Merge pull request adafruit#38 from rhooper/sequence-one-shot

Add OneShot sequence subclass to make it easy to run a sequence once

Author: kattni

adafruit_led_animation/animation/__init__.py

@@ -99,15 +99,16 @@ def animate(self):
         for anim in self._peers:
             anim.draw()
             anim.after_draw()
+            anim.draw_count += 1
 
         for anim in self._peers:
             anim.show()
 
         # Note that the main animation cycle_complete flag is used, not the peer flag.
         for anim in self._peers:
-            if self.cycle_complete:
-                anim.on_cycle_complete()
+            if anim.cycle_complete:
                 anim.cycle_complete = False
+                anim.on_cycle_complete()
 
         self._next_update = now + self._speed_ns
         return True

adafruit_led_animation/animation/comet.py

@@ -119,12 +119,14 @@ def draw(self):
             if self.bounce:
                 self.reverse = not self.reverse
                 self._direction = -self._direction
-            if self.reverse == self._initial_reverse:
+            else:
+                self.reset()
+            if self.reverse == self._initial_reverse and self.draw_count > 0:
                 self.cycle_complete = True
 
     def reset(self):
         """
-        Resets to the first color.
+        Resets to the first state.
         """
         self.reverse = self._initial_reverse
         if self.reverse:

adafruit_led_animation/helper.py

@@ -351,7 +351,7 @@ def pulse_generator(period: float, animation_object, dotstar_pwm=False):
         last_update = now
         pos = cycle_position = (cycle_position + time_since_last_draw) % period
         if pos < last_pos:
-            animation_object.on_cycle_complete()
+            animation_object.cycle_complete = True
         last_pos = pos
         if pos > half_period:
             pos = period - pos

adafruit_led_animation/sequence.py

@@ -147,7 +147,6 @@ def on_cycle_complete(self):
                 callback(self)
 
     def _sequence_complete(self, animation):  # pylint: disable=unused-argument
-        self.on_cycle_complete()
         if self.advance_on_cycle_complete:
             self._advance()
 
@@ -194,10 +193,10 @@ def next(self):
         """
         Jump to the next animation.
         """
-        current = self._current
-        if current > self._current:
+        current = self._current + 1
+        if current >= len(self._members):
             self.on_cycle_complete()
-        self.activate((self._current + 1) % len(self._members))
+        self.activate(current % len(self._members))
 
     def random(self):
         """
@@ -275,3 +274,49 @@ def show(self):
         Draws the current animation group members.
         """
         self.current_animation.show()
+
+
+class AnimateOnce(AnimationSequence):
+    """
+    Wrapper around AnimationSequence that returns False to animate() until a sequence has completed.
+    Takes the same arguments as AnimationSequence, but overrides advance_on_cycle_complete=True
+    and advance_interval=0
+
+    Example:
+
+    This example animates a comet in one direction then pulses red momentarily
+
+    .. code-block:: python
+
+        import board
+        import neopixel
+        from adafruit_led_animation.animation.comet import Comet
+        from adafruit_led_animation.animation.pulse import Pulse
+        from adafruit_led_animation.color import BLUE, RED
+        from adafruit_led_animation.sequence import AnimateOnce
+
+        strip_pixels = neopixel.NeoPixel(board.A1, 30, brightness=0.5, auto_write=False)
+
+        comet = Comet(strip_pixels, 0.01, color=BLUE, bounce=False)
+        pulse = Pulse(strip_pixels, 0.01, color=RED, period=2)
+
+        animations = AnimateOnce(comet, pulse)
+
+        while animations.animate():
+            pass
+
+    """
+
+    def __init__(self, *members, **kwargs):
+        kwargs["advance_on_cycle_complete"] = True
+        kwargs["advance_interval"] = 0
+        super().__init__(*members, **kwargs)
+        self._running = True
+
+    def on_cycle_complete(self):
+        super().on_cycle_complete()
+        self._running = False
+
+    def animate(self):
+        super().animate()
+        return self._running