Lower CPU usage

Screen will not be always updated

mopidy_touchscreen/graphic_utils/background_manager.py

@@ -0,0 +1,54 @@
+import pygame
+
+change_speed = 2
+
+
+class DynamicBackground():
+
+    def __init__(self, size):
+        self.image_loaded = False
+        self.size = size
+        self.surface = pygame.Surface(self.size).convert()
+        self.surface.fill((145, 16, 16))
+        self.surface_image = pygame.Surface(self.size).convert()
+        self.update = True
+
+    def draw_background(self):
+        if self.image_loaded:
+            return self.surface_image.copy()
+        else:
+            return self.surface.copy()
+
+    def should_update(self):
+        if self.update:
+            self.update = False
+            return True
+        else:
+            return False
+
+    def set_background_image(self, image):
+        if image is not None:
+            image_size = get_aspect_scale_size(image, self.size)
+            target = pygame.transform.smoothscale(image, image_size)
+            target.set_alpha(150)
+            self.image_loaded = True
+            self.surface_image.fill((0, 0, 0))
+            pos = ((self.size[0] - image_size[0])/2,
+                   (self.size[1] - image_size[1])/2)
+            self.surface_image.blit(target, pos)
+        else:
+            self.image_loaded = False
+        self.update = True
+
+
+def get_aspect_scale_size(img, (bx, by)):
+    size = img.get_size()
+    aspect_x = bx / float(size[0])
+    aspect_y = by / float(size[1])
+    if aspect_x > aspect_y:
+        aspect = aspect_x
+    else:
+        aspect = aspect_y
+
+    new_size = (int(aspect*size[0]), int(aspect*size[1]))
+    return new_size