Intermediate changes

commit_hash:6f99e4234152d8dc77848a96be0b67a933e60c0d

36 files changed, 545 insertions, 340 deletions

diff --git a/contrib/python/textual/.dist-info/METADATA b/contrib/python/textual/.dist-info/METADATA
index d99b9bcfe07..a03aa2700b6 100644
--- a/contrib/python/textual/.dist-info/METADATA
+++ b/contrib/python/textual/.dist-info/METADATA
@@ -1,6 +1,6 @@
 Metadata-Version: 2.1
 Name: textual
-Version: 2.1.2
+Version: 3.0.1
 Summary: Modern Text User Interface framework
 Home-page: https://github.com/Textualize/textual
 License: MIT
diff --git a/contrib/python/textual/textual/_compositor.py b/contrib/python/textual/textual/_compositor.py
index 528ec258f67..76103ec47cc 100644
--- a/contrib/python/textual/textual/_compositor.py
+++ b/contrib/python/textual/textual/_compositor.py
@@ -900,6 +900,9 @@ class Compositor:
         x -= region.x + gutter_left
         y -= region.y + gutter_right
 
+        if y < 0:
+            return None, None
+
         visible_screen_stack.set(widget.app._background_screens)
         line = widget.render_line(y)
 
diff --git a/contrib/python/textual/textual/_tree_sitter.py b/contrib/python/textual/textual/_tree_sitter.py
index 193bf16fd41..9d099c109b7 100644
--- a/contrib/python/textual/textual/_tree_sitter.py
+++ b/contrib/python/textual/textual/_tree_sitter.py
@@ -1,49 +1,44 @@
 from __future__ import annotations
+from importlib import import_module
+
+from textual import log
+
 
 try:
-    import tree_sitter_bash
-    import tree_sitter_css
-    import tree_sitter_go
-    import tree_sitter_html
-    import tree_sitter_java
-    import tree_sitter_javascript
-    import tree_sitter_json
-    import tree_sitter_markdown
-    import tree_sitter_python
-    import tree_sitter_regex
-    import tree_sitter_rust
-    import tree_sitter_sql
-    import tree_sitter_toml
-    import tree_sitter_xml
-    import tree_sitter_yaml
     from tree_sitter import Language
 
-    _tree_sitter = True
+    _LANGUAGE_CACHE: dict[str, Language] = {}
 
-    _languages = {
-        "python": Language(tree_sitter_python.language()),
-        "json": Language(tree_sitter_json.language()),
-        "markdown": Language(tree_sitter_markdown.language()),
-        "yaml": Language(tree_sitter_yaml.language()),
-        "toml": Language(tree_sitter_toml.language()),
-        "rust": Language(tree_sitter_rust.language()),
-        "html": Language(tree_sitter_html.language()),
-        "css": Language(tree_sitter_css.language()),
-        "xml": Language(tree_sitter_xml.language_xml()),
-        "regex": Language(tree_sitter_regex.language()),
-        "sql": Language(tree_sitter_sql.language()),
-        "javascript": Language(tree_sitter_javascript.language()),
-        "java": Language(tree_sitter_java.language()),
-        "bash": Language(tree_sitter_bash.language()),
-        "go": Language(tree_sitter_go.language()),
-    }
+    _tree_sitter = True
 
     def get_language(language_name: str) -> Language | None:
-        return _languages.get(language_name)
+        if language_name in _LANGUAGE_CACHE:
+            return _LANGUAGE_CACHE[language_name]
+
+        try:
+            module = import_module(f"tree_sitter_{language_name}")
+        except ImportError:
+            return None
+        else:
+            try:
+                if language_name == "xml":
+                    # xml uses language_xml() instead of language()
+                    # it's the only outlier amongst the languages in the `textual[syntax]` extra
+                    language = Language(module.language_xml(), name=language_name)
+                else:
+                    language = Language(module.language(), name=language_name)
+            except (OSError, AttributeError):
+                log.warning(f"Could not load language {language_name!r}.")
+                return None
+            else:
+                _LANGUAGE_CACHE[language_name] = language
+                return language
 
 except ImportError:
     _tree_sitter = False
-    _languages = {}
+
+    def get_language(language_name: str) -> Language | None:
+        return None
+
 
 TREE_SITTER = _tree_sitter
-BUILTIN_LANGUAGES: dict[str, "Language"] = _languages
diff --git a/contrib/python/textual/textual/app.py b/contrib/python/textual/textual/app.py
index 0dc77cae309..94bafee479b 100644
--- a/contrib/python/textual/textual/app.py
+++ b/contrib/python/textual/textual/app.py
@@ -798,6 +798,9 @@ class App(Generic[ReturnType], DOMNode):
         self.supports_smooth_scrolling: bool = False
         """Does the terminal support smooth scrolling?"""
 
+        self._compose_screen: Screen | None = None
+        """The screen composed by App.compose."""
+
         if self.ENABLE_COMMAND_PALETTE:
             for _key, binding in self._bindings:
                 if binding.action in {"command_palette", "app.command_palette"}:
@@ -833,6 +836,10 @@ class App(Generic[ReturnType], DOMNode):
 
         return super().__init_subclass__(*args, **kwargs)
 
+    def _get_dom_base(self) -> DOMNode:
+        """When querying from the app, we want to query the default screen."""
+        return self.default_screen
+
     def validate_title(self, title: Any) -> str:
         """Make sure the title is set to a string."""
         return str(title)
@@ -842,6 +849,11 @@ class App(Generic[ReturnType], DOMNode):
         return str(sub_title)
 
     @property
+    def default_screen(self) -> Screen:
+        """The default screen instance."""
+        return self.screen if self._compose_screen is None else self._compose_screen
+
+    @property
     def workers(self) -> WorkerManager:
         """The [worker](/guide/workers/) manager.
 
@@ -1026,7 +1038,7 @@ class App(Generic[ReturnType], DOMNode):
     @property
     def debug(self) -> bool:
         """Is debug mode enabled?"""
-        return "debug" in self.features
+        return "debug" in self.features or constants.DEBUG
 
     @property
     def is_headless(self) -> bool:
@@ -1773,6 +1785,10 @@ class App(Generic[ReturnType], DOMNode):
     ) -> None:
         """Bind a key to an action.
 
+        !!! warning
+            This method may be private or removed in a future version of Textual.
+            See [dynamic actions](/guide/actions#dynamic-actions) for a more flexible alternative to updating bindings.
+
         Args:
             keys: A comma separated list of keys, i.e.
             action: Action to bind to.
@@ -2671,6 +2687,7 @@ class App(Generic[ReturnType], DOMNode):
 
         if self._screen_stack:
             self.screen.post_message(events.ScreenSuspend())
+            self.screen.refresh()
         next_screen, await_mount = self._get_screen(screen)
         try:
             message_pump = active_message_pump.get()
@@ -3240,6 +3257,7 @@ class App(Generic[ReturnType], DOMNode):
 
     async def _on_compose(self) -> None:
         _rich_traceback_omit = True
+        self._compose_screen = self.screen
         try:
             widgets = [*self.screen._nodes, *compose(self)]
         except TypeError as error:
diff --git a/contrib/python/textual/textual/content.py b/contrib/python/textual/textual/content.py
index 397addff475..08b45aec6f9 100644
--- a/contrib/python/textual/textual/content.py
+++ b/contrib/python/textual/textual/content.py
@@ -1,6 +1,6 @@
 """
 Content is a container for text, with spans marked up with color / style.
-If is equivalent to Rich's Text object, with support for more of Textual features.
+It is equivalent to Rich's Text object, with support for more of Textual features.
 
 Unlike Rich Text, Content is *immutable* so you can't modify it in place, and most methods will return a new Content instance.
 This is more like the builtin str, and allows Textual to make some significant optimizations.
@@ -39,6 +39,9 @@ __all__ = ["ContentType", "Content", "Span"]
 ContentType: TypeAlias = Union["Content", str]
 """Type alias used where content and a str are interchangeable in a function."""
 
+ContentText: TypeAlias = Union["Content", Text, str]
+"""A type that may be used to construct Text."""
+
 ANSI_DEFAULT = Style(
     background=Color(0, 0, 0, 0, ansi=-1),
     foreground=Color(0, 0, 0, 0, ansi=-1),
@@ -119,11 +122,12 @@ class Content(Visual):
 
     def __init__(
         self,
-        text: str,
+        text: str = "",
         spans: list[Span] | None = None,
         cell_length: int | None = None,
     ) -> None:
         """
+        Initialize a Content object.
 
         Args:
             text: text content.
@@ -133,6 +137,8 @@ class Content(Visual):
         self._text: str = _strip_control_codes(text)
         self._spans: list[Span] = [] if spans is None else spans
         self._cell_length = cell_length
+        self._optimal_width_cache: int | None = None
+        self._height_cache: tuple[tuple[int, str, bool] | None, int] = (None, 0)
 
     def __str__(self) -> str:
         return self._text
@@ -168,6 +174,46 @@ class Content(Visual):
         return markup
 
     @classmethod
+    def empty(cls) -> Content:
+        """Get an empty (blank) content"""
+        return EMPTY_CONTENT
+
+    @classmethod
+    def from_text(
+        cls, markup_content_or_text: ContentText, markup: bool = True
+    ) -> Content:
+        """Construct content from Text or str. If the argument is already Content, then
+        return it unmodified.
+
+        This method exists to make (Rich) Text and Content interchangeable. While Content
+        is preferred, we don't want to make it harder than necessary for apps to use Text.
+
+        Args:
+            markup_content_or_text: Value to create Content from.
+            markup: If `True`, then str values will be parsed as markup, otherwise they will
+                be considered literals.
+
+        Raises:
+            TypeError: If the supplied argument is not a valid type.
+
+        Returns:
+            A new Content instance.
+        """
+        if isinstance(markup_content_or_text, Content):
+            return markup_content_or_text
+        elif isinstance(markup_content_or_text, str):
+            if markup:
+                return cls.from_markup(markup_content_or_text)
+            else:
+                return cls(markup_content_or_text)
+        elif isinstance(markup_content_or_text, Text):
+            return cls.from_rich_text(markup_content_or_text)
+        else:
+            raise TypeError(
+                "This method expects a str, a Text instance, or a Content instance"
+            )
+
+    @classmethod
     def from_markup(cls, markup: str | Content, **variables: object) -> Content:
         """Create content from Textual markup, optionally combined with template variables.
 
@@ -207,6 +253,8 @@ class Content(Visual):
 
         Args:
             text: String or Rich Text.
+            console: A Console object to use if parsing Rich Console markup, or `None` to
+                use app default.
 
         Returns:
             New Content.
@@ -219,7 +267,12 @@ class Content(Visual):
         if console is not None:
             get_style = console.get_style
         else:
-            get_style = RichStyle.parse
+            try:
+                app = active_app.get()
+            except LookupError:
+                get_style = RichStyle.parse
+            else:
+                get_style = app.console.get_style
 
         if text._spans:
             try:
@@ -279,7 +332,7 @@ class Content(Visual):
 
     @classmethod
     def assemble(
-        cls, *parts: str | Content | tuple[str, str], end: str = ""
+        cls, *parts: str | Content | tuple[str, str | Style], end: str = ""
     ) -> Content:
         """Construct new content from string, content, or tuples of (TEXT, STYLE).
 
@@ -366,11 +419,7 @@ class Content(Visual):
             return False
         return self.spans == content.spans
 
-    def get_optimal_width(
-        self,
-        rules: RulesMap,
-        container_width: int,
-    ) -> int:
+    def get_optimal_width(self, rules: RulesMap, container_width: int) -> int:
         """Get optimal width of the Visual to display its content.
 
         The exact definition of "optimal width" is dependant on the Visual, but
@@ -379,14 +428,18 @@ class Content(Visual):
 
         Args:
             rules: A mapping of style rules, such as the Widgets `styles` object.
-            container_width: The size of the container in cells.
 
         Returns:
             A width in cells.
 
         """
-        width = max(cell_len(line) for line in self.plain.split("\n"))
-        return width
+        if self._optimal_width_cache is None:
+            self._optimal_width_cache = width = max(
+                cell_len(line) for line in self.plain.split("\n")
+            )
+        else:
+            width = self._optimal_width_cache
+        return width + rules.get("line_pad", 0) * 2
 
     def get_height(self, rules: RulesMap, width: int) -> int:
         """Get the height of the Visual if rendered at the given width.
@@ -398,12 +451,20 @@ class Content(Visual):
         Returns:
             A height in lines.
         """
-        lines = self.without_spans._wrap_and_format(
-            width,
-            overflow=rules.get("text_overflow", "fold"),
-            no_wrap=rules.get("text_wrap", "wrap") == "nowrap",
-        )
-        return len(lines)
+        get_rule = rules.get
+        line_pad = get_rule("line_pad", 0) * 2
+        overflow = get_rule("text_overflow", "fold")
+        no_wrap = get_rule("text_wrap", "wrap") == "nowrap"
+        cache_key = (width + line_pad, overflow, no_wrap)
+        if self._height_cache[0] == cache_key:
+            height = self._height_cache[1]
+        else:
+            lines = self.without_spans._wrap_and_format(
+                width - line_pad, overflow=overflow, no_wrap=no_wrap
+            )
+            height = len(lines)
+            self._height_cache = (cache_key, height)
+        return height
 
     def _wrap_and_format(
         self,
@@ -411,9 +472,11 @@ class Content(Visual):
         align: TextAlign = "left",
         overflow: TextOverflow = "fold",
         no_wrap: bool = False,
+        line_pad: int = 0,
         tab_size: int = 8,
         selection: Selection | None = None,
         selection_style: Style | None = None,
+        post_style: Style | None = None,
     ) -> list[_FormattedLine]:
         """Wraps the text and applies formatting.
 
@@ -439,6 +502,10 @@ class Content(Visual):
                 return None
 
         for y, line in enumerate(self.split(allow_blank=True)):
+
+            if post_style is not None:
+                line = line.stylize(post_style)
+
             if selection_style is not None and (span := get_span(y)) is not None:
                 start, end = span
                 if end == -1:
@@ -460,15 +527,27 @@ class Content(Visual):
                     new_lines = [content_line]
             else:
                 content_line = _FormattedLine(line, width, y=y, align=align)
-                offsets = divide_line(line.plain, width, fold=overflow == "fold")
+                offsets = divide_line(
+                    line.plain, width - line_pad * 2, fold=overflow == "fold"
+                )
                 divided_lines = content_line.content.divide(offsets)
+                ellipsis = overflow == "ellipsis"
                 divided_lines = [
-                    line.truncate(width, ellipsis=overflow == "ellipsis")
-                    for line in divided_lines
+                    (
+                        line.truncate(width, ellipsis=ellipsis)
+                        if last
+                        else line.rstrip().truncate(width, ellipsis=ellipsis)
+                    )
+                    for last, line in loop_last(divided_lines)
                 ]
+
                 new_lines = [
                     _FormattedLine(
-                        content.rstrip_end(width), width, offset, y, align=align
+                        content.rstrip_end(width).pad(line_pad, line_pad),
+                        width,
+                        offset,
+                        y,
+                        align=align,
                     )
                     for content, offset in zip(divided_lines, [0, *offsets])
                 ]
@@ -486,6 +565,7 @@ class Content(Visual):
         style: Style,
         selection: Selection | None = None,
         selection_style: Style | None = None,
+        post_style: Style | None = None,
     ) -> list[Strip]:
         """Render the visual into an iterable of strips. Part of the Visual protocol.
 
@@ -496,6 +576,7 @@ class Content(Visual):
             style: The base style to render on top of.
             selection: Selection information, if applicable, otherwise `None`.
             selection_style: Selection style if `selection` is not `None`.
+            post_style: Style | None = None,
 
         Returns:
             An list of Strips.
@@ -504,14 +585,17 @@ class Content(Visual):
         if not width:
             return []
 
+        get_rule = rules.get
         lines = self._wrap_and_format(
             width,
-            align=rules.get("text_align", "left"),
-            overflow=rules.get("text_overflow", "fold"),
-            no_wrap=rules.get("text_wrap", "wrap") == "nowrap",
+            align=get_rule("text_align", "left"),
+            overflow=get_rule("text_overflow", "fold"),
+            no_wrap=get_rule("text_wrap", "wrap") == "nowrap",
+            line_pad=get_rule("line_pad", 0),
             tab_size=8,
             selection=selection,
             selection_style=selection_style,
+            post_style=post_style,
         )
 
         if height is not None:
@@ -565,6 +649,13 @@ class Content(Visual):
         """The content with no spans"""
         return Content(self.plain, [], self._cell_length)
 
+    @property
+    def first_line(self) -> Content:
+        """The first line of the content."""
+        if "\n" not in self.plain:
+            return self
+        return self[: self.plain.index("\n")]
+
     def __getitem__(self, slice: int | slice) -> Content:
         def get_text_at(offset: int) -> "Content":
             _Span = Span
@@ -836,6 +927,34 @@ class Content(Visual):
             )
         return self
 
+    def pad(self, left: int, right: int, character: str = " ") -> Content:
+        """Pad both the left and right edges with a given number of characters.
+
+        Args:
+            left (int): Number of characters to pad on the left.
+            right (int): Number of characters to pad on the right.
+            character (str, optional): Character to pad with. Defaults to " ".
+        """
+        assert len(character) == 1, "Character must be a string of length 1"
+        if left or right:
+            text = f"{character * left}{self.plain}{character * right}"
+            _Span = Span
+            if left:
+                spans = [
+                    _Span(start + left, end + left, style)
+                    for start, end, style in self._spans
+                ]
+            else:
+                spans = self._spans
+            content = Content(
+                text,
+                spans,
+                None if self._cell_length is None else self._cell_length + left + right,
+            )
+            return content
+
+        return self
+
     def center(self, width: int, ellipsis: bool = False) -> Content:
         """Align a line to the center.
 
@@ -849,7 +968,7 @@ class Content(Visual):
         content = self.rstrip().truncate(width, ellipsis=ellipsis)
         left = (width - content.cell_length) // 2
         right = width - left
-        content = content.pad_left(left).pad_right(right)
+        content = content.pad(left, right)
         return content
 
     def right(self, width: int, ellipsis: bool = False) -> Content:
@@ -1403,3 +1522,6 @@ class _FormattedLine:
             if style is not None
         ]
         return segments
+
+
+EMPTY_CONTENT: Final = Content("")
diff --git a/contrib/python/textual/textual/css/_style_properties.py b/contrib/python/textual/textual/css/_style_properties.py
index be591276a9b..472e5fd26c4 100644
--- a/contrib/python/textual/textual/css/_style_properties.py
+++ b/contrib/python/textual/textual/css/_style_properties.py
@@ -126,7 +126,7 @@ class IntegerProperty(GenericProperty[int, int]):
         if isinstance(value, (int, float)):
             return int(value)
         else:
-            raise StyleValueError(f"Expected a number here, got f{value}")
+            raise StyleValueError(f"Expected a number here, got {value!r}")
 
 
 class BooleanProperty(GenericProperty[bool, bool]):
diff --git a/contrib/python/textual/textual/css/_styles_builder.py b/contrib/python/textual/textual/css/_styles_builder.py
index 668a7606610..fe52f639033 100644
--- a/contrib/python/textual/textual/css/_styles_builder.py
+++ b/contrib/python/textual/textual/css/_styles_builder.py
@@ -1069,6 +1069,7 @@ class StylesBuilder:
     process_row_span = _process_integer
     process_grid_size_columns = _process_integer
     process_grid_size_rows = _process_integer
+    process_line_pad = _process_integer
 
     def process_grid_gutter(self, name: str, tokens: list[Token]) -> None:
         if not tokens:
diff --git a/contrib/python/textual/textual/css/styles.py b/contrib/python/textual/textual/css/styles.py
index 24930f4810a..03907bea4a9 100644
--- a/contrib/python/textual/textual/css/styles.py
+++ b/contrib/python/textual/textual/css/styles.py
@@ -204,6 +204,8 @@ class RulesMap(TypedDict, total=False):
     text_wrap: TextWrap
     text_overflow: TextOverflow
 
+    line_pad: int
+
 
 RULE_NAMES = list(RulesMap.__annotations__.keys())
 RULE_NAMES_SET = frozenset(RULE_NAMES)
@@ -243,6 +245,7 @@ class StylesBase:
         "link_background_hover",
         "text_wrap",
         "text_overflow",
+        "line_pad",
     }
 
     node: DOMNode | None = None
@@ -489,6 +492,8 @@ class StylesBase:
     text_overflow: StringEnumProperty[TextOverflow] = StringEnumProperty(
         VALID_TEXT_OVERFLOW, "fold"
     )
+    line_pad = IntegerProperty(default=0, layout=True)
+    """Padding added to left and right of lines."""
 
     def __textual_animation__(
         self,
@@ -1284,6 +1289,8 @@ class Styles(StylesBase):
             append_declaration("text-wrap", self.text_wrap)
         if "text_overflow" in rules:
             append_declaration("text-overflow", self.text_overflow)
+        if "line_pad" in rules:
+            append_declaration("line-pad", str(self.line_pad))
         lines.sort()
         return lines
 
diff --git a/contrib/python/textual/textual/document/_syntax_aware_document.py b/contrib/python/textual/textual/document/_syntax_aware_document.py
index 162d3fbd544..00305dcec2f 100644
--- a/contrib/python/textual/textual/document/_syntax_aware_document.py
+++ b/contrib/python/textual/textual/document/_syntax_aware_document.py
@@ -8,7 +8,6 @@ except ImportError:
     TREE_SITTER = False
 
 
-from textual._tree_sitter import BUILTIN_LANGUAGES
 from textual.document._document import Document, EditResult, Location, _utf8_encode
 
 
@@ -17,59 +16,30 @@ class SyntaxAwareDocumentError(Exception):
 
 
 class SyntaxAwareDocument(Document):
-    """A wrapper around a Document which also maintains a tree-sitter syntax
+    """A subclass of Document which also maintains a tree-sitter syntax
     tree when the document is edited.
-
-    The primary reason for this split is actually to keep tree-sitter stuff separate,
-    since it isn't supported in Python 3.7. By having the tree-sitter code
-    isolated in this subclass, it makes it easier to conditionally import. However,
-    it does come with other design flaws (e.g. Document is required to have methods
-    which only really make sense on SyntaxAwareDocument).
-
-    If you're reading this and Python 3.7 is no longer supported by Textual,
-    consider merging this subclass into the `Document` superclass.
     """
 
     def __init__(
         self,
         text: str,
-        language: str | Language,
+        language: Language,
     ):
         """Construct a SyntaxAwareDocument.
 
         Args:
             text: The initial text contained in the document.
-            language: The language to use. You can pass a string to use a supported
-                language, or pass in your own tree-sitter `Language` object.
+            language: The tree-sitter language to use.
         """
 
         if not TREE_SITTER:
-            raise RuntimeError("SyntaxAwareDocument unavailable.")
+            raise RuntimeError(
+                "SyntaxAwareDocument unavailable - tree-sitter is not installed."
+            )
 
         super().__init__(text)
-        self.language: Language | None = None
-        """The tree-sitter Language or None if tree-sitter is unavailable."""
-
-        self._parser: Parser | None = None
-
-        from textual._tree_sitter import get_language
-
-        # If the language is `None`, then avoid doing any parsing related stuff.
-        if isinstance(language, str):
-            if language not in BUILTIN_LANGUAGES:
-                raise SyntaxAwareDocumentError(f"Invalid language {language!r}")
-            # If tree-sitter-languages is not installed properly, get_language
-            # and get_parser may raise an OSError when unable to load their
-            # resources
-
-            try:
-                self.language = get_language(language)
-            except OSError as e:
-                raise SyntaxAwareDocumentError(
-                    f"Could not find binaries for {language!r}"
-                ) from e
-        else:
-            self.language = language
+        self.language: Language = language
+        """The tree-sitter Language."""
 
         self._parser = Parser(self.language)
         """The tree-sitter Parser or None if tree-sitter is unavailable."""
@@ -90,16 +60,6 @@ class SyntaxAwareDocument(Document):
         Returns:
             The prepared query.
         """
-        if not TREE_SITTER:
-            raise SyntaxAwareDocumentError(
-                "Couldn't prepare query - tree-sitter is not available on this architecture."
-            )
-
-        if self.language is None:
-            raise SyntaxAwareDocumentError(
-                "Couldn't prepare query - no language assigned."
-            )
-
         return self.language.query(query)
 
     def query_syntax_tree(
@@ -122,12 +82,6 @@ class SyntaxAwareDocument(Document):
         Returns:
             A tuple containing the nodes and text captured by the query.
         """
-
-        if not TREE_SITTER:
-            raise SyntaxAwareDocumentError(
-                "tree-sitter is not available on this architecture."
-            )
-
         captures_kwargs = {}
         if start_point is not None:
             captures_kwargs["start_point"] = start_point
diff --git a/contrib/python/textual/textual/dom.py b/contrib/python/textual/textual/dom.py
index 9587bca5865..00b5595c659 100644
--- a/contrib/python/textual/textual/dom.py
+++ b/contrib/python/textual/textual/dom.py
@@ -235,6 +235,17 @@ class DOMNode(MessagePump):
 
         super().__init__()
 
+    def _get_dom_base(self) -> DOMNode:
+        """Get the DOM base node (typically self).
+
+        All DOM queries on this node will use the return value as the root node.
+        This method allows the App to query the default screen, and not the active screen.
+
+        Returns:
+            DOMNode.
+        """
+        return self
+
     def set_reactive(
         self, reactive: Reactive[ReactiveType], value: ReactiveType
     ) -> None:
@@ -1380,10 +1391,11 @@ class DOMNode(MessagePump):
         from textual.css.query import DOMQuery, QueryType
         from textual.widget import Widget
 
+        node = self._get_dom_base()
         if isinstance(selector, str) or selector is None:
-            return DOMQuery[Widget](self, filter=selector)
+            return DOMQuery[Widget](node, filter=selector)
         else:
-            return DOMQuery[QueryType](self, filter=selector.__name__)
+            return DOMQuery[QueryType](node, filter=selector.__name__)
 
     if TYPE_CHECKING:
 
@@ -1411,10 +1423,11 @@ class DOMNode(MessagePump):
         from textual.css.query import DOMQuery, QueryType
         from textual.widget import Widget
 
+        node = self._get_dom_base()
         if isinstance(selector, str) or selector is None:
-            return DOMQuery[Widget](self, deep=False, filter=selector)
+            return DOMQuery[Widget](node, deep=False, filter=selector)
         else:
-            return DOMQuery[QueryType](self, deep=False, filter=selector.__name__)
+            return DOMQuery[QueryType](node, deep=False, filter=selector.__name__)
 
     if TYPE_CHECKING:
 
@@ -1449,6 +1462,8 @@ class DOMNode(MessagePump):
         """
         _rich_traceback_omit = True
 
+        base_node = self._get_dom_base()
+
         if isinstance(selector, str):
             query_selector = selector
         else:
@@ -1462,20 +1477,20 @@ class DOMNode(MessagePump):
             ) from None
 
         if all(selectors.is_simple for selectors in selector_set):
-            cache_key = (self._nodes._updates, query_selector, expect_type)
-            cached_result = self._query_one_cache.get(cache_key)
+            cache_key = (base_node._nodes._updates, query_selector, expect_type)
+            cached_result = base_node._query_one_cache.get(cache_key)
             if cached_result is not None:
                 return cached_result
         else:
             cache_key = None
 
-        for node in walk_depth_first(self, with_root=False):
+        for node in walk_depth_first(base_node, with_root=False):
             if not match(selector_set, node):
                 continue
             if expect_type is not None and not isinstance(node, expect_type):
                 continue
             if cache_key is not None:
-                self._query_one_cache[cache_key] = node
+                base_node._query_one_cache[cache_key] = node
             return node
 
         raise NoMatches(f"No nodes match {selector!r} on {self!r}")
@@ -1518,6 +1533,8 @@ class DOMNode(MessagePump):
         """
         _rich_traceback_omit = True
 
+        base_node = self._get_dom_base()
+
         if isinstance(selector, str):
             query_selector = selector
         else:
@@ -1531,14 +1548,14 @@ class DOMNode(MessagePump):
             ) from None
 
         if all(selectors.is_simple for selectors in selector_set):
-            cache_key = (self._nodes._updates, query_selector, expect_type)
-            cached_result = self._query_one_cache.get(cache_key)
+            cache_key = (base_node._nodes._updates, query_selector, expect_type)
+            cached_result = base_node._query_one_cache.get(cache_key)
             if cached_result is not None:
                 return cached_result
         else:
             cache_key = None
 
-        children = walk_depth_first(self, with_root=False)
+        children = walk_depth_first(base_node, with_root=False)
         iter_children = iter(children)
         for node in iter_children:
             if not match(selector_set, node):
@@ -1553,7 +1570,7 @@ class DOMNode(MessagePump):
                         "Call to query_one resulted in more than one matched node"
                     )
             if cache_key is not None:
-                self._query_one_cache[cache_key] = node
+                base_node._query_one_cache[cache_key] = node
             return node
 
         raise NoMatches(f"No nodes match {selector!r} on {self!r}")
@@ -1589,6 +1606,7 @@ class DOMNode(MessagePump):
         Returns:
             A DOMNode or subclass if `expect_type` is provided.
         """
+        base_node = self._get_dom_base()
         if isinstance(selector, str):
             query_selector = selector
         else:
@@ -1600,8 +1618,8 @@ class DOMNode(MessagePump):
             raise InvalidQueryFormat(
                 f"Unable to parse {query_selector!r} as a query; check for syntax errors"
             ) from None
-        if self.parent is not None:
-            for node in self.parent.ancestors_with_self:
+        if base_node.parent is not None:
+            for node in base_node.parent.ancestors_with_self:
                 if not match(selector_set, node):
                     continue
                 if expect_type is not None and not isinstance(node, expect_type):
diff --git a/contrib/python/textual/textual/drivers/_writer_thread.py b/contrib/python/textual/textual/drivers/_writer_thread.py
index 572d353aaba..a26ef46fbbc 100644
--- a/contrib/python/textual/textual/drivers/_writer_thread.py
+++ b/contrib/python/textual/textual/drivers/_writer_thread.py
@@ -13,7 +13,7 @@ class WriterThread(threading.Thread):
     """A thread / file-like to do writes to stdout in the background."""
 
     def __init__(self, file: IO[str]) -> None:
-        super().__init__(daemon=True)
+        super().__init__(daemon=True, name="textual-output")
         self._queue: Queue[str | None] = Queue(MAX_QUEUED_WRITES)
         self._file = file
 
diff --git a/contrib/python/textual/textual/drivers/linux_driver.py b/contrib/python/textual/textual/drivers/linux_driver.py
index 4d1c34ce975..66f4c4d9784 100644
--- a/contrib/python/textual/textual/drivers/linux_driver.py
+++ b/contrib/python/textual/textual/drivers/linux_driver.py
@@ -276,7 +276,7 @@ class LinuxDriver(Driver):
         self.write("\x1b[>1u")  # https://sw.kovidgoyal.net/kitty/keyboard-protocol/
 
         self.flush()
-        self._key_thread = Thread(target=self._run_input_thread)
+        self._key_thread = Thread(target=self._run_input_thread, name="textual-input")
         send_size_event()
         self._key_thread.start()
         self._request_terminal_sync_mode_support()
diff --git a/contrib/python/textual/textual/drivers/linux_inline_driver.py b/contrib/python/textual/textual/drivers/linux_inline_driver.py
index 173cb606b79..14aa61fba0a 100644
--- a/contrib/python/textual/textual/drivers/linux_inline_driver.py
+++ b/contrib/python/textual/textual/drivers/linux_inline_driver.py
@@ -237,7 +237,7 @@ class LinuxInlineDriver(Driver):
 
             termios.tcsetattr(self.fileno, termios.TCSANOW, newattr)
 
-        self._key_thread = Thread(target=self._run_input_thread)
+        self._key_thread = Thread(target=self._run_input_thread, name="textual-input")
         send_size_event()
         self._key_thread.start()
         self._request_terminal_sync_mode_support()
diff --git a/contrib/python/textual/textual/drivers/web_driver.py b/contrib/python/textual/textual/drivers/web_driver.py
index 2dd319f54de..f21d19ed381 100644
--- a/contrib/python/textual/textual/drivers/web_driver.py
+++ b/contrib/python/textual/textual/drivers/web_driver.py
@@ -62,7 +62,9 @@ class WebDriver(Driver):
         self.fileno = sys.__stdout__.fileno()
         self._write = partial(os.write, self.fileno)
         self.exit_event = Event()
-        self._key_thread: Thread = Thread(target=self.run_input_thread)
+        self._key_thread: Thread = Thread(
+            target=self.run_input_thread, name="textual-input"
+        )
         self._input_reader = InputReader()
 
         self._deliveries: dict[str, BinaryIO | TextIO] = {}
diff --git a/contrib/python/textual/textual/drivers/win32.py b/contrib/python/textual/textual/drivers/win32.py
index 059bb0275a1..a8eee1724b6 100644
--- a/contrib/python/textual/textual/drivers/win32.py
+++ b/contrib/python/textual/textual/drivers/win32.py
@@ -223,7 +223,7 @@ class EventMonitor(threading.Thread):
         self.app = app
         self.exit_event = exit_event
         self.process_event = process_event
-        super().__init__()
+        super().__init__(name="textual-input")
 
     def run(self) -> None:
         exit_requested = self.exit_event.is_set
diff --git a/contrib/python/textual/textual/markup.py b/contrib/python/textual/textual/markup.py
index 93d1d12ed5e..11ee5a132ff 100644
--- a/contrib/python/textual/textual/markup.py
+++ b/contrib/python/textual/textual/markup.py
@@ -119,12 +119,22 @@ class StyleTokenizer(TokenizerState):
     }
 
 
-STYLES = {"bold", "dim", "italic", "underline", "reverse", "strike"}
+STYLES = {
+    "bold",
+    "dim",
+    "italic",
+    "underline",
+    "underline2",
+    "reverse",
+    "strike",
+    "blink",
+}
 STYLE_ABBREVIATIONS = {
     "b": "bold",
     "d": "dim",
     "i": "italic",
     "u": "underline",
+    "uu": "underline2",
     "r": "reverse",
     "s": "strike",
 }
diff --git a/contrib/python/textual/textual/pilot.py b/contrib/python/textual/textual/pilot.py
index 115c10cb703..a9ff1d2067c 100644
--- a/contrib/python/textual/textual/pilot.py
+++ b/contrib/python/textual/textual/pilot.py
@@ -414,7 +414,7 @@ class Pilot(Generic[ReturnType]):
         elif isinstance(widget, Widget):
             target_widget = widget
         else:
-            target_widget = app.query_one(widget)
+            target_widget = app.screen.query_one(widget)
 
         message_arguments = _get_mouse_message_arguments(
             target_widget,
diff --git a/contrib/python/textual/textual/screen.py b/contrib/python/textual/textual/screen.py
index df69e690a8c..3178435c4ab 100644
--- a/contrib/python/textual/textual/screen.py
+++ b/contrib/python/textual/textual/screen.py
@@ -1306,7 +1306,7 @@ class Screen(Generic[ScreenResultType], Widget):
         inline_height = min(self.app.size.height, inline_height)
         return inline_height
 
-    def _screen_resized(self, size: Size):
+    def _screen_resized(self, size: Size) -> None:
         """Called by App when the screen is resized."""
         if self.stack_updates:
             self._refresh_layout(size)
diff --git a/contrib/python/textual/textual/scroll_view.py b/contrib/python/textual/textual/scroll_view.py
index 9cb1c9f1ede..03a05013b18 100644
--- a/contrib/python/textual/textual/scroll_view.py
+++ b/contrib/python/textual/textual/scroll_view.py
@@ -33,13 +33,15 @@ class ScrollView(ScrollableContainer):
         return True
 
     def watch_scroll_x(self, old_value: float, new_value: float) -> None:
-        if self.show_horizontal_scrollbar and old_value != new_value:
+        if self.show_horizontal_scrollbar:
             self.horizontal_scrollbar.position = new_value
+        if round(old_value) != round(new_value):
             self.refresh()
 
     def watch_scroll_y(self, old_value: float, new_value: float) -> None:
-        if self.show_vertical_scrollbar and (old_value) != (new_value):
+        if self.show_vertical_scrollbar:
             self.vertical_scrollbar.position = new_value
+        if round(old_value) != round(new_value):
             self.refresh()
 
     def on_mount(self):
@@ -174,7 +176,6 @@ class ScrollView(ScrollableContainer):
             y_start: First line to refresh.
             line_count: Total number of lines to refresh.
         """
-
         refresh_region = Region(
             0,
             y_start - self.scroll_offset.y,
diff --git a/contrib/python/textual/textual/scrollbar.py b/contrib/python/textual/textual/scrollbar.py
index 4f5ab6212fa..e28d9db9419 100644
--- a/contrib/python/textual/textual/scrollbar.py
+++ b/contrib/python/textual/textual/scrollbar.py
@@ -394,9 +394,6 @@ class ScrollBarCorner(Widget):
     """Widget which fills the gap between horizontal and vertical scrollbars,
     should they both be present."""
 
-    def __init__(self, name: str | None = None):
-        super().__init__(name=name)
-
     def render(self) -> RenderableType:
         assert self.parent is not None
         styles = self.parent.styles
diff --git a/contrib/python/textual/textual/style.py b/contrib/python/textual/textual/style.py
index c96c9b7af65..43c4be09207 100644
--- a/contrib/python/textual/textual/style.py
+++ b/contrib/python/textual/textual/style.py
@@ -10,6 +10,7 @@ from __future__ import annotations
 from dataclasses import dataclass
 from functools import cached_property, lru_cache
 from marshal import dumps, loads
+from operator import attrgetter
 from typing import TYPE_CHECKING, Any, Iterable, Mapping
 
 import rich.repr
@@ -23,6 +24,23 @@ if TYPE_CHECKING:
     from textual.css.styles import StylesBase
 
 
+_get_hash_attributes = attrgetter(
+    "background",
+    "foreground",
+    "bold",
+    "dim",
+    "italic",
+    "underline",
+    "underline2",
+    "reverse",
+    "strike",
+    "blink",
+    "link",
+    "auto_color",
+    "_meta",
+)
+
+
 @rich.repr.auto(angular=True)
 @dataclass(frozen=True)
 class Style:
@@ -38,8 +56,10 @@ class Style:
     dim: bool | None = None
     italic: bool | None = None
     underline: bool | None = None
+    underline2: bool | None = None
     reverse: bool | None = None
     strike: bool | None = None
+    blink: bool | None = None
     link: str | None = None
     _meta: bytes | None = None
     auto_color: bool = False
@@ -51,8 +71,10 @@ class Style:
         yield "dim", self.dim, None
         yield "italic", self.italic, None
         yield "underline", self.underline, None
+        yield "underline2", self.underline2, None
         yield "reverse", self.reverse, None
         yield "strike", self.strike, None
+        yield "blink", self.blink, None
         yield "link", self.link, None
 
         if self._meta is not None:
@@ -67,29 +89,18 @@ class Style:
             and self.dim is None
             and self.italic is None
             and self.underline is None
+            and self.underline2 is None
             and self.reverse is None
             and self.strike is None
+            and self.blink is None
             and self.link is None
             and self._meta is None
         )
 
     @cached_property
     def hash(self) -> int:
-        return hash(
-            (
-                self.background,
-                self.foreground,
-                self.bold,
-                self.dim,
-                self.italic,
-                self.underline,
-                self.reverse,
-                self.strike,
-                self.link,
-                self.auto_color,
-                self._meta,
-            )
-        )
+        """A hash of the style's attributes."""
+        return hash(_get_hash_attributes(self))
 
     def __hash__(self) -> int:
         return self.hash
@@ -122,8 +133,12 @@ class Style:
             output_append("italic" if self.italic else "not italic")
         if self.underline is not None:
             output_append("underline" if self.underline else "not underline")
+        if self.underline2 is not None:
+            output_append("underline2" if self.underline2 else "not underline2")
         if self.strike is not None:
             output_append("strike" if self.strike else "not strike")
+        if self.blink is not None:
+            output_append("blink" if self.blink else "not blink")
         if self.link is not None:
             if "'" not in self.link:
                 output_append(f"link='{self.link}'")
@@ -160,8 +175,12 @@ class Style:
             output_append("italic" if self.italic else "not italic")
         if self.underline is not None:
             output_append("underline" if self.underline else "not underline")
+        if self.underline2 is not None:
+            output_append("underline2" if self.underline2 else "not underline2")
         if self.strike is not None:
             output_append("strike" if self.strike else "not strike")
+        if self.blink is not None:
+            output_append("blink" if self.blink else "not blink")
         if self.link is not None:
             output_append("link")
         if self._meta is not None:
@@ -189,8 +208,10 @@ class Style:
                 self.dim if other.dim is None else other.dim,
                 self.italic if other.italic is None else other.italic,
                 self.underline if other.underline is None else other.underline,
+                self.underline2 if other.underline2 is None else other.underline2,
                 self.reverse if other.reverse is None else other.reverse,
                 self.strike if other.strike is None else other.strike,
+                self.blink if other.blink is None else other.blink,
                 self.link if other.link is None else other.link,
                 (
                     dumps({**self.meta, **other.meta})
@@ -275,8 +296,10 @@ class Style:
             dim=rich_style.dim,
             italic=rich_style.italic,
             underline=rich_style.underline,
+            underline2=rich_style.underline2,
             reverse=rich_style.reverse,
             strike=rich_style.strike,
+            blink=rich_style.blink,
             link=rich_style.link,
             _meta=rich_style._meta,
         )
@@ -301,13 +324,14 @@ class Style:
             dim=text_style.italic,
             italic=text_style.italic,
             underline=text_style.underline,
+            underline2=text_style.underline2,
             reverse=text_style.reverse,
             strike=text_style.strike,
             auto_color=styles.auto_color,
         )
 
     @classmethod
-    def from_meta(cls, meta: dict[str, str]) -> Style:
+    def from_meta(cls, meta: Mapping[str, Any]) -> Style:
         """Create a Visual Style containing meta information.
 
         Args:
@@ -333,8 +357,10 @@ class Style:
             dim=self.dim,
             italic=self.italic,
             underline=self.underline,
+            underline2=self.underline2,
             reverse=self.reverse,
             strike=self.strike,
+            blink=self.blink,
             link=self.link,
             meta=None if self._meta is None else self.meta,
         )
@@ -359,8 +385,10 @@ class Style:
             dim=self.dim,
             italic=self.italic,
             underline=self.underline,
+            underline2=self.underline2,
             reverse=self.reverse,
             strike=self.strike,
+            blink=self.blink,
             link=self.link,
             meta={**self.meta, "offset": (x, y)},
         )
@@ -373,8 +401,10 @@ class Style:
             dim=self.dim,
             italic=self.italic,
             underline=self.underline,
+            underline2=self.underline2,
             reverse=self.reverse,
             strike=self.strike,
+            blink=self.blink,
             link=self.link,
             _meta=self._meta,
         )
@@ -384,6 +414,11 @@ class Style:
         """Just the background color, with no other attributes."""
         return Style(self.background, _meta=self._meta)
 
+    @property
+    def has_transparent_foreground(self) -> bool:
+        """Is the foreground transparent (or not set)?"""
+        return self.foreground is None or self.foreground.a == 0
+
     @classmethod
     def combine(cls, styles: Iterable[Style]) -> Style:
         """Add a number of styles and get the result."""
diff --git a/contrib/python/textual/textual/visual.py b/contrib/python/textual/textual/visual.py
index af58d5ef0a7..edd20e31d42 100644
--- a/contrib/python/textual/textual/visual.py
+++ b/contrib/python/textual/textual/visual.py
@@ -119,6 +119,7 @@ class Visual(ABC):
         style: Style,
         selection: Selection | None = None,
         selection_style: Style | None = None,
+        post_style: Style | None = None,
     ) -> list[Strip]:
         """Render the Visual into an iterable of strips.
 
@@ -129,6 +130,7 @@ class Visual(ABC):
             style: The base style to render on top of.
             selection: Selection information, if applicable, otherwise `None`.
             selection_style: Selection style if `selection` is not `None`.
+            post_style: Optional style to apply post render.
 
         Returns:
             An list of Strips.
@@ -144,7 +146,8 @@ class Visual(ABC):
 
         Args:
             rules: A mapping of style rules, such as the Widgets `styles` object.
-            container_width: The size of the container in cells.
+            container_width: The width of the container, used by Rich Renderables.
+                May be ignored for Textual Visuals.
 
         Returns:
             A width in cells.
@@ -173,6 +176,7 @@ class Visual(ABC):
         style: Style,
         *,
         pad: bool = False,
+        post_style: Style | None = None,
     ) -> list[Strip]:
         """High level function to render a visual to strips.
 
@@ -183,6 +187,7 @@ class Visual(ABC):
             height: Desired height (in lines) or `None` for no limit.
             style: A (Visual) Style instance.
             pad: Pad to desired width?
+            post_style: Optional Style to apply to strips after rendering.
 
         Returns:
             A list of Strips containing the render.
@@ -208,7 +213,7 @@ class Visual(ABC):
 
         if height is None:
             height = len(strips)
-        rich_style = style.rich_style
+        rich_style = (style + Style(reverse=False)).rich_style
         if pad:
             strips = [strip.extend_cell_length(width, rich_style) for strip in strips]
         content_align = widget.styles.content_align
@@ -261,7 +266,6 @@ class RichVisual(Visual):
         width = measure(
             console, self._renderable, container_width, container_width=container_width
         )
-
         return width
 
     def get_height(self, rules: RulesMap, width: int) -> int:
@@ -292,6 +296,7 @@ class RichVisual(Visual):
         style: Style,
         selection: Selection | None = None,
         selection_style: Style | None = None,
+        post_style: Style | None = None,
     ) -> list[Strip]:
         console = active_app.get().console
         options = console.options.update(
@@ -340,7 +345,10 @@ class Padding(Visual):
         )
 
     def get_height(self, rules: RulesMap, width: int) -> int:
-        return self._visual.get_height(rules, width) + self._spacing.height
+        return (
+            self._visual.get_height(rules, width - self._spacing.width)
+            + self._spacing.height
+        )
 
     def render_strips(
         self,
@@ -350,6 +358,7 @@ class Padding(Visual):
         style: Style,
         selection: Selection | None = None,
         selection_style: Style | None = None,
+        post_style: Style | None = None,
     ) -> list[Strip]:
         padding = self._spacing
         top, right, bottom, left = self._spacing
diff --git a/contrib/python/textual/textual/widget.py b/contrib/python/textual/textual/widget.py
index 2d56a37ff97..21214c0e465 100644
--- a/contrib/python/textual/textual/widget.py
+++ b/contrib/python/textual/textual/widget.py
@@ -651,6 +651,22 @@ class Widget(DOMNode):
         """Text selection information, or `None` if no text is selected in this widget."""
         return self.screen.selections.get(self, None)
 
+    def preflight_checks(self) -> None:
+        """Called in debug mode to do preflight checks.
+
+        This is used by Textual to log some common errors, but you could implement this
+        in custom widgets to perform additional checks.
+
+        """
+
+        if hasattr(self, "CSS"):
+            from textual.screen import Screen
+
+            if not isinstance(self, Screen):
+                self.log.warning(
+                    f"'{self.__class__.__name__}.CSS' will be ignored (use 'DEFAULT_CSS' class variable for widgets)"
+                )
+
     def _cover(self, widget: Widget) -> None:
         """Set a widget used to replace the visuals of this widget (used for loading indicator).
 
@@ -1090,7 +1106,7 @@ class Widget(DOMNode):
                 else:
                     text_background = background
                 if has_rule("color"):
-                    color = styles.color
+                    color = styles.color.multiply_alpha(styles.text_opacity)
                 style += styles.text_style
                 if has_rule("auto_color") and styles.auto_color:
                     color = text_background.get_contrast_text(color.a)
@@ -1114,7 +1130,7 @@ class Widget(DOMNode):
     @overload
     def render_str(self, text_content: Content) -> Content: ...
 
-    def render_str(self, text_content: str | Content) -> Content | Text:
+    def render_str(self, text_content: str | Content) -> Content:
         """Convert str into a [Content][textual.content.Content] instance.
 
         If you pass in an existing Content instance it will be returned unaltered.
@@ -1475,6 +1491,8 @@ class Widget(DOMNode):
                 tie_breaker=tie_breaker,
                 scope=scope,
             )
+        if app.debug:
+            app.call_next(self.preflight_checks)
 
     def _get_box_model(
         self,
@@ -1642,7 +1660,7 @@ class Widget(DOMNode):
             return self._content_width_cache[1]
 
         visual = self._render()
-        width = visual.get_optimal_width(self, container.width)
+        width = visual.get_optimal_width(self.styles, container.width)
 
         if self.expand:
             width = max(container.width, width)
@@ -3853,6 +3871,7 @@ class Widget(DOMNode):
             bold=style.bold,
             dim=style.dim,
             italic=style.italic,
+            reverse=style.reverse,
             underline=style.underline,
             strike=style.strike,
         )
@@ -3984,7 +4003,6 @@ class Widget(DOMNode):
         Returns:
             The `Widget` instance.
         """
-
         if layout:
             self._layout_required = True
             for ancestor in self.ancestors:
@@ -4314,10 +4332,11 @@ class Widget(DOMNode):
 
     async def _on_click(self, event: events.Click) -> None:
         if event.widget is self:
-            if event.chain == 2:
-                self.text_select_all()
-            elif event.chain == 3 and self.parent is not None:
-                self.select_container.text_select_all()
+            if self.allow_select and self.screen.allow_select and self.app.ALLOW_SELECT:
+                if event.chain == 2:
+                    self.text_select_all()
+                elif event.chain == 3 and self.parent is not None:
+                    self.select_container.text_select_all()
 
         await self.broker_event("click", event)
 
diff --git a/contrib/python/textual/textual/widgets/_button.py b/contrib/python/textual/textual/widgets/_button.py
index 20b45722071..c11ff39fb09 100644
--- a/contrib/python/textual/textual/widgets/_button.py
+++ b/contrib/python/textual/textual/widgets/_button.py
@@ -6,7 +6,6 @@ from typing import TYPE_CHECKING, cast
 import rich.repr
 from rich.cells import cell_len
 from rich.console import ConsoleRenderable, RenderableType
-from rich.text import Text, TextType
 from typing_extensions import Literal, Self
 
 from textual import events
@@ -17,10 +16,10 @@ if TYPE_CHECKING:
 from rich.style import Style
 
 from textual.binding import Binding
+from textual.content import Content, ContentText
 from textual.css._error_tools import friendly_list
 from textual.geometry import Size
 from textual.message import Message
-from textual.pad import HorizontalPad
 from textual.reactive import reactive
 from textual.widget import Widget
 
@@ -58,6 +57,7 @@ class Button(Widget, can_focus=True):
         text-align: center;
         content-align: center middle;
         text-style: bold;
+        line-pad: 1;
 
         &:disabled {            
             text-opacity: 0.6;
@@ -154,7 +154,7 @@ class Button(Widget, can_focus=True):
 
     BINDINGS = [Binding("enter", "press", "Press button", show=False)]
 
-    label: reactive[TextType] = reactive[TextType]("")
+    label: reactive[ContentText] = reactive[ContentText](Content.empty)
     """The text label that appears within the button."""
 
     variant = reactive("default", init=False)
@@ -182,7 +182,7 @@ class Button(Widget, can_focus=True):
 
     def __init__(
         self,
-        label: TextType | None = None,
+        label: ContentText | None = None,
         variant: ButtonVariant = "default",
         *,
         name: str | None = None,
@@ -209,7 +209,7 @@ class Button(Widget, can_focus=True):
         if label is None:
             label = self.css_identifier_styled
 
-        self.label = label
+        self.label = Content.from_text(label)
         self.variant = variant
         self.action = action
         self.active_effect_duration = 0.2
@@ -219,6 +219,7 @@ class Button(Widget, can_focus=True):
             self.tooltip = tooltip
 
     def get_content_width(self, container: Size, viewport: Size) -> int:
+        assert isinstance(self.label, Content)
         try:
             return max([cell_len(line) for line in self.label.plain.splitlines()]) + 2
         except ValueError:
@@ -240,23 +241,13 @@ class Button(Widget, can_focus=True):
         self.remove_class(f"-{old_variant}")
         self.add_class(f"-{variant}")
 
-    def validate_label(self, label: TextType) -> Text:
+    def validate_label(self, label: ContentText) -> Content:
         """Parse markup for self.label"""
-        if isinstance(label, str):
-            return Text.from_markup(label)
-        return label
+        return Content.from_text(label)
 
     def render(self) -> RenderResult:
-        assert isinstance(self.label, Text)
-        label = self.label.copy()
-        label.stylize_before(self.rich_style)
-        return HorizontalPad(
-            label,
-            1,
-            1,
-            self.rich_style,
-            self._get_justify_method() or "center",
-        )
+        assert isinstance(self.label, Content)
+        return self.label
 
     def post_render(
         self, renderable: RenderableType, base_style: Style
@@ -305,7 +296,7 @@ class Button(Widget, can_focus=True):
     @classmethod
     def success(
         cls,
-        label: TextType | None = None,
+        label: ContentText | None = None,
         *,
         name: str | None = None,
         id: str | None = None,
@@ -338,7 +329,7 @@ class Button(Widget, can_focus=True):
     @classmethod
     def warning(
         cls,
-        label: TextType | None = None,
+        label: ContentText | None = None,
         *,
         name: str | None = None,
         id: str | None = None,
@@ -371,7 +362,7 @@ class Button(Widget, can_focus=True):
     @classmethod
     def error(
         cls,
-        label: TextType | None = None,
+        label: ContentText | None = None,
         *,
         name: str | None = None,
         id: str | None = None,
diff --git a/contrib/python/textual/textual/widgets/_label.py b/contrib/python/textual/textual/widgets/_label.py
index 9cd739e729b..89a1dc1db18 100644
--- a/contrib/python/textual/textual/widgets/_label.py
+++ b/contrib/python/textual/textual/widgets/_label.py
@@ -4,9 +4,7 @@ from __future__ import annotations
 
 from typing import Literal
 
-from rich.console import RenderableType
-
-from textual.visual import SupportsVisual
+from textual.visual import VisualType
 from textual.widgets._static import Static
 
 LabelVariant = Literal["success", "error", "warning", "primary", "secondary", "accent"]
@@ -50,7 +48,8 @@ class Label(Static):
 
     def __init__(
         self,
-        renderable: RenderableType | SupportsVisual = "",
+        # TODO: Should probably be renamed to `content`.
+        renderable: VisualType = "",
         *,
         variant: LabelVariant | None = None,
         expand: bool = False,
diff --git a/contrib/python/textual/textual/widgets/_log.py b/contrib/python/textual/textual/widgets/_log.py
index 7e7fadaefaf..bcf9c871320 100644
--- a/contrib/python/textual/textual/widgets/_log.py
+++ b/contrib/python/textual/textual/widgets/_log.py
@@ -195,16 +195,21 @@ class Log(ScrollView, can_focus=True):
             self.scroll_end(animate=False, immediate=True, x_axis=False)
         return self
 
-    def write_line(self, line: str) -> Self:
+    def write_line(
+        self,
+        line: str,
+        scroll_end: bool | None = None,
+    ) -> Self:
         """Write content on a new line.
 
         Args:
             line: String to write to the log.
+            scroll_end: Scroll to the end after writing, or `None` to use `self.auto_scroll`.
 
         Returns:
             The `Log` instance.
         """
-        self.write_lines([line])
+        self.write_lines([line], scroll_end)
         return self
 
     def write_lines(
diff --git a/contrib/python/textual/textual/widgets/_select.py b/contrib/python/textual/textual/widgets/_select.py
index c87112ae923..5ba4df571a4 100644
--- a/contrib/python/textual/textual/widgets/_select.py
+++ b/contrib/python/textual/textual/widgets/_select.py
@@ -477,7 +477,8 @@ class Select(Generic[SelectType], Vertical, can_focus=True):
 
         """
         value = self.value
-        assert not isinstance(value, NoSelection)
+        if isinstance(value, NoSelection):
+            return None
         return value
 
     def _setup_variables_for_options(
diff --git a/contrib/python/textual/textual/widgets/_selection_list.py b/contrib/python/textual/textual/widgets/_selection_list.py
index 8ef829491ca..7fe2636f05d 100644
--- a/contrib/python/textual/textual/widgets/_selection_list.py
+++ b/contrib/python/textual/textual/widgets/_selection_list.py
@@ -8,11 +8,11 @@ from typing import Callable, ClassVar, Generic, Iterable, TypeVar, cast
 from rich.repr import Result
 from rich.segment import Segment
 from rich.style import Style
-from rich.text import Text, TextType
 from typing_extensions import Self
 
 from textual import events
 from textual.binding import Binding
+from textual.content import Content, ContentText
 from textual.messages import Message
 from textual.strip import Strip
 from textual.widgets._option_list import (
@@ -39,7 +39,7 @@ class Selection(Generic[SelectionType], Option):
 
     def __init__(
         self,
-        prompt: TextType,
+        prompt: ContentText,
         value: SelectionType,
         initial_state: bool = False,
         id: str | None = None,
@@ -54,10 +54,9 @@ class Selection(Generic[SelectionType], Option):
             id: The optional ID for the selection.
             disabled: The initial enabled/disabled state. Enabled by default.
         """
-        if isinstance(prompt, str):
-            prompt = Text.from_markup(prompt, overflow="ellipsis")
-        prompt.no_wrap = True
-        super().__init__(prompt.split()[0], id, disabled)
+
+        selection_prompt = Content.from_text(prompt)
+        super().__init__(selection_prompt.split()[0], id, disabled)
         self._value: SelectionType = value
         """The value associated with the selection."""
         self._initial_state: bool = initial_state
@@ -102,6 +101,8 @@ class SelectionList(Generic[SelectionType], OptionList):
     DEFAULT_CSS = """
     SelectionList {
         height: auto;
+        text-wrap: nowrap;
+        text-overflow: ellipsis;
         
         & > .selection-list--button {
             color: $panel-darken-2;
@@ -213,8 +214,8 @@ class SelectionList(Generic[SelectionType], OptionList):
     def __init__(
         self,
         *selections: Selection[SelectionType]
-        | tuple[TextType, SelectionType]
-        | tuple[TextType, SelectionType, bool],
+        | tuple[ContentText, SelectionType]
+        | tuple[ContentText, SelectionType, bool],
         name: str | None = None,
         id: str | None = None,
         classes: str | None = None,
@@ -440,8 +441,8 @@ class SelectionList(Generic[SelectionType], OptionList):
         self,
         selection: (
             Selection[SelectionType]
-            | tuple[TextType, SelectionType]
-            | tuple[TextType, SelectionType, bool]
+            | tuple[ContentText, SelectionType]
+            | tuple[ContentText, SelectionType, bool]
         ),
     ) -> Selection[SelectionType]:
         """Turn incoming selection data into a `Selection` instance.
@@ -461,7 +462,7 @@ class SelectionList(Generic[SelectionType], OptionList):
         if isinstance(selection, tuple):
             if len(selection) == 2:
                 selection = cast(
-                    "tuple[TextType, SelectionType, bool]", (*selection, False)
+                    "tuple[ContentText, SelectionType, bool]", (*selection, False)
                 )
             elif len(selection) != 3:
                 raise SelectionError(f"Expected 2 or 3 values, got {len(selection)}")
@@ -626,8 +627,8 @@ class SelectionList(Generic[SelectionType], OptionList):
         items: Iterable[
             OptionListContent
             | Selection[SelectionType]
-            | tuple[TextType, SelectionType]
-            | tuple[TextType, SelectionType, bool]
+            | tuple[ContentText, SelectionType]
+            | tuple[ContentText, SelectionType, bool]
         ],
     ) -> Self:
         """Add new selection options to the end of the list.
@@ -654,7 +655,7 @@ class SelectionList(Generic[SelectionType], OptionList):
                 cleaned_options.append(
                     self._make_selection(
                         cast(
-                            "tuple[TextType, SelectionType] | tuple[TextType, SelectionType, bool]",
+                            "tuple[ContentText, SelectionType] | tuple[ContentText, SelectionType, bool]",
                             item,
                         )
                     )
@@ -681,8 +682,8 @@ class SelectionList(Generic[SelectionType], OptionList):
         item: (
             OptionListContent
             | Selection
-            | tuple[TextType, SelectionType]
-            | tuple[TextType, SelectionType, bool]
+            | tuple[ContentText, SelectionType]
+            | tuple[ContentText, SelectionType, bool]
         ) = None,
     ) -> Self:
         """Add a new selection option to the end of the list.
diff --git a/contrib/python/textual/textual/widgets/_static.py b/contrib/python/textual/textual/widgets/_static.py
index 7a354dab738..097d2cb165d 100644
--- a/contrib/python/textual/textual/widgets/_static.py
+++ b/contrib/python/textual/textual/widgets/_static.py
@@ -2,14 +2,13 @@ from __future__ import annotations
 
 from typing import TYPE_CHECKING
 
-from rich.console import RenderableType
 from rich.protocol import is_renderable
 
 if TYPE_CHECKING:
     from textual.app import RenderResult
 
 from textual.errors import RenderError
-from textual.visual import SupportsVisual, Visual, VisualType, visualize
+from textual.visual import Visual, VisualType, visualize
 from textual.widget import Widget
 
 
@@ -33,7 +32,7 @@ class Static(Widget, inherit_bindings=False):
     """A widget to display simple static content, or use as a base class for more complex widgets.
 
     Args:
-        content: A Rich renderable, or string containing console markup.
+        content: A Content object, Rich renderable, or string containing console markup.
         expand: Expand content if required to fill container.
         shrink: Shrink content if required to fill container.
         markup: True if markup should be parsed and rendered.
@@ -49,11 +48,11 @@ class Static(Widget, inherit_bindings=False):
     }
     """
 
-    _renderable: RenderableType | SupportsVisual
+    _renderable: VisualType
 
     def __init__(
         self,
-        content: RenderableType | SupportsVisual = "",
+        content: VisualType = "",
         *,
         expand: bool = False,
         shrink: bool = False,
@@ -78,11 +77,12 @@ class Static(Widget, inherit_bindings=False):
         return self._visual
 
     @property
-    def renderable(self) -> RenderableType | SupportsVisual:
+    def renderable(self) -> VisualType:
         return self._content or ""
 
+    # TODO: Should probably be renamed to `content`.
     @renderable.setter
-    def renderable(self, renderable: RenderableType | SupportsVisual) -> None:
+    def renderable(self, renderable: VisualType) -> None:
         self._renderable = renderable
         self._visual = None
         self.clear_cached_dimensions()
diff --git a/contrib/python/textual/textual/widgets/_tabbed_content.py b/contrib/python/textual/textual/widgets/_tabbed_content.py
index cca85280904..a7fcb9b0aa6 100644
--- a/contrib/python/textual/textual/widgets/_tabbed_content.py
+++ b/contrib/python/textual/textual/widgets/_tabbed_content.py
@@ -6,13 +6,12 @@ from itertools import zip_longest
 from typing import Awaitable
 
 from rich.repr import Result
-from rich.text import TextType
 from typing_extensions import Final
 
 from textual import events
 from textual.app import ComposeResult
 from textual.await_complete import AwaitComplete
-from textual.content import ContentType
+from textual.content import ContentText, ContentType
 from textual.css.query import NoMatches
 from textual.message import Message
 from textual.reactive import reactive
@@ -79,7 +78,7 @@ class ContentTabs(Tabs):
 
     def __init__(
         self,
-        *tabs: Tab | TextType,
+        *tabs: Tab | ContentText,
         active: str | None = None,
         tabbed_content: TabbedContent,
     ):
diff --git a/contrib/python/textual/textual/widgets/_tabs.py b/contrib/python/textual/textual/widgets/_tabs.py
index d4d2f455c30..ac856ebd651 100644
--- a/contrib/python/textual/textual/widgets/_tabs.py
+++ b/contrib/python/textual/textual/widgets/_tabs.py
@@ -1,29 +1,28 @@
 from __future__ import annotations
 
 from dataclasses import dataclass
-from typing import TYPE_CHECKING, ClassVar
+from typing import ClassVar
 
 import rich.repr
 from rich.style import Style
-from rich.text import Text, TextType
+from rich.text import Text
 
 from textual import events
 from textual.app import ComposeResult, RenderResult
 from textual.await_complete import AwaitComplete
 from textual.binding import Binding, BindingType
 from textual.containers import Container, Horizontal, Vertical
+from textual.content import Content, ContentText
 from textual.css.query import NoMatches
 from textual.events import Mount
 from textual.geometry import Offset
 from textual.message import Message
 from textual.reactive import reactive
 from textual.renderables.bar import Bar
+from textual.visual import VisualType
 from textual.widget import Widget
 from textual.widgets import Static
 
-if TYPE_CHECKING:
-    from textual.content import Content, ContentType
-
 
 class Underline(Widget):
     """The animated underline beneath tabs."""
@@ -150,7 +149,7 @@ class Tab(Static):
 
     def __init__(
         self,
-        label: ContentType,
+        label: ContentText,
         *,
         id: str | None = None,
         classes: str | None = None,
@@ -167,7 +166,7 @@ class Tab(Static):
         super().__init__(id=id, classes=classes, disabled=disabled)
         self._label: Content
         # Setter takes Text or str
-        self.label = label  # type: ignore[assignment]
+        self.label = Content.from_text(label)
 
     @property
     def label(self) -> Content:
@@ -175,13 +174,13 @@ class Tab(Static):
         return self._label
 
     @label.setter
-    def label(self, label: ContentType) -> None:
-        self._label = self.render_str(label)
+    def label(self, label: ContentText) -> None:
+        self._label = Content.from_text(label)
         self.update(self._label)
 
-    def update(self, content: ContentType = "") -> None:
+    def update(self, content: VisualType = "") -> None:
         self.post_message(self.Relabelled(self))
-        return super().update(self.render_str(content))
+        return super().update(content)
 
     @property
     def label_text(self) -> str:
@@ -347,7 +346,7 @@ class Tabs(Widget, can_focus=True):
 
     def __init__(
         self,
-        *tabs: Tab | TextType,
+        *tabs: Tab | ContentText,
         active: str | None = None,
         name: str | None = None,
         id: str | None = None,
@@ -369,7 +368,7 @@ class Tabs(Widget, can_focus=True):
         add_tabs = [
             (
                 Tab(tab, id=f"tab-{self._new_tab_id}")
-                if isinstance(tab, (str, Text))
+                if isinstance(tab, (str, Content, Text))
                 else self._auto_tab_id(tab)
             )
             for tab in tabs
@@ -435,7 +434,7 @@ class Tabs(Widget, can_focus=True):
 
     def add_tab(
         self,
-        tab: Tab | str | Text,
+        tab: Tab | ContentText,
         *,
         before: Tab | str | None = None,
         after: Tab | str | None = None,
@@ -487,7 +486,7 @@ class Tabs(Widget, can_focus=True):
         from_empty = self.tab_count == 0
         tab_widget = (
             Tab(tab, id=f"tab-{self._new_tab_id}")
-            if isinstance(tab, (str, Text))
+            if isinstance(tab, (str, Content, Text))
             else self._auto_tab_id(tab)
         )
 
diff --git a/contrib/python/textual/textual/widgets/_text_area.py b/contrib/python/textual/textual/widgets/_text_area.py
index 687ef8107d1..542ff28cd1b 100644
--- a/contrib/python/textual/textual/widgets/_text_area.py
+++ b/contrib/python/textual/textual/widgets/_text_area.py
@@ -14,7 +14,7 @@ from rich.text import Text
 from typing_extensions import Literal
 
 from textual._text_area_theme import TextAreaTheme
-from textual._tree_sitter import BUILTIN_LANGUAGES, TREE_SITTER
+from textual._tree_sitter import TREE_SITTER, get_language
 from textual.color import Color
 from textual.document._document import (
     Document,
@@ -57,6 +57,25 @@ HighlightName = str
 Highlight = Tuple[StartColumn, EndColumn, HighlightName]
 """A tuple representing a syntax highlight within one line."""
 
+BUILTIN_LANGUAGES = [
+    "python",
+    "markdown",
+    "json",
+    "toml",
+    "yaml",
+    "html",
+    "css",
+    "javascript",
+    "rust",
+    "go",
+    "regex",
+    "sql",
+    "java",
+    "bash",
+    "xml",
+]
+"""Languages that are included in the `syntax` extras."""
+
 
 class ThemeDoesNotExist(Exception):
     """Raised when the user tries to use a theme which does not exist.
@@ -72,17 +91,16 @@ class LanguageDoesNotExist(Exception):
 
 @dataclass
 class TextAreaLanguage:
-    """A container for a language which has been registered with the TextArea.
-
-    Attributes:
-        name: The name of the language.
-        language: The tree-sitter Language.
-        highlight_query: The tree-sitter highlight query corresponding to the language, as a string.
-    """
+    """A container for a language which has been registered with the TextArea."""
 
     name: str
-    language: "Language"
+    """The name of the language"""
+
+    language: "Language" | None
+    """The tree-sitter language object if that has been overridden, or None if it is a built-in language."""
+
     highlight_query: str
+    """The tree-sitter highlight query to use for syntax highlighting."""
 
 
 class TextArea(ScrollView):
@@ -423,14 +441,12 @@ TextArea {
         super().__init__(name=name, id=id, classes=classes, disabled=disabled)
 
         self._languages: dict[str, TextAreaLanguage] = {}
-        """Maps language names to TextAreaLanguage."""
-
-        for language_name, language_object in BUILTIN_LANGUAGES.items():
-            self._languages[language_name] = TextAreaLanguage(
-                language_name,
-                language_object,
-                self._get_builtin_highlight_query(language_name),
-            )
+        """Maps language names to TextAreaLanguage. This is only used for languages
+        registered by end-users using `TextArea.register_language`. If a user attempts
+        to set `TextArea.language` to a language that is not registered here, we'll
+        attempt to get it from the environment. If that fails, we'll fall back to
+        plain text.
+        """
 
         self._themes: dict[str, TextAreaTheme] = {}
         """Maps theme names to TextAreaTheme."""
@@ -740,16 +756,6 @@ TextArea {
 
     def _watch_language(self, language: str | None) -> None:
         """When the language is updated, update the type of document."""
-        if not TREE_SITTER:
-            return
-
-        if language is not None and language not in self.available_languages:
-            raise LanguageDoesNotExist(
-                f"{language!r} is not a builtin language, or it has not been registered. "
-                f"To use a custom language, register it first using `register_language`, "
-                f"then switch to it by setting the `TextArea.language` attribute."
-            )
-
         self._set_document(self.document.text, language)
 
     def _watch_show_line_numbers(self) -> None:
@@ -839,14 +845,13 @@ TextArea {
 
     @property
     def available_languages(self) -> set[str]:
-        """A list of the names of languages available to the `TextArea`.
+        """A set of the names of languages available to the `TextArea`.
 
-        The values in this list can be assigned to the `language` reactive attribute
+        The values in this set can be assigned to the `language` reactive attribute
         of `TextArea`.
 
-        The returned list contains the builtin languages plus those registered via the
-        `register_language` method. Builtin languages will be listed before
-        user-registered languages, but there are no other ordering guarantees.
+        The returned set contains the builtin languages installed with the syntax extras,
+        plus those registered via the `register_language` method.
         """
         return set(BUILTIN_LANGUAGES) | self._languages.keys()
 
@@ -872,8 +877,6 @@ TextArea {
             language: A tree-sitter `Language` object.
             highlight_query: The highlight query to use for syntax highlighting this language.
         """
-        if not TREE_SITTER:
-            return
         self._languages[name] = TextAreaLanguage(name, language, highlight_query)
 
     def update_highlight_query(self, name: str, highlight_query: str) -> None:
@@ -884,11 +887,12 @@ TextArea {
             highlight_query: The highlight query to use for syntax highlighting this language.
         """
         if name not in self._languages:
-            raise LanguageDoesNotExist(
-                f"{name!r} is not a registered language.\n"
-                f"To register a language, call `TextArea.register_language`."
-            )
-        self._languages[name].highlight_query = highlight_query
+            self._languages[name] = TextAreaLanguage(name, None, highlight_query)
+        else:
+            self._languages[name].highlight_query = highlight_query
+
+        # If this is the currently loaded language, reload the document because
+        # it could be a different highlight query for the same language.
         if name == self.language:
             self._set_document(self.text, name)
 
@@ -897,39 +901,57 @@ TextArea {
 
         Args:
             text: The text of the document.
-            language: The name of the language to use. This must either be a
-                built-in supported language, or a language previously registered
-                via the `register_language` method.
+            language: The name of the language to use. This must correspond to a tree-sitter
+                language available in the current environment (e.g. use `python` for `tree-sitter-python`).
+                If None, the document will be treated as plain text.
         """
         self._highlight_query = None
         if TREE_SITTER and language:
-            # Attempt to get the override language.
-            text_area_language = self._languages.get(language, None)
-            document_language: "str | Language"
-            if text_area_language:
-                document_language = text_area_language.language
-                highlight_query = text_area_language.highlight_query
+            if language in self._languages:
+                # User-registered languages take priority.
+                highlight_query = self._languages[language].highlight_query
+                document_language = self._languages[language].language
+                if document_language is None:
+                    document_language = get_language(language)
             else:
-                document_language = language
+                # No user-registered language, so attempt to use a built-in language.
                 highlight_query = self._get_builtin_highlight_query(language)
-            document: DocumentBase
-            try:
-                document = SyntaxAwareDocument(text, document_language)
-            except SyntaxAwareDocumentError:
-                document = Document(text)
-                log.warning(
-                    f"Parser not found for language {document_language!r}. Parsing disabled."
+                document_language = get_language(language)
+
+            # No built-in language, and no user-registered language: use plain text and warn.
+            if document_language is None:
+                raise LanguageDoesNotExist(
+                    f"tree-sitter is available, but no built-in or user-registered language called {language!r}.\n"
+                    f"Ensure the language is installed (e.g. `pip install tree-sitter-ruby`)\n"
+                    f"Falling back to plain text."
                 )
             else:
-                self._highlight_query = document.prepare_query(highlight_query)
+                document: DocumentBase
+                try:
+                    document = SyntaxAwareDocument(text, document_language)
+                except SyntaxAwareDocumentError:
+                    document = Document(text)
+                    log.warning(
+                        f"Parser not found for language {document_language!r}. Parsing disabled."
+                    )
+                else:
+                    self._highlight_query = document.prepare_query(highlight_query)
         elif language and not TREE_SITTER:
+            # User has supplied a language i.e. `TextArea(language="python")`, but they
+            # don't have tree-sitter available in the environment. We fallback to plain text.
             log.warning(
                 "tree-sitter not available in this environment. Parsing disabled.\n"
                 "You may need to install the `syntax` extras alongside textual.\n"
-                "Try `pip install 'textual[syntax]'` or '`poetry add textual[syntax]'."
+                "Try `pip install 'textual[syntax]'` or '`poetry add textual[syntax]' to get started quickly.\n\n"
+                "Alternatively, install tree-sitter manually (`pip install tree-sitter`) and then\n"
+                "install the required language (e.g. `pip install tree-sitter-ruby`), then register it.\n"
+                "and it's highlight query using TextArea.register_language().\n\n"
+                "Falling back to plain text for now."
             )
             document = Document(text)
         else:
+            # tree-sitter is available, but the user has supplied None or "" for the language.
+            # Use a regular plain-text document.
             document = Document(text)
 
         self.document = document
diff --git a/contrib/python/textual/textual/widgets/_toggle_button.py b/contrib/python/textual/textual/widgets/_toggle_button.py
index 0b35ca2a8ea..d36b386ccda 100644
--- a/contrib/python/textual/textual/widgets/_toggle_button.py
+++ b/contrib/python/textual/textual/widgets/_toggle_button.py
@@ -8,15 +8,14 @@ from __future__ import annotations
 from typing import TYPE_CHECKING, ClassVar
 
 from rich.console import RenderableType
-from rich.style import Style
-from rich.text import Text, TextType
 
-from textual.app import RenderResult
 from textual.binding import Binding, BindingType
+from textual.content import Content, ContentText
 from textual.events import Click
 from textual.geometry import Size
 from textual.message import Message
 from textual.reactive import reactive
+from textual.style import Style
 from textual.widgets._static import Static
 
 if TYPE_CHECKING:
@@ -59,6 +58,8 @@ class ToggleButton(Static, can_focus=True):
         border: tall $border-blurred;
         padding: 0 1;
         background: $surface;
+        text-wrap: nowrap;
+        text-overflow: ellipsis;
 
         & > .toggle--button {
             color: $panel-darken-2;
@@ -101,7 +102,7 @@ class ToggleButton(Static, can_focus=True):
 
     def __init__(
         self,
-        label: TextType = "",
+        label: ContentText = "",
         value: bool = False,
         button_first: bool = True,
         *,
@@ -132,76 +133,72 @@ class ToggleButton(Static, can_focus=True):
         if tooltip is not None:
             self.tooltip = tooltip
 
-    def _make_label(self, label: TextType) -> Text:
-        """Make a `Text` label from a `TextType` value.
+    def _make_label(self, label: ContentText) -> Content:
+        """Make label content.
 
         Args:
             label: The source value for the label.
 
         Returns:
-            A `Text` rendering of the label for use in the button.
+            A `Content` rendering of the label for use in the button.
         """
-        label = Text.from_markup(label) if isinstance(label, str) else label
-        try:
-            # Only use the first line if it's a multi-line label.
-            label = label.split()[0]
-        except IndexError:
-            pass
-
+        label = Content.from_text(label).first_line
         return label
 
     @property
-    def label(self) -> Text:
+    def label(self) -> Content:
         """The label associated with the button."""
         return self._label
 
     @label.setter
-    def label(self, label: TextType) -> None:
+    def label(self, label: ContentText) -> None:
         self._label = self._make_label(label)
         self.refresh(layout=True)
 
     @property
-    def _button(self) -> Text:
+    def _button(self) -> Content:
         """The button, reflecting the current value."""
 
         # Grab the button style.
-        button_style = self.get_component_rich_style("toggle--button")
+        button_style = self.get_visual_style("toggle--button")
 
         # Building the style for the side characters. Note that this is
         # sensitive to the type of character used, so pay attention to
         # BUTTON_LEFT and BUTTON_RIGHT.
-        side_style = Style.from_color(
-            button_style.bgcolor, self.background_colors[1].rich_color
+        side_style = Style(
+            foreground=button_style.background,
+            background=self.background_colors[1],
         )
 
-        return Text.assemble(
+        return Content.assemble(
             (self.BUTTON_LEFT, side_style),
             (self.BUTTON_INNER, button_style),
             (self.BUTTON_RIGHT, side_style),
         )
 
-    def render(self) -> RenderResult:
+    def render(self) -> Content:
         """Render the content of the widget.
 
         Returns:
             The content to render for the widget.
         """
         button = self._button
-        label = self._label.copy()
-        label.stylize_before(self.get_component_rich_style("toggle--label"))
+        label_style = self.get_visual_style("toggle--label")
+        label = self._label.stylize_before(label_style)
         spacer = " " if label else ""
-        return Text.assemble(
-            *(
-                (button, spacer, label)
-                if self._button_first
-                else (label, spacer, button)
-            ),
-            no_wrap=True,
-            overflow="ellipsis",
-        )
+
+        if self._button_first:
+            content = Content.assemble(button, spacer, label)
+        else:
+            content = Content.assemble(label, spacer, button)
+        return content
 
     def get_content_width(self, container: Size, viewport: Size) -> int:
-        return self._button.cell_len + (1 if self._label else 0) + self._label.cell_len
+        return (
+            self._button.get_optimal_width(self.styles, 0)
+            + (1 if self._label else 0)
+            + self._label.get_optimal_width(self.styles, 0)
+        )
 
     def get_content_height(self, container: Size, viewport: Size, width: int) -> int:
         return 1
diff --git a/contrib/python/textual/textual/widgets/_tree.py b/contrib/python/textual/textual/widgets/_tree.py
index 1614fc8a308..8f9119a5560 100644
--- a/contrib/python/textual/textual/widgets/_tree.py
+++ b/contrib/python/textual/textual/widgets/_tree.py
@@ -553,7 +553,7 @@ class Tree(Generic[TreeDataType], ScrollView, can_focus=True):
     | Key(s) | Description |
     | :- | :- |
     | enter | Select the current item. |
-    | space | Toggle the expand/collapsed space of the current item. |
+    | space | Toggle the expand/collapsed state of the current item. |
     | up | Move the cursor up. |
     | down | Move the cursor down. |
     """
diff --git a/contrib/python/textual/textual/widgets/text_area.py b/contrib/python/textual/textual/widgets/text_area.py
index 1d4621a78b8..a879e2594c6 100644
--- a/contrib/python/textual/textual/widgets/text_area.py
+++ b/contrib/python/textual/textual/widgets/text_area.py
@@ -1,5 +1,4 @@
 from textual._text_area_theme import TextAreaTheme
-from textual._tree_sitter import BUILTIN_LANGUAGES
 from textual.document._document import (
     Document,
     DocumentBase,
@@ -19,6 +18,7 @@ from textual.widgets._text_area import (
     LanguageDoesNotExist,
     StartColumn,
     ThemeDoesNotExist,
+    BUILTIN_LANGUAGES,
 )
 
 __all__ = [
diff --git a/contrib/python/textual/ya.make b/contrib/python/textual/ya.make
index d5b22285e75..b8f5dd8bb08 100644
--- a/contrib/python/textual/ya.make
+++ b/contrib/python/textual/ya.make
@@ -2,7 +2,7 @@
 
 PY3_LIBRARY()
 
-VERSION(2.1.2)
+VERSION(3.0.1)
 
 LICENSE(MIT)