ui: fix smoothing in urwid progress bar

pqcli/ui/custom_progress_bar.py

@@ -1,9 +1,68 @@
+import typing as T
+
 import urwid
 
+# workaround for https://github.com/urwid/urwid/issues/317
+
+
+class CustomProgressBar(urwid.Widget):
+    _sizing = frozenset(["flow"])
+    text_align = "center"
+    eighths = u" ▏▎▍▌▋▊▉"
 
-class CustomProgressBar(urwid.ProgressBar):
     def __init__(self) -> None:
-        super().__init__("progressbar-incomplete", "progressbar-done", 0, 1)
+        self.position = 0.0
+        self.max_ = 1.0
+        self.normal = "progressbar-normal"
+        self.complete = "progressbar-done"
+        self.smooth = "progressbar-smooth"
 
-    def set_max(self, value: int) -> None:
-        self._done = value
+    def set_completion(self, value: float) -> None:
+        self.position = value
+        self._invalidate()
+
+    def set_max(self, value: T.Union[int, float]) -> None:
+        self.max_ = value
+        self._invalidate()
+
+    def rows(self, size: T.Tuple[int, int], focus: bool = False) -> int:
+        return 1
+
+    def get_text(self) -> str:
+        percent = min(100, max(0, int(self.position * 100 / self.max_)))
+        return str(percent) + " %"
+
+    def render(self, size: T.Tuple[int, int], focus: bool = False) -> None:
+        (maxcol,) = size
+        txt = urwid.Text(self.get_text(), self.text_align, "clip")
+        c = txt.render((maxcol,))
+        t = c._text[0]
+
+        cf = self.position * maxcol / self.max_
+        ccol_dirty = int(cf)
+        ccol = len(
+            c._text[0][:ccol_dirty].decode("utf-8", "ignore").encode("utf-8")
+        )
+
+        cs = 0
+        cs = int((cf - ccol) * 8)
+
+        if ccol < 0 or (ccol == 0 and cs == 0):
+            c._attr = [[(self.normal, maxcol)]]
+        elif ccol >= maxcol:
+            c._attr = [[(self.complete, maxcol)]]
+        elif cs and c._text[0][ccol] == 32:
+            t = c._text[0]
+            cenc = self.eighths[cs].encode("utf-8")
+            c._text[0] = t[:ccol] + cenc + t[ccol + 1 :]
+            a = []
+            if ccol > 0:
+                a.append((self.complete, ccol))
+            a.append((self.smooth, len(cenc)))
+            if maxcol - ccol - 1 > 0:
+                a.append((self.normal, maxcol - ccol - 1))
+            c._attr = [a]
+            c._cs = [[(None, len(c._text[0]))]]
+        else:
+            c._attr = [[(self.complete, ccol), (self.normal, maxcol - ccol)]]
+        return c