Improve documentation.

CHANGELOG.md

@@ -46,6 +46,9 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 - Rich markup in markdown headings is now escaped when building the TOC https://github.com/Textualize/textual/issues/3689
 - Mechanics behind mouse clicks. See [this](https://github.com/Textualize/textual/pull/3495#issue-1934915047) for more details. https://github.com/Textualize/textual/pull/3495
 - Breaking change: max/min-width/height now includes padding and border. https://github.com/Textualize/textual/pull/3712
+- Method `MarkdownTableOfContents.set_table_of_contents` renamed to `MarkdownTableOfContents.rebuild_table_of_contents` https://github.com/Textualize/textual/pull/3730
+- Exception `Tree.UnknownNodeID` moved out of `Tree`, import from `textual.widgets.tree` https://github.com/Textualize/textual/pull/3730
+- Exception `TreeNode.RemoveRootError` moved out of `TreeNode`, import from `textual.widgets.tree` https://github.com/Textualize/textual/pull/3730
 
 
 ## [0.41.0] - 2023-10-31

docs/api/await_complete.md

@@ -0,0 +1 @@
+::: textual.await_complete

docs/widgets/markdown_viewer.md

@@ -57,3 +57,9 @@ This widget has no component classes.
 ::: textual.widgets.MarkdownViewer
     options:
       heading_level: 2
+
+
+::: textual.widgets.markdown
+    options:
+      show_root_heading: true
+      show_root_toc_entry: true

docs/widgets/tree.md

@@ -69,6 +69,6 @@ The tree widget provides the following component classes:
 
 ---
 
-::: textual.widgets.tree.TreeNode
+::: textual.widgets.tree
     options:
       heading_level: 2

mkdocs-nav.yml

@@ -169,6 +169,7 @@ nav:
   - API:
       - "api/index.md"
       - "api/app.md"
+      - "api/await_complete.md"
       - "api/await_remove.md"
       - "api/binding.md"
       - "api/color.md"

src/textual/_text_area_theme.py

@@ -110,7 +110,7 @@ class TextAreaTheme:
             )
 
     @classmethod
-    def get_builtin_theme(cls, theme_name: str) -> "TextAreaTheme" | None:
+    def get_builtin_theme(cls, theme_name: str) -> TextAreaTheme | None:
         """Get a `TextAreaTheme` by name.
 
         Given a `theme_name`, return the corresponding `TextAreaTheme` object.
@@ -120,7 +120,7 @@ class TextAreaTheme:
 
         Returns:
             The `TextAreaTheme` corresponding to the name or `None` if the theme isn't
-            found.
+                found.
         """
         return _BUILTIN_THEMES.get(theme_name)
 

src/textual/await_remove.py

@@ -1,5 +1,4 @@
 """
-
 An *optionally* awaitable object returned by methods that remove widgets.
 """
 

src/textual/document/_document.py

@@ -133,10 +133,10 @@ class DocumentBase(ABC):
 
     def query_syntax_tree(
         self,
-        query: "Query",
+        query: Query,
         start_point: tuple[int, int] | None = None,
         end_point: tuple[int, int] | None = None,
-    ) -> list[tuple["Node", str]]:
+    ) -> list[tuple[Node, str]]:
         """Query the tree-sitter syntax tree.
 
         The default implementation always returns an empty list.
@@ -153,7 +153,7 @@ class DocumentBase(ABC):
         """
         return []
 
-    def prepare_query(self, query: str) -> "Query" | None:
+    def prepare_query(self, query: str) -> Query | None:
         return None
 
     @property

src/textual/types.py

@@ -14,8 +14,15 @@ from ._types import (
 )
 from .actions import ActionParseResult
 from .css.styles import RenderStyles
-from .widgets._data_table import CursorType
+from .widgets._directory_tree import DirEntry
 from .widgets._input import InputValidationOn
+from .widgets._option_list import (
+    DuplicateID,
+    NewOptionListContent,
+    OptionDoesNotExist,
+    OptionListContent,
+)
+from .widgets._placeholder import PlaceholderVariant
 from .widgets._select import NoSelection, SelectType
 
 __all__ = [
@@ -24,13 +31,18 @@ __all__ = [
     "CallbackType",
     "CSSPathError",
     "CSSPathType",
-    "CursorType",
+    "DirEntry",
+    "DuplicateID",
     "EasingFunction",
     "IgnoreReturnCallbackType",
     "InputValidationOn",
     "MessageTarget",
+    "NewOptionListContent",
     "NoActiveAppError",
     "NoSelection",
+    "OptionDoesNotExist",
+    "OptionListContent",
+    "PlaceholderVariant",
     "RenderStyles",
     "SelectType",
     "UnusedParameter",

src/textual/widgets/_data_table.py

@@ -40,6 +40,7 @@ RowCacheKey: TypeAlias = "tuple[RowKey, int, Style, Coordinate, Coordinate, Curs
 CursorType = Literal["cell", "row", "column", "none"]
 """The valid types of cursors for [`DataTable.cursor_type`][textual.widgets.DataTable.cursor_type]."""
 CellType = TypeVar("CellType")
+"""Type used for cells in the DataTable."""
 
 _DEFAULT_CELL_X_PADDING = 1
 """Default padding to use on each side of a column in the data table."""

src/textual/widgets/_directory_tree.py

@@ -22,7 +22,7 @@ from ._tree import TOGGLE_STYLE, Tree, TreeNode
 
 @dataclass
 class DirEntry:
-    """Attaches directory information to a node."""
+    """Attaches directory information to a [DirectoryTree][textual.widgets.DirectoryTree] node."""
 
     path: Path
     """The path of the directory entry."""

src/textual/widgets/_loading_indicator.py

@@ -71,7 +71,7 @@ class LoadingIndicator(Widget):
             widget: A widget.
 
         Returns:
-            AwaitMount: An awaitable for mounting the indicator.
+            An awaitable for mounting the indicator.
         """
         self.add_class("-overlay")
         await_mount = widget.mount(self)

src/textual/widgets/_markdown.py

@@ -1,7 +1,7 @@
 from __future__ import annotations
 
 from pathlib import Path, PurePath
-from typing import Callable, Iterable
+from typing import Callable, Iterable, Optional
 
 from markdown_it import MarkdownIt
 from markdown_it.token import Token
@@ -22,6 +22,10 @@ from ..widget import AwaitMount, Widget
 from ..widgets import Static, Tree
 
 TableOfContentsType: TypeAlias = "list[tuple[int, str, str | None]]"
+"""Information about the table of contents of a markdown document.
+
+The triples encode the level, the label, and the optional block id of each heading.
+"""
 
 
 class Navigator:
@@ -709,7 +713,7 @@ class Markdown(Widget):
         """Process an unhandled token.
 
         Args:
-            token: The token to handle.
+            token: The MarkdownIt token to handle.
 
         Returns:
             Either a widget to be added to the output, or `None`.
@@ -872,6 +876,8 @@ class Markdown(Widget):
 
 
 class MarkdownTableOfContents(Widget, can_focus_children=True):
+    """Displays a table of contents for a markdown document."""
+
     DEFAULT_CSS = """
     MarkdownTableOfContents {
         width: auto;
@@ -884,7 +890,8 @@ class MarkdownTableOfContents(Widget, can_focus_children=True):
     }
     """
 
-    table_of_contents = reactive["TableOfContentsType | None"](None, init=False)
+    table_of_contents = reactive[Optional[TableOfContentsType]](None, init=False)
+    """Underlying data to populate the table of contents widget."""
 
     def __init__(
         self,
@@ -903,7 +910,7 @@ class MarkdownTableOfContents(Widget, can_focus_children=True):
             classes: The CSS classes for the widget.
             disabled: Whether the widget is disabled or not.
         """
-        self.markdown = markdown
+        self.markdown: Markdown = markdown
         """The Markdown document associated with this table of contents."""
         super().__init__(name=name, id=id, classes=classes, disabled=disabled)
 
@@ -917,10 +924,10 @@ class MarkdownTableOfContents(Widget, can_focus_children=True):
 
     def watch_table_of_contents(self, table_of_contents: TableOfContentsType) -> None:
         """Triggered when the table of contents changes."""
-        self.set_table_of_contents(table_of_contents)
+        self.rebuild_table_of_contents(table_of_contents)
 
-    def set_table_of_contents(self, table_of_contents: TableOfContentsType) -> None:
-        """Set the table of contents.
+    def rebuild_table_of_contents(self, table_of_contents: TableOfContentsType) -> None:
+        """Rebuilds the tree representation of the table of contents data.
 
         Args:
             table_of_contents: Table of contents.
@@ -1005,12 +1012,12 @@ class MarkdownViewer(VerticalScroll, can_focus=True, can_focus_children=True):
 
     @property
     def document(self) -> Markdown:
-        """The Markdown document object."""
+        """The [Markdown][textual.widgets.Markdown] document widget."""
         return self.query_one(Markdown)
 
     @property
     def table_of_contents(self) -> MarkdownTableOfContents:
-        """The table of contents widget"""
+        """The [table of contents][textual.widgets.markdown.MarkdownTableOfContents] widget."""
         return self.query_one(MarkdownTableOfContents)
 
     def _on_mount(self, _: Mount) -> None:

src/textual/widgets/_option_list.py

@@ -26,11 +26,11 @@ from ..strip import Strip
 
 
 class DuplicateID(Exception):
-    """Exception raised if a duplicate ID is used."""
+    """Raised if a duplicate ID is used when adding options to an option list."""
 
 
 class OptionDoesNotExist(Exception):
-    """Exception raised when a request has been made for an option that doesn't exist."""
+    """Raised when a request has been made for an option that doesn't exist."""
 
 
 class Option:
@@ -126,7 +126,7 @@ NewOptionListContent: TypeAlias = "OptionListContent | None | RenderableType"
 """The type of a new item of option list content to be added to an option list.
 
 This type represents all of the types that will be accepted when adding new
-content to the option list. This is a superset of `OptionListContent`.
+content to the option list. This is a superset of [`OptionListContent`][textual.types.OptionListContent].
 """
 
 

src/textual/widgets/_placeholder.py

@@ -3,19 +3,20 @@
 from __future__ import annotations
 
 from itertools import cycle
-from typing import Iterator
+from typing import TYPE_CHECKING, Iterator
 from weakref import WeakKeyDictionary
 
 from rich.console import RenderableType
 from typing_extensions import Literal, Self
 
-from textual.app import App
-
 from .. import events
 from ..css._error_tools import friendly_list
 from ..reactive import Reactive, reactive
 from ..widget import Widget
 
+if TYPE_CHECKING:
+    from textual.app import App
+
 PlaceholderVariant = Literal["default", "size", "text"]
 """The different variants of placeholder."""
 

src/textual/widgets/_tabbed_content.py

@@ -306,7 +306,7 @@ class TabbedContent(Widget):
 
         Note:
             Only one of `before` or `after` can be provided. If both are
-            provided a `Tabs.TabError` will be raised.
+            provided an exception is raised.
         """
         if isinstance(before, TabPane):
             before = before.id

src/textual/widgets/_tree.py

@@ -42,6 +42,14 @@ LineCacheKey: TypeAlias = "tuple[int | tuple, ...]"
 TOGGLE_STYLE = Style.from_meta({"toggle": True})
 
 
+class RemoveRootError(Exception):
+    """Exception raised when trying to remove the root of a [`TreeNode`][textual.widgets.tree.TreeNode]."""
+
+
+class UnknownNodeID(Exception):
+    """Exception raised when referring to an unknown [`TreeNode`][textual.widgets.tree.TreeNode] ID."""
+
+
 @dataclass
 class _TreeLine(Generic[TreeDataType]):
     path: list[TreeNode[TreeDataType]]
@@ -352,9 +360,6 @@ class TreeNode(Generic[TreeDataType]):
         node = self.add(label, data, expand=False, allow_expand=False)
         return node
 
-    class RemoveRootError(Exception):
-        """Exception raised when trying to remove a tree's root node."""
-
     def _remove_children(self) -> None:
         """Remove child nodes of this node.
 
@@ -381,10 +386,10 @@ class TreeNode(Generic[TreeDataType]):
         """Remove this node from the tree.
 
         Raises:
-            TreeNode.RemoveRootError: If there is an attempt to remove the root.
+            RemoveRootError: If there is an attempt to remove the root.
         """
         if self.is_root:
-            raise self.RemoveRootError("Attempt to remove the root node of a Tree.")
+            raise RemoveRootError("Attempt to remove the root node of a Tree.")
         self._remove()
         self._tree._invalidate()
 
@@ -758,9 +763,6 @@ class Tree(Generic[TreeDataType], ScrollView, can_focus=True):
         else:
             return line.node
 
-    class UnknownNodeID(Exception):
-        """Exception raised when referring to an unknown `TreeNode` ID."""
-
     def get_node_by_id(self, node_id: NodeID) -> TreeNode[TreeDataType]:
         """Get a tree node by its ID.
 
@@ -771,12 +773,12 @@ class Tree(Generic[TreeDataType], ScrollView, can_focus=True):
             The node associated with that ID.
 
         Raises:
-            Tree.UnknownID: Raised if the `TreeNode` ID is unknown.
+            UnknownNodeID: Raised if the `TreeNode` ID is unknown.
         """
         try:
             return self._tree_nodes[node_id]
         except KeyError:
-            raise self.UnknownNodeID(f"Unknown NodeID ({node_id}) in tree") from None
+            raise UnknownNodeID(f"Unknown NodeID ({node_id}) in tree") from None
 
     def validate_cursor_line(self, value: int) -> int:
         """Prevent cursor line from going outside of range.

src/textual/widgets/markdown.py

@@ -1,3 +1,13 @@
-from ._markdown import Markdown, MarkdownBlock, MarkdownTableOfContents
+from ._markdown import (
+    Markdown,
+    MarkdownBlock,
+    MarkdownTableOfContents,
+    TableOfContentsType,
+)
 
-__all__ = ["MarkdownTableOfContents", "Markdown", "MarkdownBlock"]
+__all__ = [
+    "MarkdownTableOfContents",
+    "Markdown",
+    "MarkdownBlock",
+    "TableOfContentsType",
+]

src/textual/widgets/tree.py

@@ -1,5 +1,19 @@
 """Make non-widget Tree support classes available."""
 
-from ._tree import TreeNode
+from ._tree import (
+    EventTreeDataType,
+    NodeID,
+    RemoveRootError,
+    TreeDataType,
+    TreeNode,
+    UnknownNodeID,
+)
 
-__all__ = ["TreeNode"]
+__all__ = [
+    "EventTreeDataType",
+    "NodeID",
+    "RemoveRootError",
+    "TreeDataType",
+    "TreeNode",
+    "UnknownNodeID",
+]

tests/tree/test_tree_clearing.py

@@ -4,7 +4,7 @@ import pytest
 
 from textual.app import App, ComposeResult
 from textual.widgets import Tree
-from textual.widgets.tree import TreeNode
+from textual.widgets.tree import RemoveRootError
 
 
 class VerseBody:
@@ -106,5 +106,5 @@ async def test_tree_remove_children_of_root():
 async def test_attempt_to_remove_root():
     """Attempting to remove the root should be an error."""
     async with TreeClearApp().run_test() as pilot:
-        with pytest.raises(TreeNode.RemoveRootError):
+        with pytest.raises(RemoveRootError):
             pilot.app.query_one(VerseTree).root.remove()

tests/tree/test_tree_get_node_by_id.py

@@ -3,7 +3,7 @@ from typing import cast
 import pytest
 
 from textual.widgets import Tree
-from textual.widgets._tree import NodeID
+from textual.widgets.tree import NodeID, UnknownNodeID
 
 
 def test_get_tree_node_by_id() -> None:
@@ -14,5 +14,5 @@ def test_get_tree_node_by_id() -> None:
     assert tree.get_node_by_id(tree.root.id).id == tree.root.id
     assert tree.get_node_by_id(child.id).id == child.id
     assert tree.get_node_by_id(grandchild.id).id == grandchild.id
-    with pytest.raises(Tree.UnknownNodeID):
+    with pytest.raises(UnknownNodeID):
         tree.get_node_by_id(cast(NodeID, grandchild.id + 1000))