implement windows ContextManager

Author: Cube707

readchar/_win_read.py

@@ -1,38 +1,58 @@
 import msvcrt
+import signal
 
+from . import _win_key as key
 from ._config import config
 
 
 class ReadChar:
     """A ContextManager allowing for keypress collection without requiering the user to
     confirm presses with ENTER. Can be used non-blocking while inside the context."""
 
+    @staticmethod
+    def __silent_CTRL_C_callback(signum, frame):
+        msvcrt.ungetch(key.CTRL_C.encode("ascii"))
+
     def __init__(self, cfg: config = None) -> None:
         self.config = cfg if cfg is not None else config
 
     def __enter__(self) -> "ReadChar":
-        raise NotImplementedError("ToDo")
+        self.__org_SIGBREAK_handler = signal.getsignal(signal.SIGBREAK)
+        self.__org_SIGINT_handler = signal.getsignal(signal.SIGINT)
+        signal.signal(signal.SIGBREAK, signal.default_int_handler)
+        signal.signal(signal.SIGINT, ReadChar.__silent_CTRL_C_callback)
         return self
 
     def __exit__(self, type, value, traceback) -> None:
-        raise NotImplementedError("ToDo")
+        signal.signal(signal.SIGBREAK, self.__org_SIGBREAK_handler)
+        signal.signal(signal.SIGINT, self.__org_SIGINT_handler)
 
     @property
     def key_waiting(self) -> bool:
         """True if a key has been pressed and is waiting to be read. False if not."""
-        raise NotImplementedError("ToDo")
+        return msvcrt.kbhit()
 
     def char(self) -> str:
         """Reads a singel char from the input stream and returns it as a string of
         length one. Does not require the user to press ENTER."""
-        raise NotImplementedError("ToDo")
+        return msvcrt.getch().decode("latin1")
 
     def key(self) -> str:
         """Reads a keypress from the input stream and returns it as a string. Keypressed
         consisting of multiple characterrs will be read completly and be returned as a
         string matching the definitions in `key.py`.
         Does not require the user to press ENTER."""
-        raise NotImplementedError("ToDo")
+        c = self.char()
+
+        if c in self.config.INTERRUPT_KEYS:
+            raise KeyboardInterrupt
+
+        # if it is a normal character:
+        if c not in "\x00\xe0":
+            return c
+
+        # if it is a special key, read second half:
+        return "\x00" + self.char()
 
 
 def readchar() -> str: