path: root/ranger/core/actions.py

# Copyright (C) 2009, 2010, 2011  Roman Zimbelmann <romanz@lavabit.com>
# This software is distributed under the terms of the GNU GPL version 3.

import codecs
import os
import re
import shutil
import string
import tempfile
from os.path import join, isdir, realpath, exists
from os import link, symlink, getcwd, listdir, stat
from inspect import cleandoc

import ranger
from ranger.ext.direction import Direction
from ranger.ext.relative_symlink import relative_symlink
from ranger.ext.keybinding_parser import key_to_string, construct_keybinding
from ranger.ext.shell_escape import shell_quote
from ranger.ext.next_available_filename import next_available_filename
from ranger.ext.rifle import squash_flags, ASK_COMMAND
from ranger.core.shared import FileManagerAware, EnvironmentAware, \
		SettingsAware
from ranger.core.tab import Tab
from ranger.fsobject import File
from ranger.core.loader import CommandLoader, CopyLoader
from ranger.container.settingobject import ALLOWED_SETTINGS

MACRO_FAIL = "<\x01\x01MACRO_HAS_NO_VALUE\x01\01>"

class _MacroTemplate(string.Template):
	"""A template for substituting macros in commands"""
	delimiter = ranger.MACRO_DELIMITER

class Actions(FileManagerAware, EnvironmentAware, SettingsAware):
	# --------------------------
	# -- Basic Commands
	# --------------------------

	def exit(self):
		"""Exit the program"""
		raise SystemExit()

	def reset(self):
		"""Reset the filemanager, clearing the directory buffer"""
		old_path = self.thisdir.path
		self.restorable_tabs = {}
		self.previews = {}
		self.garbage_collect(-1)
		self.enter_dir(old_path)
		self.change_mode('normal')

	def change_mode(self, mode):
		if mode == self.mode:
			return
		if mode == 'visual':
			self._visual_start       = self.thisdir.pointed_obj
			self._visual_start_pos   = self.thisdir.pointer
			self._previous_selection = set(self.thisdir.marked_items)
			self.mark_files(val=not self._visual_reverse, movedown=False)
		elif mode == 'normal':
			if self.mode == 'visual':
				self._visual_start       = None
				self._visual_start_pos   = None
				self._previous_selection = None
		else:
			return
		self.mode = mode
		self.ui.status.request_redraw()

	def set_option_from_string(self, option_name, value, localpath=None):
		if option_name not in ALLOWED_SETTINGS:
			raise ValueError("The option named `%s' does not exist" %
					option_name)
		if not isinstance(value, str):
			raise ValueError("The value for an option needs to be a string.")

		self.settings.set(option_name, self._parse_option_value(option_name, value), localpath)


	def _parse_option_value(self, name, value):
		types = self.fm.settings.types_of(name)
		if bool in types:
			if value.lower() in ('false', 'off', '0'):
				return False
			elif value.lower() in ('true', 'on', '1'):
				return True
		if type(None) in types and value.lower() == 'none':
			return None
		if int in types:
			try:
				return int(value)
			except ValueError:
				pass
		if str in types:
			return value
		if list in types:
			return value.split(',')
		raise ValueError("Invalid value `%s' for option `%s'!" % (name, value))

	def toggle_visual_mode(self, reverse=False):
		if self.mode == 'normal':
			self._visual_reverse = reverse
			self.change_mode('visual')
		else:
			self.change_mode('normal')

	def reload_cwd(self):
		try:
			cwd = self.thisdir
		except:
			pass
		cwd.unload()
		cwd.load_content()

	def notify(self, text, duration=4, bad=False):
		if isinstance(text, Exception):
			if ranger.arg.debug:
				raise
			bad = True
		text = str(text)
		self.log.appendleft(text)
		if self.ui and self.ui.is_on:
			self.ui.status.notify("  ".join(text.split("\n")),
					duration=duration, bad=bad)
		else:
			print(text)

	def abort(self):
		try:
			item = self.loader.queue[0]
		except:
			self.notify("Type Q or :quit<Enter> to exit ranger")
		else:
			self.notify("Aborting: " + item.get_description())
			self.loader.remove(index=0)

	def get_cumulative_size(self):
		for f in self.thistab.get_selection() or ():
			f.look_up_cumulative_size()
		self.ui.status.request_redraw()
		self.ui.redraw_main_column()

	def redraw_window(self):
		"""Redraw the window"""
		self.ui.redraw_window()

	def open_console(self, string='', prompt=None, position=None):
		"""Open the console"""
		self.change_mode('normal')
		self.ui.open_console(string, prompt=prompt, position=position)

	def execute_console(self, string='', wildcards=[], quantifier=None):
		"""Execute a command for the console"""
		command_name = string.split()[0]
		cmd_class = self.commands.get_command(command_name, abbrev=False)
		if cmd_class is None:
			self.notify("Command not found: `%s'" % command_name, bad=True)
			return
		cmd = cmd_class(string)
		if cmd.resolve_macros and _MacroTemplate.delimiter in string:
			macros = dict(('any%d'%i, key_to_string(char)) \
					for i, char in enumerate(wildcards))
			if 'any0' in macros:
				macros['any'] = macros['any0']
			try:
				string = self.substitute_macros(string, additional=macros,
						escape=cmd.escape_macros_for_shell)
			except ValueError as e:
				if ranger.arg.debug:
					raise
				else:
					return self.notify(e)
		try:
			cmd_class(string, quantifier=quantifier).execute()
		except Exception as e:
			if ranger.arg.debug:
				raise
			else:
				self.notify(e)

	def substitute_macros(self, string, additional=dict(), escape=False):
		macros = self._get_macros()
		macros.update(additional)
		if escape:
			for key, value in macros.items():
				if isinstance(value, list):
					macros[key] = " ".join(shell_quote(s) for s in value)
				elif value != MACRO_FAIL:
					macros[key] = shell_quote(value)
		else:
			for key, value in macros.items():
				if isinstance(value, list):
					macros[key] = " ".join(value)
		result = _MacroTemplate(string).safe_substitute(macros)
		if MACRO_FAIL in result:
			raise ValueError("Could not apply macros to `%s'" % string)
		return result

	def _get_macros(self):
		macros = {}

		macros['rangerdir'] = ranger.RANGERDIR

		if self.fm.thisfile:
			macros['f'] = self.fm.thisfile.basename
		else:
			macros['f'] = MACRO_FAIL

		if self.fm.thistab.get_selection:
			macros['s'] = [fl.basename for fl in self.fm.thistab.get_selection()]
		else:
			macros['s'] = MACRO_FAIL

		if self.fm.copy_buffer:
			macros['c'] = [fl.path for fl in self.fm.copy_buffer]
		else:
			macros['c'] = MACRO_FAIL

		if self.fm.thisdir.files:
			macros['t'] = [fl.basename for fl in self.fm.thisdir.files
					if fl.realpath in (self.fm.tags or [])]
		else:
			macros['t'] = MACRO_FAIL

		if self.fm.thisdir:
			macros['d'] = self.fm.thisdir.path
		else:
			macros['d'] = '.'

		# define d/f/s macros for each tab
		for i in range(1,10):
			try:
				tab = self.fm.tabs[i]
			except:
				continue
			tabdir = tab.thisdir
			if not tabdir:
				continue
			i = str(i)
			macros[i + 'd'] = tabdir.path
			if tabdir.get_selection():
				macros[i + 's'] = [fl.path for fl in tabdir.get_selection()]
			else:
				macros[i + 's'] = MACRO_FAIL
			if tabdir.pointed_obj:
				macros[i + 'f'] = tabdir.pointed_obj.path
			else:
				macros[i + 'f'] = MACRO_FAIL

		# define D/F/S for the next tab
		found_current_tab = False
		next_tab = None
		first_tab = None
		for tabname in self.fm.tabs:
			if not first_tab:
				first_tab = tabname
			if found_current_tab:
				next_tab = self.fm.tabs[tabname]
				break
			if self.fm.current_tab == tabname:
				found_current_tab = True
		if found_current_tab and next_tab is None:
			next_tab = self.fm.tabs[first_tab]
		next_tab_dir = next_tab.thisdir

		if next_tab_dir:
			macros['D'] = str(next_tab_dir.path)
			if next_tab_dir.pointed_obj:
				macros['F'] = next_tab_dir.pointed_obj.path
			else:
				macros['F'] = MACRO_FAIL
			if next_tab_dir.get_selection():
				macros['S'] = [fl.path for fl in next_tab_dir.get_selection()]
			else:
				macros['S'] = MACRO_FAIL
		else:
			macros['D'] = MACRO_FAIL
			macros['F'] = MACRO_FAIL
			macros['S'] = MACRO_FAIL

		return macros

	def source(self, filename):
		filename = os.path.expanduser(filename)
		for line in open(filename, 'r'):
			line = line.rstrip("\r\n")
			if line.startswith("#") or not line.strip():
				continue
			try:
				self.execute_console(line)
			except Exception as e:
				if ranger.arg.debug:
					raise
				else:
					self.notify('Error in line `%s\':\n  %s' %
							(line, str(e)), bad=True)

	def execute_file(self, files, **kw):
		"""Execute a file.
		app is the name of a method in Applications, without the "app_"
		flags is a string consisting of runner.ALLOWED_FLAGS
		mode is a positive integer.
		Both flags and mode specify how the program is run."""

		mode = kw['mode'] if 'mode' in kw else 0

		# ranger can act as a file chooser when running with --choosefile=...
		if mode == 0 and 'label' not in kw:
			if ranger.arg.choosefile:
				open(ranger.arg.choosefile, 'w').write(self.fm.thisfile.path)

			if ranger.arg.choosefiles:
				open(ranger.arg.choosefiles, 'w').write("".join(
					f.path + "\n" for f in self.fm.thistab.get_selection()))

			if ranger.arg.choosefile or ranger.arg.choosefiles:
				raise SystemExit()

		if isinstance(files, set):
			files = list(files)
		elif type(files) not in (list, tuple):
			files = [files]

		flags = kw.get('flags', '')
		if 'c' in squash_flags(flags):
			files = [self.fm.thisfile]

		self.signal_emit('execute.before', keywords=kw)
		filenames = [f.path for f in files]
		label = kw.get('label', kw.get('app', None))
		try:
			return self.rifle.execute(filenames, mode, label, flags, None)
		finally:
			self.signal_emit('execute.after')

	# --------------------------
	# -- Moving Around
	# --------------------------

	def move(self, narg=None, **kw):
		"""
		A universal movement method.

		Accepts these parameters:
		(int) down, (int) up, (int) left, (int) right, (int) to,
		(bool) absolute, (bool) relative, (bool) pages,
		(bool) percentage

		to=X is translated to down=X, absolute=True

		Example:
		self.move(down=4, pages=True)  # moves down by 4 pages.
		self.move(to=2, pages=True)  # moves to page 2.
		self.move(to=1, percentage=True)  # moves to 80%
		"""
		cwd = self.thisdir
		direction = Direction(kw)
		if 'left' in direction or direction.left() > 0:
			steps = direction.left()
			if narg is not None:
				steps *= narg
			try:
				directory = os.path.join(*(['..'] * steps))
			except:
				return
			self.thistab.enter_dir(directory)
			self.change_mode('normal')
		if cwd and cwd.accessible and cwd.content_loaded:
			if 'right' in direction:
				mode = 0
				if narg is not None:
					mode = narg
				cf = self.thisfile
				selection = self.thistab.get_selection()
				if not self.thistab.enter_dir(cf) and selection:
					result = self.execute_file(selection, mode=mode)
					if result in (False, ASK_COMMAND):
						self.open_console('open_with ')
			elif direction.vertical() and cwd.files:
				newpos = direction.move(
						direction=direction.down(),
						override=narg,
						maximum=len(cwd),
						current=cwd.pointer,
						pagesize=self.ui.browser.hei)
				cwd.move(to=newpos)
				if self.mode == 'visual':
					try:
						startpos = cwd.index(self._visual_start)
					except:
						self._visual_start = None
						startpos = min(self._visual_start_pos, len(cwd))
					# The files between here and _visual_start_pos
					targets = set(cwd.files[min(startpos, newpos):\
							max(startpos, newpos) + 1])
					# The selection before activating visual mode
					old = self._previous_selection
					# The current selection
					current = set(cwd.marked_items)

					# Set theory anyone?
					if not self._visual_reverse:
						for f in targets - current:
							cwd.mark_item(f, True)
						for f in current - old - targets:
							cwd.mark_item(f, False)
					else:
						for f in targets & current:
							cwd.mark_item(f, False)
						for f in old - current - targets:
							cwd.mark_item(f, True)

	def move_parent(self, n, narg=None):
		self.change_mode('normal')
		if narg is not None:
			n *= narg
		parent = self.thistab.at_level(-1)
		if parent is not None:
			if parent.pointer + n < 0:
				n = 0 - parent.pointer
			try:
				self.thistab.enter_dir(parent.files[parent.pointer+n])
			except IndexError:
				pass

	def select_file(self, path):
		path = path.strip()
		if self.enter_dir(os.path.dirname(path)):
			self.thisdir.move_to_obj(path)

	def history_go(self, relative):
		"""Move back and forth in the history"""
		self.thistab.history_go(int(relative))

	# TODO: remove this method since it is not used?
	def scroll(self, relative):
		"""Scroll down by <relative> lines"""
		if self.ui.browser and self.ui.browser.main_column:
			self.ui.browser.main_column.scroll(relative)
			self.thisfile = self.thisdir.pointed_obj

	def enter_dir(self, path, remember=False, history=True):
		"""Enter the directory at the given path"""
		cwd = self.thisdir
		result = self.thistab.enter_dir(path, history=history)
		if cwd != self.thisdir:
			if remember:
				self.bookmarks.remember(cwd)
			self.change_mode('normal')
		return result

	def cd(self, path, remember=True):
		"""enter the directory at the given path, remember=True"""
		self.enter_dir(path, remember=remember)

	def traverse(self):
		self.change_mode('normal')
		cf = self.thisfile
		cwd = self.thisdir
		if cf is not None and cf.is_directory:
			self.enter_dir(cf.path)
		elif cwd.pointer >= len(cwd) - 1:
			while True:
				self.move(left=1)
				cwd = self.thisdir
				if cwd.pointer < len(cwd) - 1:
					break
				if cwd.path == '/':
					break
			self.move(down=1)
			self.traverse()
		else:
			self.move(down=1)
			self.traverse()

	# --------------------------
	# -- Shortcuts / Wrappers
	# --------------------------

	def pager_move(self, narg=None, **kw):
		self.ui.browser.pager.move(narg=narg, **kw)

	def taskview_move(self, narg=None, **kw):
		self.ui.taskview.move(narg=narg, **kw)

	def pause_tasks(self):
		self.loader.pause(-1)

	def pager_close(self):
		if self.ui.pager.visible:
			self.ui.close_pager()
		if self.ui.browser.pager.visible:
			self.ui.close_embedded_pager()

	def taskview_open(self):
		self.ui.open_taskview()

	def taskview_close(self):
		self.ui.close_taskview()

	def execute_command(self, cmd, **kw):
		return self.run(cmd, **kw)

	def edit_file(self, file=None):
		"""Calls execute_file with the current file and label='editor'"""
		if file is None:
			file = self.thisfile
		elif isinstance(file, str):
			file = File(os.path.expanduser(file))
		if file is None:
			return
		self.execute_file(file, label='editor')

	def toggle_option(self, string):
		"""Toggle a boolean option named <string>"""
		if isinstance(self.settings[string], bool):
			self.settings[string] ^= True

	def set_option(self, optname, value):
		"""Set the value of an option named <optname>"""
		self.settings[optname] = value

	def sort(self, func=None, reverse=None):
		if reverse is not None:
			self.settings['sort_reverse'] = bool(reverse)

		if func is not None:
			self.settings['sort'] = str(func)

	def set_filter(self, fltr):
		try:
			self.thisdir.filter = fltr
		except:
			pass

	def mark_files(self, all=False, toggle=False, val=None, movedown=None, narg=1):
		"""
		A wrapper for the directory.mark_xyz functions.

		Arguments:
		all - change all files of the current directory at once?
		toggle - toggle the marked-status?
		val - mark or unmark?
		"""

		if self.thisdir is None:
			return

		cwd = self.thisdir

		if not cwd.accessible:
			return

		if movedown is None:
			movedown = not all

		if val is None and toggle is False:
			return

		if all:
			if toggle:
				cwd.toggle_all_marks()
			else:
				cwd.mark_all(val)
			if self.mode == 'visual':
				self.change_mode('normal')
		else:
			for i in range(cwd.pointer, min(cwd.pointer + narg, len(cwd))):
				item = cwd.files[i]
				if item is not None:
					if toggle:
						cwd.toggle_mark(item)
					else:
						cwd.mark_item(item, val)

		if movedown:
			self.move(down=narg)

		self.ui.redraw_main_column()
		self.ui.status.need_redraw = True

	def mark_in_direction(self, val=True, dirarg=None):
		cwd = self.thisdir
		direction = Direction(dirarg)
		pos, selected = direction.select(lst=cwd.files, current=cwd.pointer,
				pagesize=self.ui.termsize[0])
		cwd.pointer = pos
		cwd.correct_pointer()
		for item in selected:
			cwd.mark_item(item, val)

	# --------------------------
	# -- Searching
	# --------------------------

	def search_file(self, text, offset=1, regexp=True):
		if isinstance(text, str) and regexp:
			try:
				text = re.compile(text, re.L | re.U | re.I)
			except:
				return False
		self.thistab.last_search = text
		self.search_next(order='search', offset=offset)

	def search_next(self, order=None, offset=1, forward=True):
		original_order = order

		if order is None:
			order = self.search_method
		else:
			self.set_search_method(order=order)

		if order in ('search', 'tag'):
			if order == 'search':
				arg = self.thistab.last_search
				if arg is None:
					return False
				if hasattr(arg, 'search'):
					fnc = lambda x: arg.search(x.basename)
				else:
					fnc = lambda x: arg in x.basename
			elif order == 'tag':
				fnc = lambda x: x.realpath in self.tags

			return self.thisdir.search_fnc(fnc=fnc, offset=offset, forward=forward)

		elif order in ('size', 'mimetype', 'ctime', 'mtime', 'atime'):
			cwd = self.thisdir
			if original_order is not None or not cwd.cycle_list:
				lst = list(cwd.files)
				if order == 'size':
					fnc = lambda item: -item.size
				elif order == 'mimetype':
					fnc = lambda item: item.mimetype or ''
				elif order == 'ctime':
					fnc = lambda item: -int(item.stat and item.stat.st_ctime)
				elif order == 'atime':
					fnc = lambda item: -int(item.stat and item.stat.st_atime)
				elif order == 'mtime':
					fnc = lambda item: -int(item.stat and item.stat.st_mtime)
				lst.sort(key=fnc)
				cwd.set_cycle_list(lst)
				return cwd.cycle(forward=None)

			return cwd.cycle(forward=forward)

	def set_search_method(self, order, forward=True):
		if order in ('search', 'tag', 'size', 'mimetype', 'ctime',
				'mtime', 'atime'):
			self.search_method = order

	# --------------------------
	# -- Tags
	# --------------------------
	# Tags are saved in ~/.config/ranger/tagged and simply mark if a
	# file is important to you in any context.

	def tag_toggle(self, paths=None, value=None, movedown=None, tag=None):
		if not self.tags:
			return
		if paths is None:
			tags = tuple(x.realpath for x in self.thistab.get_selection())
		else:
			tags = [realpath(path) for path in paths]
		if value is True:
			self.tags.add(*tags, tag=tag or self.tags.default_tag)
		elif value is False:
			self.tags.remove(*tags)
		else:
			self.tags.toggle(*tags, tag=tag or self.tags.default_tag)

		if movedown is None:
			movedown = len(tags) == 1 and paths is None
		if movedown:
			self.move(down=1)

		self.ui.redraw_main_column()

	def tag_remove(self, paths=None, movedown=None):
		self.tag_toggle(paths=paths, value=False, movedown=movedown)

	def tag_add(self, paths=None, movedown=None):
		self.tag_toggle(paths=paths, value=True, movedown=movedown)

	# --------------------------
	# -- Bookmarks
	# --------------------------
	# Using ranger.container.bookmarks.

	def enter_bookmark(self, key):
		"""Enter the bookmark with the name <key>"""
		try:
			self.bookmarks.update_if_outdated()
			destination = self.bookmarks[str(key)]
			cwd = self.thisdir
			if destination.path != cwd.path:
				self.bookmarks.enter(str(key))
				self.bookmarks.remember(cwd)
		except KeyError:
			pass

	def set_bookmark(self, key):
		"""Set the bookmark with the name <key> to the current directory"""
		self.bookmarks.update_if_outdated()
		self.bookmarks[str(key)] = self.thisdir

	def unset_bookmark(self, key):
		"""Delete the bookmark with the name <key>"""
		self.bookmarks.update_if_outdated()
		self.bookmarks.delete(str(key))

	def draw_bookmarks(self):
		self.ui.browser.draw_bookmarks = True

	def hide_bookmarks(self):
		self.ui.browser.draw_bookmarks = False

	def draw_possible_programs(self):
		try:
			target = self.thistab.get_selection()[0]
		except:
			self.ui.browser.draw_info = []
			return
		programs = self.rifle.list_commands([target.path], None)
		programs = ['%s | %s' % program[0:2] for program in programs]
		self.ui.browser.draw_info = programs

	def hide_console_info(self):
		self.ui.browser.draw_info = False

	# --------------------------
	# -- Pager
	# --------------------------
	# These commands open the built-in pager and set specific sources.

	def display_command_help(self, console_widget):
		try:
			command = console_widget._get_cmd_class()
		except:
			self.notify("Feature not available!", bad=True)
			return

		if not command:
			self.notify("Command not found!", bad=True)
			return

		if not command.__doc__:
			self.notify("Command has no docstring. Try using python without -OO",
					bad=True)
			return

		pager = self.ui.open_pager()
		lines = cleandoc(command.__doc__).split('\n')
		pager.set_source(lines)

	def display_help(self):
		manualpath = self.relpath('../doc/ranger.1')
		if os.path.exists(manualpath):
			process = self.run(['man', manualpath])
			if process.poll() != 16:
				return
		process = self.run(['man', 'ranger'])
		if process.poll() == 16:
			self.notify("Could not find manpage.", bad=True)

	def display_log(self):
		pager = self.ui.open_pager()
		if self.log:
			pager.set_source(["Message Log:"] + list(self.log))
		else:
			pager.set_source(["Message Log:", "No messages!"])

	def display_file(self):
		if not self.thisfile or not self.thisfile.is_file:
			return

		pager = self.ui.open_embedded_pager()
		pager.set_source(self.thisfile.get_preview_source(pager.wid, pager.hei))

	# --------------------------
	# -- Previews
	# --------------------------
	def update_preview(self, path):
		try:
			del self.previews[path]
			self.ui.need_redraw = True
		except:
			return False

	def get_preview(self, path, width, height):
		if self.settings.preview_script and self.settings.use_preview_script:
			# self.previews is a 2 dimensional dict:
			# self.previews['/tmp/foo.jpg'][(80, 24)] = "the content..."
			# self.previews['/tmp/foo.jpg']['loading'] = False
			# A -1 in tuples means "any"; (80, -1) = wid. of 80 and any hei.
			# The key 'foundpreview' is added later. Values in (True, False)
			# XXX: Previews can break when collapse_preview is on and the
			# preview column is popping out as you move the cursor on e.g. a
			# PDF file.
			try:
				data = self.previews[path]
			except:
				data = self.previews[path] = {'loading': False}
			else:
				if data['loading']:
					return None

			found = data.get((-1, -1), data.get((width, -1),
				data.get((-1, height), data.get((width, height), False))))
			if found == False:
				data['loading'] = True
				loadable = CommandLoader(args=[self.settings.preview_script,
					path, str(width), str(height)], read=True,
					silent=True, descr="Getting preview of %s" % path)
				def on_after(signal):
					exit = signal.process.poll()
					content = signal.loader.stdout_buffer
					data['foundpreview'] = True
					if exit == 0:
						data[(width, height)] = content
					elif exit == 3:
						data[(-1, height)] = content
					elif exit == 4:
						data[(width, -1)] = content
					elif exit == 5:
						data[(-1, -1)] = content
					elif exit == 1:
						data[(-1, -1)] = None
						data['foundpreview'] = False
					elif exit == 2:
						f = codecs.open(path, 'r', errors='ignore')
						try:
							data[(-1, -1)] = f.read(1024 * 32)
						except UnicodeDecodeError:
							f.close()
							f = codecs.open(path, 'r', encoding='latin-1',
									errors='ignore')
							data[(-1, -1)] = f.read(1024 * 32)
						f.close()
					else:
						data[(-1, -1)] = None
					if self.thisfile.realpath == path:
						self.ui.browser.need_redraw = True
					data['loading'] = False
					pager = self.ui.browser.pager
					if self.thisfile and self.thisfile.is_file:
						pager.set_source(self.thisfile.get_preview_source(
							pager.wid, pager.hei))
				def on_destroy(signal):
					try:
						del self.previews[path]
					except:
						pass
				loadable.signal_bind('after', on_after)
				loadable.signal_bind('destroy', on_destroy)
				self.loader.add(loadable)
				return None
			else:
				return found
		else:
			try:
				return codecs.open(path, 'r', errors='ignore')
			except:
				return None

	# --------------------------
	# -- Tabs
	# --------------------------
	def tab_open(self, name, path=None):
		tab_has_changed = (name != self.current_tab)
		self.current_tab = name
		previous_tab = self.thistab
		try:
			tab = self.tabs[name]
		except KeyError:
			# create a new tab
			if path:
				tab = Tab(path)
			else:
				tab = Tab(self.thistab.path)
			self.tabs[name] = tab
			self.thistab = tab
			tab.enter_dir(tab.path, history=True)
			if previous_tab:
				tab.inherit_history(previous_tab.history)
		else:
			self.thistab = tab
			tab.enter_dir(tab.path, history=False)

		if tab_has_changed:
			self.change_mode('normal')
			self.signal_emit('tab.change', old=previous_tab, new=self.thistab)

	def tab_close(self, name=None):
		if name is None:
			name = self.current_tab
		tab = self.tabs[name]
		if name == self.current_tab:
			direction = -1 if name == self._get_tab_list()[-1] else 1
			previous = self.current_tab
			self.tab_move(direction)
			if previous == self.current_tab:
				return  # can't close last tab
		if name in self.tabs:
			del self.tabs[name]
		self.restorable_tabs.append(tab)

	def tab_restore(self):
		# NOTE: The name of the tab is not restored.
		previous_tab = self.thistab
		if self.restorable_tabs:
			tab = self.restorable_tabs.pop()
			for name in range(1, len(self.tabs) + 2):
				if not name in self.tabs:
					self.current_tab = name
					self.tabs[name] = tab
					tab.enter_dir(tab.path, history=False)
					self.thistab = tab
					self.change_mode('normal')
					self.signal_emit('tab.change', old=previous_tab,
							new=self.thistab)
					break

	def tab_move(self, offset):
		assert isinstance(offset, int)
		tablist = self._get_tab_list()
		current_index = tablist.index(self.current_tab)
		newtab = tablist[(current_index + offset) % len(tablist)]
		if newtab != self.current_tab:
			self.tab_open(newtab)

	def tab_new(self, path=None):
		for i in range(1, 10):
			if not i in self.tabs:
				self.tab_open(i, path)
				break

	def _get_tab_list(self):
		assert len(self.tabs) > 0, "There must be >=1 tabs at all times"
		return sorted(self.tabs)

	# --------------------------
	# -- Overview of internals
	# --------------------------

	def dump_keybindings(self, *contexts):
		if not contexts:
			contexts = 'browser', 'console', 'pager', 'taskview'

		temporary_file = tempfile.NamedTemporaryFile()
		def write(string):
			temporary_file.write(string.encode('utf-8'))

		def recurse(before, pointer):
			for key, value in pointer.items():
				keys = before + [key]
				if isinstance(value, dict):
					recurse(keys, value)
				else:
					write("%12s %s\n" % (construct_keybinding(keys), value))

		for context in contexts:
			write("Keybindings in `%s'\n" % context)
			if context in self.fm.ui.keymaps:
				recurse([], self.fm.ui.keymaps[context])
			else:
				write("  None\n")
			write("\n")

		temporary_file.flush()
		pager = os.environ.get('PAGER', ranger.DEFAULT_PAGER)
		self.run([pager, temporary_file.name])

	def dump_commands(self):
		temporary_file = tempfile.NamedTemporaryFile()
		def write(string):
			temporary_file.write(string.encode('utf-8'))

		undocumented = []
		for cmd_name in sorted(self.commands.commands):
			cmd = self.commands.commands[cmd_name]
			if hasattr(cmd, '__doc__') and cmd.__doc__:
				write(cleandoc(cmd.__doc__))
				write("\n\n" + "-" * 60 + "\n")
			else:
				undocumented.append(cmd)

		if undocumented:
			write("Undocumented commands:\n\n")
			for cmd in undocumented:
				write("    :%s\n" % cmd.get_name())

		temporary_file.flush()
		pager = os.environ.get('PAGER', ranger.DEFAULT_PAGER)
		self.run([pager, temporary_file.name])

	def dump_settings(self):
		from ranger.container.settingobject import ALLOWED_SETTINGS
		temporary_file = tempfile.NamedTemporaryFile()
		def write(string):
			temporary_file.write(string.encode('utf-8'))

		for setting in sorted(ALLOWED_SETTINGS):
			write("%30s = %s\n" % (setting, getattr(self.settings, setting)))

		temporary_file.flush()
		pager = os.environ.get('PAGER', ranger.DEFAULT_PAGER)
		self.run([pager, temporary_file.name])

	# --------------------------
	# -- File System Operations
	# --------------------------

	def uncut(self):
		self.copy_buffer = set()
		self.do_cut = False
		self.ui.browser.main_column.request_redraw()

	def copy(self, mode='set', narg=None, dirarg=None):
		"""Copy the selected items.  Modes are: 'set', 'add', 'remove'."""
		assert mode in ('set', 'add', 'remove')
		cwd = self.thisdir
		if not narg and not dirarg:
			selected = (f for f in self.thistab.get_selection() if f in cwd.files)
		else:
			if not dirarg and narg:
				direction = Direction(down=1)
				offset = 0
			else:
				direction = Direction(dirarg)
				offset = 1
			pos, selected = direction.select(
					override=narg, lst=cwd.files, current=cwd.pointer,
					pagesize=self.ui.termsize[0], offset=offset)
			cwd.pointer = pos
			cwd.correct_pointer()
		if mode == 'set':
			self.copy_buffer = set(selected)
		elif mode == 'add':
			self.copy_buffer.update(set(selected))
		elif mode == 'remove':
			self.copy_buffer.difference_update(set(selected))
		self.do_cut = False
		self.ui.browser.main_column.request_redraw()

	def cut(self, mode='set', narg=None, dirarg=None):
		self.copy(mode=mode, narg=narg, dirarg=dirarg)
		self.do_cut = True
		self.ui.browser.main_column.request_redraw()

	def paste_symlink(self, relative=False):
		copied_files = self.copy_buffer
		for f in copied_files:
			self.notify(next_available_filename(f.basename))
			try:
				new_name = next_available_filename(f.basename)
				if relative:
					relative_symlink(f.path, join(getcwd(), new_name))
				else:
					symlink(f.path, join(getcwd(), new_name))
			except Exception as x:
				self.notify(x)

	def paste_hardlink(self):
		for f in self.copy_buffer:
			try:
				new_name = next_available_filename(f.basename)
				link(f.path, join(getcwd(), new_name))
			except Exception as x:
				self.notify(x)

	def paste_hardlinked_subtree(self):
		for f in self.copy_buffer:
			try:
				target_path = join(getcwd(), f.basename)
				self._recurse_hardlinked_tree(f.path, target_path)
			except Exception as x:
				self.notify(x)

	def _recurse_hardlinked_tree(self, source_path, target_path):
		if isdir(source_path):
			if not exists(target_path):
				os.mkdir(target_path, stat(source_path).st_mode)
			for item in listdir(source_path):
				self._recurse_hardlinked_tree(
					join(source_path, item),
					join(target_path, item))
		else:
			if not exists(target_path) \
			or stat(source_path).st_ino != stat(target_path).st_ino:
				link(source_path,
					next_available_filename(target_path))

	def paste(self, overwrite=False):
		"""Paste the selected items into the current directory"""
		self.loader.add(CopyLoader(self.copy_buffer, self.do_cut, overwrite))
		self.do_cut = False

	def delete(self):
		# XXX: warn when deleting mount points/unseen marked files?
		self.notify("Deleting!")
		selected = self.thistab.get_selection()
		self.copy_buffer -= set(selected)
		if selected:
			for f in selected:
				if isdir(f.path) and not os.path.islink(f.path):
					try:
						shutil.rmtree(f.path)
					except OSError as err:
						self.notify(err)
				else:
					try:
						os.remove(f.path)
					except OSError as err:
						self.notify(err)
		self.thistab.ensure_correct_pointer()

	def mkdir(self, name):
		try:
			os.mkdir(os.path.join(self.thisdir.path, name))
		except OSError as err:
			self.notify(err)

	def rename(self, src, dest):
		if hasattr(src, 'path'):
			src = src.path

		try:
			os.renames(src, dest)
		except OSError as err:
			self.notify(err)