optimize touch_indicator

Author: gottadiveintopython

examples/_uix/touch_indicator.py

@@ -4,68 +4,64 @@
 from typing import Unpack
 
 import pygame
-from pygame import Color, Event
+from pygame import Color, Event, Surface
 import pygame.constants as C
 import asyncpygame as apg
 
 
-class Ring:
-    __slots__ = ('draw', 'pos', )
-
-    def __init__(self, draw_target: pygame.Surface, color, initial_pos, radius, line_width):
-        ring_img = pygame.Surface((radius * 2, radius * 2)).convert(draw_target)
-        color = Color(color)
-        bgcolor = Color("black")
-        if color == bgcolor:
-            bgcolor = Color("white")
-            ring_img.fill(bgcolor)
-        ring_img.set_colorkey(bgcolor)
-        pygame.draw.circle(ring_img, color, (radius, radius), radius, line_width)
-
-        self.draw = partial(self.__class__._draw, self, draw_target.blit, ring_img, ring_img.get_rect())
-        self.pos = initial_pos
-
-    def _draw(self, blit, ring_img, ring_dest):
-        ring_dest.center = self.pos
-        blit(ring_img, ring_dest)
+def generate_ring_image(color, radius, line_width) -> Surface:
+    ring_img = Surface((radius * 2, radius * 2))
+    color = Color(color)
+    bgcolor = Color("black")
+    if color == bgcolor:
+        bgcolor = Color("white")
+        ring_img.fill(bgcolor)
+    pygame.draw.circle(ring_img, color, (radius, radius), radius, line_width)
+    ring_img = ring_img.convert()
+    ring_img.set_colorkey(bgcolor)
+    return ring_img
 
 
 async def touch_indicator(*, color="white", radius=60, line_width=4, priority, **kwargs: Unpack[apg.CommonParams]):
-    color = Color(color)
-    draw_target = kwargs["draw_target"]
+    ring_img = generate_ring_image(color, radius, line_width)
     async with (
         apg.open_nursery() as nursery,
         kwargs["sdlevent"].wait_freq(
             C.MOUSEBUTTONDOWN, C.FINGERDOWN, priority=priority,
             filter=lambda e: not getattr(e, 'touch', False)
         ) as touch_down,
     ):
+        funcs = (draw_ring_under_finger, draw_ring_under_mouse_cursor, )
         while True:
             e_down = await touch_down()
-            if e_down.type == C.MOUSEBUTTONDOWN:
-                f = draw_ring_under_mouse_cursor
-            else:
-                f = draw_ring_under_finger
-            nursery.start(f(e_down, priority=priority, ring=Ring(draw_target, color, e_down.pos, radius, line_width), **kwargs))
+            nursery.start(funcs[e_down.type == C.MOUSEBUTTONDOWN](ring_img, e_down, priority=priority, **kwargs))
+
 
+def on_mouse_motion(dest, e: Event):
+    dest.center = e.pos
 
-async def draw_ring_under_mouse_cursor(e_down: Event, *, priority, executor, sdlevent, ring, **__):
-    with executor.register(ring.draw, priority):
-        async with (
-            apg.move_on_when(sdlevent.wait(C.MOUSEBUTTONUP, filter=lambda e: e.button == e_down.button, priority=priority)),
-            sdlevent.wait_freq(C.MOUSEMOTION, priority=priority) as mouse_motion,
-        ):
-            while True:
-                e = await mouse_motion()
-                ring.pos = e.pos
 
+async def draw_ring_under_mouse_cursor(
+        ring_img: Surface, e_down: Event, *, priority, executor, sdlevent, draw_target, **__):
+    dest = ring_img.get_rect(center=e_down.pos)
+    with (
+        executor.register(partial(draw_target.blit, ring_img, dest), priority),
+        sdlevent.subscribe((C.MOUSEMOTION, ), partial(on_mouse_motion, dest), priority),
 
-async def draw_ring_under_finger(e_down: Event, *, priority, executor, sdlevent, ring, **__):
-    with executor.register(ring.draw, priority):
-        async with (
-            apg.move_on_when(sdlevent.wait(C.FINGERUP, filter=lambda e: e.finger_id == e_down.finger_id, priority=priority)),
-            sdlevent.wait_freq(C.FINGERMOTION, filter=lambda e: e.finger_id == e_down.finger_id, priority=priority) as finger_motion,
-        ):
-            while True:
-                e = await finger_motion()
-                ring.pos = e.pos
+    ):
+        await sdlevent.wait(C.MOUSEBUTTONUP, filter=lambda e: e.button == e_down.button, priority=priority)
+
+
+def on_finger_motion(finger_id, dest, e: Event):
+    if finger_id == e.finger_id:
+        dest.center = e.pos
+
+
+async def draw_ring_under_finger(
+        ring_img: Surface, e_down: Event, *, priority, executor, sdlevent, draw_target, **__):
+    dest = ring_img.get_rect(center=e_down.pos)
+    with (
+        executor.register(partial(draw_target.blit, ring_img, dest), priority),
+        sdlevent.subscribe((C.FINGERMOTION, ), partial(on_finger_motion, e_down.finger_id, dest), priority),
+    ):
+        await sdlevent.wait(C.FINGERUP, filter=lambda e: e.finger_id == e_down.finger_id, priority=priority)