Improved documentation

Author: laurentalacoque

scripts/constants.py

@@ -25,27 +25,34 @@
 
 """
 import os
+
+# Obsolete: This will be autodetected at runtime
 SCREEN_W = 800 ## raspi touch
 SCREEN_H = 480 ## raspi touch
 
+# Parameters for the three main effects
+# None: simple shot
+# Four: Collage of four shots
+# Animation : animated gif
 EFFECTS_PARAMETERS = {
     "None": {
-        'snap_size' : (1640,1232),
-        'logo_size' : 128,
-        'logo_padding' : 32
+        'snap_size' : (1640,1232), #(width, height) => preferably use integer division of camera resolution
+        'logo_size' : 128,         # height in pixels of the logo (will be thumbnailed to this size)
+        'logo_padding' : 32        # bottom and right padding of the logo (pixels)
     },
     "Four": { 
-        'snap_size' : (820,616),
-        'foreground_image' : "collage_four_square.png"
+        'snap_size' : (820,616),                       #(width, height) of each shots of the 2x2 collage
+        'foreground_image' : "collage_four_square.png" # Overlay image on top of the collage
     },
     "Animation": {
-        'snap_size' : (500, 500),
-        'frame_number' : 10,
-        'snap_period_millis' : 200,
-        'gif_period_millis' : 50
+        'snap_size' : (500, 500),   #(width, height) => Caution, gif animation can be huge, keep this small
+        'frame_number' : 10,        # number of frames in the animation
+        'snap_period_millis' : 200, # time interval between two snapshots
+        'gif_period_millis' : 50    # time interval in the animated gif
     }
 }
 
+# Path to icons for the software buttons (no hardware buttons setup)
 SOFTWARE_BUTTONS = {
     "None": {
         "icon" : os.path.join("ressources","ic_photo.png")
@@ -58,12 +65,19 @@
         }
 }
 
+# GPIO pin / Snapshots modes mapping
+# 'button_pins' are matched in this order ["No effect", "Four images", "Animation"]
+# 'pull_up_down' activates a pull_up or a pull_down on the GPIO pin itself (no external resistor needed)
+# 'active_state' should be 1 or 0: this is the value returned by the GPIO when switch is activated
 HARDWARE_BUTTONS = {
     "button_pins": [10,8,12], # Change this and the following to reflect your hardware buttons
     "pull_up_down": "pull_down",        # pull_up or pull_down
     "active_state": 1         # active 1 GPIO (pull_down with switch to VDD)
 }
 
+#Keyboard shorcuts for actions
+#shortcut list must be valid tkinter events
+#See : http://effbot.org/tkinterbook/tkinter-events-and-bindings.htm
 ACTIONS_KEYS_MAPPING = {
     "snap_None": ["s","S","<F1>"],
     "snap_Four": ["f","F","<F2>"],
@@ -73,21 +87,35 @@
     #,"send_print":["P"] #Uncomment if you want to a keyboard shortcut for printing
 }
 
+#Image list for in-preview countdown
+#Use as many as you want
+# COUNTDOWN_OVERLAY_IMAGES[0] will be used during the last second of countdown
+# COUNTDOWN_OVERLAY_IMAGES[1] will be used during 1s to 2s
+# ...
+# last image of the list will be used for greater counts
+# (e.g. during the first 5 secs of a 10 secs countdown in this case)
 COUNTDOWN_OVERLAY_IMAGES=[
     os.path.join("ressources","count_down_1.png"),
     os.path.join("ressources","count_down_2.png"),
     os.path.join("ressources","count_down_3.png"),
     os.path.join("ressources","count_down_4.png"),
     os.path.join("ressources","count_down_5.png"),
     os.path.join("ressources","count_down_ready.png")]
-COUNTDOWN_IMAGE_MAX_HEIGHT_RATIO = 0.2 #(0. - 1.) Ratio of the countdown images over screen height
+# this defines the height ratio of the countdown images wrt. the preview size
+COUNTDOWN_IMAGE_MAX_HEIGHT_RATIO = 0.2 #[0. - 1.] range
 
+# Path to button icon ressources
 EMAIL_BUTTON_IMG  = os.path.join("ressources","ic_email.png")
 PRINT_BUTTON_IMG  = os.path.join("ressources","ic_print.png")
+
+# Interval in ms between two authentication tokens refreshing
 OAUTH2_REFRESH_PERIOD = 1800000 # interval between two OAuth2 token refresh (ms)
-HARDWARE_POLL_PERIOD = 100      # poll interval for buttons (ms)
 
+# Polling interval for hardware buttons (ms)
+HARDWARE_POLL_PERIOD = 100
+
+# Path of various log and configuration files
 CONFIGURATION_FILE = "configuration.json"
-APP_ID_FILE = "client_id.json"
+APP_ID_FILE        = "client_id.json"
 CREDENTIALS_STORE_FILE = "credentials.dat"
 EMAILS_LOG_FILE = os.path.join("..","sendmail.log") # you should activate 'enable_mail_logging' key in configuration.json