Add support for rich formatted text using the 'rich' library.

This allows for using rich objects anywhere in prompt_toolkit where formatted
text is expected.

Author: jonathanslenders

examples/rich/choices.py

@@ -0,0 +1,46 @@
+#!/usr/bin/env python
+from rich.markdown import Markdown
+from rich.text import Text
+
+from prompt_toolkit import choice
+from prompt_toolkit.formatted_text.rich import Rich
+
+# For the header, we wrap the `Markdown` object from `rich` in a `Rich` object
+# from `prompt_toolkit`, so that we can explicitly set a width.
+header = Rich(
+    Markdown(
+        """
+# Please select a dish
+
+Choose *one* item please.
+
+```python
+def some_example_function() -> None: "test"
+```
+""".strip()
+    ),
+    width=50,
+    style="black on blue",
+)
+
+
+def main():
+    answer = choice(
+        message=header,
+        options=[
+            ("pizza", "Pizza with mushrooms"),
+            (
+                "salad",
+                Text.from_markup(
+                    ":warning: [green]Salad[/green] with [red]tomatoes[/red]"
+                ),
+            ),
+            ("sushi", "Sushi"),
+        ],
+        show_frame=True,
+    )
+    print(f"You said: {answer}")
+
+
+if __name__ == "__main__":
+    main()

examples/rich/dialog.py

@@ -0,0 +1,21 @@
+#!/usr/bin/env python
+"""
+Example of an input box dialog.
+"""
+
+from rich.text import Text
+
+from prompt_toolkit.shortcuts import input_dialog
+
+
+def main():
+    result = input_dialog(
+        title=Text.from_markup("[red]Input[/red] dialog [b]example[b]"),
+        text=Text.from_markup("Please type your [green]name[/green]:"),
+    ).run()
+
+    print(f"Result = {result}")
+
+
+if __name__ == "__main__":
+    main()

examples/rich/multiline-prompt.py

@@ -0,0 +1,32 @@
+#!/usr/bin/env python
+from rich.markdown import Markdown
+
+from prompt_toolkit import prompt
+from prompt_toolkit.formatted_text import merge_formatted_text
+from prompt_toolkit.formatted_text.rich import Rich
+
+# For the header, we wrap the `Markdown` object from `rich` in a `Rich` object
+# from `prompt_toolkit`, so that we can explicitly set a width.
+header = Rich(
+    Markdown(
+        """
+# Type the name of the following function:
+
+```python
+def fibonacci(number: int) -> int:
+    "compute Fibonacci number"
+```
+
+"""
+    ),
+    width=50,
+)
+
+
+def main():
+    answer = prompt(merge_formatted_text([header, "> "]))
+    print(f"You said: {answer}")
+
+
+if __name__ == "__main__":
+    main()

examples/rich/prompt.py

@@ -0,0 +1,13 @@
+#!/usr/bin/env python
+from rich.text import Text
+
+from prompt_toolkit import prompt
+
+
+def main():
+    answer = prompt(Text.from_markup("[green]Say[/green] [b]something[/b] > "))
+    print(f"You said: {answer}")
+
+
+if __name__ == "__main__":
+    main()

src/prompt_toolkit/formatted_text/__init__.py

@@ -26,6 +26,7 @@
 )
 from .html import HTML
 from .pygments import PygmentsTokens
+from .rich import Rich
 from .utils import (
     fragment_list_len,
     fragment_list_to_text,
@@ -50,6 +51,8 @@
     "ANSI",
     # Pygments.
     "PygmentsTokens",
+    # Rich.
+    "Rich",
     # Utils.
     "fragment_list_len",
     "fragment_list_width",

src/prompt_toolkit/formatted_text/base.py

@@ -40,10 +40,19 @@ class MagicFormattedText(Protocol):
 
         def __pt_formatted_text__(self) -> StyleAndTextTuples: ...
 
+    class RichFormattedText(Protocol):
+        """
+        Any rich text object from the rich library that implements
+        ``__rich_console__``.
+        """
+
+        def __rich_console__(self, console: Any = ..., options: Any = ...) -> Any: ...
+
 
 AnyFormattedText = Union[
     str,
     "MagicFormattedText",
+    "RichFormattedText",
     StyleAndTextTuples,
     # Callable[[], 'AnyFormattedText']  # Recursive definition not supported by mypy.
     Callable[[], Any],
@@ -78,6 +87,10 @@ def to_formatted_text(
         result = value  # StyleAndTextTuples
     elif hasattr(value, "__pt_formatted_text__"):
         result = cast("MagicFormattedText", value).__pt_formatted_text__()
+    elif hasattr(value, "__rich_console__"):
+        from .rich import Rich
+
+        result = Rich(value).__pt_formatted_text__()
     elif callable(value):
         return to_formatted_text(value(), style=style)
     elif auto_convert:

src/prompt_toolkit/formatted_text/rich.py

@@ -0,0 +1,50 @@
+from __future__ import annotations
+
+from io import StringIO
+from typing import TYPE_CHECKING, Any
+
+from .ansi import ANSI
+from .base import StyleAndTextTuples
+
+if TYPE_CHECKING:
+    from rich.style import StyleType
+
+__all__ = [
+    "Rich",
+]
+
+
+class Rich:
+    """
+    Turn any rich text object from the `rich` library into prompt_toolkit
+    formatted text, so that it can be used in a prompt or anywhere else.
+
+    Note that `to_formatted_text` automatically recognizes objects that have a
+    `__rich_console__` attribute and will wrap them in a `Rich` instance.
+    """
+
+    def __init__(
+        self,
+        rich_object: Any,
+        width: int = None,
+        style: StyleType | None = None,
+    ) -> None:
+        self.rich_object = rich_object
+        self.width = width
+        self.style = style
+
+    def __pt_formatted_text__(self) -> StyleAndTextTuples:
+        from rich.console import Console
+
+        file = StringIO()
+
+        console = Console(
+            file=file,
+            force_terminal=True,
+            color_system="truecolor",
+            width=self.width,
+            style=self.style,
+        )
+        console.print(self.rich_object, end="")
+        ansi = file.getvalue()
+        return ANSI(ansi).__pt_formatted_text__()