Implement flushing in Windows VT100 input (#2001)

Author: NewDefectus

src/prompt_toolkit/input/win32.py

@@ -104,8 +104,11 @@ def detach(self) -> ContextManager[None]:
  def read_keys(self) -> list[KeyPress]:
  return list(self.console_input_reader.read())
 
- def flush(self) -> None:
- pass
+ def flush_keys(self) -> None:
+ if self._use_virtual_terminal_input:
+ return self.console_input_reader.flush_keys()
+ else:
+ return []
 
  @property
  def closed(self) -> bool:
@@ -640,6 +643,20 @@ def read(self) -> Iterable[KeyPress]:
  self._buffer = []
  return result
 
+ def flush_keys(self) -> list[KeyPress]:
+ """
+ Flush pending keys and return them.
+ (Used for flushing the 'escape' key.)
+ """
+ # Flush all pending keys. (This is most important to flush the vt100
+ # 'Escape' key early when nothing else follows.)
+ self._vt100_parser.flush()
+
+ # Return result.
+ result = self._buffer
+ self._buffer = []
+ return result
+
  def _get_keys(
  self, read: DWORD, input_records: Array[INPUT_RECORD]
  ) -> Iterator[str]: