
+        self.themes = ThemeFactory(self.app)
         self.usepackages = self.app.registry.latex_packages
         texescape.init()
 
@@ -227,7 +229,8 @@ class LaTeXBuilder(Builder):
         self.write_stylesheet()
 
         for entry in self.document_data:
-            docname, targetname, title, author, docclass = entry[:5]
+            docname, targetname, title, author, themename = entry[:5]
+            theme = self.themes.get(themename)
             toctree_only = False
             if len(entry) > 5:
                 toctree_only = entry[5]
@@ -243,21 +246,22 @@ class LaTeXBuilder(Builder):
 
                 doctree = self.assemble_doctree(
                     docname, toctree_only,
-                    appendices=(self.config.latex_appendices if docclass != 'howto' else []))
-                doctree['docclass'] = docclass
+                    appendices=(self.config.latex_appendices if theme.name != 'howto' else []))
+                doctree['docclass'] = theme.docclass
                 doctree['contentsname'] = self.get_contentsname(docname)
                 doctree['tocdepth'] = tocdepth
                 self.post_process_images(doctree)
-                self.update_doc_context(title, author)
+                self.update_doc_context(title, author, theme)
 
             with progress_message(__("writing")):
                 docsettings._author = author
                 docsettings._title = title
                 docsettings._contentsname = doctree['contentsname']
                 docsettings._docname = docname
-                docsettings._docclass = docclass
+                docsettings._docclass = theme.name
 
                 doctree.settings = docsettings
+                docwriter.theme = theme
                 docwriter.write(doctree, destination)
 
     def get_contentsname(self, indexfile: str) -> str:
@@ -270,9 +274,11 @@ class LaTeXBuilder(Builder):
 
         return contentsname
 
-    def update_doc_context(self, title: str, author: str) -> None:
+    def update_doc_context(self, title: str, author: str, theme: Theme) -> None:
         self.context['title'] = title
         self.context['author'] = author
+        self.context['docclass'] = theme.docclass
+        self.context['wrapperclass'] = theme.wrapperclass
 
     def assemble_doctree(self, indexfile: str, toctree_only: bool, appendices: List[str]) -> nodes.document:  # NOQA
         self.docnames = set([indexfile] + appendices)

sphinx/builders/latex/theming.py

@@ -0,0 +1,76 @@
+"""
+    sphinx.builders.latex.theming
+    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+    Theming support for LaTeX builder.
+
+    :copyright: Copyright 2007-2020 by the Sphinx team, see AUTHORS.
+    :license: BSD, see LICENSE for details.
+"""
+
+from typing import Dict
+
+from sphinx.application import Sphinx
+from sphinx.config import Config
+
+
+class Theme:
+    """A set of LaTeX configurations."""
+
+    def __init__(self, name: str) -> None:
+        self.name = name
+        self.docclass = name
+        self.wrapperclass = name
+        self.toplevel_sectioning = 'chapter'
+
+
+class BuiltInTheme(Theme):
+    """A built-in LaTeX theme."""
+
+    def __init__(self, name: str, config: Config) -> None:
+        # Note: Don't call supermethod here.
+        self.name = name
+        self.latex_docclass = config.latex_docclass  # type: Dict[str, str]
+
+    @property
+    def docclass(self) -> str:  # type: ignore
+        if self.name == 'howto':
+            return self.latex_docclass.get('howto', 'article')
+        else:
+            return self.latex_docclass.get('manual', 'report')
+
+    @property
+    def wrapperclass(self) -> str:  # type: ignore
+        if self.name in ('manual', 'howto'):
+            return 'sphinx' + self.name
+        else:
+            return self.name
+
+    @property
+    def toplevel_sectioning(self) -> str:  # type: ignore
+        # we assume LaTeX class provides \chapter command except in case
+        # of non-Japanese 'howto' case
+        if self.name == 'howto' and not self.docclass.startswith('j'):
+            return 'section'
+        else:
+            return 'chapter'
+
+
+class ThemeFactory:
+    """A factory class for LaTeX Themes."""
+
+    def __init__(self, app: Sphinx) -> None:
+        self.themes = {}  # type: Dict[str, Theme]
+        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 not in self.themes:
+            return Theme(name)
+        else:
+            return self.themes[name]

sphinx/writers/latex.py

@@ -23,7 +23,9 @@ from docutils.nodes import Element, Node, Text
 
 from sphinx import addnodes
 from sphinx import highlighting
-from sphinx.deprecation import RemovedInSphinx40Warning, deprecated_alias
+from sphinx.deprecation import (
+    RemovedInSphinx40Warning, RemovedInSphinx50Warning, deprecated_alias
+)
 from sphinx.domains import IndexEntry
 from sphinx.domains.std import StandardDomain
 from sphinx.errors import SphinxError
@@ -43,6 +45,7 @@ except ImportError:
 if False:
     # For type annotation
     from sphinx.builders.latex import LaTeXBuilder
+    from sphinx.builders.latex.theming import Theme
 
 
 logger = logging.getLogger(__name__)
@@ -93,9 +96,16 @@ class LaTeXWriter(writers.Writer):
     def __init__(self, builder: "LaTeXBuilder") -> None:
         super().__init__()
         self.builder = builder
+        self.theme = None  # type: Theme
 
     def translate(self) -> None:
-        visitor = self.builder.create_translator(self.document, self.builder)
+        try:
+            visitor = self.builder.create_translator(self.document, self.builder, self.theme)
+        except TypeError:
+            warnings.warn('LaTeXTranslator now takes 3rd argument; "theme".',
+                          RemovedInSphinx50Warning)
+            visitor = self.builder.create_translator(self.document, self.builder)
+
         self.document.walkabout(visitor)
         self.output = cast(LaTeXTranslator, visitor).astext()
 
@@ -281,9 +291,15 @@ class LaTeXTranslator(SphinxTranslator):
     # sphinx specific document classes
     docclasses = ('howto', 'manual')
 
-    def __init__(self, document: nodes.document, builder: "LaTeXBuilder") -> None:
+    def __init__(self, document: nodes.document, builder: "LaTeXBuilder",
+                 theme: "Theme" = None) -> None:
         super().__init__(document, builder)
         self.body = []  # type: List[str]
+        self.theme = theme
+
+        if theme is None:
+            warnings.warn('LaTeXTranslator now takes 3rd argument; "theme".',
+                          RemovedInSphinx50Warning)
 
         # flags
         self.in_title = 0
@@ -306,21 +322,32 @@ class LaTeXTranslator(SphinxTranslator):
         # sort out some elements
         self.elements = self.builder.context.copy()
 
-        # but some have other interface in config file
-        self.elements['wrapperclass'] = self.format_docclass(document.get('docclass'))
-
-        # we assume LaTeX class provides \chapter command except in case
-        # of non-Japanese 'howto' case
+        # initial section names
         self.sectionnames = LATEXSECTIONNAMES[:]
-        if document.get('docclass') == 'howto':
-            docclass = self.config.latex_docclass.get('howto', 'article')
-            if docclass[0] == 'j':  # Japanese class...
-                pass
-            else:
+
+        if self.theme:
+            # new style: control sectioning via theme's setting
+            #
+            # .. note:: template variables(elements) are already assigned in builder
+            docclass = self.theme.docclass
+            if self.theme.toplevel_sectioning == 'section':
                 self.sectionnames.remove('chapter')
         else:
-            docclass = self.config.latex_docclass.get('manual', 'report')
-        self.elements['docclass'] = docclass
+            # old style: sectioning control is hard-coded
+            # but some have other interface in config file
+            self.elements['wrapperclass'] = self.format_docclass(self.settings.docclass)
+
+            # we assume LaTeX class provides \chapter command except in case
+            # of non-Japanese 'howto' case
+            if document.get('docclass') == 'howto':
+                docclass = self.config.latex_docclass.get('howto', 'article')
+                if docclass[0] == 'j':  # Japanese class...
+                    pass
+                else:
+                    self.sectionnames.remove('chapter')
+            else:
+                docclass = self.config.latex_docclass.get('manual', 'report')
+            self.elements['docclass'] = docclass
 
         # determine top section level
         self.top_sectionlevel = 1
@@ -472,6 +499,8 @@ class LaTeXTranslator(SphinxTranslator):
     def format_docclass(self, docclass: str) -> str:
         """ prepends prefix to sphinx document classes
         """
+        warnings.warn('LaTeXWriter.format_docclass() is deprecated.',
+                      RemovedInSphinx50Warning, stacklevel=2)
         if docclass in self.docclasses:
             docclass = 'sphinx' + docclass
         return docclass