xss-dimmer: seperate timer handling from drawing

bin/xss-dimmer

@@ -43,20 +43,13 @@ def on_realize(widget):
 
 
 def on_draw(widget, event, options, background, start):
-    def _dim():
-        r = cairo.Region(cairo.RectangleInt(0, 0, *widget.get_size()))
-        dctx = window.begin_draw_frame(r)
-        cctx = dctx.get_cairo_context()
-        dim(cctx)
-        window.end_draw_frame(dctx)
-
-    def dim(cctx, once=False):
     x, y = widget.get_position()
     wwidth, wheight = widget.get_size()
     delta = options.end_opacity - options.start_opacity
     elapsed = time.monotonic() - start
     current = easing_functions[options.easing_function](elapsed / options.delay)
     opacity = delta * current + options.start_opacity
+    cctx = event
 
     # Background
     cctx.set_operator(cairo.OPERATOR_SOURCE)
@@ -73,8 +66,6 @@ def on_draw(widget, event, options, background, start):
         cctx.restore()
 
     # Remaining time
-        if elapsed >= options.delay:
-            return
     remaining = str(round(options.delay - elapsed))
     cctx.select_font_face(
         options.font, cairo.FONT_SLANT_NORMAL, cairo.FONT_WEIGHT_BOLD
@@ -91,20 +82,13 @@ def on_draw(widget, event, options, background, start):
     cctx.text_path(remaining)
     cctx.stroke()
 
-        # Rearm timer
-        if not once:
+
+def refresh(window, options, start):
+    window.queue_draw()
+    elapsed = time.monotonic() - start
+    if elapsed < options.delay:
         next_step = min(options.step, options.delay - elapsed)
-            on_draw.timer = GLib.timeout_add(next_step * 1000, _dim)
-
-    window = widget.get_window()
-    dim(event)
-    if not hasattr(on_draw, "timer"):
-        # First time we are called.
-        dim(event)
-    else:
-        # Timers already running, just repaint
-        dim(event, once=True)
-
+        GLib.timeout_add(options.step * 1000, refresh, window, options, start)
 
 # See: https://easings.net/
 easing_functions = {
@@ -186,6 +170,9 @@ if __name__ == "__main__":
 
         window.show_all()
 
+        # Schedule refresh with window.queue_draw()
+        refresh(window, options, now)
+
     # Watch for locker window
     xdisplay = display.Display()
     root = xdisplay.screen().root