add generated christmas lights (#9)

Reviewed-on: pvx/litsimaja#9

pyleds/program/promise/ChristmasLights.py

@@ -0,0 +1,38 @@
+from lib.Program import Program
+from rpi_ws281x import Color
+import time
+
+def name():
+    return 'Christmas Lights'
+
+class ChristmasLights(Program):
+    def run(self, args: [] = None):
+        # Configuration
+        wait_ms = 0  # Speed of the animation
+
+        # Define classic festive colors
+        RED = Color(255, 0, 0)
+        GREEN = Color(0, 255, 0)
+        WARM_WHITE = Color(200, 180, 60) # A golden-ish warm white
+
+        colors = [RED, GREEN, WARM_WHITE]
+
+        # This determines how many pixels of the same color are next to each other
+        group_size = 2
+
+        offset = 0
+        while self.get_loop().status():
+            num_pixels = self._lm.count_pixels()
+
+            for i in range(num_pixels):
+                # Calculate which color index to use based on pixel position and current offset
+                # This creates the "moving" effect
+                color_index = ((i + offset) // group_size) % len(colors)
+                self._lm.set_pixel_color(i, colors[color_index])
+
+            self._lm.show()
+
+            # Increment offset to move the lights
+            offset = (offset + 1) % (len(colors) * group_size)
+            self._lm.get_tempo().wait()
+            time.sleep(wait_ms / 1000.0)