Show scrollbars only when in use

src/ScrollableContainers/_tk.py

@@ -17,20 +17,22 @@ class ScrollableFrameTk(ttk.Frame):
     def __init__(self, *args, **kwargs):
         super().__init__(*args, **kwargs)
 
+        # Using the grid geometry manager ensures that the horizontal and
+        # vertical scrollbars do not touch.
+        self._xscrollbar = ttk.Scrollbar(self, orient=tk.HORIZONTAL, command=self._xview)
+        self._xscrollbar.grid(row=1, column=0, sticky=tk.EW)
+        self._yscrollbar = ttk.Scrollbar(self, orient=tk.VERTICAL, command=self._yview)
+        self._yscrollbar.grid(row=0, column=1, sticky=tk.NS)
+
         # Scrollable canvas. This is the widget which actually manages
-        # scrolling. Using the grid geometry manager ensures that the
-        # horizontal and vertical scrollbars do not meet.
+        # scrolling. Initially, it will be above the scrollbars, so the latter
+        # won't be visible.
         self._canvas = tk.Canvas(self)
         self._canvas.bind("<Configure>", self._on_canvas_configure)
         self._canvas.bind("<Enter>", self._on_canvas_enter)
         self._canvas.bind("<Leave>", self._on_canvas_leave)
-        self._canvas.grid(row=0, column=0, sticky=tk.NSEW)
-
-        xscrollbar = ttk.Scrollbar(self, orient=tk.HORIZONTAL, command=self._xview)
-        xscrollbar.grid(row=1, column=0, sticky=tk.EW)
-        yscrollbar = ttk.Scrollbar(self, orient=tk.VERTICAL, command=self._yview)
-        yscrollbar.grid(row=0, column=1, sticky=tk.NS)
-        self._canvas.configure(xscrollcommand=xscrollbar.set, yscrollcommand=yscrollbar.set)
+        self._canvas.configure(xscrollcommand=self._xscrollbar.set, yscrollcommand=self._yscrollbar.set)
+        self._canvas.grid(row=0, column=0, rowspan=2, columnspan=2, sticky=tk.NSEW)
 
         self.grid_rowconfigure(0, weight=1)
         self.grid_columnconfigure(0, weight=1)
@@ -46,6 +48,32 @@ def __init__(self, *args, **kwargs):
         self._canvas.xview_moveto(0.0)
         self._canvas.yview_moveto(0.0)
 
+    def _show_scrollbars(self):
+        """
+        Move the horizontal and vertical scrollbars above the scrollable
+        canvas.
+        """
+        self._xscrollbar.lift()
+        self._yscrollbar.lift()
+
+    def _hide_scrollbars(self):
+        """
+        Move the horizontal and vertical scrollbars below the scrollable
+        canvas.
+        """
+        self._xscrollbar.lower()
+        self._yscrollbar.lower()
+
+    def _peek_scrollbars(self, ms=1000):
+        """
+        Show the horizontal and vertical scrollbars, and hide them after a
+        delay.
+
+        :param ms: Delay in milliseconds.
+        """
+        self._show_scrollbars()
+        self.after(ms, self._hide_scrollbars)
+
     def _xview(self, *args, width: int | None = None):
         """
         Called when a horizontal scroll is requested. Called by other callbacks
@@ -165,3 +193,4 @@ def _on_mouse_scroll(self, event: tk.Event):
             case _:
                 message = f"event {event.num} on OS {_system!r} is not supported"
                 raise ValueError(message)
+        self._peek_scrollbars()