ui/curses: add curses interface draft

pqcli/ui/curses/widgets/menu.py

@@ -0,0 +1,79 @@
+import curses
+import typing as T
+
+from ..util import Choice
+from .base import Widget
+
+
+class Menu(Widget):
+    def __init__(
+        self,
+        header: str,
+        choices: T.List[Choice],
+        scr_height: int,
+        scr_width: int,
+    ) -> None:
+        self.header_lines = header.split("\n")
+        self.choices = choices
+        self.scr_width = scr_width
+        self.scr_height = scr_height
+
+        w = max(map(len, self.header_lines))
+        h = len(self.header_lines) + 1 + len(choices)
+        self._pad: T.Optional[T.Any] = curses.newpad(h, w)
+
+        for y, line in enumerate(self.header_lines):
+            self._pad.move(y, 0)
+            self._pad.addstr(line)
+
+        self.active_choice = 0
+
+    def stop(self) -> None:
+        del self._pad
+        self._pad = None
+
+    def getmaxyx(self) -> T.Tuple[int, int]:
+        if not self._pad:
+            return (0, 0)
+        return self._pad.getmaxyx()
+
+    def next(self) -> None:
+        self.active_choice = min(len(self.choices) - 1, self.active_choice + 1)
+
+    def prev(self) -> None:
+        self.active_choice = max(0, self.active_choice - 1)
+
+    def keypress(self, key: int) -> None:
+        for choice in self.choices:
+            if key in choice.keys:
+                choice.callback()
+                return
+
+        if key in set(map(ord, "jJ")) | {curses.KEY_DOWN}:
+            self.next()
+            return
+
+        if key in set(map(ord, "kK")) | {curses.KEY_UP}:
+            self.prev()
+            return
+
+    def render(self) -> None:
+        if not self._pad:
+            return
+
+        for y, choice in enumerate(self.choices):
+            self._pad.move(len(self.header_lines) + 1 + y, 0)
+            if y == self.active_choice:
+                self._pad.standout()
+            self._pad.addstr(choice.desc)
+            if y == self.active_choice:
+                self._pad.standend()
+
+        self._pad.refresh(
+            0,
+            0,
+            (self.scr_height - self._pad.getmaxyx()[0]) // 2,
+            (self.scr_width - self._pad.getmaxyx()[1]) // 2,
+            self.scr_height - 1,
+            self.scr_width - 1,
+        )