Add object description options mechanism

This replaces manny config options with a more general "object
description options" mechanism that allows various options to be
configured on a per domain/object type basis.

This commit also adds a number of features built on top of that mechanism:

- Generating object description synopses for the std domain, including
  custom object types added using `app.add_object_type`.

- Excluding certain object types from the TOC

- Excluding the object type from the cross-reference tooltip.

Fixes #70.

Co-authored-by: Brendan <2bndy5@gmail.com>

docs/api.rst

@@ -1,23 +1,186 @@
 General API customization
 =========================
 
-.. confval:: include_object_description_fields_in_toc
+This theme supports a number of options that can be customized for each
+domain/object type pair.
 
-   :python:`bool` indicating whether to include domain object description
-   fields, like "Parameters", "Returns", "Raises", etc. in the table of
-   contents.  Defaults to :python:`True`.
+.. confval:: object_description_options
+
+   :python:`list` of :python:`(pattern, options)` pairs, where :python:`pattern`
+   is a regular expression matching strings of the form
+   :python:`"domain:objtype"` and :python:`options` is a dictionary of supported
+   `object-description-options`.
+
+   We need something `object_description_options`.
+
+   The actual options for a given object type are determined by first
+   initializing each option to its default value, and then applying as overrides
+   the options associated with each matching pattern in order.
+
+.. _object-description-options:
+
+Object description options
+--------------------------
+
+The following options can be customized for each object type using
+:confval:`object_description_options`.
+
+.. objconf:: include_in_toc
+
+   Indicates whether to include the object description in the table of contents.
+
+   .. admonition:: Example
+      :class: example
+
+      To prevent C++ parameter descriptions from appearing in the TOC, add the
+      following to :file:`conf.py`:
+
+      .. code-block:: python
+
+         object_description_options = [
+             ("cpp:.*Param": dict(include_in_toc=False)),
+         ]
+
+.. objconf:: generate_synopses
+
+   Indicates whether to generate a *synopsis* from the object description.  The
+   synopsis is shown as a tooltip when hovering over a cross-reference link, and
+   is also shown in the search results list.  Supported values are:
+
+   :python:`None`
+     Disables synopsis generation.
+
+   :python:`"first_paragraph"`
+     Uses the first paragraph of the description as the synopsis.
+
+   :python:`"first_sentence"`
+     Uses the first sentence of the first paragraph of the description as the synopsis.
+
+   The default is :python:`"first_paragraph"` except for :regexp:`c(pp)?:.*Param`
+   where the default is :python:`"first_sentence"`.
+
+   .. note::
+
+      Synopsis generation is currently supported only for the following domains:
+
+      - ``std`` (including object types added using :py:obj:`sphinx.application.Sphinx.add_object_type`)
+      - ``c`` and ``cpp``
+
+   .. admonition:: Example
+      :class: example
+
+      To use the first sentence rather than the first paragraph as the synopsis
+      for C++ class descriptions, add the following to :file:`conf.py`:
+
+      .. code-block:: python
+
+         object_description_options = [
+             ("cpp:class", dict(generate_synopses="first_sentence")),
+         ]
+
+.. objconf:: include_object_type_in_xref_tooltip
+
+   Indicates whether to include the object type in cross-reference and TOC
+   tooltips.
+
+   .. note::
+
+      For TOC entries, this is supported for all domains.  For regular cross
+      references, this is supported only for the following domains:
+
+      - ``std`` (including object types added using :py:obj:`sphinx.application.Sphinx.add_object_type`)
+      - ``c`` and ``cpp``
+
+   .. admonition:: Example
+      :class: example
+
+      To exclude the object type from all ``py`` domain xrefs, add the following
+      to :file:`conf.py`:
+
+      .. code-block:: python
+
+         object_description_options = [
+             ("py:.*", dict(include_object_type_in_xref_tooltip=False)),
+         ]
+
+.. objconf:: include_fields_in_toc
+
+   Indicates whether to include fields, like "Parameters", "Returns", "Raises",
+   etc. in the table of contents.
 
    For an example, see: :cpp:expr:`synopses_ex::Foo` and note the ``Template
    Parameters``, ``Parameters``, and ``Returns`` headings shown in the
    right-side table of contents.
 
    .. note::
 
-      This option does not control whether there are separate TOC entries for
-      individual parameters, such as for :cpp:expr:`synopses_ex::Foo::T`,
+      To control whether there are separate TOC entries for individual
+      parameters, such as for :cpp:expr:`synopses_ex::Foo::T`,
       :cpp:expr:`synopses_ex::Foo::N`, :cpp:expr:`synopses_ex::Foo::param`, and
-      :cpp:expr:`synopses_ex::Foo::arr`.  Currently, for the C and C++ domains,
-      any parameter documented by a :rst:``:param x:`` field will always result
-      in a TOC entry, regardless of the value of
-      :confval:`include_object_description_fields_in_toc`.  Other domains are
-      not yet supported.
+      :cpp:expr:`synopses_ex::Foo::arr`, use the :objconf:`include_in_toc`
+      option.
+
+
+   .. admonition:: Example
+      :class: example
+
+      To exclude object description fields from the table of contents for all
+      ``py`` domain objects, add the following to :file:`conf.py`:
+
+      .. code-block:: python
+
+         object_description_options = [
+             ("py:.*", dict(include_fields_in_toc=False)),
+         ]
+
+Other options described elsewhere include:
+
+- :objconf:`wrap_signatures_with_css`
+- :objconf:`wrap_signatures_column_limit`
+- :objconf:`clang_format_style`
+
+Table of contents icons
+^^^^^^^^^^^^^^^^^^^^^^^
+
+For object descriptions included in the table of contents (when
+:objconf:`include_in_toc` is :python:`True`), a text-based "icon" can optionally
+be included to indicate the object type.
+
+Default icons are specified for a number of object types, but they can be
+overridden using the following options:
+
+.. objconf:: toc_icon_class
+
+   Indicates the icon class, or :python:`None` to disable the icon.  The class
+   must be one of:
+
+   - :python:`"alias"`
+   - :python:`"procedure"`
+   - :python:`"data"`
+   - :python:`"sub-data"`
+
+.. objconf:: toc_icon_text
+
+   Indicates the text content of the icon, or :python:`None` to disable the
+   icon.  This should normally be a single character, such as :python:`"C"` to
+   indicate a class or :python:`"F"` to indicate a function.
+
+.. admonition:: Example
+   :class: example
+
+   To define a custom object type and specify an icon for it, add the following to
+   :file:`conf.py`:
+
+   .. code-block:: python
+
+      object_description_options = [
+          ("std:confval", dict(toc_icon_class="data", toc_icon_text="C")),
+      ]
+
+      def setup(app):
+          app.add_object_type(
+              "confval",
+              "confval",
+              objname="configuration value",
+              indextemplate="pair: %s; configuration value",
+          )

docs/conf.py

@@ -12,6 +12,17 @@
 
 sys.path.insert(0, os.path.abspath("."))
 
+import docutils
+import sphinx
+import sphinx.domains.python
+import sphinx.environment
+import sphinx.util.logging
+import sphinx.util.typing
+
+from sphinx_immaterial import apidoc_formatting
+
+logger = sphinx.util.logging.getLogger(__name__)
+
 # -- Project information -----------------------------------------------------
 
 project = "Sphinx-Immaterial"
@@ -161,16 +172,15 @@
     "dudir": ("http://docutils.sourceforge.net/docs/ref/rst/directives.html#%s", ""),
 }
 
+object_description_options = []
+
 # BEGIN: sphinx_immaterial.format_signatures extension options
-clang_format_signatures_domain_styles = {
-    "cpp": """{
-    BasedOnStyle: LLVM,
-    ColumnLimit: 68,
-    }""",
-}
+object_description_options.append(
+    ("cpp:.*", dict(clang_format_style={"BasedOnStyle": "LLVM"}))
+)
 # END: sphinx_immaterial.format_signatures extension options
 
-html_wrap_signatures_with_css = ["py"]
+object_description_options.append(("py:.*", dict(wrap_signatures_with_css=True)))
 
 # BEGIN: sphinx_immaterial.external_cpp_references extension options
 external_cpp_references = {
@@ -210,10 +220,63 @@
 """
 
 
+object_description_options.append(
+    (
+        "std:confval",
+        dict(
+            toc_icon_class="data", toc_icon_text="C", generate_synopses="first_sentence"
+        ),
+    )
+)
+
+object_description_options.append(
+    (
+        "std:objconf",
+        dict(
+            toc_icon_class="data", toc_icon_text="O", generate_synopses=None,
+        ),
+    )
+)
+
+
+def _parse_object_description_signature(
+    env: sphinx.environment.BuildEnvironment, signature: str, node: docutils.nodes.Node
+) -> str:
+    registry = apidoc_formatting.get_object_description_option_registry(env.app)
+    registry_option = registry.get(signature)
+    node += sphinx.addnodes.desc_name(signature, signature)
+    if registry_option is None:
+        logger.error("Invalid object description option: %r", signature)
+    else:
+        node += sphinx.addnodes.desc_sig_punctuation(" : ", " : ")
+        annotations = sphinx.domains.python._parse_annotation(
+            sphinx.util.typing.stringify(registry_option.type_constraint), env
+        )
+        node += sphinx.addnodes.desc_type("", "", *annotations)
+        node += sphinx.addnodes.desc_sig_punctuation(" = ", " = ")
+        default_repr = repr(registry_option.default)
+        node += docutils.nodes.literal(
+            default_repr,
+            default_repr,
+            language="python",
+            classes=["python", "code", "highlight"],
+        )
+    return signature
+
+
 def setup(app):
     app.add_object_type(
         "confval",
         "confval",
         objname="configuration value",
         indextemplate="pair: %s; configuration value",
     )
+
+    app.add_object_type(
+        "objconf",
+        "objconf",
+        objname="object description option",
+        indextemplate="pair: %s; object description option",
+        parse_node=_parse_object_description_signature,
+    )
+    return {"parallel_read_safe": True, "parallel_write_safe": True}

docs/cpp.rst

@@ -1,59 +1,6 @@
 C++ domain customization
 ========================
 
-.. confval:: cpp_generate_synopses
-
-   :python:`bool` specifying whether to generate a *synopsis* for C++ domain
-   objects based on the first paragraph of their content (first sentence for
-   parameters).  The synopsis is shown as a tooltip when hovering over a
-   cross-reference link, and is also shown in the search results list.
-
-   Defaults to :python:`True`.
-
-   .. rst-example:: C++ synopses
-
-      .. cpp:type:: synopses_ex::SomeType
-
-         Description will be shown as a tooltip when hovering over
-         cross-references to :cpp:expr:`SomeType` in other signatures as well as
-         in the TOC.
-
-         Additional description not shown in tooltip.  This is the return type
-         for :cpp:expr:`Foo`.
-
-      .. cpp:function:: template <typename T, int N> \
-                        synopses_ex::SomeType synopses_ex::Foo(\
-                          T param, \
-                          const int (&arr)[N]\
-                        );
-
-         Synopsis for this function, shown when hovering over cross references
-         as well as in the TOC.
-
-         :tparam T: Tooltip shown when hovering over cross-references to this
-             template parameter.  Additional description not included in
-             tooltip.
-         :tparam N: Tooltip shown for N.
-         :param param: Tooltip shown for cross-references to this function
-             parameter param.
-         :param arr: Tooltip shown for cross-references to this function
-             parameter arr.  To cross reference another parameter, use the
-             :rst:role:`cpp:expr` role, e.g.: :cpp:expr:`N`.  Parameters can
-             also be referenced via their fake qualified name,
-             e.g. :cpp:expr:`synopses_ex::Foo::N`.
-         :returns: Something or other.
-
-
-   .. rst-example::
-
-      .. cpp:class:: synopses_ex::Class
-
-          .. cpp:function:: Class(uint16_t _cepin, uint16_t _cspin, uint32_t _spi_speed=RF24_SPI_SPEED)
-
-              :param _cepin: The pin attached to Chip Enable on the RF module
-              :param _cspin: The pin attached to Chip Select (often labeled CSN) on the radio module.
-              :param _spi_speed: The SPI speed in Hz ie: 1000000 == 1Mhz
-
 .. confval:: cpp_strip_namespaces_from_signatures
 
    :python:`list[str]` specifying namespaces to strip from signatures.  This