Added persitant image counter

src/camera.py

 import os
+import json
 import time
 import datetime
 import numpy as np
@@ -13,6 +14,40 @@ try:
 except ImportError:
     from fake_rpi.picamera import PiCamera
 
+
+class ImageCounter:
+    def __init__(self, storage_dir):
+        self.__persitance_storage = \
+            os.path.join(storage_dir, '.counter'):
+        self.__current_counter = None
+
+    def __read(self):
+        if not os.path.exists(self.__persitance_storage):
+            self.__current_counter = 0
+            return 0
+        with open(self.__persitance_storage, 'r') as f:
+            self.__current_counter = int(f.read())
+
+    def __store(self)
+        with open(self.__persitance_storage, 'w') as f:
+            f.write(self.__current_counter)
+
+    @property
+    def count(self):
+        if self.__current_counter is None:
+            self.__current_counter = self.__read()
+        return self.__current_counter
+
+
+    def increase(self):
+        self.__current_counter = self.count + 1
+        self.__store()
+
+    def __str__(self):
+        return str(self.__current_counter)
+
+
+
 class Camera(object):
     def __init__(self, storage_dir, resolution=(800, 480), framerate=30):
         self.__camera = PiCamera()
@@ -20,12 +55,12 @@ class Camera(object):
         self.__image_size = (resolution[0], resolution[1], 3)
         self.__framerate = framerate
         self.__camera_lock = Lock()
-        self.__nb_images = 0
+        self.__nb_images = ImageCounter()
         self.__storage_dir = storage_dir
 
     def open(self):
         pass
-        
+
     def image(self, resolution=None):
         with self.__camera_lock:
             if resolution is None:
@@ -48,16 +83,17 @@ class Camera(object):
                 self.__camera.resolution = resolution
             ts = datetime.datetime.utcnow().strftime("%Y%m%d-%H%M%S%f")
             #cap_filename = os.path.join(self.__storage_dir, str(uuid.uuid4()) + '.jpg')
-            cap_filename = os.path.join(self.__storage_dir, f'{self.__nb_images}-{ts}.jpg')
+            img_nr  = self.__nb_images.count + 1
+            cap_filename = os.path.join(self.__storage_dir, f'{img_nr}-{ts}.jpg')
             start = time.time()
             self.__camera.capture(cap_filename, use_video_port=True)
             end = time.time() - start
-            logging.debug("capturing and istoring image took %f s" % end)
-            self.__nb_images += 1
+            logging.debug("capturing and storing image took %f s" % end)
+            self.__nb_images.increase()
             os.sync()
 
     def nb_images(self):
-        return self.__nb_images
+        return self.__nb_images.count
 
 
     def led_on(self):

src/lobster.py

@@ -21,7 +21,7 @@ def filesize(kbytes):
         return (kbytes, units[c])
 
     return (0, units[0])
-        
+
 
 
 
@@ -65,7 +65,7 @@ class QMainWidget(QMainWindow):
     def flash_off(self):
         self.flash.off()
 
-    
+
     def led_on(self):
         self.led.on()