#!/usr/bin/python

# Point-and-shoot camera for Raspberry Pi w/camera and Adafruit PiTFT.
# This must run as root (sudo python cam.py) due to framebuffer, etc.
#
# Adafruit invests time and resources providing this open source code, 
# please support Adafruit and open-source development by purchasing 
# products from Adafruit, thanks!
#
# http://www.adafruit.com/products/998  (Raspberry Pi Model B)
# http://www.adafruit.com/products/1367 (Raspberry Pi Camera Board)
# http://www.adafruit.com/products/1601 (PiTFT Mini Kit)
# This can also work with the Model A board and/or the Pi NoIR camera.
#
# Prerequisite tutorials: aside from the basic Raspbian setup and
# enabling the camera in raspi-config, you should configure WiFi (if
# using wireless with the Dropbox upload feature) and read these:
# PiTFT setup (the tactile switch buttons are not required for this
# project, but can be installed if you want them for other things):
# http://learn.adafruit.com/adafruit-pitft-28-inch-resistive-touchscreen-display-raspberry-pi
# Dropbox setup (if using the Dropbox upload feature):
# http://raspi.tv/2013/how-to-use-dropbox-with-raspberry-pi
#
# Written by Phil Burgess / Paint Your Dragon for Adafruit Industries.
# BSD license, all text above must be included in any redistribution.

# -------------------------------------------------------------------------------
# Changes from the original version by Bernhard Bablok (mail a_t bablokb dot de)
# Tested with picamera 1.8

# new feature: added screen for setting AWB
# new feature: add thumbnail to captured image and save to /home/pi/.cache
# performance: display cached thumbnails instead of scaled down images
# performance: keep list of images-numbers instead of testing existence
#              of files with thousands of os-calls
# change:      name images rpi_XXXX.jpg instead of IMG_XXXX.JPG
#              (unix-tools usually expect lower case in filenames)
# fix:         change owner of captured images to pi:pi
# fix:         capture raw RGB directly, no need to scale result with C-code
# fix:         removed buggy cropping code (camera.crop is deprecated)
# fix:         added shebang (no need to call python explicitly to execute code)
# fix:         start cam.py from any directory
#              (in *nix, you should stay at HOME)
# fix:         read and write cam.pkl in user's HOME-directory
# -------------------------------------------------------------------------------

import atexit
import cPickle as pickle
import errno
import fnmatch
import io
import sys
import os
import os.path
import pwd
import picamera
import pyexiv2
import pygame
import stat
import threading
import time
from pygame.locals import *
from subprocess import call  

# UI classes ---------------------------------------------------------------

# Small resistive touchscreen is best suited to simple tap interactions.
# Importing a big widget library seemed a bit overkill.  Instead, a couple
# of rudimentary classes are sufficient for the UI elements:

# Icon is a very simple bitmap class, just associates a name and a pygame
# image (PNG loaded from icons directory) for each.
# There isn't a globally-declared fixed list of Icons.  Instead, the list
# is populated at runtime from the contents of the 'icons' directory.

class Icon:

	def __init__(self, name):
	  self.name = name
	  try:
	    self.bitmap = pygame.image.load(iconPath + '/' + name + '.png')
	  except:
	    pass

# Button is a simple tappable screen region.  Each has:
#  - bounding rect ((X,Y,W,H) in pixels)
#  - optional background color and/or Icon (or None), always centered
#  - optional foreground Icon, always centered
#  - optional single callback function
#  - optional single value passed to callback
# Occasionally Buttons are used as a convenience for positioning Icons
# but the taps are ignored.  Stacking order is important; when Buttons
# overlap, lowest/first Button in list takes precedence when processing
# input, and highest/last Button is drawn atop prior Button(s).  This is
# used, for example, to center an Icon by creating a passive Button the
# width of the full screen, but with other buttons left or right that
# may take input precedence (e.g. the Effect labels & buttons).
# After Icons are loaded at runtime, a pass is made through the global
# buttons[] list to assign the Icon objects (from names) to each Button.

class Button:

	def __init__(self, rect, **kwargs):
	  self.rect     = rect # Bounds
	  self.color    = None # Background fill color, if any
	  self.iconBg   = None # Background Icon (atop color fill)
	  self.iconFg   = None # Foreground Icon (atop background)
	  self.bg       = None # Background Icon name
	  self.fg       = None # Foreground Icon name
	  self.callback = None # Callback function
	  self.value    = None # Value passed to callback
	  for key, value in kwargs.iteritems():
	    if   key == 'color': self.color    = value
	    elif key == 'bg'   : self.bg       = value
	    elif key == 'fg'   : self.fg       = value
	    elif key == 'cb'   : self.callback = value
	    elif key == 'value': self.value    = value

	def selected(self, pos):
	  x1 = self.rect[0]
	  y1 = self.rect[1]
	  x2 = x1 + self.rect[2] - 1
	  y2 = y1 + self.rect[3] - 1
	  if ((pos[0] >= x1) and (pos[0] <= x2) and
	      (pos[1] >= y1) and (pos[1] <= y2)):
	    if self.callback:
	      if self.value is None: self.callback()
	      else:                  self.callback(self.value)
	    return True
	  return False

	def draw(self, screen):
	  if self.color:
	    screen.fill(self.color, self.rect)
	  if self.iconBg:
	    screen.blit(self.iconBg.bitmap,
	      (self.rect[0]+(self.rect[2]-self.iconBg.bitmap.get_width())/2,
	       self.rect[1]+(self.rect[3]-self.iconBg.bitmap.get_height())/2))
	  if self.iconFg:
	    screen.blit(self.iconFg.bitmap,
	      (self.rect[0]+(self.rect[2]-self.iconFg.bitmap.get_width())/2,
	       self.rect[1]+(self.rect[3]-self.iconFg.bitmap.get_height())/2))

	def setBg(self, name):
	  if name is None:
	    self.iconBg = None
	  else:
	    for i in icons:
	      if name == i.name:
	        self.iconBg = i
	        break


# UI callbacks -------------------------------------------------------------
# These are defined before globals because they're referenced by items in
# the global buttons[] list.

def isoCallback(n): # Pass 1 (next ISO) or -1 (prev ISO)
	global isoMode
	setIsoMode((isoMode + n) % len(isoData))

def awbCallback(n): # Pass 1 (next AWB) or -1 (prev AWB)
	global awbMode
	setAwbMode((awbMode + n) % len(awbData))

def settingCallback(n): # Pass 1 (next setting) or -1 (prev setting)
	global screenMode
	screenMode += n
	if screenMode < 4:               screenMode = len(buttons) - 1
	elif screenMode >= len(buttons): screenMode = 4

def fxCallback(n): # Pass 1 (next effect) or -1 (prev effect)
	global fxMode
	setFxMode((fxMode + n) % len(fxData))

def quitCallback(): # Quit confirmation button
	saveSettings()
	raise SystemExit

def viewCallback(n): # Viewfinder buttons
	global imgNums, loadIdx, scaled, screenMode, screenModePrior, settingMode, storeMode

	if n is 0:   # Gear icon (settings)
	  screenMode = settingMode # Switch to last settings mode
	elif n is 1: # Play icon (image playback)
	  if scaled: # Last photo is already memory-resident
	    loadIdx         = len(imgNums)-1
	    screenMode      =  0 # Image playback
	    screenModePrior = -1 # Force screen refresh
	  else:      # Load image
            if len(imgNums):
	      loadIdx = len(imgNums)-1
	      showImage(loadIdx)
	    else: screenMode = 2  # No images
	else: # Rest of screen = shutter
	  takePicture()

def doneCallback(): # Exit settings
	global screenMode, settingMode
	if screenMode > 3:
	  settingMode = screenMode
	  saveSettings()
	screenMode = 3 # Switch back to viewfinder mode

def imageCallback(n): # Pass 1 (next image), -1 (prev image) or 0 (delete)
	global screenMode
	if n is 0:
	  screenMode = 1 # Delete confirmation
	else:
	  showNextImage(n)

def deleteCallback(n): # Delete confirmation
	global loadIdx, imgNums, scaled, screenMode, storeMode
	screenMode      =  0
	screenModePrior = -1
	if n is True:
	  os.remove(pathData[storeMode] +
		    '/rpi_' + '%04d' % imgNums[loadIdx] + '.jpg')
	  os.remove(cacheDir + '/rpi_' + '%04d' % imgNums[loadIdx] + '.jpg')
	  del imgNums[loadIdx]
	  if len(imgNums):
	    screen.fill(0)
	    pygame.display.update()
	    showNextImage(-1 if loadIdx==len(imgNums) else 0)
	  else: # Last image deleteted; go to 'no images' mode
	    screenMode = 2
	    scaled     = None
	    loadIdx    = -1

def storeModeCallback(n): # Radio buttons on storage settings screen
	global pathData, storeMode
	buttons[4][storeMode + 3].setBg('radio3-0')
	storeMode = n
	buttons[4][storeMode + 3].setBg('radio3-1')

        #create directory if it does not exist
	if not os.path.isdir(pathData[storeMode]):
	  try:
	    os.makedirs(pathData[storeMode])
	    # Set new directory ownership to pi user, mode to 755
	    os.chown(pathData[storeMode], uid, gid)
	    os.chmod(pathData[storeMode],
	      stat.S_IRUSR | stat.S_IWUSR | stat.S_IXUSR |
	      stat.S_IRGRP | stat.S_IXGRP |
	      stat.S_IROTH | stat.S_IXOTH)
	  except OSError as e:
	    # errno = 2 if can't create folder
	    print errno.errorcode[e.errno]
	    raise SystemExit
    
        # read all existing image numbers
	readImgNumsList(storeMode)

def sizeModeCallback(n): # Radio buttons on size settings screen
	global sizeMode
	buttons[5][sizeMode + 3].setBg('radio3-0')
	sizeMode = n
	buttons[5][sizeMode + 3].setBg('radio3-1')
	camera.resolution = sizeData[sizeMode][1]


# Global stuff -------------------------------------------------------------

screenMode      =  3      # Current screen mode; default = viewfinder
screenModePrior = -1      # Prior screen mode (for detecting changes)
settingMode     =  4      # Last-used settings mode (default = storage)
storeMode       =  0      # Storage mode; default = Photos folder
storeModePrior  = -1      # Prior storage mode (for detecting changes)
sizeMode        =  0      # Image size; default = Large
fxMode          =  0      # Image effect; default = Normal
isoMode         =  0      # ISO setting; default = Auto
awbMode         =  0      # AWB setting; default = auto
iconPath        = 'icons' # Subdirectory containing UI bitmaps (PNG format)
loadIdx         = -1      # Image index for loading
scaled          = None    # pygame Surface w/last-loaded image

# list of existing image numbers. Read by storeModeCallback using
# readImgNumsList
imgNums = []

# To use Dropbox uploader, must have previously run the dropbox_uploader.sh
# script to set up the app key and such.  If this was done as the normal pi
# user, set upconfig to the .dropbox_uploader config file in that account's
# home directory.  Alternately, could run the setup script as root and
# delete the upconfig line below.
uploader        = '/home/pi/Dropbox-Uploader/dropbox_uploader.sh'
upconfig        = '/home/pi/.dropbox_uploader'

sizeData = [ # Camera parameters for different size settings
 # Full res      Viewfinder
 [(2592, 1944), (320, 240)], # Large
 [(1920, 1080), (320, 180)], # Med
 [(1440, 1080), (320, 240)]] # Small

isoData = [ # Values for ISO settings [ISO value, indicator X position]
 [  0,  27], [100,  64], [200,  97], [320, 137],
 [400, 164], [500, 197], [640, 244], [800, 297]]

# Setting for auto white balance. A fixed list is used because
# we have pre-generated icons.
awbData = [ 'auto', 'off', 'sunlight',
  'cloudy', 'shade', 'tungsten', 'fluorescent', 'incandescent',
  'flash', 'horizon' ]

# A fixed list of image effects is used (rather than polling
# camera.IMAGE_EFFECTS) because the latter contains a few elements
# that aren't valid (at least in video_port mode) -- e.g. blackboard,
# whiteboard, posterize (but posterise, British spelling, is OK).
# Others have no visible effect (or might require setting add'l
# camera parameters for which there's no GUI yet) -- e.g. saturation,
# colorbalance, colorpoint.
fxData = [
  'none', 'sketch', 'gpen', 'pastel', 'watercolor', 'oilpaint', 'hatch',
  'negative', 'colorswap', 'posterise', 'denoise', 'blur', 'film',
  'washedout', 'emboss', 'cartoon', 'solarize' ]

# cache directory for thumbnails
cacheDir = '/home/pi/.cache/picam'

pathData = [
  '/home/pi/Photos',     # Path for storeMode = 0 (Photos folder)
  '/boot/DCIM/CANON999', # Path for storeMode = 1 (Boot partition)
  '/home/pi/Photos']     # Path for storeMode = 2 (Dropbox)

icons = [] # This list gets populated at startup

# buttons[] is a list of lists; each top-level list element corresponds
# to one screen mode (e.g. viewfinder, image playback, storage settings),
# and each element within those lists corresponds to one UI button.
# There's a little bit of repetition (e.g. prev/next buttons are
# declared for each settings screen, rather than a single reusable
# set); trying to reuse those few elements just made for an ugly
# tangle of code elsewhere.

buttons = [
  # Screen mode 0 is photo playback
  [Button((  0,188,320, 52), bg='done' , cb=doneCallback),
   Button((  0,  0, 80, 52), bg='prev' , cb=imageCallback, value=-1),
   Button((240,  0, 80, 52), bg='next' , cb=imageCallback, value= 1),
   Button(( 88, 70,157,102)), # 'Working' label (when enabled)
   Button((148,129, 22, 22)), # Spinner (when enabled)
   Button((121,  0, 78, 52), bg='trash', cb=imageCallback, value= 0)],

  # Screen mode 1 is delete confirmation
  [Button((  0,35,320, 33), bg='delete'),
   Button(( 32,86,120,100), bg='yn', fg='yes',
    cb=deleteCallback, value=True),
   Button((168,86,120,100), bg='yn', fg='no',
    cb=deleteCallback, value=False)],

  # Screen mode 2 is 'No Images'
  [Button((0,  0,320,240), cb=doneCallback), # Full screen = button
   Button((0,188,320, 52), bg='done'),       # Fake 'Done' button
   Button((0, 53,320, 80), bg='empty')],     # 'Empty' message

  # Screen mode 3 is viewfinder / snapshot
  [Button((  0,188,156, 52), bg='gear', cb=viewCallback, value=0),
   Button((164,188,156, 52), bg='play', cb=viewCallback, value=1),
   Button((  0,  0,320,240)           , cb=viewCallback, value=2),
   Button(( 88, 51,157,102)),  # 'Working' label (when enabled)
   Button((148, 110,22, 22))], # Spinner (when enabled)

  # Remaining screens are settings modes

  # Screen mode 4 is storage settings
  [Button((  0,188,320, 52), bg='done', cb=doneCallback),
   Button((  0,  0, 80, 52), bg='prev', cb=settingCallback, value=-1),
   Button((240,  0, 80, 52), bg='next', cb=settingCallback, value= 1),
   Button((  2, 60,100,120), bg='radio3-1', fg='store-folder',
    cb=storeModeCallback, value=0),
   Button((110, 60,100,120), bg='radio3-0', fg='store-boot',
    cb=storeModeCallback, value=1),
   Button((218, 60,100,120), bg='radio3-0', fg='store-dropbox',
    cb=storeModeCallback, value=2),
   Button((  0, 10,320, 35), bg='storage')],

  # Screen mode 5 is size settings
  [Button((  0,188,320, 52), bg='done', cb=doneCallback),
   Button((  0,  0, 80, 52), bg='prev', cb=settingCallback, value=-1),
   Button((240,  0, 80, 52), bg='next', cb=settingCallback, value= 1),
   Button((  2, 60,100,120), bg='radio3-1', fg='size-l',
    cb=sizeModeCallback, value=0),
   Button((110, 60,100,120), bg='radio3-0', fg='size-m',
    cb=sizeModeCallback, value=1),
   Button((218, 60,100,120), bg='radio3-0', fg='size-s',
    cb=sizeModeCallback, value=2),
   Button((  0, 10,320, 29), bg='size')],

  # Screen mode 6 is graphic effect
  [Button((  0,188,320, 52), bg='done', cb=doneCallback),
   Button((  0,  0, 80, 52), bg='prev', cb=settingCallback, value=-1),
   Button((240,  0, 80, 52), bg='next', cb=settingCallback, value= 1),
   Button((  0, 70, 80, 52), bg='prev', cb=fxCallback     , value=-1),
   Button((240, 70, 80, 52), bg='next', cb=fxCallback     , value= 1),
   Button((  0, 67,320, 91), bg='fx-none'),
   Button((  0, 11,320, 29), bg='fx')],

  # Screen mode 7 is ISO
  [Button((  0,188,320, 52), bg='done', cb=doneCallback),
   Button((  0,  0, 80, 52), bg='prev', cb=settingCallback, value=-1),
   Button((240,  0, 80, 52), bg='next', cb=settingCallback, value= 1),
   Button((  0, 70, 80, 52), bg='prev', cb=isoCallback    , value=-1),
   Button((240, 70, 80, 52), bg='next', cb=isoCallback    , value= 1),
   Button((  0, 79,320, 33), bg='iso-0'),
   Button((  9,134,302, 26), bg='iso-bar'),
   Button(( 17,157, 21, 19), bg='iso-arrow'),
   Button((  0, 10,320, 29), bg='iso')],

  # Screen mode 8 is auto white balance (awb)
  [Button((  0,188,320, 52), bg='done', cb=doneCallback),
   Button((  0,  0, 80, 52), bg='prev', cb=settingCallback, value=-1),
   Button((240,  0, 80, 52), bg='next', cb=settingCallback, value= 1),
   Button((  0, 70, 80, 52), bg='prev', cb=awbCallback     , value=-1),
   Button((240, 70, 80, 52), bg='next', cb=awbCallback     , value= 1),
   Button((  0, 67,320, 91), bg='awb-auto'),
   Button((  0, 11,320, 29), bg='awb')],

  # Screen mode 9 is quit confirmation
  [Button((  0,188,320, 52), bg='done'   , cb=doneCallback),
   Button((  0,  0, 80, 52), bg='prev'   , cb=settingCallback, value=-1),
   Button((240,  0, 80, 52), bg='next'   , cb=settingCallback, value= 1),
   Button((110, 60,100,120), bg='quit-ok', cb=quitCallback),
   Button((  0, 10,320, 35), bg='quit')]
]


# Assorted utility functions -----------------------------------------------

def setFxMode(n):
	global fxMode
	fxMode = n
	camera.image_effect = fxData[fxMode]
	buttons[6][5].setBg('fx-' + fxData[fxMode])

def setIsoMode(n):
	global isoMode
	isoMode    = n
	camera.ISO = isoData[isoMode][0]
	buttons[7][5].setBg('iso-' + str(isoData[isoMode][0]))
	buttons[7][7].rect = ((isoData[isoMode][1] - 10,) +
	  buttons[7][7].rect[1:])

def setAwbMode(n):
	global awbMode
	awbMode = n
	camera.awb_mode = awbData[awbMode]
	buttons[8][5].setBg('awb-' + awbData[awbMode])

def saveSettings():
	try:
	  outfile = open(os.path.expanduser('~')+'/cam.pkl', 'wb')
	  # Use a dictionary (rather than pickling 'raw' values) so
	  # the number & order of things can change without breaking.
	  d = { 'fx'    : fxMode,
	        'iso'   : isoMode,
		'awb'   : awbMode,
	        'size'  : sizeMode,
	        'store' : storeMode }
	  pickle.dump(d, outfile)
	  outfile.close()
	except:
	  pass

def loadSettings():
	try:
	  infile = open(os.path.expanduser('~')+'/cam.pkl', 'rb')
	  d      = pickle.load(infile)
	  infile.close()
	  if 'fx'    in d: setFxMode(   d['fx'])
	  if 'iso'   in d: setIsoMode(  d['iso'])
	  if 'awb'   in d: setAwbMode(  d['awb'])
	  if 'size'  in d: sizeModeCallback( d['size'])
	  if 'store' in d: storeModeCallback(d['store'])
	except:
	  storeModeCallback(storeMode)

# Read existing numbers into imgNums. Triggerd by a change of
# storeMode.
def readImgNumsList(n):
	global pathData, imgNums
	imgNums = []
	for file in os.listdir(pathData[n]):
	  if fnmatch.fnmatch(file,'rpi_[0-9][0-9][0-9][0-9].jpg'):
	    imgNums.append(int(file[4:8]))
	imgNums.sort()

# Busy indicator.  To use, run in separate thread, set global 'busy'
# to False when done.
def spinner():
	global busy, screenMode, screenModePrior

	buttons[screenMode][3].setBg('working')
	buttons[screenMode][3].draw(screen)
	pygame.display.update()

	busy = True
	n    = 0
	while busy is True:
	  buttons[screenMode][4].setBg('work-' + str(n))
	  buttons[screenMode][4].draw(screen)
	  pygame.display.update()
	  n = (n + 1) % 5
	  time.sleep(0.15)

	buttons[screenMode][3].setBg(None)
	buttons[screenMode][4].setBg(None)
	screenModePrior = -1 # Force refresh

def saveThumbnail(fname,tname):      # fname: filename with extension
	metadata = pyexiv2.ImageMetadata(fname)
	metadata.read()
	thumb = metadata.exif_thumbnail
	thumb.write_to_file(tname)   # tname: thumbname without extension
	os.chown(tname+".jpg", uid, gid)
	os.chmod(tname+".jpg",
	    stat.S_IRUSR | stat.S_IWUSR | stat.S_IRGRP | stat.S_IROTH)
	
def takePicture():
	global busy, gid, loadIdx, scaled, sizeMode, storeMode, storeModePrior, uid, cacheDir, imgNums

	saveNum = imgNums[-1] + 1 % 10000 if len(imgNums) else 0
	filename = pathData[storeMode] + '/rpi_' + '%04d' % saveNum + '.jpg'
	cachename = cacheDir+'/rpi_' + '%04d' % saveNum

	t = threading.Thread(target=spinner)
	t.start()

	scaled = None
	camera.resolution = sizeData[sizeMode][0]
	try:
	  camera.capture(filename, use_video_port=False, format='jpeg',
	    thumbnail=(340,240,60))
	  imgNums.append(saveNum)
	  # Set image file ownership to pi user, mode to 644
	  os.chown(filename, uid, gid)
	  os.chmod(filename,
	    stat.S_IRUSR | stat.S_IWUSR | stat.S_IRGRP | stat.S_IROTH)
	  saveThumbnail(filename,cachename)
	  scaled  = pygame.image.load(cachename+'.jpg')
	  if storeMode == 2: # Dropbox
	    if upconfig:
	      cmd = uploader + ' -f ' + upconfig + ' upload ' + filename + ' Photos/' + os.path.basename(filename)
	    else:
	      cmd = uploader + ' upload ' + filename + ' Photos/' + os.path.basename(filename)
	    call ([cmd], shell=True)

	finally:
	  # Add error handling/indicator (disk full, etc.)
	  camera.resolution = sizeData[sizeMode][1]

	busy = False
	t.join()

	if scaled:
	  if scaled.get_height() < 240: # Letterbox
	    screen.fill(0)
	  screen.blit(scaled,
	    ((320 - scaled.get_width() ) / 2,
	     (240 - scaled.get_height()) / 2))
	  pygame.display.update()
	  time.sleep(2.5)
	  loadIdx = len(imgNums)-1

def showNextImage(direction):
	global busy, loadIdx, imgNums
	
	loadIdx += direction
	if loadIdx == len(imgNums):  # past end of list, continue at beginning
	  loadIdx = 0
        elif loadIdx == -1:            # before start of list, continue with end of list
	  loadIdx = len(imgNums)-1
	showImage(loadIdx)

def showImage(n):
	global busy, imgNums, loadIdx, scaled, screenMode, screenModePrior, sizeMode, storeMode

	t = threading.Thread(target=spinner)
	t.start()

	scaled   = pygame.image.load(
	            cacheDir + '/rpi_' + '%04d' % imgNums[n] + '.jpg')

	busy = False
	t.join()

	screenMode      =  0 # Photo playback
	screenModePrior = -1 # Force screen refresh


# Initialization -----------------------------------------------------------

# fix iconPath: it's relative to the executable
thisDir,thisFile = os.path.split(sys.argv[0])
iconPath = thisDir + os.path.sep + iconPath

# Init framebuffer/touchscreen environment variables
os.putenv('SDL_VIDEODRIVER', 'fbcon')
os.putenv('SDL_FBDEV'      , '/dev/fb1')
os.putenv('SDL_MOUSEDRV'   , 'TSLIB')
os.putenv('SDL_MOUSEDEV'   , '/dev/input/touchscreen')

# running as root from /etc/rc.local and not under sudo control, so
# query ids directly
uid = pwd.getpwnam("pi").pw_uid
gid = pwd.getpwnam("pi").pw_gid

# Buffers for viewfinder data
rgb = bytearray(320 * 240 * 3)

# Init pygame and screen
pygame.init()
pygame.mouse.set_visible(False)
screen = pygame.display.set_mode((0,0), pygame.FULLSCREEN)

# Init camera and set up default values
camera            = picamera.PiCamera()
atexit.register(camera.close)
camera.resolution = sizeData[sizeMode][1]

# Load all icons at startup.
for file in os.listdir(iconPath):
  if fnmatch.fnmatch(file, '*.png'):
    icons.append(Icon(file.split('.')[0]))

# Assign Icons to Buttons, now that they're loaded
for s in buttons:        # For each screenful of buttons...
  for b in s:            #  For each button on screen...
    for i in icons:      #   For each icon...
      if b.bg == i.name: #    Compare names; match?
        b.iconBg = i     #     Assign Icon to Button
        b.bg     = None  #     Name no longer used; allow garbage collection
      if b.fg == i.name:
        b.iconFg = i
        b.fg     = None

# one-time initialization of cache-directory
if not os.path.isdir(cacheDir):
  try:
    os.makedirs(cacheDir)
    # Set new directory ownership to pi user, mode to 755
    os.chown(cacheDir, uid, gid)
    os.chmod(cacheDir,
      stat.S_IRUSR | stat.S_IWUSR | stat.S_IXUSR |
      stat.S_IRGRP | stat.S_IXGRP |
      stat.S_IROTH | stat.S_IXOTH)
  except OSError as e:
    # errno = 2 if can't create folder
    print errno.errorcode[e.errno]
    raise SystemExit

loadSettings() # Must come last; fiddles with Button/Icon states

# Main loop ----------------------------------------------------------------

while(True):

  # Process touchscreen input
  while True:
    for event in pygame.event.get():
      if(event.type is MOUSEBUTTONDOWN):
        pos = pygame.mouse.get_pos()
        for b in buttons[screenMode]:
          if b.selected(pos): break
    # If in viewfinder or settings modes, stop processing touchscreen
    # and refresh the display to show the live preview.  In other modes
    # (image playback, etc.), stop and refresh the screen only when
    # screenMode changes.
    if screenMode >= 3 or screenMode != screenModePrior: break

  # Refresh display
  if screenMode >= 3: # Viewfinder or settings modes
    stream = io.BytesIO() # Capture into in-memory stream
    camera.capture(stream, resize=sizeData[sizeMode][1],use_video_port=True, format='rgb')
    stream.seek(0)
    stream.readinto(rgb)
    stream.close()
    img = pygame.image.frombuffer(rgb[0:
      (sizeData[sizeMode][1][0] * sizeData[sizeMode][1][1] * 3)],
      sizeData[sizeMode][1], 'RGB')
  elif screenMode < 2: # Playback mode or delete confirmation
    img = scaled       # Show last-loaded image
  else:                # 'No Photos' mode
    img = None         # You get nothing, good day sir

  if img is None or img.get_height() < 240: # Letterbox, clear background
    screen.fill(0)
  if img:
    screen.blit(img,
      ((320 - img.get_width() ) / 2,
       (240 - img.get_height()) / 2))

  # Overlay buttons on display and update
  for i,b in enumerate(buttons[screenMode]):
    b.draw(screen)
  pygame.display.update()

  screenModePrior = screenMode