Adding upstream version 3.0.43.upstream/3.0.43upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

6 files changed, 816 insertions, 0 deletions

diff --git a/src/prompt_toolkit/formatted_text/__init__.py b/src/prompt_toolkit/formatted_text/__init__.py
new file mode 100644
index 0000000..db44ab9
--- /dev/null
+++ b/src/prompt_toolkit/formatted_text/__init__.py
@@ -0,0 +1,58 @@
+"""
+Many places in prompt_toolkit can take either plain text, or formatted text.
+For instance the :func:`~prompt_toolkit.shortcuts.prompt` function takes either
+plain text or formatted text for the prompt. The
+:class:`~prompt_toolkit.layout.FormattedTextControl` can also take either plain
+text or formatted text.
+
+In any case, there is an input that can either be just plain text (a string),
+an :class:`.HTML` object, an :class:`.ANSI` object or a sequence of
+`(style_string, text)` tuples. The :func:`.to_formatted_text` conversion
+function takes any of these and turns all of them into such a tuple sequence.
+"""
+from __future__ import annotations
+
+from .ansi import ANSI
+from .base import (
+    AnyFormattedText,
+    FormattedText,
+    OneStyleAndTextTuple,
+    StyleAndTextTuples,
+    Template,
+    is_formatted_text,
+    merge_formatted_text,
+    to_formatted_text,
+)
+from .html import HTML
+from .pygments import PygmentsTokens
+from .utils import (
+    fragment_list_len,
+    fragment_list_to_text,
+    fragment_list_width,
+    split_lines,
+    to_plain_text,
+)
+
+__all__ = [
+    # Base.
+    "AnyFormattedText",
+    "OneStyleAndTextTuple",
+    "to_formatted_text",
+    "is_formatted_text",
+    "Template",
+    "merge_formatted_text",
+    "FormattedText",
+    "StyleAndTextTuples",
+    # HTML.
+    "HTML",
+    # ANSI.
+    "ANSI",
+    # Pygments.
+    "PygmentsTokens",
+    # Utils.
+    "fragment_list_len",
+    "fragment_list_width",
+    "fragment_list_to_text",
+    "split_lines",
+    "to_plain_text",
+]
diff --git a/src/prompt_toolkit/formatted_text/ansi.py b/src/prompt_toolkit/formatted_text/ansi.py
new file mode 100644
index 0000000..08ec0b3
--- /dev/null
+++ b/src/prompt_toolkit/formatted_text/ansi.py
@@ -0,0 +1,299 @@
+from __future__ import annotations
+
+from string import Formatter
+from typing import Generator
+
+from prompt_toolkit.output.vt100 import BG_ANSI_COLORS, FG_ANSI_COLORS
+from prompt_toolkit.output.vt100 import _256_colors as _256_colors_table
+
+from .base import StyleAndTextTuples
+
+__all__ = [
+    "ANSI",
+    "ansi_escape",
+]
+
+
+class ANSI:
+    """
+    ANSI formatted text.
+    Take something ANSI escaped text, for use as a formatted string. E.g.
+
+    ::
+
+        ANSI('\\x1b[31mhello \\x1b[32mworld')
+
+    Characters between ``\\001`` and ``\\002`` are supposed to have a zero width
+    when printed, but these are literally sent to the terminal output. This can
+    be used for instance, for inserting Final Term prompt commands.  They will
+    be translated into a prompt_toolkit '[ZeroWidthEscape]' fragment.
+    """
+
+    def __init__(self, value: str) -> None:
+        self.value = value
+        self._formatted_text: StyleAndTextTuples = []
+
+        # Default style attributes.
+        self._color: str | None = None
+        self._bgcolor: str | None = None
+        self._bold = False
+        self._underline = False
+        self._strike = False
+        self._italic = False
+        self._blink = False
+        self._reverse = False
+        self._hidden = False
+
+        # Process received text.
+        parser = self._parse_corot()
+        parser.send(None)  # type: ignore
+        for c in value:
+            parser.send(c)
+
+    def _parse_corot(self) -> Generator[None, str, None]:
+        """
+        Coroutine that parses the ANSI escape sequences.
+        """
+        style = ""
+        formatted_text = self._formatted_text
+
+        while True:
+            # NOTE: CSI is a special token within a stream of characters that
+            #       introduces an ANSI control sequence used to set the
+            #       style attributes of the following characters.
+            csi = False
+
+            c = yield
+
+            # Everything between \001 and \002 should become a ZeroWidthEscape.
+            if c == "\001":
+                escaped_text = ""
+                while c != "\002":
+                    c = yield
+                    if c == "\002":
+                        formatted_text.append(("[ZeroWidthEscape]", escaped_text))
+                        c = yield
+                        break
+                    else:
+                        escaped_text += c
+
+            # Check for CSI
+            if c == "\x1b":
+                # Start of color escape sequence.
+                square_bracket = yield
+                if square_bracket == "[":
+                    csi = True
+                else:
+                    continue
+            elif c == "\x9b":
+                csi = True
+
+            if csi:
+                # Got a CSI sequence. Color codes are following.
+                current = ""
+                params = []
+
+                while True:
+                    char = yield
+
+                    # Construct number
+                    if char.isdigit():
+                        current += char
+
+                    # Eval number
+                    else:
+                        # Limit and save number value
+                        params.append(min(int(current or 0), 9999))
+
+                        # Get delimiter token if present
+                        if char == ";":
+                            current = ""
+
+                        # Check and evaluate color codes
+                        elif char == "m":
+                            # Set attributes and token.
+                            self._select_graphic_rendition(params)
+                            style = self._create_style_string()
+                            break
+
+                        # Check and evaluate cursor forward
+                        elif char == "C":
+                            for i in range(params[0]):
+                                # add <SPACE> using current style
+                                formatted_text.append((style, " "))
+                            break
+
+                        else:
+                            # Ignore unsupported sequence.
+                            break
+            else:
+                # Add current character.
+                # NOTE: At this point, we could merge the current character
+                #       into the previous tuple if the style did not change,
+                #       however, it's not worth the effort given that it will
+                #       be "Exploded" once again when it's rendered to the
+                #       output.
+                formatted_text.append((style, c))
+
+    def _select_graphic_rendition(self, attrs: list[int]) -> None:
+        """
+        Taken a list of graphics attributes and apply changes.
+        """
+        if not attrs:
+            attrs = [0]
+        else:
+            attrs = list(attrs[::-1])
+
+        while attrs:
+            attr = attrs.pop()
+
+            if attr in _fg_colors:
+                self._color = _fg_colors[attr]
+            elif attr in _bg_colors:
+                self._bgcolor = _bg_colors[attr]
+            elif attr == 1:
+                self._bold = True
+            # elif attr == 2:
+            #   self._faint = True
+            elif attr == 3:
+                self._italic = True
+            elif attr == 4:
+                self._underline = True
+            elif attr == 5:
+                self._blink = True  # Slow blink
+            elif attr == 6:
+                self._blink = True  # Fast blink
+            elif attr == 7:
+                self._reverse = True
+            elif attr == 8:
+                self._hidden = True
+            elif attr == 9:
+                self._strike = True
+            elif attr == 22:
+                self._bold = False  # Normal intensity
+            elif attr == 23:
+                self._italic = False
+            elif attr == 24:
+                self._underline = False
+            elif attr == 25:
+                self._blink = False
+            elif attr == 27:
+                self._reverse = False
+            elif attr == 28:
+                self._hidden = False
+            elif attr == 29:
+                self._strike = False
+            elif not attr:
+                # Reset all style attributes
+                self._color = None
+                self._bgcolor = None
+                self._bold = False
+                self._underline = False
+                self._strike = False
+                self._italic = False
+                self._blink = False
+                self._reverse = False
+                self._hidden = False
+
+            elif attr in (38, 48) and len(attrs) > 1:
+                n = attrs.pop()
+
+                # 256 colors.
+                if n == 5 and len(attrs) >= 1:
+                    if attr == 38:
+                        m = attrs.pop()
+                        self._color = _256_colors.get(m)
+                    elif attr == 48:
+                        m = attrs.pop()
+                        self._bgcolor = _256_colors.get(m)
+
+                # True colors.
+                if n == 2 and len(attrs) >= 3:
+                    try:
+                        color_str = "#{:02x}{:02x}{:02x}".format(
+                            attrs.pop(),
+                            attrs.pop(),
+                            attrs.pop(),
+                        )
+                    except IndexError:
+                        pass
+                    else:
+                        if attr == 38:
+                            self._color = color_str
+                        elif attr == 48:
+                            self._bgcolor = color_str
+
+    def _create_style_string(self) -> str:
+        """
+        Turn current style flags into a string for usage in a formatted text.
+        """
+        result = []
+        if self._color:
+            result.append(self._color)
+        if self._bgcolor:
+            result.append("bg:" + self._bgcolor)
+        if self._bold:
+            result.append("bold")
+        if self._underline:
+            result.append("underline")
+        if self._strike:
+            result.append("strike")
+        if self._italic:
+            result.append("italic")
+        if self._blink:
+            result.append("blink")
+        if self._reverse:
+            result.append("reverse")
+        if self._hidden:
+            result.append("hidden")
+
+        return " ".join(result)
+
+    def __repr__(self) -> str:
+        return f"ANSI({self.value!r})"
+
+    def __pt_formatted_text__(self) -> StyleAndTextTuples:
+        return self._formatted_text
+
+    def format(self, *args: str, **kwargs: str) -> ANSI:
+        """
+        Like `str.format`, but make sure that the arguments are properly
+        escaped. (No ANSI escapes can be injected.)
+        """
+        return ANSI(FORMATTER.vformat(self.value, args, kwargs))
+
+    def __mod__(self, value: object) -> ANSI:
+        """
+        ANSI('<b>%s</b>') % value
+        """
+        if not isinstance(value, tuple):
+            value = (value,)
+
+        value = tuple(ansi_escape(i) for i in value)
+        return ANSI(self.value % value)
+
+
+# Mapping of the ANSI color codes to their names.
+_fg_colors = {v: k for k, v in FG_ANSI_COLORS.items()}
+_bg_colors = {v: k for k, v in BG_ANSI_COLORS.items()}
+
+# Mapping of the escape codes for 256colors to their 'ffffff' value.
+_256_colors = {}
+
+for i, (r, g, b) in enumerate(_256_colors_table.colors):
+    _256_colors[i] = f"#{r:02x}{g:02x}{b:02x}"
+
+
+def ansi_escape(text: object) -> str:
+    """
+    Replace characters with a special meaning.
+    """
+    return str(text).replace("\x1b", "?").replace("\b", "?")
+
+
+class ANSIFormatter(Formatter):
+    def format_field(self, value: object, format_spec: str) -> str:
+        return ansi_escape(format(value, format_spec))
+
+
+FORMATTER = ANSIFormatter()
diff --git a/src/prompt_toolkit/formatted_text/base.py b/src/prompt_toolkit/formatted_text/base.py
new file mode 100644
index 0000000..92de353
--- /dev/null
+++ b/src/prompt_toolkit/formatted_text/base.py
@@ -0,0 +1,180 @@
+from __future__ import annotations
+
+from typing import TYPE_CHECKING, Any, Callable, Iterable, List, Tuple, Union, cast
+
+from prompt_toolkit.mouse_events import MouseEvent
+
+if TYPE_CHECKING:
+    from typing_extensions import Protocol
+
+    from prompt_toolkit.key_binding.key_bindings import NotImplementedOrNone
+
+__all__ = [
+    "OneStyleAndTextTuple",
+    "StyleAndTextTuples",
+    "MagicFormattedText",
+    "AnyFormattedText",
+    "to_formatted_text",
+    "is_formatted_text",
+    "Template",
+    "merge_formatted_text",
+    "FormattedText",
+]
+
+OneStyleAndTextTuple = Union[
+    Tuple[str, str], Tuple[str, str, Callable[[MouseEvent], "NotImplementedOrNone"]]
+]
+
+# List of (style, text) tuples.
+StyleAndTextTuples = List[OneStyleAndTextTuple]
+
+
+if TYPE_CHECKING:
+    from typing_extensions import TypeGuard
+
+    class MagicFormattedText(Protocol):
+        """
+        Any object that implements ``__pt_formatted_text__`` represents formatted
+        text.
+        """
+
+        def __pt_formatted_text__(self) -> StyleAndTextTuples:
+            ...
+
+
+AnyFormattedText = Union[
+    str,
+    "MagicFormattedText",
+    StyleAndTextTuples,
+    # Callable[[], 'AnyFormattedText']  # Recursive definition not supported by mypy.
+    Callable[[], Any],
+    None,
+]
+
+
+def to_formatted_text(
+    value: AnyFormattedText, style: str = "", auto_convert: bool = False
+) -> FormattedText:
+    """
+    Convert the given value (which can be formatted text) into a list of text
+    fragments. (Which is the canonical form of formatted text.) The outcome is
+    always a `FormattedText` instance, which is a list of (style, text) tuples.
+
+    It can take a plain text string, an `HTML` or `ANSI` object, anything that
+    implements `__pt_formatted_text__` or a callable that takes no arguments and
+    returns one of those.
+
+    :param style: An additional style string which is applied to all text
+        fragments.
+    :param auto_convert: If `True`, also accept other types, and convert them
+        to a string first.
+    """
+    result: FormattedText | StyleAndTextTuples
+
+    if value is None:
+        result = []
+    elif isinstance(value, str):
+        result = [("", value)]
+    elif isinstance(value, list):
+        result = value  # StyleAndTextTuples
+    elif hasattr(value, "__pt_formatted_text__"):
+        result = cast("MagicFormattedText", value).__pt_formatted_text__()
+    elif callable(value):
+        return to_formatted_text(value(), style=style)
+    elif auto_convert:
+        result = [("", f"{value}")]
+    else:
+        raise ValueError(
+            "No formatted text. Expecting a unicode object, "
+            f"HTML, ANSI or a FormattedText instance. Got {value!r}"
+        )
+
+    # Apply extra style.
+    if style:
+        result = cast(
+            StyleAndTextTuples,
+            [(style + " " + item_style, *rest) for item_style, *rest in result],
+        )
+
+    # Make sure the result is wrapped in a `FormattedText`. Among other
+    # reasons, this is important for `print_formatted_text` to work correctly
+    # and distinguish between lists and formatted text.
+    if isinstance(result, FormattedText):
+        return result
+    else:
+        return FormattedText(result)
+
+
+def is_formatted_text(value: object) -> TypeGuard[AnyFormattedText]:
+    """
+    Check whether the input is valid formatted text (for use in assert
+    statements).
+    In case of a callable, it doesn't check the return type.
+    """
+    if callable(value):
+        return True
+    if isinstance(value, (str, list)):
+        return True
+    if hasattr(value, "__pt_formatted_text__"):
+        return True
+    return False
+
+
+class FormattedText(StyleAndTextTuples):
+    """
+    A list of ``(style, text)`` tuples.
+
+    (In some situations, this can also be ``(style, text, mouse_handler)``
+    tuples.)
+    """
+
+    def __pt_formatted_text__(self) -> StyleAndTextTuples:
+        return self
+
+    def __repr__(self) -> str:
+        return "FormattedText(%s)" % super().__repr__()
+
+
+class Template:
+    """
+    Template for string interpolation with formatted text.
+
+    Example::
+
+        Template(' ... {} ... ').format(HTML(...))
+
+    :param text: Plain text.
+    """
+
+    def __init__(self, text: str) -> None:
+        assert "{0}" not in text
+        self.text = text
+
+    def format(self, *values: AnyFormattedText) -> AnyFormattedText:
+        def get_result() -> AnyFormattedText:
+            # Split the template in parts.
+            parts = self.text.split("{}")
+            assert len(parts) - 1 == len(values)
+
+            result = FormattedText()
+            for part, val in zip(parts, values):
+                result.append(("", part))
+                result.extend(to_formatted_text(val))
+            result.append(("", parts[-1]))
+            return result
+
+        return get_result
+
+
+def merge_formatted_text(items: Iterable[AnyFormattedText]) -> AnyFormattedText:
+    """
+    Merge (Concatenate) several pieces of formatted text together.
+    """
+
+    def _merge_formatted_text() -> AnyFormattedText:
+        result = FormattedText()
+        for i in items:
+            result.extend(to_formatted_text(i))
+        return result
+
+    return _merge_formatted_text
diff --git a/src/prompt_toolkit/formatted_text/html.py b/src/prompt_toolkit/formatted_text/html.py
new file mode 100644
index 0000000..a940ac8
--- /dev/null
+++ b/src/prompt_toolkit/formatted_text/html.py
@@ -0,0 +1,145 @@
+from __future__ import annotations
+
+import xml.dom.minidom as minidom
+from string import Formatter
+from typing import Any
+
+from .base import FormattedText, StyleAndTextTuples
+
+__all__ = ["HTML"]
+
+
+class HTML:
+    """
+    HTML formatted text.
+    Take something HTML-like, for use as a formatted string.
+
+    ::
+
+        # Turn something into red.
+        HTML('<style fg="ansired" bg="#00ff44">...</style>')
+
+        # Italic, bold, underline and strike.
+        HTML('<i>...</i>')
+        HTML('<b>...</b>')
+        HTML('<u>...</u>')
+        HTML('<s>...</s>')
+
+    All HTML elements become available as a "class" in the style sheet.
+    E.g. ``<username>...</username>`` can be styled, by setting a style for
+    ``username``.
+    """
+
+    def __init__(self, value: str) -> None:
+        self.value = value
+        document = minidom.parseString(f"<html-root>{value}</html-root>")
+
+        result: StyleAndTextTuples = []
+        name_stack: list[str] = []
+        fg_stack: list[str] = []
+        bg_stack: list[str] = []
+
+        def get_current_style() -> str:
+            "Build style string for current node."
+            parts = []
+            if name_stack:
+                parts.append("class:" + ",".join(name_stack))
+
+            if fg_stack:
+                parts.append("fg:" + fg_stack[-1])
+            if bg_stack:
+                parts.append("bg:" + bg_stack[-1])
+            return " ".join(parts)
+
+        def process_node(node: Any) -> None:
+            "Process node recursively."
+            for child in node.childNodes:
+                if child.nodeType == child.TEXT_NODE:
+                    result.append((get_current_style(), child.data))
+                else:
+                    add_to_name_stack = child.nodeName not in (
+                        "#document",
+                        "html-root",
+                        "style",
+                    )
+                    fg = bg = ""
+
+                    for k, v in child.attributes.items():
+                        if k == "fg":
+                            fg = v
+                        if k == "bg":
+                            bg = v
+                        if k == "color":
+                            fg = v  # Alias for 'fg'.
+
+                    # Check for spaces in attributes. This would result in
+                    # invalid style strings otherwise.
+                    if " " in fg:
+                        raise ValueError('"fg" attribute contains a space.')
+                    if " " in bg:
+                        raise ValueError('"bg" attribute contains a space.')
+
+                    if add_to_name_stack:
+                        name_stack.append(child.nodeName)
+                    if fg:
+                        fg_stack.append(fg)
+                    if bg:
+                        bg_stack.append(bg)
+
+                    process_node(child)
+
+                    if add_to_name_stack:
+                        name_stack.pop()
+                    if fg:
+                        fg_stack.pop()
+                    if bg:
+                        bg_stack.pop()
+
+        process_node(document)
+
+        self.formatted_text = FormattedText(result)
+
+    def __repr__(self) -> str:
+        return f"HTML({self.value!r})"
+
+    def __pt_formatted_text__(self) -> StyleAndTextTuples:
+        return self.formatted_text
+
+    def format(self, *args: object, **kwargs: object) -> HTML:
+        """
+        Like `str.format`, but make sure that the arguments are properly
+        escaped.
+        """
+        return HTML(FORMATTER.vformat(self.value, args, kwargs))
+
+    def __mod__(self, value: object) -> HTML:
+        """
+        HTML('<b>%s</b>') % value
+        """
+        if not isinstance(value, tuple):
+            value = (value,)
+
+        value = tuple(html_escape(i) for i in value)
+        return HTML(self.value % value)
+
+
+class HTMLFormatter(Formatter):
+    def format_field(self, value: object, format_spec: str) -> str:
+        return html_escape(format(value, format_spec))
+
+
+def html_escape(text: object) -> str:
+    # The string interpolation functions also take integers and other types.
+    # Convert to string first.
+    if not isinstance(text, str):
+        text = f"{text}"
+
+    return (
+        text.replace("&", "&amp;")
+        .replace("<", "&lt;")
+        .replace(">", "&gt;")
+        .replace('"', "&quot;")
+    )
+
+
+FORMATTER = HTMLFormatter()
diff --git a/src/prompt_toolkit/formatted_text/pygments.py b/src/prompt_toolkit/formatted_text/pygments.py
new file mode 100644
index 0000000..d4ef3ad
--- /dev/null
+++ b/src/prompt_toolkit/formatted_text/pygments.py
@@ -0,0 +1,32 @@
+from __future__ import annotations
+
+from typing import TYPE_CHECKING
+
+from prompt_toolkit.styles.pygments import pygments_token_to_classname
+
+from .base import StyleAndTextTuples
+
+if TYPE_CHECKING:
+    from pygments.token import Token
+
+__all__ = [
+    "PygmentsTokens",
+]
+
+
+class PygmentsTokens:
+    """
+    Turn a pygments token list into a list of prompt_toolkit text fragments
+    (``(style_str, text)`` tuples).
+    """
+
+    def __init__(self, token_list: list[tuple[Token, str]]) -> None:
+        self.token_list = token_list
+
+    def __pt_formatted_text__(self) -> StyleAndTextTuples:
+        result: StyleAndTextTuples = []
+
+        for token, text in self.token_list:
+            result.append(("class:" + pygments_token_to_classname(token), text))
+
+        return result
diff --git a/src/prompt_toolkit/formatted_text/utils.py b/src/prompt_toolkit/formatted_text/utils.py
new file mode 100644
index 0000000..c8c37e0
--- /dev/null
+++ b/src/prompt_toolkit/formatted_text/utils.py
@@ -0,0 +1,102 @@
+"""
+Utilities for manipulating formatted text.
+
+When ``to_formatted_text`` has been called, we get a list of ``(style, text)``
+tuples. This file contains functions for manipulating such a list.
+"""
+from __future__ import annotations
+
+from typing import Iterable, cast
+
+from prompt_toolkit.utils import get_cwidth
+
+from .base import (
+    AnyFormattedText,
+    OneStyleAndTextTuple,
+    StyleAndTextTuples,
+    to_formatted_text,
+)
+
+__all__ = [
+    "to_plain_text",
+    "fragment_list_len",
+    "fragment_list_width",
+    "fragment_list_to_text",
+    "split_lines",
+]
+
+
+def to_plain_text(value: AnyFormattedText) -> str:
+    """
+    Turn any kind of formatted text back into plain text.
+    """
+    return fragment_list_to_text(to_formatted_text(value))
+
+
+def fragment_list_len(fragments: StyleAndTextTuples) -> int:
+    """
+    Return the amount of characters in this text fragment list.
+
+    :param fragments: List of ``(style_str, text)`` or
+        ``(style_str, text, mouse_handler)`` tuples.
+    """
+    ZeroWidthEscape = "[ZeroWidthEscape]"
+    return sum(len(item[1]) for item in fragments if ZeroWidthEscape not in item[0])
+
+
+def fragment_list_width(fragments: StyleAndTextTuples) -> int:
+    """
+    Return the character width of this text fragment list.
+    (Take double width characters into account.)
+
+    :param fragments: List of ``(style_str, text)`` or
+        ``(style_str, text, mouse_handler)`` tuples.
+    """
+    ZeroWidthEscape = "[ZeroWidthEscape]"
+    return sum(
+        get_cwidth(c)
+        for item in fragments
+        for c in item[1]
+        if ZeroWidthEscape not in item[0]
+    )
+
+
+def fragment_list_to_text(fragments: StyleAndTextTuples) -> str:
+    """
+    Concatenate all the text parts again.
+
+    :param fragments: List of ``(style_str, text)`` or
+        ``(style_str, text, mouse_handler)`` tuples.
+    """
+    ZeroWidthEscape = "[ZeroWidthEscape]"
+    return "".join(item[1] for item in fragments if ZeroWidthEscape not in item[0])
+
+
+def split_lines(
+    fragments: Iterable[OneStyleAndTextTuple],
+) -> Iterable[StyleAndTextTuples]:
+    """
+    Take a single list of (style_str, text) tuples and yield one such list for each
+    line. Just like str.split, this will yield at least one item.
+
+    :param fragments: Iterable of ``(style_str, text)`` or
+        ``(style_str, text, mouse_handler)`` tuples.
+    """
+    line: StyleAndTextTuples = []
+
+    for style, string, *mouse_handler in fragments:
+        parts = string.split("\n")
+
+        for part in parts[:-1]:
+            if part:
+                line.append(cast(OneStyleAndTextTuple, (style, part, *mouse_handler)))
+            yield line
+            line = []
+
+        line.append(cast(OneStyleAndTextTuple, (style, parts[-1], *mouse_handler)))
+
+    # Always yield the last line, even when this is an empty line. This ensures
+    # that when `fragments` ends with a newline character, an additional empty
+    # line is yielded. (Otherwise, there's no way to differentiate between the
+    # cases where `fragments` does and doesn't end with a newline.)
+    yield line