1 files changed, 102 insertions, 0 deletions
diff --git a/src/prompt_toolkit/output/defaults.py b/src/prompt_toolkit/output/defaults.py
new file mode 100644
index 0000000..ed114e3
--- /dev/null
+++ b/src/prompt_toolkit/output/defaults.py
@@ -0,0 +1,102 @@
+from __future__ import annotations
+
+import sys
+from typing import TextIO, cast
+
+from prompt_toolkit.utils import (
+    get_bell_environment_variable,
+    get_term_environment_variable,
+    is_conemu_ansi,
+)
+
+from .base import DummyOutput, Output
+from .color_depth import ColorDepth
+from .plain_text import PlainTextOutput
+
+__all__ = [
+    "create_output",
+]
+
+
+def create_output(
+    stdout: TextIO | None = None, always_prefer_tty: bool = False
+) -> Output:
+    """
+    Return an :class:`~prompt_toolkit.output.Output` instance for the command
+    line.
+
+    :param stdout: The stdout object
+    :param always_prefer_tty: When set, look for `sys.stderr` if `sys.stdout`
+        is not a TTY. Useful if `sys.stdout` is redirected to a file, but we
+        still want user input and output on the terminal.
+
+        By default, this is `False`. If `sys.stdout` is not a terminal (maybe
+        it's redirected to a file), then a `PlainTextOutput` will be returned.
+        That way, tools like `print_formatted_text` will write plain text into
+        that file.
+    """
+    # Consider TERM, PROMPT_TOOLKIT_BELL, and PROMPT_TOOLKIT_COLOR_DEPTH
+    # environment variables. Notice that PROMPT_TOOLKIT_COLOR_DEPTH value is
+    # the default that's used if the Application doesn't override it.
+    term_from_env = get_term_environment_variable()
+    bell_from_env = get_bell_environment_variable()
+    color_depth_from_env = ColorDepth.from_env()
+
+    if stdout is None:
+        # By default, render to stdout. If the output is piped somewhere else,
+        # render to stderr.
+        stdout = sys.stdout
+
+        if always_prefer_tty:
+            for io in [sys.stdout, sys.stderr]:
+                if io is not None and io.isatty():
+                    # (This is `None` when using `pythonw.exe` on Windows.)
+                    stdout = io
+                    break
+
+    # If the output is still `None`, use a DummyOutput.
+    # This happens for instance on Windows, when running the application under
+    # `pythonw.exe`. In that case, there won't be a terminal Window, and
+    # stdin/stdout/stderr are `None`.
+    if stdout is None:
+        return DummyOutput()
+
+    # If the patch_stdout context manager has been used, then sys.stdout is
+    # replaced by this proxy. For prompt_toolkit applications, we want to use
+    # the real stdout.
+    from prompt_toolkit.patch_stdout import StdoutProxy
+
+    while isinstance(stdout, StdoutProxy):
+        stdout = stdout.original_stdout
+
+    if sys.platform == "win32":
+        from .conemu import ConEmuOutput
+        from .win32 import Win32Output
+        from .windows10 import Windows10_Output, is_win_vt100_enabled
+
+        if is_win_vt100_enabled():
+            return cast(
+                Output,
+                Windows10_Output(stdout, default_color_depth=color_depth_from_env),
+            )
+        if is_conemu_ansi():
+            return cast(
+                Output, ConEmuOutput(stdout, default_color_depth=color_depth_from_env)
+            )
+        else:
+            return Win32Output(stdout, default_color_depth=color_depth_from_env)
+    else:
+        from .vt100 import Vt100_Output
+
+        # Stdout is not a TTY? Render as plain text.
+        # This is mostly useful if stdout is redirected to a file, and
+        # `print_formatted_text` is used.
+        if not stdout.isatty():
+            return PlainTextOutput(stdout)
+
+        return Vt100_Output.from_pty(
+            stdout,
+            term=term_from_env,
+            default_color_depth=color_depth_from_env,
+            enable_bell=bell_from_env,
+        )