browse.py

Urwid is a Python library for making text console applications. It has many features including fluid

		widget = dir.get_widget( name )
		return widget, self.focus
		
	def set_focus(self, focus):
		parent, name = focus
		self.focus = parent, name
		self._modified()
	
	def get_next(self, start_from):
		parent, name = start_from
		dir = get_directory( parent )
		widget = dir.get_widget(name)
		target = widget.next_inorder()
		if target is None:
			return None, None
		return target, (target.dir, target.name)

	def get_prev(self, start_from):
		parent, name = start_from
		dir = get_directory( parent )
		widget = dir.get_widget(name)
		target = widget.prev_inorder()
		if target is None:
			return None, None
		return target, (target.dir, target.name)
				

		
class DirectoryBrowser:
	palette = [
		('body', 'black', 'light gray'),
		('selected', 'black', 'dark green', ('bold','underline')),
		('focus', 'light gray', 'dark blue', 'standout'),
		('selected focus', 'yellow', 'dark cyan', 
				('bold','standout','underline')),
		('head', 'yellow', 'black', 'standout'),
		('foot', 'light gray', 'black'),
		('key', 'light cyan', 'black','underline'),
		('title', 'white', 'black', 'bold'),
		('dirmark', 'black', 'dark cyan', 'bold'),
		('flag', 'dark gray', 'light gray'),
		('error', 'dark red', 'light gray'),
		]
	
	footer_text = [
		('title', "Directory Browser"), "    ",
		('key', "UP"), ",", ('key', "DOWN"), ",",
		('key', "PAGE UP"), ",", ('key', "PAGE DOWN"),
		"  ",
		('key', "SPACE" ), "  ",
		('key', "+"), ",",
		('key', "-"), "  ",
		('key', "LEFT"), "  ",
		('key', "HOME"), "  ", 
		('key', "END"), "  ",
		('key', "Q"),
		]
	
	
	def __init__(self):
		cwd = os.getcwd()
		store_initial_cwd( cwd )
		self.listbox = urwid.ListBox( DirectoryWalker( cwd ) )
		self.listbox.offset_rows = 1
		self.header = urwid.Text( "" )
		self.footer = urwid.AttrWrap( urwid.Text( self.footer_text ),
			'foot')
		self.view = urwid.Frame( 
			urwid.AttrWrap( self.listbox, 'body' ), 
			header=urwid.AttrWrap(self.header, 'head' ), 
			footer=self.footer )

	def main(self):
		"""Run the program."""
		
		self.ui = urwid.raw_display.Screen()
		self.ui.register_palette( self.palette )
		self.ui.run_wrapper( self.run )
	
		# on exit, write the selected filenames to the console
		names = [escape_filename_sh(x) for x in get_selected_names()]
		print " ".join(names)

	def run(self):
		"""Handle user input and display updating."""
		
		self.ui.set_mouse_tracking()
		
		size = self.ui.get_cols_rows()
		while 1:
			focus, _ign = self.listbox.body.get_focus()
			# update display of focus directory
			self.header.set_text( focus.dir )
			canvas = self.view.render( size, focus=1 )
			self.ui.draw_screen( size, canvas )
			keys = None
			while not keys: 
				keys = self.ui.get_input()
			for k in keys:
				if urwid.is_mouse_event(k):
					event, button, col, row = k
					self.view.mouse_event( size, 
						event, button, col, row,
						focus=True )
					continue

				if k == 'window resize':
					size = self.ui.get_cols_rows()
				elif k in ('q','Q'):
					return
				elif k == 'right':
					# right can behave like +
					k = "+"
				k = self.view.keypress( size, k )
				# k = unhandled key or None
				if k == 'left':
					self.move_focus_to_parent( size )
				elif k == '-':
					self.collapse_focus_parent( size )
				elif k == 'home':
					self.focus_home( size )
				elif k == 'end':
					self.focus_end( size )
					
	def collapse_focus_parent(self, size):
		"""Collapse parent directory."""
		
		widget, pos = self.listbox.body.get_focus()
		self.move_focus_to_parent( size )
		
		pwidget, ppos = self.listbox.body.get_focus()
		if widget.dir != pwidget.dir:
			self.view.keypress( size, "-")

	def move_focus_to_parent(self, size):
		"""Move focus to parent of widget in focus."""
		
		middle,top,bottom = self.listbox.calculate_visible( size )
		
		row_offset, focus_widget, focus_pos, focus_rows, cursor = middle
		trim_top, fill_above = top

		parent,name = os.path.split(focus_widget.dir)
		
		if parent == focus_widget.dir:
			# no root dir, choose first element instead
			self.focus_home( size )
			return
		
		for widget, pos, rows in fill_above:
			row_offset -= rows
			if pos == (parent,name):
				self.listbox.change_focus(size, pos, row_offset)
				return
		
		self.listbox.change_focus( size, (parent, name) )
		return 
		
	def focus_home(	self, size ):
		"""Move focus to very top."""
		
		dir = get_directory("/")
		widget = dir.get_first()
		parent, name = widget.dir, widget.name
		self.listbox.change_focus( size, (parent, name) )

	def focus_end( self, size ):
		"""Move focus to far bottom."""
		
		maxrow, maxcol = size
		dir = get_directory("/")
		widget = dir.get_last()
		parent, name = widget.dir, widget.name
		self.listbox.change_focus( size, (parent, name), maxrow-1 )






def main():
	DirectoryBrowser().main()




#######
# global cache of directory information
_dir_cache = {}

def get_directory(name):
	"""Return the Directory object for a given path.  Create if necessary."""
	
	if not _dir_cache.has_key(name):
		_dir_cache[name] = Directory(name)
	return _dir_cache[name]

def directory_cached(name):
	"""Return whether the directory is in the cache."""
	
	return _dir_cache.has_key(name)

def get_selected_names():
	"""Return a list of all filenames marked as selected."""
	
	l = []
	for d in _dir_cache.values():
		for w in d.widgets.values():
			if w.selected:
				l.append( os.path.join( w.dir, w.name ) )
	return l
			


######
# store path components of initial current working directory
_initial_cwd = []

def store_initial_cwd( name ):
	"""Store the initial current working directory path components."""
	
	global _initial_cwd
	_initial_cwd = name.split( dir_sep() )

def starts_expanded( name ):
	"""Return True if directory is a parent of initial cwd."""
	
	l = name.split( dir_sep() )
	if len(l) > len( _initial_cwd ):
		return False
	
	if l != _initial_cwd[:len(l)]:
		return False
	
	return True


def escape_filename_sh( name ):
	"""Return a hopefully safe shell-escaped version of a filename."""

	# check whether we have unprintable characters
	for ch in name: 
		if ord(ch) < 32: 
			# found one so use the ansi-c escaping
			return escape_filename_sh_ansic( name )
			
	# all printable characters, so return a double-quoted version
	name.replace('\\','\\\\')
	name.replace('"','\\"')
	name.replace('`','\\`')
	name.replace('$','\\$')
	return '"'+name+'"'


def escape_filename_sh_ansic( name ):
	"""Return an ansi-c shell-escaped version of a filename."""
	
	out =[]
	# gather the escaped characters into a list
	for ch in name:
		if ord(ch) < 32:
			out.append("\\x%02x"% ord(ch))
		elif ch == '\\':
			out.append('\\\\')
		else:
			out.append( ch )
			
	# slap them back together in an ansi-c quote  $'...'
	return "$'" + "".join(out) + "'"


def sensible_cmp( name_a, name_b ):
	"""Case insensitive compare with sensible numeric ordering.
	
	"blah7" < "BLAH08" < "blah9" < "blah10" """
	
	# ai, bi are indexes into name_a, name_b
	ai = bi = 0
	
	def next_atom( name, i ):
		"""Return the next 'atom' and the next index.
		
		An 'atom' is either a nonnegative integer or an uppercased 
		character used for defining sort order."""
		
		a = name[i].upper()
		i += 1
		if a.isdigit():
			while i < len(name) and name[i].isdigit():
				a += name[i]
				i += 1
			a = long(a)
		return a, i
		
	# compare one atom at a time
	while ai < len(name_a) and bi < len(name_b):
		a, ai = next_atom( name_a, ai )
		b, bi = next_atom( name_b, bi )
		if a < b: return -1
		if a > b: return 1
	
	# if all out of atoms to compare, do a regular cmp
	if ai == len(name_a) and bi == len(name_b): 
		return cmp(name_a,name_b)
	
	# the shorter one comes first
	if ai == len(name_a): return -1
	return 1


def dir_sep():
	"""Return the separator used in this os."""
	return getattr(os.path,'sep','/')


if __name__=="__main__": 
	main()