implemented pacman screensaver

foobarpay.py

@@ -12,6 +12,7 @@ from foobarpay.scanner import EvdevScanner, FifoScanner
 from foobarpay.logic import Logic
 from foobarpay.model.product import Product
 from foobarpay.tokens import TokenGenerator
+from foobarpay.screensaver import Screensaver
 
 
 class FooBarPay:
@@ -19,7 +20,7 @@ class FooBarPay:
     DEFAULT_DISPLAY = '/dev/hidraw1'
     DEFAULT_DATABASE = 'sqlite:///foobarpay.sqlite'
     ALLOW_CUSTOMER_CREATION = False
-    INPUT_BLOCK_TIME = 0.5
+    TICK_TIME = 0.1
     IDLE_TIMEOUT = 10
 
     def __init__(self, cli_arguments):
@@ -38,6 +39,7 @@ class FooBarPay:
         self.logic = Logic(self.display, self.database,
                            allow_customer_creation=self.ALLOW_CUSTOMER_CREATION,
                            idle_timeout=self.IDLE_TIMEOUT)
+        self.screensaver = Screensaver(self.display, self.TICK_TIME)
 
     def initialize_products(self):
         self.database.get_or_create(Product, id=4100060009503, name="Extaler Mineralquell", price=100)
@@ -63,12 +65,15 @@ class FooBarPay:
         logging.info("Welcome to foobarpay")
         signal(SIGINT, lambda s, f: exit(0))
         while True:
-            sleep(self.INPUT_BLOCK_TIME)
+            sleep(self.TICK_TIME)
             line = self.scanner.read()
             if line:
                 self.logic.handle_scanned_text(line)
+                self.screensaver.reset()
                 continue
-            self.logic.tick()
+            if self.logic.tick():
+                continue
+            self.screensaver.tick()
 
 if __name__ == "__main__":
     parser = ArgumentParser()

foobarpay/screensaver.py

+from time import sleep
+
+
+class Screensaver(object):
+    def __init__(self, display, tick_time):
+        self.display = display
+        self.screensavers = [PacmanScreensaver(display, tick_time)]
+        self.active_screensaver = self.screensavers[0]
+
+    def get_active_screensaver(self):
+        return self.screensavers[self.active_screensaver].reset()
+
+    def reset(self):
+        self.active_screensaver.reset()
+
+    def tick(self):
+        if not self.active_screensaver.tick():
+            self.active_screensaver.reset()
+
+
+class PacmanScreensaver(object):
+    def __init__(self, display, tick_time):
+        self.display = display
+        self.tick_time = tick_time
+        self.pacman = ['c', 'C']
+        self.reset()
+
+    def reset(self):
+        self.pacman_index = 0
+        self.pacman_position = -1
+        self.line_index = 0
+        self.lines = [self.generate_line(init_pacman=True), self.generate_line()]
+
+    def generate_line(self, width=24, init_pacman=False):
+        line = list(" " * width)
+        for i in range(1, width, 3):
+            line[i] = 'o'
+        if init_pacman:
+            line[0] = self.pacman[self.pacman_index]
+        return "".join(line)
+
+    def show(self):
+        self.display.show_two_messages(self.lines[0], self.lines[1])
+        sleep(0.5 - self.tick_time)
+
+    """ Returns True while active and False when finished """
+    def tick(self):
+        # just show the first frame and return
+        if self.pacman_position < 0:
+            self.pacman_position += 1
+            self.show()
+            return True
+        # unset last position and increment counters
+        line = list(self.lines[self.line_index])
+        line[self.pacman_position] = ' '
+        self.pacman_index = (self.pacman_index + 1) % len(self.pacman)
+        self.pacman_position += 1
+        # switch line after reaching the end
+        if self.pacman_position >= len(line):
+            line[self.pacman_position - 1] = ' '
+            self.pacman_position = 0
+            self.lines[self.line_index] = "".join(line)
+            self.line_index = (self.line_index + 1)
+            # finish if last line reached the end
+            if self.line_index >= len(self.lines):
+                self.lines[self.line_index - 1] = "".join(line)
+                self.show()
+                return False
+            line = list(self.lines[self.line_index])
+        # assign pacman char and show on display
+        line[self.pacman_position] = self.pacman[self.pacman_index]
+        self.lines[self.line_index] = "".join(line)
+        self.show()
+        return True