File Sidebar For Pythonista

FileSidebar.py

import keychaindb, ui, editor, os

class FileBarEntry (object):
	def __init__(self, filename, open, delete):
		self.filename = filename
		self.open = open
		self.delete = delete

class FileSidebar(object):
	def __init__(self):
		self.view = ui.View()
		self.view.width=120
		self.db = keychaindb.KeychainDB('openfile')
		self.buttonheight = 30
		self.files = []
		self.update()
		b_new = ui.Button(frame=(2,30,30,30), image=ui.Image.named('ionicons-plus-24'))
		b_new.action = self.add
		self.view.add_subview(b_new)
		self.view.present('sidebar')
		
	@ui.in_background
	def add(self, sender): 
		if not editor.get_path() in self.db.values():
			self.db[editor.get_path()] = editor.get_path()
			self.update()
			
	@ui.in_background
	def openfile(self, sender):
		file = next(x for x in self.files if x.open == sender)
		editor.open_file(file.filename)
		
	@ui.in_background
	def deletefile(self, sender):
		file = next(x for x in self.files if x.delete == sender)
		del self.db[file.filename]
		self.update()
		
	@ui.in_background
	def update(self):
		for file in self.files:
			self.view.remove_subview(file.open)
			self.view.remove_subview(file.delete)
		self.files = []
		#Add subviews to main view and 'present' ui
		offset = 50
		for key,file in self.db.items():
			#print os.path.basename(file)
			filetitle = os.path.basename(file).replace('.py', '')
			openf = ui.Button(frame=(2,offset,40,self.buttonheight), title=filetitle)
			openf.width = 100
			openf.content_mode = ui.CONTENT_SCALE_ASPECT_FIT
			openf.action = self.openfile
			self.view.add_subview(openf)
			
			delfile = ui.Button(frame=(100,offset,20,self.buttonheight), image=ui.Image.named('ionicons-trash-a-24'))
			delfile.action = self.deletefile
			self.view.add_subview(delfile)
			self.files.append(FileBarEntry(file, openf, delfile))
			offset += self.buttonheight
		self.view.set_needs_display()

if __name__=='__main__':
	sidebar = FileSidebar()

Keystoredb.py

#KeychainDB.py
#A script which enables the use of
#the Pythonista keychain as a persistent
#database. The database is accessed like a dict.
#Usage:
#   from keychaindb import KeychainDB
#   kdb = KeychainDB()
#   kdb['key']

#Unfortunately the keychain can only hold
#strings, but it should be easy to type cast

import keychain
from UserDict import DictMixin

DB_NAME = 'KeychainDB'

class KeychainDB (DictMixin):
  def __init__(self, appname, init=None):
    self._keys = []
    self._data = {}
    self._dbname = DB_NAME+appname
    if init is not None:
      for key, value in init:
        self[key] = value

  def __setitem__(self, key, value):
    keychain.set_password(self._dbname, key, value)

  def __delitem__(self, key):
    for service in keychain.get_services():
      if key in service:
        keychain.delete_password(self._dbname, key)
    #No KeyError because user doesn't want the key there anyway

  def __getitem__(self, key):
    for service in keychain.get_services():
      if key == service[1]:
        return keychain.get_password(self._dbname, key)
    raise KeyError

  def keys(self):
    return [s[1] for s in keychain.get_services() if s[0] == self._dbname]

  def values(self):
    return [keychain.get_password(self._dbname, k) for k in self.keys()]

Subtle bug: It is not safe to use len(dict) to generate unique dict keys if the dict can shrink.

• Add file 'A'.
• Add file 'B'.
• Del file 'A'.
• Add file 'A'.

Result: File 'B' will be removed from the list because the last add overwrote it.
Instead, you could consider using key = str(hash(filename)).

Also, FileBarEntry could be replaced by:

import collections
FileBarEntry = collections.namedtuple('FileBarEntry', 'filename open delete')

Finally, add_file() does not appear to be used and could be commented out or deleted.

Thanks for your suggestions.