dirnotes/c_dirnotes.py

#!/usr/bin/python3 

# TOTO: when changing directories, keep the sort order?
# TODO: fix the 'reload' function....need 'this_dir' in Files class
# TODO: write color scheme
# TODO: add file copy/move/del
# TODO: add database access & preference
# TODO: re-read date/author to xattr after an edit

# scroll
# up/down - change focus, at limit: move 1 line,
# pgup/down - move by (visible_range - 1), leave focus on the remaining element
# home/end - top/bottom, focus on first/last

# three main classes:
#   Pane: smart curses window cluster: main, status & scrolling pad
#   FileObj: a file with its xattr-comment and db-comment data
#   Files: a collection of FileObjs, sortable

import os, time, stat, sys, shutil

import time, math
import curses, sqlite3, curses.textpad
import logging, getpass

VERSION = "1.4"
# these may be different on MacOS
XATTR_COMMENT = "user.xdg.comment"
XATTR_AUTHOR = "user.xdg.comment.author"
XATTR_DATE = "user.xdg.comment.date"
COMMENT_OWNER = os.getlogin()

# convert the ~/ form to a fully qualified path
DATABASE_NAME = "~/.dirnotes.db"
DATABASE_NAME = os.path.expanduser(DATABASE_NAME)   # doesn't deref symlinks

MODE_DATABASE = 0
MODE_XATTR = 1
mode_names = ["<Database mode> ","<Xattr mode>"]
mode = MODE_XATTR

### commands
CMD_COPY   = ord('c')  # open dialog to copy-with-comment
CMD_DETAIL = ord('d')  # open dialog
CMD_EDIT   = ord('e')  # open dialog for typing & <esc> or <enter>
CMD_HELP   = ord('h')  # open dialog
CMD_MOVE   = ord('m')  # open dialog to move-with-comment
CMD_QUIT   = ord('q')
CMD_RELOAD = ord('r')  # reload
CMD_SORT   = ord('s')  # open dialog for N,S,D,C
CMD_CMNT_CP= ord('C')  # open dialog to copy comments accept 1 or a or <esc>
CMD_MODE   = ord('M')  # switch between xattr and database mode
CMD_ESC    = 27
CMD_CD     = ord('\n')

# other options will be stored in database at ~/.dirnotes.db or /etc/dirnotes.db
#   - option to use MacOSX xattr labels
#  

# at first launch (neither database is found), give the user a choice of
# ~/.dirnotes.db or /var/lib/dirnotes.db
# at usage time, check for ~/.dirnotes.db first

# there should be a copy db -> xattr (one file or all-in-dir)
#   and copy xattr -> db (one file or all-in-dir)

# file copy/move will copy the comments IN BOTH DB AND XATTR

# file comments will ALWAYS be written to both xattrs & database
#   access failure is shown once per directory

### colors

CP_TITLE  = 1
CP_BODY   = 2
CP_FOCUS  = 3
CP_ERROR  = 4
CP_HELP   = 5
CP_DIFFER = 6
COLOR_DIFFER = COLOR_TITLE = COLOR_BODY = COLOR_FOCUS = COLOR_ERROR = COLOR_HELP = None

COLOR_THEME = ''' { "heading": ("yellow","blue"),
  "body":("white","blue"),
  "focus":("black","cyan") }
'''

now = time.time()
YEAR = 3600*24*365

class Pane:
  ''' holds the whole display: handles file list directly,
      fills a child pad with the file info,
        draws scroll bar
        defers the status line to a child 
        draws a border
      line format: filename=30%, size=7, date=12, comment=rest
      line 1=current directory + border
      line 2...h-4 = filename
      line h-3 = border
      line h-2 = status
      line h-1 = border
      column 0, sep1, sep2, sep3 and w-1 are borders w.r.t. pad
      filename starts in column 1 (border in 0)

      most methods take y=0..h-1 where y is the line number WITHIN the borders
  '''
  def __init__(self, win, curdir, files):
    self.curdir = curdir
    self.cursor = None
    self.first_visible = 0
    self.nFiles = len(files)
    
    self.h, self.w = win.getmaxyx()
    
    self.main_win = win                               # whole screen
    self.win = win.subwin(self.h-1,self.w,0,0)        # upper window, for border
    self.statusbar = win.subwin(1,self.w,self.h-1,0)  # status at the bottom
    self.pad_height = max(self.nFiles,self.h-4)
    self.file_pad = curses.newpad(self.pad_height,self.w)
    self.file_pad.keypad(True)

    self.win.bkgdset(' ',curses.color_pair(CP_BODY))
    self.statusbar.bkgdset(' ',curses.color_pair(CP_BODY))
    self.file_pad.bkgdset(' ',curses.color_pair(CP_BODY))
    self.resize()

    logging.info("made the pane")

  def resize(self):   # and refill
    logging.info("got to resize")
    self.h, self.w = self.main_win.getmaxyx()
    self.sep1 = self.w // 3
    self.sep2 = self.sep1 + 8
    self.sep3 = self.sep2 + 13
    self.win.resize(self.h-1,self.w)
    self.statusbar.resize(1,self.w)
    self.statusbar.mvwin(self.h-1,0)
    self.pad_height = max(len(files),self.h-4)
    self.pad_visible = self.h-4
    self.file_pad.resize(self.pad_height+1,self.w-2)
    self.refill()
    self.refresh()

  def refresh(self):
    self.win.refresh()
 
    if self.some_comments_differ:
      self.setStatus("The xattr and database comments differ where shown in green")
    #  time.sleep(2)

    self.file_pad.refresh(self.first_visible,0,2,1,self.h-3,self.w-2)
 
  def refill(self):
    self.win.bkgdset(' ',curses.color_pair(CP_BODY))
    self.win.erase()
    self.win.border()  # TODO: or .box() ?
    h,w = self.win.getmaxyx()
    self.win.addnstr(0,3,os.path.realpath(self.curdir),w-4)
    n = len(files.getMasterComment())
    self.win.addnstr(0,w-n-1,files.getMasterComment(),w-n-1)  # TODO: fix
    self.win.attron(COLOR_TITLE | curses.A_BOLD)
    self.win.addstr(1,1,'Name'.center(self.sep1-1))
    self.win.addstr(1,self.sep1+2,'Size')
    self.win.addstr(1,self.sep2+4,'Date')
    self.win.addstr(1,self.sep3+2,'Comments')
    self.win.attroff(COLOR_BODY)

    self.some_comments_differ = False
    # now fill the file_pad
    for i,f in enumerate(files):
      self.fill_line(i)    # fill the file_pad
    if self.nFiles < self.pad_height:
      for i in range(self.nFiles, self.pad_height):
        self.file_pad.addstr(i,0,' ' * (self.w-2))

    # and display the file_pan
    if self.cursor == None:
      self.cursor = 0
    self.focus_line()

  def fill_line(self,y):
    #logging.info(f"about to add {self.w-2} spaces at {y} to the file_pad size: {self.file_pad.getmaxyx()}")
    # TODO: why do we have to have one extra line in the pad?
    f = files[y]  
    self.file_pad.addstr(y,0,' ' * (self.w-2))
    self.file_pad.addnstr(y,0,f.getFileName(),self.sep1-1)
    self.file_pad.addstr(y,self.sep1,makeSize(f.size))
    self.file_pad.addstr(y,self.sep2,makeDate(f.date))

    dbComment = f.getDbComment()
    xattrComment = f.getXattrComment()
    comment = xattrComment if mode==MODE_XATTR else dbComment
    if dbComment != xattrComment:
      self.some_comments_differ = True
      self.file_pad.attron(COLOR_HELP)
      self.file_pad.addnstr(y,self.sep3,comment,self.w-self.sep3-2)
      self.file_pad.attroff(COLOR_HELP)
    else:
      self.file_pad.addnstr(y,self.sep3,comment,self.w-self.sep3-2)

    self.file_pad.vline(y,self.sep1-1,curses.ACS_VLINE,1)
    self.file_pad.vline(y,self.sep2-1,curses.ACS_VLINE,1)
    self.file_pad.vline(y,self.sep3-1,curses.ACS_VLINE,1)

  def unfocus_line(self):
    self.fill_line(self.cursor)
  def focus_line(self):
    self.file_pad.attron(COLOR_FOCUS)
    self.fill_line(self.cursor)
    self.file_pad.attroff(COLOR_FOCUS)

  def line_move(self,direction):
    # try a move first
    new_cursor = self.cursor + direction
    if new_cursor < 0:
      new_cursor = 0
    if new_cursor >= self.nFiles:
      new_cursor = self.nFiles - 1
    if new_cursor == self.cursor:
      return
    # then adjust the window
    if new_cursor < self.first_visible:
      self.first_visible = new_cursor
      self.file_pad.redrawwin()
    if new_cursor >= self.first_visible + self.pad_visible - 1:
      self.first_visible = new_cursor - self.pad_visible + 1
      self.file_pad.redrawwin()
    self.unfocus_line()
    self.cursor = new_cursor
    self.focus_line()
    self.file_pad.move(self.cursor,0)   # just move the flashing cursor
    self.file_pad.refresh(self.first_visible,0,2,1,self.h-3,self.w-2)
    
  def setStatus(self,data):
    h,w = self.statusbar.getmaxyx()
    self.statusbar.clear()
    self.statusbar.attron(curses.A_REVERSE)
    self.statusbar.addstr(0,0,mode_names[mode])
    self.statusbar.attroff(curses.A_REVERSE)
    y,x = self.statusbar.getyx()
    self.statusbar.addnstr(" " + data,w-x-1)
    self.statusbar.refresh()

# two helpers to format the date & size visuals
def makeDate(when):
  ''' arg when is epoch seconds in localtime '''
  diff = now - when
  if diff > YEAR:
    fmt = "%b %e  %Y"
  else:
    fmt = "%b %d %H:%M"
  return time.strftime(fmt, time.localtime(when))

def makeSize(size):
  if size == FileObj.FILE_IS_DIR:
    return " <DIR> "
  elif size == FileObj.FILE_IS_LINK:
    return " <LINK>"
  log = int((math.log10(size+1)-2)/3)
  s = " KMGTE"[log]
  base = int(size/math.pow(10,log*3))
  return f"{base}{s}".strip().rjust(7)
  

## to hold the FileObj collection

class Files():
  def __init__(self,directory):
    self.directory = FileObj(directory)

    self.files = []
    if directory != '/':
      self.files.append(FileObj(directory + "/.."))
    # TODO: switch to os.scandir()
    f = os.listdir(directory)
    for i in f:
      self.files.append(FileObj(directory + '/' + i))
    self.sort()

    self.db = None
    try:
      self.db = sqlite3.connect(DATABASE_NAME)
      c = self.db.cursor()
      c.execute("select * from dirnotes")
    except sqlite3.OperationalError:
      # TODO: problem with database....create one?
      c.execute("create table dirnotes (name TEXT, date DATETIME, size INTEGER, comment TEXT, comment_date DATETIME, author TEXT)")

    try:
      c = self.db.cursor()
      self.directory.loadDbComment(c)
      for f in self.files:
        f.loadDbComment(c)
    except sqlite3.OperationalError:
      errorBox("serial problem with the database")


  def sortName(a):
    if a.getFileName() == '..':
      return "\x00"
    return a.getFileName()

  def sortDate(a):
    if a.getFileName() == '..':
      return 0
    return a.getDate()

  def sortSize(a):
    if a.getFileName() == '..':
      return 0
    return a.getSize()

  def getCurDir(self):
    return self.directory
  def getMasterComment(self):
    return self.directory.xattrComment if mode==MODE_XATTR else self.directory.dbComment

  sort_mode = sortName
  def sort(self):
    self.files.sort(key = Files.sort_mode)

  ## accessors ##
  def __len__(self):
    return len(self.files)
  def __getitem__(self, i):
    return self.files[i]
  def __iter__(self):
    return self.files.__iter__()
      
def errorBox(string):
  werr = curses.newwin(3,len(string)+8,5,5)
  werr.bkgd(' ',COLOR_ERROR)
  werr.clear()
  werr.border()
  werr.addstr(1,1,string)
  werr.getch()  # any key
  del werr
  

## one for each file
## a special one called .. exists for the parent
class FileObj():
  FILE_IS_DIR = -1
  FILE_IS_LINK = -2
  def __init__(self, fileName):
    self.fileName = os.path.realpath(fileName)
    self.displayName = '..' if fileName.endswith('/..') else os.path.split(fileName)[1] 
    s = os.lstat(fileName)
    self.date = s.st_mtime
    if stat.S_ISDIR(s.st_mode):
      self.size = FileObj.FILE_IS_DIR
    elif stat.S_ISLNK(s.st_mode):
      self.size = FileObj.FILE_IS_LINK
    else:
      self.size = s.st_size
    self.xattrComment = ''
    self.xattrAuthor = None
    self.xattrDate = None
    self.dbComment = ''
    self.dbAuthor = None
    self.dbDate = None
    self.commentsDiffer = False
    try:
      self.xattrComment = os.getxattr(fileName, XATTR_COMMENT, follow_symlinks=False).decode()
      self.xattrAuthor = os.getxattr(fileName, XATTR_AUTHOR, follow_symlinks=False).decode()
      self.xattrDate = float(os.getxattr(fileName, XATTR_DATE, follow_symlinks=False).decode())
      self.commentsDiffer = True if self.xattrComment == self.dbComment else False
    except:  # no xattr comment
      pass

  def getName(self):
    return self.fileName
  def getFileName(self):
    return self.displayName

  # with an already open database cursor
  def loadDbComment(self,c):
    c.execute("select comment,author,comment_date from dirnotes where name=? and comment<>'' order by comment_date desc",(self.fileName,))
    a = c.fetchone()
    if a:
      self.dbComment, self.dbAuthor, self.dbDate = a
      self.commentsDiffer = True if self.xattrComment == self.dbComment else False
  
  def getDbComment(self):
    return self.dbComment
  def getDbAuthor(self):
    return self.dbAuthor
  def getDbDate(self):
    return self.dbDate
  def setDbComment(self,newComment):
    try:
      self.db = sqlite3.connect(DATABASE_NAME)
    except sqlite3.OperationalError:
      logging.info(f"database {DATABASE_NAME} not found")
      raise OperationalError
    c = self.db.cursor()
    s = os.lstat(self.fileName)
    try:
      c.execute("insert into dirnotes (name,date,size,comment,comment_date,author) values (?,datetime(?,'unixepoch','localtime'),?,?,datetime(?,'unixepoch','localtime'),?)",
          (os.path.abspath(self.fileName), s.st_mtime, s.st_size, 
          str(newComment), time.time(), getpass.getuser()))
      self.db.commit()
      logging.info(f"database write for {self.fileName}")
      self.dbComment = newComment
    except sqlite3.OperationalError:
      logging.info("database is locked or unwritable")
      errorBox("the database that stores comments is locked or unwritable")
      self.commentsDiffer = True if self.xattrComment == self.dbComment else False
    
  def getXattrComment(self):
    return self.xattrComment
  def getXattrAuthor(self):
    return self.xattrAuthor
  def getXattrDate(self):
    logging.info(f"someone accessed date on {self.fileName} {self.xattrDate}")
    return self.xattrDate
  def setXattrComment(self,newComment):
    logging.info(f"set comment {newComment} on file {self.fileName}")
    try:
      os.setxattr(self.fileName,XATTR_COMMENT,bytes(newComment,'utf8'),follow_symlinks=False)
      os.setxattr(self.fileName,XATTR_AUTHOR,bytes(getpass.getuser(),'utf8'),follow_symlinks=False)
      os.setxattr(self.fileName,XATTR_DATE,bytes(str(time.time()),'utf8'),follow_symlinks=False)
      self.xattrAuthor = getpass.getuser()
      self.xattrDate = time.time()      # alternatively, re-instantiate this FileObj
      self.xattrComment = newComment
      self.commentsDiffer = True if self.xattrComment == self.dbComment else False
      return True
    # we need to move these cases out to a handler 
    except Exception as e:
      errorBox("problem setting the comment on file %s" % self.getName())
      errorBox("error "+repr(e))
      ## todo: elif file.is_sym() the kernel won't allow comments on symlinks....stored in database
      if self.size == FileObj.FILE_IS_LINK:
        errorBox("Linux does not allow comments on symlinks; comment is stored in database")
      elif os.access(self.fileName, os.W_OK)!=True:
        errorBox("you don't appear to have write permissions on this file")
        # change the listbox background to yellow
        self.displayBox.notifyUnchanged()               
      elif "Errno 95" in str(e):
        errorBox("is this a VFAT or EXFAT volume? these don't allow comments")
      return False

  def getDate(self):
   return self.date
  def getSize(self):
    return self.size
  def isDir(self):
    return self.size == self.FILE_IS_DIR

##########  dest folder picker ###############
# returns None if the user hits <esc>
class showFolderPicker:
  def __init__(self,starting_dir,title):
    self.W = curses.newwin(20,60,5,5)
    self.W.bkgd(' ',COLOR_HELP)
    self.W.keypad(True)
    self.title = title
    self.starting_dir = starting_dir
    self.cwd = starting_dir
    self.fill()
    self.selected = None

    indialog = True
    selected = ''
    while indialog:
      c = self.W.getch()
      y,x = self.W.getyx()
      if c == curses.KEY_UP:
        if y>1: self.W.move(y-1,1)
      elif c == curses.KEY_DOWN:
        if y<len(self.fs)+1: self.W.move(y+1,1)
      elif c == CMD_CD:
        # cd to new dir and refill
        if y==1 and self.fs[0].startswith('<'):    # current dir
          self.selected = self.cwd
          indialog = False
        else:
          self.cwd = self.cwd + '/' + self.fs[y-1]
          self.cwd = os.path.realpath(self.cwd)
          #logging.info(f"change dir to {self.cwd}")
          self.fill()
      elif c == CMD_ESC:
        indialog = False
    del self.W

  def value(self):
    #logging.info(f"dir picker returns {self.selected}")
    return self.selected

  def fill(self):
    h, w = self.W.getmaxyx()
    self.W.clear()
    self.W.border()
    self.W.addnstr(0,1,self.title,w-2)
    self.W.addstr(h-1,1,"<Enter> to select or change dir, <esc> to exit")
    self.fs = os.listdir(self.cwd)
    self.fs = [a for a in self.fs if os.path.isdir(a)]
    self.fs.sort()
    if self.cwd != '/':
      self.fs.insert(0,"..")
    if self.cwd != self.starting_dir:
      self.fs.insert(0,f"<use this dir> {os.path.basename(self.cwd)}")
    for i,f in enumerate(self.fs):
      self.W.addnstr(i+1,1,f,w-2)
    self.W.move(1,1)


########### comment management code #################

# paint a dialog window with a border and contents
#  discard the 1st line, use the next line to set the width
def paint_dialog(b_color,data):
  lines = data.split('\n')[1:]
  n = len(lines[0])
  w = curses.newwin(len(lines)+2,n+3,5,5)
  w.bkgd(' ',b_color)
  w.clear()
  w.border()
  for i,d in enumerate(lines):
    w.addnstr(i+1,1,d,n)
  #w.refresh I don't know why this isn't needed :(
  return w

help_string = """
Dirnotes   add descriptions to files  
           uses xattrs and a database
           version %s
 h   help window (h1/h2 for more help)
 e   edit file description
 d   see file+comment details
 s   sort
 q   quit
 M   switch between xattr & database
 C   copy comment between modes
 p   preferences/settings [not impl]
 c   copy file
 m   move file
<enter> to enter directory""" % (VERSION,)
def show_help():
  w = paint_dialog(COLOR_HELP,help_string)
  c = w.getch()
  del w
  if c==ord('1'):
    show_help1()
  if c==ord('2'):
    show_help2()

help1_string = """
Dirnotes stores its comments in the xattr property of files 
where it can, and in a database.

XATTR
=====
The xattr comments are attached to the 'user.xdg.comment' 
property.  If you copy/move/tar the file, there are often 
options to move the xattrs with the file. 

The xattr comments don't always work. For example, you may 
not have write permission on a file. Or you may be using 
an exFat/fuse filesystem that doesn't support xattr. You 
cannot add xattr comments to symlinks.

DATABASE
========
The database isvstored at ~/.dirnotes.db using sqlite3.
The comments are indexed by the realpath(filename), which 
may change if you use external drives and use varying 
mountpoints.

These comments will not move with a file unless you use the
move/copy commands inside this program.

The database allows you to add comments to files you don't 
own, or which are read-only.

When the comments in the two systems differ, the comment is
highlighted in green. The 'M' command lets you view either
xattr or database comments. The 'C' command allows you to 
copy comments between xattr and database."""
def show_help1():
  w = paint_dialog(COLOR_HELP,help1_string)
  c = w.getch()
  del w

help2_string = """
The comments are also stored with the date-of-the-comment and
the username of the comment's author. The 'd' key will 
display that info.

Optionally, the database can be stored at 
  /var/lib/dirnotes/dirnotes.db 
which allows access to all users (not implimented)"""
def show_help2():
  w = paint_dialog(COLOR_HELP,help2_string)
  c = w.getch()
  del w

#TODO: fix this to paint_dialog
sort_string = """
Select sort order: 
 
  Name
  Date
  Size
  Comment"""
def show_sort():
  h = paint_dialog(COLOR_HELP,sort_string)
  h.attron(COLOR_TITLE)
  h.addstr(3,3,"N") or h.addstr(4,3,"D") or h.addstr(5,3,"S") or h.addstr(6,3,"C")
  h.attroff(COLOR_TITLE)
  h.refresh()
  c = h.getch()
  del h
  return c

detail_string = """
Comments detail:                                          
  Comment: 
  Author: 
  Date:  """

def show_detail(f):
  global mode
  h = paint_dialog(COLOR_HELP,detail_string)
  if mode==MODE_XATTR:
    h.addstr(1,20,"from xattrs")
    c = f.getXattrComment()
    a = f.getXattrAuthor()
    d = time.ctime(f.getXattrDate())
  else:
    h.addstr(1,20,"from database")
    c = f.getDbComment()
    a = f.getDbAuthor()
    d = f.getDbDate()
  h.addnstr(2,12,c,h.getmaxyx()[1]-13)
  h.addstr(3,12,a if a else "<not set>")
  h.addstr(4,12,d if d else "<not set>")
  h.refresh()
  c = h.getch()
  del h
  return c


## used by the comment editor to pick up <ENTER> and <ESC>
edit_done = False
def edit_fn(c):
  global edit_done
  if c==ord('\n'):
    edit_done = True
    return 7
  if c==27:
    return 7
  return c

def main(w):
  global files, edit_done, mode
  global COLOR_TITLE, COLOR_BODY, COLOR_FOCUS, COLOR_ERROR, COLOR_HELP
  logging.basicConfig(filename='/tmp/dirnotes.log', level=logging.DEBUG)
  logging.info("starting curses dirnotes")
  curses.init_pair(CP_TITLE, curses.COLOR_YELLOW,curses.COLOR_BLUE)
  curses.init_pair(CP_BODY,  curses.COLOR_WHITE,curses.COLOR_BLUE)
  curses.init_pair(CP_FOCUS, curses.COLOR_BLACK,curses.COLOR_CYAN)
  curses.init_pair(CP_ERROR, curses.COLOR_BLACK,curses.COLOR_RED)
  curses.init_pair(CP_HELP,  curses.COLOR_WHITE,curses.COLOR_CYAN)
  curses.init_pair(CP_DIFFER,curses.COLOR_WHITE,curses.COLOR_GREEN)

  COLOR_TITLE = curses.color_pair(CP_TITLE) | curses.A_BOLD
  COLOR_BODY  = curses.color_pair(CP_BODY)
  COLOR_FOCUS = curses.color_pair(CP_FOCUS)
  COLOR_ERROR = curses.color_pair(CP_ERROR)
  COLOR_HELP  = curses.color_pair(CP_HELP)  
  COLOR_DIFFER = curses.color_pair(CP_DIFFER)
  logging.info(f"COLOR_DIFFER is {COLOR_DIFFER}")

  if len(sys.argv) > 1:
    cwd = sys.argv[1]
  else:
    cwd = os.getcwd()
  files = Files(cwd)
  logging.info(f"got files, len={len(files)}")

  mywin = Pane(w,cwd,files)
    
  showing_edit = False

  while True:
    c = mywin.file_pad.getch(mywin.cursor,1)
    
    if c == CMD_QUIT or c == CMD_ESC:
      break

    elif c == CMD_HELP:
      show_help()
      mywin.refresh()

    elif c == CMD_SORT:
      c = show_sort()
      if c == ord('s'):
        Files.sort_mode = Files.sortSize
      elif c == ord('n'):
        Files.sort_mode = Files.sortName
      elif c == ord('d'):
        Files.sort_mode = Files.sortDate
      files.sort()
      mywin.refill()
      mywin.refresh()

    elif c == curses.KEY_UP:
      mywin.line_move(-1)
    elif c == curses.KEY_DOWN:
      mywin.line_move(1)
    elif c == curses.KEY_PPAGE:
      mywin.line_move(-mywin.pad_visible+1)
    elif c == curses.KEY_NPAGE:
      mywin.line_move(mywin.pad_visible-1)
    elif c == curses.KEY_HOME:
      mywin.line_move(-len(files)+1)
    elif c == curses.KEY_END:
      mywin.line_move(len(files)-1)

    elif c == CMD_DETAIL:
      show_detail(files[mywin.cursor])
      mywin.refresh()

    elif c == CMD_MODE:
      mode = MODE_DATABASE if mode==MODE_XATTR else MODE_XATTR
      mywin.refill()
      mywin.refresh()

    elif c == CMD_RELOAD:
      where = files.getCurDir().fileName
      files = Files(where)
      mywin = Pane(w,where,files)

    elif c == CMD_CD:
      f = files[mywin.cursor]
      if f.isDir():
        cwd = f.getName()
        logging.info(f"CD change to {cwd}")
        files = Files(cwd)
        mywin = Pane(w,cwd,files)
        # TODO: should this simply re-fill() the existing Pane instead of destroy?

    elif c == CMD_EDIT:
      showing_edit = True
      edit_window = curses.newwin(5,(4*mywin.w) // 5,mywin.h // 2 - 3, mywin.w // 10)
      edit_window.border()
      edit_window.addstr(0,1,"<enter> when done, <esc> to cancel")
      he,we = edit_window.getmaxyx()
      edit_sub = edit_window.derwin(3,we-2,1,1)
      
      f = files[mywin.cursor]
      mywin.setStatus(f"Edit file: {f.getFileName()}")
      existing_comment = f.getXattrComment()
      edit_sub.addstr(0,0,existing_comment) 
      text = curses.textpad.Textbox(edit_sub)
      edit_window.refresh()

      comment = text.edit(edit_fn).strip()  

      logging.info(f"comment: {comment} and flag-ok {edit_done}")
      if edit_done:
        comment = comment.replace('\n',' ')
        logging.info(f"got a new comment as '{comment}'")
        edit_done = False
        f.setXattrComment(comment)
        f.setDbComment(comment)
        logging.info(f"set file {f.fileName} with comment <{comment}>")
        mywin.main_win.redrawln(mywin.cursor-mywin.first_visible+2,1)
      del text, edit_sub, edit_window
      mywin.main_win.redrawln(mywin.h // 2 - 3, 5)
      mywin.statusbar.redrawwin()
      mywin.focus_line()
      mywin.refresh()

    elif c == CMD_CMNT_CP:
      # copy comments to the other mode
      cp_cmnt_ask = curses.newwin(6,40,5,5)
      cp_cmnt_ask.border()
      cp_cmnt_ask.addstr(1,1,"Copy comments to ==> ")
      cp_cmnt_ask.addstr(1,22,"database" if mode==MODE_XATTR else "xattr")
      cp_cmnt_ask.addstr(2,1,"1  just this file")
      cp_cmnt_ask.addstr(3,1,"a  all files with comments")
      cp_cmnt_ask.addstr(4,1,"esc to cancel")
      cp_cmnt_ask.refresh()
       
      c = cp_cmnt_ask.getch()
      # esc
      if c!=ord('1') and c!=ord('a') and c!=ord('A'):
        continue
      # copy comments for one file or all
      if c==ord('1'):
        collection = [files[mywin.cursor]]
      else:
        collection = files
      for f in collection:
        if mode==MODE_XATTR:
          if f.getXattrComment():
            f.setDbComment(f.getXattrComment())
        else:
          if f.getDbComment():
            f.setXattrComment(f.getDbComment())
      mywin.refill()
      mywin.refresh()

    elif c == CMD_COPY:
      if files[mywin.cursor].displayName == "..":
        continue
      if os.path.isdir(files[mywin.cursor].fileName):
        errorBox(f"<{files[mywin.cursor].displayName}> is a directory. Copy not allowed")
        continue
      dest_dir = showFolderPicker(cwd,"Select folder for copy").value()
      if dest_dir:
        #errorBox(f"copy cmd to {dest_dir}")
        src = cwd + '/' + files[mywin.cursor].displayName
        dest = dest_dir + '/' + files[mywin.cursor].displayName
        # copy2 preserves dates & chmod/chown & xattr
        logging.info(f"copy from {src} to {dest_dir}")
        shutil.copy2(src, dest_dir)
        # and copy the database record
        f = FileObj(dest)
        f.setDbComment(files[mywin.cursor].getDbComment())
      mywin.refresh()

    elif c == CMD_MOVE:
      if files[mywin.cursor].displayName == "..":
        continue
      if os.path.isdir(files[mywin.cursor].fileName):
        errorBox(f"<{files[mywin.cursor].displayName}> is a directory. Move not allowed")
        continue
      dest_dir = showFolderPicker(cwd,"Select folder for move").value()
      if dest_dir:
        #errorBox(f"move cmd to {dest_dir}")      
        src = cwd + '/' + files[mywin.cursor].displayName
        dest = dest_dir + '/' + files[mywin.cursor].displayName
        # move preserves dates & chmod/chown & xattr
        logging.info(f"move from {src} to {dest_dir}")
        shutil.move(src, dest_dir)
        # and copy the database record
        f = FileObj(dest)
        f.setDbComment(files[mywin.cursor].getDbComment())
        files = Files(cwd)
        mywin = Pane(w,cwd,files)

    elif c == curses.KEY_RESIZE:
      mywin.resize()
    #mywin.refresh()

curses.wrapper(main)

# dirnotes database is name, date, size, comment, comment_date, author