Add example using image icons

src/example_icons.py

@@ -0,0 +1,106 @@
+#!/usr/bin/env python3
+
+#         Python Stream Deck Library
+#      Released under the MIT license
+#
+#   dean [at] fourwalledcubicle [dot] com
+#         www.fourwalledcubicle.com
+#
+
+import StreamDeck.StreamDeck as StreamDeck
+import threading
+import random
+import sys
+import os
+import random
+from PIL import Image
+# only required for SVG
+from svglib.svglib import svg2rlg
+from reportlab.graphics import renderPM
+
+def get_random_icon():
+    key = random.choice(list(icons.keys()))
+    return key, icons[key]
+
+def key_change_callback(deck, key, state):
+    print("Deck {} Key {} = {}".format(deck.id(), key, state), flush=True)
+
+    if key == d.key_count() - 1:
+            deck.reset()
+            deck.close()
+            return
+
+    if state:
+        icon_name, icon = get_random_icon()
+        print("Key: {}".format(icon_name))
+        deck.set_key_image(key, icon)
+
+def image_to_bgr_bytes(rgb_image):
+    r, g, b = rgb_image.transpose(Image.FLIP_LEFT_RIGHT).split()
+    return Image.merge("RGB", (b, g, r)).tobytes()
+
+def force_size(rgb_image):
+    if max(rgb_image.size) > 72:
+        rgb_image.thumbnail((72,72), Image.ANTIALIAS)
+    if rgb_image.size != (72, 72):
+        wrong_size = rgb_image
+        img_w, img_h = wrong_size.size
+        rgb_image = Image.new('RGB', (72, 72), color = 'black')
+        offset = ((72 - img_w) // 2, (72 - img_h) // 2)
+        rgb_image.paste(wrong_size, offset)
+    return rgb_image
+
+def load_icons(path = "./icons"):
+    '''
+        Supports images PIL can open.
+
+        There is also rudimentary SVG support, but i.e. gradients often
+        fail. SVG support was tested using https://github.com/icons8/flat-color-icons,
+        that gave quite good results.
+    '''
+    path = os.path.abspath(path)
+    icons = {}
+
+    for entry in os.scandir(path):
+        if entry.is_file():
+            rgb_image = None
+            if entry.path.endswith(".svg") or entry.path.endswith(".svgz"):
+                drawing = svg2rlg(entry.path)
+                rgb_image = renderPM.drawToPIL(drawing,dpi=72, bg=0x000000)
+            else:
+                rgb_image = Image.open(entry.path)
+            rgb_image = force_size(rgb_image)
+            icons[entry.name] = image_to_bgr_bytes(rgb_image)
+            rgb_image.close()
+    return icons
+
+if __name__ == "__main__":
+
+    icons = load_icons("./icons")
+
+    manager = StreamDeck.DeviceManager()
+    decks = manager.enumerate()
+
+    print("Found {} Stream Decks.".format(len(decks)), flush=True)
+
+    for d in decks:
+        d.open()
+        d.reset()
+
+        print("Press key {} to exit.".format(d.key_count() - 1), flush=True)
+
+        d.set_brightness(30)
+
+        for k in range(d.key_count()):
+            d.set_key_image(k, get_random_icon()[1])
+
+        current_key_states = d.key_states()
+        print("Initial key states: {}".format(current_key_states))
+
+        d.set_key_callback(key_change_callback)
+
+        for t in threading.enumerate():
+            if t is threading.currentThread():
+                continue
+
+            t.join()