ui/curses: add scrollbars

pqcli/ui/curses/widgets/data_table.py

@@ -44,9 +44,8 @@ class DataTable(Scrollable):
                 return idx
         return None
 
-    def _render_impl(self) -> None:
+    def _render_impl(self, h: int, w: int) -> None:
         assert self._pad
-        h, w = self.getmaxyx()
         if self._align_right:
             for y, row in enumerate(self._items):
                 self._pad.move(y, 0)
@@ -64,8 +63,5 @@ class DataTable(Scrollable):
                         y, col2_x, row[1], min(len(row[1]), w - col2_x)
                     )
 
-        y, x = self.getbegyx()
-        self._pad.refresh(self._scroll_y, 0, y, x, y + h - 1, x + w - 1)
-
     def _get_col_width(self, x: int) -> int:
         return max([len(row[0]) for row in self._items] + [0])

pqcli/ui/curses/widgets/list_box.py

@@ -30,11 +30,7 @@ class ListBox(Scrollable):
     def delete(self, idx: int, count: int = 1) -> None:
         del self._items[idx : idx + count]
 
-    def _render_impl(self) -> None:
+    def _render_impl(self, h: int, w: int) -> None:
         assert self._pad
-        h, w = self.getmaxyx()
         for y, item in enumerate(self._items):
             self._pad.addnstr(y, 0, item, min(len(item), w))
-
-        y, x = self.getbegyx()
-        self._pad.refresh(self._scroll_y, 0, y, x, y + h - 1, x + w - 1)

pqcli/ui/curses/widgets/scrollable.py

@@ -5,8 +5,8 @@ from .base import WindowWrapper
 
 
 class Scrollable(WindowWrapper):
-    def __init__(self, *args: T.Any, **kwargs: T.Any) -> None:
-        super().__init__(*args, **kwargs)
+    def __init__(self, parent: T.Any, h: int, w: int, y: int, x: int) -> None:
+        super().__init__(parent, h, w, y, x)
         self._scroll_y = 0
         self._pad: T.Optional[T.Any] = curses.newpad(1, 1)
         self._items: T.List[T.Any] = []
@@ -32,7 +32,7 @@ class Scrollable(WindowWrapper):
         return len(self._items)
 
     def render(self) -> None:
-        if not self._pad:
+        if not self._pad or not self._win:
             return
 
         if self._items:
@@ -43,8 +43,29 @@ class Scrollable(WindowWrapper):
             self._pad.resize(1, 1)
 
         self._pad.erase()
+        h, w = self.getmaxyx()
+        y, x = self.getbegyx()
+
         try:
-            self._render_impl()
+            if self._scroll_y > 0 or self._scroll_y + h < len(self._items):
+                y1 = self._scroll_y
+                y2 = self._scroll_y + h
+                win_y1 = int(y1 * h // len(self._items))
+                win_y2 = int(y2 * h // len(self._items))
+                for win_y in range(win_y1, win_y2):
+                    self._win.chgat(win_y, 0, curses.A_REVERSE)
+                self._win.refresh()
+
+                self._render_impl(h, w - 1)
+                self._pad.refresh(
+                    self._scroll_y, 0, y, x, y + h - 1, x + w - 2
+                )
+            else:
+                self._render_impl(h, w)
+                self._pad.refresh(
+                    self._scroll_y, 0, y, x, y + h - 1, x + w - 1
+                )
+
         except curses.error:
             pass