1 files changed, 331 insertions, 0 deletions
diff --git a/src/prompt_toolkit/output/base.py b/src/prompt_toolkit/output/base.py
new file mode 100644
index 0000000..3c38cec
--- /dev/null
+++ b/src/prompt_toolkit/output/base.py
@@ -0,0 +1,331 @@
+"""
+Interface for an output.
+"""
+from __future__ import annotations
+
+from abc import ABCMeta, abstractmethod
+from typing import TextIO
+
+from prompt_toolkit.cursor_shapes import CursorShape
+from prompt_toolkit.data_structures import Size
+from prompt_toolkit.styles import Attrs
+
+from .color_depth import ColorDepth
+
+__all__ = [
+    "Output",
+    "DummyOutput",
+]
+
+
+class Output(metaclass=ABCMeta):
+    """
+    Base class defining the output interface for a
+    :class:`~prompt_toolkit.renderer.Renderer`.
+
+    Actual implementations are
+    :class:`~prompt_toolkit.output.vt100.Vt100_Output` and
+    :class:`~prompt_toolkit.output.win32.Win32Output`.
+    """
+
+    stdout: TextIO | None = None
+
+    @abstractmethod
+    def fileno(self) -> int:
+        "Return the file descriptor to which we can write for the output."
+
+    @abstractmethod
+    def encoding(self) -> str:
+        """
+        Return the encoding for this output, e.g. 'utf-8'.
+        (This is used mainly to know which characters are supported by the
+        output the data, so that the UI can provide alternatives, when
+        required.)
+        """
+
+    @abstractmethod
+    def write(self, data: str) -> None:
+        "Write text (Terminal escape sequences will be removed/escaped.)"
+
+    @abstractmethod
+    def write_raw(self, data: str) -> None:
+        "Write text."
+
+    @abstractmethod
+    def set_title(self, title: str) -> None:
+        "Set terminal title."
+
+    @abstractmethod
+    def clear_title(self) -> None:
+        "Clear title again. (or restore previous title.)"
+
+    @abstractmethod
+    def flush(self) -> None:
+        "Write to output stream and flush."
+
+    @abstractmethod
+    def erase_screen(self) -> None:
+        """
+        Erases the screen with the background color and moves the cursor to
+        home.
+        """
+
+    @abstractmethod
+    def enter_alternate_screen(self) -> None:
+        "Go to the alternate screen buffer. (For full screen applications)."
+
+    @abstractmethod
+    def quit_alternate_screen(self) -> None:
+        "Leave the alternate screen buffer."
+
+    @abstractmethod
+    def enable_mouse_support(self) -> None:
+        "Enable mouse."
+
+    @abstractmethod
+    def disable_mouse_support(self) -> None:
+        "Disable mouse."
+
+    @abstractmethod
+    def erase_end_of_line(self) -> None:
+        """
+        Erases from the current cursor position to the end of the current line.
+        """
+
+    @abstractmethod
+    def erase_down(self) -> None:
+        """
+        Erases the screen from the current line down to the bottom of the
+        screen.
+        """
+
+    @abstractmethod
+    def reset_attributes(self) -> None:
+        "Reset color and styling attributes."
+
+    @abstractmethod
+    def set_attributes(self, attrs: Attrs, color_depth: ColorDepth) -> None:
+        "Set new color and styling attributes."
+
+    @abstractmethod
+    def disable_autowrap(self) -> None:
+        "Disable auto line wrapping."
+
+    @abstractmethod
+    def enable_autowrap(self) -> None:
+        "Enable auto line wrapping."
+
+    @abstractmethod
+    def cursor_goto(self, row: int = 0, column: int = 0) -> None:
+        "Move cursor position."
+
+    @abstractmethod
+    def cursor_up(self, amount: int) -> None:
+        "Move cursor `amount` place up."
+
+    @abstractmethod
+    def cursor_down(self, amount: int) -> None:
+        "Move cursor `amount` place down."
+
+    @abstractmethod
+    def cursor_forward(self, amount: int) -> None:
+        "Move cursor `amount` place forward."
+
+    @abstractmethod
+    def cursor_backward(self, amount: int) -> None:
+        "Move cursor `amount` place backward."
+
+    @abstractmethod
+    def hide_cursor(self) -> None:
+        "Hide cursor."
+
+    @abstractmethod
+    def show_cursor(self) -> None:
+        "Show cursor."
+
+    @abstractmethod
+    def set_cursor_shape(self, cursor_shape: CursorShape) -> None:
+        "Set cursor shape to block, beam or underline."
+
+    @abstractmethod
+    def reset_cursor_shape(self) -> None:
+        "Reset cursor shape."
+
+    def ask_for_cpr(self) -> None:
+        """
+        Asks for a cursor position report (CPR).
+        (VT100 only.)
+        """
+
+    @property
+    def responds_to_cpr(self) -> bool:
+        """
+        `True` if the `Application` can expect to receive a CPR response after
+        calling `ask_for_cpr` (this will come back through the corresponding
+        `Input`).
+
+        This is used to determine the amount of available rows we have below
+        the cursor position. In the first place, we have this so that the drop
+        down autocompletion menus are sized according to the available space.
+
+        On Windows, we don't need this, there we have
+        `get_rows_below_cursor_position`.
+        """
+        return False
+
+    @abstractmethod
+    def get_size(self) -> Size:
+        "Return the size of the output window."
+
+    def bell(self) -> None:
+        "Sound bell."
+
+    def enable_bracketed_paste(self) -> None:
+        "For vt100 only."
+
+    def disable_bracketed_paste(self) -> None:
+        "For vt100 only."
+
+    def reset_cursor_key_mode(self) -> None:
+        """
+        For vt100 only.
+        Put the terminal in normal cursor mode (instead of application mode).
+
+        See: https://vt100.net/docs/vt100-ug/chapter3.html
+        """
+
+    def scroll_buffer_to_prompt(self) -> None:
+        "For Win32 only."
+
+    def get_rows_below_cursor_position(self) -> int:
+        "For Windows only."
+        raise NotImplementedError
+
+    @abstractmethod
+    def get_default_color_depth(self) -> ColorDepth:
+        """
+        Get default color depth for this output.
+
+        This value will be used if no color depth was explicitly passed to the
+        `Application`.
+
+        .. note::
+
+            If the `$PROMPT_TOOLKIT_COLOR_DEPTH` environment variable has been
+            set, then `outputs.defaults.create_output` will pass this value to
+            the implementation as the default_color_depth, which is returned
+            here. (This is not used when the output corresponds to a
+            prompt_toolkit SSH/Telnet session.)
+        """
+
+
+class DummyOutput(Output):
+    """
+    For testing. An output class that doesn't render anything.
+    """
+
+    def fileno(self) -> int:
+        "There is no sensible default for fileno()."
+        raise NotImplementedError
+
+    def encoding(self) -> str:
+        return "utf-8"
+
+    def write(self, data: str) -> None:
+        pass
+
+    def write_raw(self, data: str) -> None:
+        pass
+
+    def set_title(self, title: str) -> None:
+        pass
+
+    def clear_title(self) -> None:
+        pass
+
+    def flush(self) -> None:
+        pass
+
+    def erase_screen(self) -> None:
+        pass
+
+    def enter_alternate_screen(self) -> None:
+        pass
+
+    def quit_alternate_screen(self) -> None:
+        pass
+
+    def enable_mouse_support(self) -> None:
+        pass
+
+    def disable_mouse_support(self) -> None:
+        pass
+
+    def erase_end_of_line(self) -> None:
+        pass
+
+    def erase_down(self) -> None:
+        pass
+
+    def reset_attributes(self) -> None:
+        pass
+
+    def set_attributes(self, attrs: Attrs, color_depth: ColorDepth) -> None:
+        pass
+
+    def disable_autowrap(self) -> None:
+        pass
+
+    def enable_autowrap(self) -> None:
+        pass
+
+    def cursor_goto(self, row: int = 0, column: int = 0) -> None:
+        pass
+
+    def cursor_up(self, amount: int) -> None:
+        pass
+
+    def cursor_down(self, amount: int) -> None:
+        pass
+
+    def cursor_forward(self, amount: int) -> None:
+        pass
+
+    def cursor_backward(self, amount: int) -> None:
+        pass
+
+    def hide_cursor(self) -> None:
+        pass
+
+    def show_cursor(self) -> None:
+        pass
+
+    def set_cursor_shape(self, cursor_shape: CursorShape) -> None:
+        pass
+
+    def reset_cursor_shape(self) -> None:
+        pass
+
+    def ask_for_cpr(self) -> None:
+        pass
+
+    def bell(self) -> None:
+        pass
+
+    def enable_bracketed_paste(self) -> None:
+        pass
+
+    def disable_bracketed_paste(self) -> None:
+        pass
+
+    def scroll_buffer_to_prompt(self) -> None:
+        pass
+
+    def get_size(self) -> Size:
+        return Size(rows=40, columns=80)
+
+    def get_rows_below_cursor_position(self) -> int:
+        return 40
+
+    def get_default_color_depth(self) -> ColorDepth:
+        return ColorDepth.DEPTH_1_BIT