1 files changed, 152 insertions, 0 deletions
diff --git a/src/prompt_toolkit/input/base.py b/src/prompt_toolkit/input/base.py
new file mode 100644
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+++ b/src/prompt_toolkit/input/base.py
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+"""
+Abstraction of CLI Input.
+"""
+from __future__ import annotations
+
+from abc import ABCMeta, abstractmethod, abstractproperty
+from contextlib import contextmanager
+from typing import Callable, ContextManager, Generator
+
+from prompt_toolkit.key_binding import KeyPress
+
+__all__ = [
+    "Input",
+    "PipeInput",
+    "DummyInput",
+]
+
+
+class Input(metaclass=ABCMeta):
+    """
+    Abstraction for any input.
+
+    An instance of this class can be given to the constructor of a
+    :class:`~prompt_toolkit.application.Application` and will also be
+    passed to the :class:`~prompt_toolkit.eventloop.base.EventLoop`.
+    """
+
+    @abstractmethod
+    def fileno(self) -> int:
+        """
+        Fileno for putting this in an event loop.
+        """
+
+    @abstractmethod
+    def typeahead_hash(self) -> str:
+        """
+        Identifier for storing type ahead key presses.
+        """
+
+    @abstractmethod
+    def read_keys(self) -> list[KeyPress]:
+        """
+        Return a list of Key objects which are read/parsed from the input.
+        """
+
+    def flush_keys(self) -> list[KeyPress]:
+        """
+        Flush the underlying parser. and return the pending keys.
+        (Used for vt100 input.)
+        """
+        return []
+
+    def flush(self) -> None:
+        "The event loop can call this when the input has to be flushed."
+        pass
+
+    @abstractproperty
+    def closed(self) -> bool:
+        "Should be true when the input stream is closed."
+        return False
+
+    @abstractmethod
+    def raw_mode(self) -> ContextManager[None]:
+        """
+        Context manager that turns the input into raw mode.
+        """
+
+    @abstractmethod
+    def cooked_mode(self) -> ContextManager[None]:
+        """
+        Context manager that turns the input into cooked mode.
+        """
+
+    @abstractmethod
+    def attach(self, input_ready_callback: Callable[[], None]) -> ContextManager[None]:
+        """
+        Return a context manager that makes this input active in the current
+        event loop.
+        """
+
+    @abstractmethod
+    def detach(self) -> ContextManager[None]:
+        """
+        Return a context manager that makes sure that this input is not active
+        in the current event loop.
+        """
+
+    def close(self) -> None:
+        "Close input."
+        pass
+
+
+class PipeInput(Input):
+    """
+    Abstraction for pipe input.
+    """
+
+    @abstractmethod
+    def send_bytes(self, data: bytes) -> None:
+        """Feed byte string into the pipe"""
+
+    @abstractmethod
+    def send_text(self, data: str) -> None:
+        """Feed a text string into the pipe"""
+
+
+class DummyInput(Input):
+    """
+    Input for use in a `DummyApplication`
+
+    If used in an actual application, it will make the application render
+    itself once and exit immediately, due to an `EOFError`.
+    """
+
+    def fileno(self) -> int:
+        raise NotImplementedError
+
+    def typeahead_hash(self) -> str:
+        return "dummy-%s" % id(self)
+
+    def read_keys(self) -> list[KeyPress]:
+        return []
+
+    @property
+    def closed(self) -> bool:
+        # This needs to be true, so that the dummy input will trigger an
+        # `EOFError` immediately in the application.
+        return True
+
+    def raw_mode(self) -> ContextManager[None]:
+        return _dummy_context_manager()
+
+    def cooked_mode(self) -> ContextManager[None]:
+        return _dummy_context_manager()
+
+    def attach(self, input_ready_callback: Callable[[], None]) -> ContextManager[None]:
+        # Call the callback immediately once after attaching.
+        # This tells the callback to call `read_keys` and check the
+        # `input.closed` flag, after which it won't receive any keys, but knows
+        # that `EOFError` should be raised. This unblocks `read_from_input` in
+        # `application.py`.
+        input_ready_callback()
+
+        return _dummy_context_manager()
+
+    def detach(self) -> ContextManager[None]:
+        return _dummy_context_manager()
+
+
+@contextmanager
+def _dummy_context_manager() -> Generator[None, None, None]:
+    yield