ui/curses: add curses interface draft

pqcli/ui/curses/widgets/base.py

@@ -0,0 +1,41 @@
+import curses
+import typing as T
+
+
+class Widget:
+    def __del__(self) -> None:
+        self.stop()
+
+    def stop(self) -> None:
+        pass
+
+
+class WindowWrapper(Widget):
+    def __init__(
+        self, parent: T.Optional[T.Any], h: int, w: int, y: int, x: int
+    ) -> None:
+        self._parent = parent
+        self._win: T.Optional[T.Any]
+
+        if not parent:
+            self._win = None
+        else:
+            try:
+                self._win = parent.derwin(h, w, y, x)
+                self._win.refresh()
+            except curses.error:
+                self._win = None
+
+    def stop(self) -> None:
+        del self._win
+        self._win = None
+
+    def getbegyx(self) -> T.Tuple[int, int]:
+        if not self._win:
+            return (0, 0)
+        return self._win.getbegyx()
+
+    def getmaxyx(self) -> T.Tuple[int, int]:
+        if not self._win:
+            return (0, 0)
+        return self._win.getmaxyx()