Merge pull request #865 from Ackis/master

Blank display when quitting via CTRL-C (Catch SIGINT)

Author: ladyada

Pi_Hole_Ad_Blocker/fonts/readme.txt

@@ -0,0 +1,6 @@
+Silkscreen was created by Jason Kottke and is distributed under the Open Font License, which means that you can use, distribute, or modify it however you wish. More information about the license and Silkscreen is available on the web:
+
+http://scripts.sil.org/OFL
+http://www.kottke.org/plus/type/silkscreen/
+
+To install Silkscreen, simply copy the two .ttf files to your fonts directory.

Pi_Hole_Ad_Blocker/fonts/slkscr.ttf

@@ -39,11 +39,34 @@
 # Import Python Imaging Library
 from PIL import Image, ImageDraw, ImageFont
 
+# Signal/sys are used to catch SIGINT.
+import signal
+import sys
+
+# URL of Pi Hole
 api_url = 'http://localhost/admin/api.php'
 
+# Load nice silkscreen font
+font = ImageFont.truetype('fonts/slkscr.ttf', 8)
+
 # Create the I2C interface.
 i2c = busio.I2C(SCL, SDA)
 
+# Blanks the Pi OLED display.
+def blank_screen(display):
+  display.fill(0)
+  display.show()
+
+def SIGINT(sig, frame):
+  print('Ctrl+C detected. Quitting.')
+  # Clear display.
+  blank_screen(disp)
+  sys.exit(0)
+
+# Catch SIGINT (ctrl-c) and blank the screen.
+# This ensures that the screen will be blank when we exit.
+signal.signal(signal.SIGINT, SIGINT)
+
 # Create the SSD1306 OLED class.
 # The first two parameters are the pixel width and pixel height.  Change these
 # to the right size for your display!
@@ -55,8 +78,7 @@
 DISPLAY_OFF = 50 # off time in seconds
 
 # Clear display.
-disp.fill(0)
-disp.show()
+blank_screen(disp)
 
 # Create blank image for drawing.
 # Make sure to create image with mode '1' for 1-bit color.
@@ -79,9 +101,6 @@
 # for drawing shapes.
 x = 0
 
-# Load nice silkscreen font
-font = ImageFont.truetype('/home/pi/slkscr.ttf', 8)
-
 while True:
     # Draw a black filled box to clear the image.
     draw.rectangle((0, 0, width, height), outline=0, fill=0)
@@ -131,6 +150,6 @@
     disp.image(image)
     disp.show()
     time.sleep(DISPLAY_ON)
-    disp.fill(0)
-    disp.show()
+    # Clear display.
+    blank_screen(disp)
     time.sleep(DISPLAY_OFF)