Issue #27518: Merge from 3.5

1 files changed, 1639 insertions, 0 deletions

diff --git a/Lib/idlelib/editor.py b/Lib/idlelib/editor.py
new file mode 100644
index 0000000000..7372ecf2d7
--- /dev/null
+++ b/Lib/idlelib/editor.py
@@ -0,0 +1,1639 @@
+import importlib
+import importlib.abc
+import importlib.util
+import os
+import platform
+import re
+import string
+import sys
+from tkinter import *
+from tkinter.ttk import Scrollbar
+import tkinter.simpledialog as tkSimpleDialog
+import tkinter.messagebox as tkMessageBox
+import traceback
+import webbrowser
+
+from idlelib.multicall import MultiCallCreator
+from idlelib import query
+from idlelib import windows
+from idlelib import search
+from idlelib import grep
+from idlelib import replace
+from idlelib import pyparse
+from idlelib.config import idleConf
+from idlelib import help_about, textview, configdialog
+from idlelib import macosx
+from idlelib import help
+
+# The default tab setting for a Text widget, in average-width characters.
+TK_TABWIDTH_DEFAULT = 8
+_py_version = ' (%s)' % platform.python_version()
+
+
+def _sphinx_version():
+    "Format sys.version_info to produce the Sphinx version string used to install the chm docs"
+    major, minor, micro, level, serial = sys.version_info
+    release = '%s%s' % (major, minor)
+    release += '%s' % (micro,)
+    if level == 'candidate':
+        release += 'rc%s' % (serial,)
+    elif level != 'final':
+        release += '%s%s' % (level[0], serial)
+    return release
+
+
+class EditorWindow(object):
+    from idlelib.percolator import Percolator
+    from idlelib.colorizer import ColorDelegator, color_config
+    from idlelib.undo import UndoDelegator
+    from idlelib.iomenu import IOBinding, encoding
+    from idlelib import mainmenu
+    from tkinter import Toplevel
+    from idlelib.statusbar import MultiStatusBar
+
+    filesystemencoding = sys.getfilesystemencoding()  # for file names
+    help_url = None
+
+    def __init__(self, flist=None, filename=None, key=None, root=None):
+        if EditorWindow.help_url is None:
+            dochome =  os.path.join(sys.base_prefix, 'Doc', 'index.html')
+            if sys.platform.count('linux'):
+                # look for html docs in a couple of standard places
+                pyver = 'python-docs-' + '%s.%s.%s' % sys.version_info[:3]
+                if os.path.isdir('/var/www/html/python/'):  # "python2" rpm
+                    dochome = '/var/www/html/python/index.html'
+                else:
+                    basepath = '/usr/share/doc/'  # standard location
+                    dochome = os.path.join(basepath, pyver,
+                                           'Doc', 'index.html')
+            elif sys.platform[:3] == 'win':
+                chmfile = os.path.join(sys.base_prefix, 'Doc',
+                                       'Python%s.chm' % _sphinx_version())
+                if os.path.isfile(chmfile):
+                    dochome = chmfile
+            elif sys.platform == 'darwin':
+                # documentation may be stored inside a python framework
+                dochome = os.path.join(sys.base_prefix,
+                        'Resources/English.lproj/Documentation/index.html')
+            dochome = os.path.normpath(dochome)
+            if os.path.isfile(dochome):
+                EditorWindow.help_url = dochome
+                if sys.platform == 'darwin':
+                    # Safari requires real file:-URLs
+                    EditorWindow.help_url = 'file://' + EditorWindow.help_url
+            else:
+                EditorWindow.help_url = "https://docs.python.org/%d.%d/" % sys.version_info[:2]
+        self.flist = flist
+        root = root or flist.root
+        self.root = root
+        try:
+            sys.ps1
+        except AttributeError:
+            sys.ps1 = '>>> '
+        self.menubar = Menu(root)
+        self.top = top = windows.ListedToplevel(root, menu=self.menubar)
+        if flist:
+            self.tkinter_vars = flist.vars
+            #self.top.instance_dict makes flist.inversedict available to
+            #configdialog.py so it can access all EditorWindow instances
+            self.top.instance_dict = flist.inversedict
+        else:
+            self.tkinter_vars = {}  # keys: Tkinter event names
+                                    # values: Tkinter variable instances
+            self.top.instance_dict = {}
+        self.recent_files_path = os.path.join(idleConf.GetUserCfgDir(),
+                'recent-files.lst')
+        self.text_frame = text_frame = Frame(top)
+        self.vbar = vbar = Scrollbar(text_frame, name='vbar')
+        self.width = idleConf.GetOption('main', 'EditorWindow',
+                                        'width', type='int')
+        text_options = {
+                'name': 'text',
+                'padx': 5,
+                'wrap': 'none',
+                'highlightthickness': 0,
+                'width': self.width,
+                'tabstyle': 'wordprocessor',  # new in 8.5
+                'height': idleConf.GetOption(
+                        'main', 'EditorWindow', 'height', type='int'),
+                }
+        self.text = text = MultiCallCreator(Text)(text_frame, **text_options)
+        self.top.focused_widget = self.text
+
+        self.createmenubar()
+        self.apply_bindings()
+
+        self.top.protocol("WM_DELETE_WINDOW", self.close)
+        self.top.bind("<<close-window>>", self.close_event)
+        if macosx.isAquaTk():
+            # Command-W on editorwindows doesn't work without this.
+            text.bind('<<close-window>>', self.close_event)
+            # Some OS X systems have only one mouse button, so use
+            # control-click for popup context menus there. For two
+            # buttons, AquaTk defines <2> as the right button, not <3>.
+            text.bind("<Control-Button-1>",self.right_menu_event)
+            text.bind("<2>", self.right_menu_event)
+        else:
+            # Elsewhere, use right-click for popup menus.
+            text.bind("<3>",self.right_menu_event)
+        text.bind("<<cut>>", self.cut)
+        text.bind("<<copy>>", self.copy)
+        text.bind("<<paste>>", self.paste)
+        text.bind("<<center-insert>>", self.center_insert_event)
+        text.bind("<<help>>", self.help_dialog)
+        text.bind("<<python-docs>>", self.python_docs)
+        text.bind("<<about-idle>>", self.about_dialog)
+        text.bind("<<open-config-dialog>>", self.config_dialog)
+        text.bind("<<open-module>>", self.open_module)
+        text.bind("<<do-nothing>>", lambda event: "break")
+        text.bind("<<select-all>>", self.select_all)
+        text.bind("<<remove-selection>>", self.remove_selection)
+        text.bind("<<find>>", self.find_event)
+        text.bind("<<find-again>>", self.find_again_event)
+        text.bind("<<find-in-files>>", self.find_in_files_event)
+        text.bind("<<find-selection>>", self.find_selection_event)
+        text.bind("<<replace>>", self.replace_event)
+        text.bind("<<goto-line>>", self.goto_line_event)
+        text.bind("<<smart-backspace>>",self.smart_backspace_event)
+        text.bind("<<newline-and-indent>>",self.newline_and_indent_event)
+        text.bind("<<smart-indent>>",self.smart_indent_event)
+        text.bind("<<indent-region>>",self.indent_region_event)
+        text.bind("<<dedent-region>>",self.dedent_region_event)
+        text.bind("<<comment-region>>",self.comment_region_event)
+        text.bind("<<uncomment-region>>",self.uncomment_region_event)
+        text.bind("<<tabify-region>>",self.tabify_region_event)
+        text.bind("<<untabify-region>>",self.untabify_region_event)
+        text.bind("<<toggle-tabs>>",self.toggle_tabs_event)
+        text.bind("<<change-indentwidth>>",self.change_indentwidth_event)
+        text.bind("<Left>", self.move_at_edge_if_selection(0))
+        text.bind("<Right>", self.move_at_edge_if_selection(1))
+        text.bind("<<del-word-left>>", self.del_word_left)
+        text.bind("<<del-word-right>>", self.del_word_right)
+        text.bind("<<beginning-of-line>>", self.home_callback)
+
+        if flist:
+            flist.inversedict[self] = key
+            if key:
+                flist.dict[key] = self
+            text.bind("<<open-new-window>>", self.new_callback)
+            text.bind("<<close-all-windows>>", self.flist.close_all_callback)
+            text.bind("<<open-class-browser>>", self.open_class_browser)
+            text.bind("<<open-path-browser>>", self.open_path_browser)
+            text.bind("<<open-turtle-demo>>", self.open_turtle_demo)
+
+        self.set_status_bar()
+        vbar['command'] = text.yview
+        vbar.pack(side=RIGHT, fill=Y)
+        text['yscrollcommand'] = vbar.set
+        text['font'] = idleConf.GetFont(self.root, 'main', 'EditorWindow')
+        text_frame.pack(side=LEFT, fill=BOTH, expand=1)
+        text.pack(side=TOP, fill=BOTH, expand=1)
+        text.focus_set()
+
+        # usetabs true  -> literal tab characters are used by indent and
+        #                  dedent cmds, possibly mixed with spaces if
+        #                  indentwidth is not a multiple of tabwidth,
+        #                  which will cause Tabnanny to nag!
+        #         false -> tab characters are converted to spaces by indent
+        #                  and dedent cmds, and ditto TAB keystrokes
+        # Although use-spaces=0 can be configured manually in config-main.def,
+        # configuration of tabs v. spaces is not supported in the configuration
+        # dialog.  IDLE promotes the preferred Python indentation: use spaces!
+        usespaces = idleConf.GetOption('main', 'Indent',
+                                       'use-spaces', type='bool')
+        self.usetabs = not usespaces
+
+        # tabwidth is the display width of a literal tab character.
+        # CAUTION:  telling Tk to use anything other than its default
+        # tab setting causes it to use an entirely different tabbing algorithm,
+        # treating tab stops as fixed distances from the left margin.
+        # Nobody expects this, so for now tabwidth should never be changed.
+        self.tabwidth = 8    # must remain 8 until Tk is fixed.
+
+        # indentwidth is the number of screen characters per indent level.
+        # The recommended Python indentation is four spaces.
+        self.indentwidth = self.tabwidth
+        self.set_notabs_indentwidth()
+
+        # If context_use_ps1 is true, parsing searches back for a ps1 line;
+        # else searches for a popular (if, def, ...) Python stmt.
+        self.context_use_ps1 = False
+
+        # When searching backwards for a reliable place to begin parsing,
+        # first start num_context_lines[0] lines back, then
+        # num_context_lines[1] lines back if that didn't work, and so on.
+        # The last value should be huge (larger than the # of lines in a
+        # conceivable file).
+        # Making the initial values larger slows things down more often.
+        self.num_context_lines = 50, 500, 5000000
+        self.per = per = self.Percolator(text)
+        self.undo = undo = self.UndoDelegator()
+        per.insertfilter(undo)
+        text.undo_block_start = undo.undo_block_start
+        text.undo_block_stop = undo.undo_block_stop
+        undo.set_saved_change_hook(self.saved_change_hook)
+        # IOBinding implements file I/O and printing functionality
+        self.io = io = self.IOBinding(self)
+        io.set_filename_change_hook(self.filename_change_hook)
+        self.good_load = False
+        self.set_indentation_params(False)
+        self.color = None # initialized below in self.ResetColorizer
+        if filename:
+            if os.path.exists(filename) and not os.path.isdir(filename):
+                if io.loadfile(filename):
+                    self.good_load = True
+                    is_py_src = self.ispythonsource(filename)
+                    self.set_indentation_params(is_py_src)
+            else:
+                io.set_filename(filename)
+                self.good_load = True
+
+        self.ResetColorizer()
+        self.saved_change_hook()
+        self.update_recent_files_list()
+        self.load_extensions()
+        menu = self.menudict.get('windows')
+        if menu:
+            end = menu.index("end")
+            if end is None:
+                end = -1
+            if end >= 0:
+                menu.add_separator()
+                end = end + 1
+            self.wmenu_end = end
+            windows.register_callback(self.postwindowsmenu)
+
+        # Some abstractions so IDLE extensions are cross-IDE
+        self.askyesno = tkMessageBox.askyesno
+        self.askinteger = tkSimpleDialog.askinteger
+        self.showerror = tkMessageBox.showerror
+
+    def _filename_to_unicode(self, filename):
+        """Return filename as BMP unicode so diplayable in Tk."""
+        # Decode bytes to unicode.
+        if isinstance(filename, bytes):
+            try:
+                filename = filename.decode(self.filesystemencoding)
+            except UnicodeDecodeError:
+                try:
+                    filename = filename.decode(self.encoding)
+                except UnicodeDecodeError:
+                    # byte-to-byte conversion
+                    filename = filename.decode('iso8859-1')
+        # Replace non-BMP char with diamond questionmark.
+        return re.sub('[\U00010000-\U0010FFFF]', '\ufffd', filename)
+
+    def new_callback(self, event):
+        dirname, basename = self.io.defaultfilename()
+        self.flist.new(dirname)
+        return "break"
+
+    def home_callback(self, event):
+        if (event.state & 4) != 0 and event.keysym == "Home":
+            # state&4==Control. If <Control-Home>, use the Tk binding.
+            return
+        if self.text.index("iomark") and \
+           self.text.compare("iomark", "<=", "insert lineend") and \
+           self.text.compare("insert linestart", "<=", "iomark"):
+            # In Shell on input line, go to just after prompt
+            insertpt = int(self.text.index("iomark").split(".")[1])
+        else:
+            line = self.text.get("insert linestart", "insert lineend")
+            for insertpt in range(len(line)):
+                if line[insertpt] not in (' ','\t'):
+                    break
+            else:
+                insertpt=len(line)
+        lineat = int(self.text.index("insert").split('.')[1])
+        if insertpt == lineat:
+            insertpt = 0
+        dest = "insert linestart+"+str(insertpt)+"c"
+        if (event.state&1) == 0:
+            # shift was not pressed
+            self.text.tag_remove("sel", "1.0", "end")
+        else:
+            if not self.text.index("sel.first"):
+                # there was no previous selection
+                self.text.mark_set("my_anchor", "insert")
+            else:
+                if self.text.compare(self.text.index("sel.first"), "<",
+                                     self.text.index("insert")):
+                    self.text.mark_set("my_anchor", "sel.first") # extend back
+                else:
+                    self.text.mark_set("my_anchor", "sel.last") # extend forward
+            first = self.text.index(dest)
+            last = self.text.index("my_anchor")
+            if self.text.compare(first,">",last):
+                first,last = last,first
+            self.text.tag_remove("sel", "1.0", "end")
+            self.text.tag_add("sel", first, last)
+        self.text.mark_set("insert", dest)
+        self.text.see("insert")
+        return "break"
+
+    def set_status_bar(self):
+        self.status_bar = self.MultiStatusBar(self.top)
+        sep = Frame(self.top, height=1, borderwidth=1, background='grey75')
+        if sys.platform == "darwin":
+            # Insert some padding to avoid obscuring some of the statusbar
+            # by the resize widget.
+            self.status_bar.set_label('_padding1', '    ', side=RIGHT)
+        self.status_bar.set_label('column', 'Col: ?', side=RIGHT)
+        self.status_bar.set_label('line', 'Ln: ?', side=RIGHT)
+        self.status_bar.pack(side=BOTTOM, fill=X)
+        sep.pack(side=BOTTOM, fill=X)
+        self.text.bind("<<set-line-and-column>>", self.set_line_and_column)
+        self.text.event_add("<<set-line-and-column>>",
+                            "<KeyRelease>", "<ButtonRelease>")
+        self.text.after_idle(self.set_line_and_column)
+
+    def set_line_and_column(self, event=None):
+        line, column = self.text.index(INSERT).split('.')
+        self.status_bar.set_label('column', 'Col: %s' % column)
+        self.status_bar.set_label('line', 'Ln: %s' % line)
+
+    menu_specs = [
+        ("file", "_File"),
+        ("edit", "_Edit"),
+        ("format", "F_ormat"),
+        ("run", "_Run"),
+        ("options", "_Options"),
+        ("windows", "_Window"),
+        ("help", "_Help"),
+    ]
+
+
+    def createmenubar(self):
+        mbar = self.menubar
+        self.menudict = menudict = {}
+        for name, label in self.menu_specs:
+            underline, label = prepstr(label)
+            menudict[name] = menu = Menu(mbar, name=name, tearoff=0)
+            mbar.add_cascade(label=label, menu=menu, underline=underline)
+        if macosx.isCarbonTk():
+            # Insert the application menu
+            menudict['application'] = menu = Menu(mbar, name='apple',
+                                                  tearoff=0)
+            mbar.add_cascade(label='IDLE', menu=menu)
+        self.fill_menus()
+        self.recent_files_menu = Menu(self.menubar, tearoff=0)
+        self.menudict['file'].insert_cascade(3, label='Recent Files',
+                                             underline=0,
+                                             menu=self.recent_files_menu)
+        self.base_helpmenu_length = self.menudict['help'].index(END)
+        self.reset_help_menu_entries()
+
+    def postwindowsmenu(self):
+        # Only called when Windows menu exists
+        menu = self.menudict['windows']
+        end = menu.index("end")
+        if end is None:
+            end = -1
+        if end > self.wmenu_end:
+            menu.delete(self.wmenu_end+1, end)
+        windows.add_windows_to_menu(menu)
+
+    rmenu = None
+
+    def right_menu_event(self, event):
+        self.text.mark_set("insert", "@%d,%d" % (event.x, event.y))
+        if not self.rmenu:
+            self.make_rmenu()
+        rmenu = self.rmenu
+        self.event = event
+        iswin = sys.platform[:3] == 'win'
+        if iswin:
+            self.text.config(cursor="arrow")
+
+        for item in self.rmenu_specs:
+            try:
+                label, eventname, verify_state = item
+            except ValueError: # see issue1207589
+                continue
+
+            if verify_state is None:
+                continue
+            state = getattr(self, verify_state)()
+            rmenu.entryconfigure(label, state=state)
+
+
+        rmenu.tk_popup(event.x_root, event.y_root)
+        if iswin:
+            self.text.config(cursor="ibeam")
+
+    rmenu_specs = [
+        # ("Label", "<<virtual-event>>", "statefuncname"), ...
+        ("Close", "<<close-window>>", None), # Example
+    ]
+
+    def make_rmenu(self):
+        rmenu = Menu(self.text, tearoff=0)
+        for item in self.rmenu_specs:
+            label, eventname = item[0], item[1]
+            if label is not None:
+                def command(text=self.text, eventname=eventname):
+                    text.event_generate(eventname)
+                rmenu.add_command(label=label, command=command)
+            else:
+                rmenu.add_separator()
+        self.rmenu = rmenu
+
+    def rmenu_check_cut(self):
+        return self.rmenu_check_copy()
+
+    def rmenu_check_copy(self):
+        try:
+            indx = self.text.index('sel.first')
+        except TclError:
+            return 'disabled'
+        else:
+            return 'normal' if indx else 'disabled'
+
+    def rmenu_check_paste(self):
+        try:
+            self.text.tk.call('tk::GetSelection', self.text, 'CLIPBOARD')
+        except TclError:
+            return 'disabled'
+        else:
+            return 'normal'
+
+    def about_dialog(self, event=None):
+        "Handle Help 'About IDLE' event."
+        # Synchronize with macosx.overrideRootMenu.about_dialog.
+        help_about.AboutDialog(self.top,'About IDLE')
+
+    def config_dialog(self, event=None):
+        "Handle Options 'Configure IDLE' event."
+        # Synchronize with macosx.overrideRootMenu.config_dialog.
+        configdialog.ConfigDialog(self.top,'Settings')
+
+    def help_dialog(self, event=None):
+        "Handle Help 'IDLE Help' event."
+        # Synchronize with macosx.overrideRootMenu.help_dialog.
+        if self.root:
+            parent = self.root
+        else:
+            parent = self.top
+        help.show_idlehelp(parent)
+
+    def python_docs(self, event=None):
+        if sys.platform[:3] == 'win':
+            try:
+                os.startfile(self.help_url)
+            except OSError as why:
+                tkMessageBox.showerror(title='Document Start Failure',
+                    message=str(why), parent=self.text)
+        else:
+            webbrowser.open(self.help_url)
+        return "break"
+
+    def cut(self,event):
+        self.text.event_generate("<<Cut>>")
+        return "break"
+
+    def copy(self,event):
+        if not self.text.tag_ranges("sel"):
+            # There is no selection, so do nothing and maybe interrupt.
+            return
+        self.text.event_generate("<<Copy>>")
+        return "break"
+
+    def paste(self,event):
+        self.text.event_generate("<<Paste>>")
+        self.text.see("insert")
+        return "break"
+
+    def select_all(self, event=None):
+        self.text.tag_add("sel", "1.0", "end-1c")
+        self.text.mark_set("insert", "1.0")
+        self.text.see("insert")
+        return "break"
+
+    def remove_selection(self, event=None):
+        self.text.tag_remove("sel", "1.0", "end")
+        self.text.see("insert")
+
+    def move_at_edge_if_selection(self, edge_index):
+        """Cursor move begins at start or end of selection
+
+        When a left/right cursor key is pressed create and return to Tkinter a
+        function which causes a cursor move from the associated edge of the
+        selection.
+
+        """
+        self_text_index = self.text.index
+        self_text_mark_set = self.text.mark_set
+        edges_table = ("sel.first+1c", "sel.last-1c")
+        def move_at_edge(event):
+            if (event.state & 5) == 0: # no shift(==1) or control(==4) pressed
+                try:
+                    self_text_index("sel.first")
+                    self_text_mark_set("insert", edges_table[edge_index])
+                except TclError:
+                    pass
+        return move_at_edge
+
+    def del_word_left(self, event):
+        self.text.event_generate('<Meta-Delete>')
+        return "break"
+
+    def del_word_right(self, event):
+        self.text.event_generate('<Meta-d>')
+        return "break"
+
+    def find_event(self, event):
+        search.find(self.text)
+        return "break"
+
+    def find_again_event(self, event):
+        search.find_again(self.text)
+        return "break"
+
+    def find_selection_event(self, event):
+        search.find_selection(self.text)
+        return "break"
+
+    def find_in_files_event(self, event):
+        grep.grep(self.text, self.io, self.flist)
+        return "break"
+
+    def replace_event(self, event):
+        replace.replace(self.text)
+        return "break"
+
+    def goto_line_event(self, event):
+        text = self.text
+        lineno = tkSimpleDialog.askinteger("Goto",
+                "Go to line number:",parent=text)
+        if lineno is None:
+            return "break"
+        if lineno <= 0:
+            text.bell()
+            return "break"
+        text.mark_set("insert", "%d.0" % lineno)
+        text.see("insert")
+
+    def open_module(self, event=None):
+        """Get module name from user and open it.
+
+        Return module path or None for calls by open_class_browser
+        when latter is not invoked in named editor window.
+        """
+        # XXX This, open_class_browser, and open_path_browser
+        # would fit better in iomenu.IOBinding.
+        try:
+            name = self.text.get("sel.first", "sel.last").strip()
+        except TclError:
+            name = ''
+        file_path = query.ModuleName(
+                self.text, "Open Module",
+                "Enter the name of a Python module\n"
+                "to search on sys.path and open:",
+                name).result
+        if file_path is not None:
+            if self.flist:
+                self.flist.open(file_path)
+            else:
+                self.io.loadfile(file_path)
+        return file_path
+
+    def open_class_browser(self, event=None):
+        filename = self.io.filename
+        if not (self.__class__.__name__ == 'PyShellEditorWindow'
+                and filename):
+            filename = self.open_module()
+            if filename is None:
+                return
+        head, tail = os.path.split(filename)
+        base, ext = os.path.splitext(tail)
+        from idlelib import browser
+        browser.ClassBrowser(self.flist, base, [head])
+
+    def open_path_browser(self, event=None):
+        from idlelib import pathbrowser
+        pathbrowser.PathBrowser(self.flist)
+
+    def open_turtle_demo(self, event = None):
+        import subprocess
+
+        cmd = [sys.executable,
+               '-c',
+               'from turtledemo.__main__ import main; main()']
+        subprocess.Popen(cmd, shell=False)
+
+    def gotoline(self, lineno):
+        if lineno is not None and lineno > 0:
+            self.text.mark_set("insert", "%d.0" % lineno)
+            self.text.tag_remove("sel", "1.0", "end")
+            self.text.tag_add("sel", "insert", "insert +1l")
+            self.center()
+
+    def ispythonsource(self, filename):
+        if not filename or os.path.isdir(filename):
+            return True
+        base, ext = os.path.splitext(os.path.basename(filename))
+        if os.path.normcase(ext) in (".py", ".pyw"):
+            return True
+        line = self.text.get('1.0', '1.0 lineend')
+        return line.startswith('#!') and 'python' in line
+
+    def close_hook(self):
+        if self.flist:
+            self.flist.unregister_maybe_terminate(self)
+            self.flist = None
+
+    def set_close_hook(self, close_hook):
+        self.close_hook = close_hook
+
+    def filename_change_hook(self):
+        if self.flist:
+            self.flist.filename_changed_edit(self)
+        self.saved_change_hook()
+        self.top.update_windowlist_registry(self)
+        self.ResetColorizer()
+
+    def _addcolorizer(self):
+        if self.color:
+            return
+        if self.ispythonsource(self.io.filename):
+            self.color = self.ColorDelegator()
+        # can add more colorizers here...
+        if self.color:
+            self.per.removefilter(self.undo)
+            self.per.insertfilter(self.color)
+            self.per.insertfilter(self.undo)
+
+    def _rmcolorizer(self):
+        if not self.color:
+            return
+        self.color.removecolors()
+        self.per.removefilter(self.color)
+        self.color = None
+
+    def ResetColorizer(self):
+        "Update the color theme"
+        # Called from self.filename_change_hook and from configdialog.py
+        self._rmcolorizer()
+        self._addcolorizer()
+        EditorWindow.color_config(self.text)
+
+    IDENTCHARS = string.ascii_letters + string.digits + "_"
+
+    def colorize_syntax_error(self, text, pos):
+        text.tag_add("ERROR", pos)
+        char = text.get(pos)
+        if char and char in self.IDENTCHARS:
+            text.tag_add("ERROR", pos + " wordstart", pos)
+        if '\n' == text.get(pos):   # error at line end
+            text.mark_set("insert", pos)
+        else:
+            text.mark_set("insert", pos + "+1c")
+        text.see(pos)
+
+    def ResetFont(self):
+        "Update the text widgets' font if it is changed"
+        # Called from configdialog.py
+
+        self.text['font'] = idleConf.GetFont(self.root, 'main','EditorWindow')
+
+    def RemoveKeybindings(self):
+        "Remove the keybindings before they are changed."
+        # Called from configdialog.py
+        self.mainmenu.default_keydefs = keydefs = idleConf.GetCurrentKeySet()
+        for event, keylist in keydefs.items():
+            self.text.event_delete(event, *keylist)
+        for extensionName in self.get_standard_extension_names():
+            xkeydefs = idleConf.GetExtensionBindings(extensionName)
+            if xkeydefs:
+                for event, keylist in xkeydefs.items():
+                    self.text.event_delete(event, *keylist)
+
+    def ApplyKeybindings(self):
+        "Update the keybindings after they are changed"
+        # Called from configdialog.py
+        self.mainmenu.default_keydefs = keydefs = idleConf.GetCurrentKeySet()
+        self.apply_bindings()
+        for extensionName in self.get_standard_extension_names():
+            xkeydefs = idleConf.GetExtensionBindings(extensionName)
+            if xkeydefs:
+                self.apply_bindings(xkeydefs)
+        #update menu accelerators
+        menuEventDict = {}
+        for menu in self.mainmenu.menudefs:
+            menuEventDict[menu[0]] = {}
+            for item in menu[1]:
+                if item:
+                    menuEventDict[menu[0]][prepstr(item[0])[1]] = item[1]
+        for menubarItem in self.menudict:
+            menu = self.menudict[menubarItem]
+            end = menu.index(END)
+            if end is None:
+                # Skip empty menus
+                continue
+            end += 1
+            for index in range(0, end):
+                if menu.type(index) == 'command':
+                    accel = menu.entrycget(index, 'accelerator')
+                    if accel:
+                        itemName = menu.entrycget(index, 'label')
+                        event = ''
+                        if menubarItem in menuEventDict:
+                            if itemName in menuEventDict[menubarItem]:
+                                event = menuEventDict[menubarItem][itemName]
+                        if event:
+                            accel = get_accelerator(keydefs, event)
+                            menu.entryconfig(index, accelerator=accel)
+
+    def set_notabs_indentwidth(self):
+        "Update the indentwidth if changed and not using tabs in this window"
+        # Called from configdialog.py
+        if not self.usetabs:
+            self.indentwidth = idleConf.GetOption('main', 'Indent','num-spaces',
+                                                  type='int')
+
+    def reset_help_menu_entries(self):
+        "Update the additional help entries on the Help menu"
+        help_list = idleConf.GetAllExtraHelpSourcesList()
+        helpmenu = self.menudict['help']
+        # first delete the extra help entries, if any
+        helpmenu_length = helpmenu.index(END)
+        if helpmenu_length > self.base_helpmenu_length:
+            helpmenu.delete((self.base_helpmenu_length + 1), helpmenu_length)
+        # then rebuild them
+        if help_list:
+            helpmenu.add_separator()
+            for entry in help_list:
+                cmd = self.__extra_help_callback(entry[1])
+                helpmenu.add_command(label=entry[0], command=cmd)
+        # and update the menu dictionary
+        self.menudict['help'] = helpmenu
+
+    def __extra_help_callback(self, helpfile):
+        "Create a callback with the helpfile value frozen at definition time"
+        def display_extra_help(helpfile=helpfile):
+            if not helpfile.startswith(('www', 'http')):
+                helpfile = os.path.normpath(helpfile)
+            if sys.platform[:3] == 'win':
+                try:
+                    os.startfile(helpfile)
+                except OSError as why:
+                    tkMessageBox.showerror(title='Document Start Failure',
+                        message=str(why), parent=self.text)
+            else:
+                webbrowser.open(helpfile)
+        return display_extra_help
+
+    def update_recent_files_list(self, new_file=None):
+        "Load and update the recent files list and menus"
+        rf_list = []
+        if os.path.exists(self.recent_files_path):
+            with open(self.recent_files_path, 'r',
+                      encoding='utf_8', errors='replace') as rf_list_file:
+                rf_list = rf_list_file.readlines()
+        if new_file:
+            new_file = os.path.abspath(new_file) + '\n'
+            if new_file in rf_list:
+                rf_list.remove(new_file)  # move to top
+            rf_list.insert(0, new_file)
+        # clean and save the recent files list
+        bad_paths = []
+        for path in rf_list:
+            if '\0' in path or not os.path.exists(path[0:-1]):
+                bad_paths.append(path)
+        rf_list = [path for path in rf_list if path not in bad_paths]
+        ulchars = "1234567890ABCDEFGHIJK"
+        rf_list = rf_list[0:len(ulchars)]
+        try:
+            with open(self.recent_files_path, 'w',
+                        encoding='utf_8', errors='replace') as rf_file:
+                rf_file.writelines(rf_list)
+        except OSError as err:
+            if not getattr(self.root, "recentfilelist_error_displayed", False):
+                self.root.recentfilelist_error_displayed = True
+                tkMessageBox.showwarning(title='IDLE Warning',
+                    message="Cannot update File menu Recent Files list. "
+                            "Your operating system says:\n%s\n"
+                            "Select OK and IDLE will continue without updating."
+                        % self._filename_to_unicode(str(err)),
+                    parent=self.text)
+        # for each edit window instance, construct the recent files menu
+        for instance in self.top.instance_dict:
+            menu = instance.recent_files_menu
+            menu.delete(0, END)  # clear, and rebuild:
+            for i, file_name in enumerate(rf_list):
+                file_name = file_name.rstrip()  # zap \n
+                # make unicode string to display non-ASCII chars correctly
+                ufile_name = self._filename_to_unicode(file_name)
+                callback = instance.__recent_file_callback(file_name)
+                menu.add_command(label=ulchars[i] + " " + ufile_name,
+                                 command=callback,
+                                 underline=0)
+
+    def __recent_file_callback(self, file_name):
+        def open_recent_file(fn_closure=file_name):
+            self.io.open(editFile=fn_closure)
+        return open_recent_file
+
+    def saved_change_hook(self):
+        short = self.short_title()
+        long = self.long_title()
+        if short and long:
+            title = short + " - " + long + _py_version
+        elif short:
+            title = short
+        elif long:
+            title = long
+        else:
+            title = "Untitled"
+        icon = short or long or title
+        if not self.get_saved():
+            title = "*%s*" % title
+            icon = "*%s" % icon
+        self.top.wm_title(title)
+        self.top.wm_iconname(icon)
+
+    def get_saved(self):
+        return self.undo.get_saved()
+
+    def set_saved(self, flag):
+        self.undo.set_saved(flag)
+
+    def reset_undo(self):
+        self.undo.reset_undo()
+
+    def short_title(self):
+        filename = self.io.filename
+        if filename:
+            filename = os.path.basename(filename)
+        else:
+            filename = "Untitled"
+        # return unicode string to display non-ASCII chars correctly
+        return self._filename_to_unicode(filename)
+
+    def long_title(self):
+        # return unicode string to display non-ASCII chars correctly
+        return self._filename_to_unicode(self.io.filename or "")
+
+    def center_insert_event(self, event):
+        self.center()
+
+    def center(self, mark="insert"):
+        text = self.text
+        top, bot = self.getwindowlines()
+        lineno = self.getlineno(mark)
+        height = bot - top
+        newtop = max(1, lineno - height//2)
+        text.yview(float(newtop))
+
+    def getwindowlines(self):
+        text = self.text
+        top = self.getlineno("@0,0")
+        bot = self.getlineno("@0,65535")
+        if top == bot and text.winfo_height() == 1:
+            # Geometry manager hasn't run yet
+            height = int(text['height'])
+            bot = top + height - 1
+        return top, bot
+
+    def getlineno(self, mark="insert"):
+        text = self.text
+        return int(float(text.index(mark)))
+
+    def get_geometry(self):
+        "Return (width, height, x, y)"
+        geom = self.top.wm_geometry()
+        m = re.match(r"(\d+)x(\d+)\+(-?\d+)\+(-?\d+)", geom)
+        return list(map(int, m.groups()))
+
+    def close_event(self, event):
+        self.close()
+
+    def maybesave(self):
+        if self.io:
+            if not self.get_saved():
+                if self.top.state()!='normal':
+                    self.top.deiconify()
+                self.top.lower()
+                self.top.lift()
+            return self.io.maybesave()
+
+    def close(self):
+        reply = self.maybesave()
+        if str(reply) != "cancel":
+            self._close()
+        return reply
+
+    def _close(self):
+        if self.io.filename:
+            self.update_recent_files_list(new_file=self.io.filename)
+        windows.unregister_callback(self.postwindowsmenu)
+        self.unload_extensions()
+        self.io.close()
+        self.io = None
+        self.undo = None
+        if self.color:
+            self.color.close(False)
+            self.color = None
+        self.text = None
+        self.tkinter_vars = None
+        self.per.close()
+        self.per = None
+        self.top.destroy()
+        if self.close_hook:
+            # unless override: unregister from flist, terminate if last window
+            self.close_hook()
+
+    def load_extensions(self):
+        self.extensions = {}
+        self.load_standard_extensions()
+
+    def unload_extensions(self):
+        for ins in list(self.extensions.values()):
+            if hasattr(ins, "close"):
+                ins.close()
+        self.extensions = {}
+
+    def load_standard_extensions(self):
+        for name in self.get_standard_extension_names():
+            try:
+                self.load_extension(name)
+            except:
+                print("Failed to load extension", repr(name))
+                traceback.print_exc()
+
+    def get_standard_extension_names(self):
+        return idleConf.GetExtensions(editor_only=True)
+
+    extfiles = {  # map config-extension section names to new file names
+        'AutoComplete': 'autocomplete',
+        'AutoExpand': 'autoexpand',
+        'CallTips': 'calltips',
+        'CodeContext': 'codecontext',
+        'FormatParagraph': 'paragraph',
+        'ParenMatch': 'parenmatch',
+        'RstripExtension': 'rstrip',
+        'ScriptBinding': 'runscript',
+        'ZoomHeight': 'zoomheight',
+        }
+
+    def load_extension(self, name):
+        fname = self.extfiles.get(name, name)
+        try:
+            try:
+                mod = importlib.import_module('.' + fname, package=__package__)
+            except (ImportError, TypeError):
+                mod = importlib.import_module(fname)
+        except ImportError:
+            print("\nFailed to import extension: ", name)
+            raise
+        cls = getattr(mod, name)
+        keydefs = idleConf.GetExtensionBindings(name)
+        if hasattr(cls, "menudefs"):
+            self.fill_menus(cls.menudefs, keydefs)
+        ins = cls(self)
+        self.extensions[name] = ins
+        if keydefs:
+            self.apply_bindings(keydefs)
+            for vevent in keydefs:
+                methodname = vevent.replace("-", "_")
+                while methodname[:1] == '<':
+                    methodname = methodname[1:]
+                while methodname[-1:] == '>':
+                    methodname = methodname[:-1]
+                methodname = methodname + "_event"
+                if hasattr(ins, methodname):
+                    self.text.bind(vevent, getattr(ins, methodname))
+
+    def apply_bindings(self, keydefs=None):
+        if keydefs is None:
+            keydefs = self.mainmenu.default_keydefs
+        text = self.text
+        text.keydefs = keydefs
+        for event, keylist in keydefs.items():
+            if keylist:
+                text.event_add(event, *keylist)
+
+    def fill_menus(self, menudefs=None, keydefs=None):
+        """Add appropriate entries to the menus and submenus
+
+        Menus that are absent or None in self.menudict are ignored.
+        """
+        if menudefs is None:
+            menudefs = self.mainmenu.menudefs
+        if keydefs is None:
+            keydefs = self.mainmenu.default_keydefs
+        menudict = self.menudict
+        text = self.text
+        for mname, entrylist in menudefs:
+            menu = menudict.get(mname)
+            if not menu:
+                continue
+            for entry in entrylist:
+                if not entry:
+                    menu.add_separator()
+                else:
+                    label, eventname = entry
+                    checkbutton = (label[:1] == '!')
+                    if checkbutton:
+                        label = label[1:]
+                    underline, label = prepstr(label)
+                    accelerator = get_accelerator(keydefs, eventname)
+                    def command(text=text, eventname=eventname):
+                        text.event_generate(eventname)
+                    if checkbutton:
+                        var = self.get_var_obj(eventname, BooleanVar)
+                        menu.add_checkbutton(label=label, underline=underline,
+                            command=command, accelerator=accelerator,
+                            variable=var)
+                    else:
+                        menu.add_command(label=label, underline=underline,
+                                         command=command,
+                                         accelerator=accelerator)
+
+    def getvar(self, name):
+        var = self.get_var_obj(name)
+        if var:
+            value = var.get()
+            return value
+        else:
+            raise NameError(name)
+
+    def setvar(self, name, value, vartype=None):
+        var = self.get_var_obj(name, vartype)
+        if var:
+            var.set(value)
+        else:
+            raise NameError(name)
+
+    def get_var_obj(self, name, vartype=None):
+        var = self.tkinter_vars.get(name)
+        if not var and vartype:
+            # create a Tkinter variable object with self.text as master:
+            self.tkinter_vars[name] = var = vartype(self.text)
+        return var
+
+    # Tk implementations of "virtual text methods" -- each platform
+    # reusing IDLE's support code needs to define these for its GUI's
+    # flavor of widget.
+
+    # Is character at text_index in a Python string?  Return 0 for
+    # "guaranteed no", true for anything else.  This info is expensive
+    # to compute ab initio, but is probably already known by the
+    # platform's colorizer.
+
+    def is_char_in_string(self, text_index):
+        if self.color:
+            # Return true iff colorizer hasn't (re)gotten this far
+            # yet, or the character is tagged as being in a string
+            return self.text.tag_prevrange("TODO", text_index) or \
+                   "STRING" in self.text.tag_names(text_index)
+        else:
+            # The colorizer is missing: assume the worst
+            return 1
+
+    # If a selection is defined in the text widget, return (start,
+    # end) as Tkinter text indices, otherwise return (None, None)
+    def get_selection_indices(self):
+        try:
+            first = self.text.index("sel.first")
+            last = self.text.index("sel.last")
+            return first, last
+        except TclError:
+            return None, None
+
+    # Return the text widget's current view of what a tab stop means
+    # (equivalent width in spaces).
+
+    def get_tk_tabwidth(self):
+        current = self.text['tabs'] or TK_TABWIDTH_DEFAULT
+        return int(current)
+
+    # Set the text widget's current view of what a tab stop means.
+
+    def set_tk_tabwidth(self, newtabwidth):
+        text = self.text
+        if self.get_tk_tabwidth() != newtabwidth:
+            # Set text widget tab width
+            pixels = text.tk.call("font", "measure", text["font"],
+                                  "-displayof", text.master,
+                                  "n" * newtabwidth)
+            text.configure(tabs=pixels)
+
+### begin autoindent code ###  (configuration was moved to beginning of class)
+
+    def set_indentation_params(self, is_py_src, guess=True):
+        if is_py_src and guess:
+            i = self.guess_indent()
+            if 2 <= i <= 8:
+                self.indentwidth = i
+            if self.indentwidth != self.tabwidth:
+                self.usetabs = False
+        self.set_tk_tabwidth(self.tabwidth)
+
+    def smart_backspace_event(self, event):
+        text = self.text
+        first, last = self.get_selection_indices()
+        if first and last:
+            text.delete(first, last)
+            text.mark_set("insert", first)
+            return "break"
+        # Delete whitespace left, until hitting a real char or closest
+        # preceding virtual tab stop.
+        chars = text.get("insert linestart", "insert")
+        if chars == '':
+            if text.compare("insert", ">", "1.0"):
+                # easy: delete preceding newline
+                text.delete("insert-1c")
+            else:
+                text.bell()     # at start of buffer
+            return "break"
+        if  chars[-1] not in " \t":
+            # easy: delete preceding real char
+            text.delete("insert-1c")
+            return "break"
+        # Ick.  It may require *inserting* spaces if we back up over a
+        # tab character!  This is written to be clear, not fast.
+        tabwidth = self.tabwidth
+        have = len(chars.expandtabs(tabwidth))
+        assert have > 0
+        want = ((have - 1) // self.indentwidth) * self.indentwidth
+        # Debug prompt is multilined....
+        if self.context_use_ps1:
+            last_line_of_prompt = sys.ps1.split('\n')[-1]
+        else:
+            last_line_of_prompt = ''
+        ncharsdeleted = 0
+        while 1:
+            if chars == last_line_of_prompt:
+                break
+            chars = chars[:-1]
+            ncharsdeleted = ncharsdeleted + 1
+            have = len(chars.expandtabs(tabwidth))
+            if have <= want or chars[-1] not in " \t":
+                break
+        text.undo_block_start()
+        text.delete("insert-%dc" % ncharsdeleted, "insert")
+        if have < want:
+            text.insert("insert", ' ' * (want - have))
+        text.undo_block_stop()
+        return "break"
+
+    def smart_indent_event(self, event):
+        # if intraline selection:
+        #     delete it
+        # elif multiline selection:
+        #     do indent-region
+        # else:
+        #     indent one level
+        text = self.text
+        first, last = self.get_selection_indices()
+        text.undo_block_start()
+        try:
+            if first and last:
+                if index2line(first) != index2line(last):
+                    return self.indent_region_event(event)
+                text.delete(first, last)
+                text.mark_set("insert", first)
+            prefix = text.get("insert linestart", "insert")
+            raw, effective = classifyws(prefix, self.tabwidth)
+            if raw == len(prefix):
+                # only whitespace to the left
+                self.reindent_to(effective + self.indentwidth)
+            else:
+                # tab to the next 'stop' within or to right of line's text:
+                if self.usetabs:
+                    pad = '\t'
+                else:
+                    effective = len(prefix.expandtabs(self.tabwidth))
+                    n = self.indentwidth
+                    pad = ' ' * (n - effective % n)
+                text.insert("insert", pad)
+            text.see("insert")
+            return "break"
+        finally:
+            text.undo_block_stop()
+
+    def newline_and_indent_event(self, event):
+        text = self.text
+        first, last = self.get_selection_indices()
+        text.undo_block_start()
+        try:
+            if first and last:
+                text.delete(first, last)
+                text.mark_set("insert", first)
+            line = text.get("insert linestart", "insert")
+            i, n = 0, len(line)
+            while i < n and line[i] in " \t":
+                i = i+1
+            if i == n:
+                # the cursor is in or at leading indentation in a continuation
+                # line; just inject an empty line at the start
+                text.insert("insert linestart", '\n')
+                return "break"
+            indent = line[:i]
+            # strip whitespace before insert point unless it's in the prompt
+            i = 0
+            last_line_of_prompt = sys.ps1.split('\n')[-1]
+            while line and line[-1] in " \t" and line != last_line_of_prompt:
+                line = line[:-1]
+                i = i+1
+            if i:
+                text.delete("insert - %d chars" % i, "insert")
+            # strip whitespace after insert point
+            while text.get("insert") in " \t":
+                text.delete("insert")
+            # start new line
+            text.insert("insert", '\n')
+
+            # adjust indentation for continuations and block
+            # open/close first need to find the last stmt
+            lno = index2line(text.index('insert'))
+            y = pyparse.Parser(self.indentwidth, self.tabwidth)
+            if not self.context_use_ps1:
+                for context in self.num_context_lines:
+                    startat = max(lno - context, 1)
+                    startatindex = repr(startat) + ".0"
+                    rawtext = text.get(startatindex, "insert")
+                    y.set_str(rawtext)
+                    bod = y.find_good_parse_start(
+                              self.context_use_ps1,
+                              self._build_char_in_string_func(startatindex))
+                    if bod is not None or startat == 1:
+                        break
+                y.set_lo(bod or 0)
+            else:
+                r = text.tag_prevrange("console", "insert")
+                if r:
+                    startatindex = r[1]
+                else:
+                    startatindex = "1.0"
+                rawtext = text.get(startatindex, "insert")
+                y.set_str(rawtext)
+                y.set_lo(0)
+
+            c = y.get_continuation_type()
+            if c != pyparse.C_NONE:
+                # The current stmt hasn't ended yet.
+                if c == pyparse.C_STRING_FIRST_LINE:
+                    # after the first line of a string; do not indent at all
+                    pass
+                elif c == pyparse.C_STRING_NEXT_LINES:
+                    # inside a string which started before this line;
+                    # just mimic the current indent
+                    text.insert("insert", indent)
+                elif c == pyparse.C_BRACKET:
+                    # line up with the first (if any) element of the
+                    # last open bracket structure; else indent one
+                    # level beyond the indent of the line with the
+                    # last open bracket
+                    self.reindent_to(y.compute_bracket_indent())
+                elif c == pyparse.C_BACKSLASH:
+                    # if more than one line in this stmt already, just
+                    # mimic the current indent; else if initial line
+                    # has a start on an assignment stmt, indent to
+                    # beyond leftmost =; else to beyond first chunk of
+                    # non-whitespace on initial line
+                    if y.get_num_lines_in_stmt() > 1:
+                        text.insert("insert", indent)
+                    else:
+                        self.reindent_to(y.compute_backslash_indent())
+                else:
+                    assert 0, "bogus continuation type %r" % (c,)
+                return "break"
+
+            # This line starts a brand new stmt; indent relative to
+            # indentation of initial line of closest preceding
+            # interesting stmt.
+            indent = y.get_base_indent_string()
+            text.insert("insert", indent)
+            if y.is_block_opener():
+                self.smart_indent_event(event)
+            elif indent and y.is_block_closer():
+                self.smart_backspace_event(event)
+            return "break"
+        finally:
+            text.see("insert")
+            text.undo_block_stop()
+
+    # Our editwin provides an is_char_in_string function that works
+    # with a Tk text index, but PyParse only knows about offsets into
+    # a string. This builds a function for PyParse that accepts an
+    # offset.
+
+    def _build_char_in_string_func(self, startindex):
+        def inner(offset, _startindex=startindex,
+                  _icis=self.is_char_in_string):
+            return _icis(_startindex + "+%dc" % offset)
+        return inner
+
+    def indent_region_event(self, event):
+        head, tail, chars, lines = self.get_region()
+        for pos in range(len(lines)):
+            line = lines[pos]
+            if line:
+                raw, effective = classifyws(line, self.tabwidth)
+                effective = effective + self.indentwidth
+                lines[pos] = self._make_blanks(effective) + line[raw:]
+        self.set_region(head, tail, chars, lines)
+        return "break"
+
+    def dedent_region_event(self, event):
+        head, tail, chars, lines = self.get_region()
+        for pos in range(len(lines)):
+            line = lines[pos]
+            if line:
+                raw, effective = classifyws(line, self.tabwidth)
+                effective = max(effective - self.indentwidth, 0)
+                lines[pos] = self._make_blanks(effective) + line[raw:]
+        self.set_region(head, tail, chars, lines)
+        return "break"
+
+    def comment_region_event(self, event):
+        head, tail, chars, lines = self.get_region()
+        for pos in range(len(lines) - 1):
+            line = lines[pos]
+            lines[pos] = '##' + line
+        self.set_region(head, tail, chars, lines)
+
+    def uncomment_region_event(self, event):
+        head, tail, chars, lines = self.get_region()
+        for pos in range(len(lines)):
+            line = lines[pos]
+            if not line:
+                continue
+            if line[:2] == '##':
+                line = line[2:]
+            elif line[:1] == '#':
+                line = line[1:]
+            lines[pos] = line
+        self.set_region(head, tail, chars, lines)
+
+    def tabify_region_event(self, event):
+        head, tail, chars, lines = self.get_region()
+        tabwidth = self._asktabwidth()
+        if tabwidth is None: return
+        for pos in range(len(lines)):
+            line = lines[pos]
+            if line:
+                raw, effective = classifyws(line, tabwidth)
+                ntabs, nspaces = divmod(effective, tabwidth)
+                lines[pos] = '\t' * ntabs + ' ' * nspaces + line[raw:]
+        self.set_region(head, tail, chars, lines)
+
+    def untabify_region_event(self, event):
+        head, tail, chars, lines = self.get_region()
+        tabwidth = self._asktabwidth()
+        if tabwidth is None: return
+        for pos in range(len(lines)):
+            lines[pos] = lines[pos].expandtabs(tabwidth)
+        self.set_region(head, tail, chars, lines)
+
+    def toggle_tabs_event(self, event):
+        if self.askyesno(
+              "Toggle tabs",
+              "Turn tabs " + ("on", "off")[self.usetabs] +
+              "?\nIndent width " +
+              ("will be", "remains at")[self.usetabs] + " 8." +
+              "\n Note: a tab is always 8 columns",
+              parent=self.text):
+            self.usetabs = not self.usetabs
+            # Try to prevent inconsistent indentation.
+            # User must change indent width manually after using tabs.
+            self.indentwidth = 8
+        return "break"
+
+    # XXX this isn't bound to anything -- see tabwidth comments
+##     def change_tabwidth_event(self, event):
+##         new = self._asktabwidth()
+##         if new != self.tabwidth:
+##             self.tabwidth = new
+##             self.set_indentation_params(0, guess=0)
+##         return "break"
+
+    def change_indentwidth_event(self, event):
+        new = self.askinteger(
+                  "Indent width",
+                  "New indent width (2-16)\n(Always use 8 when using tabs)",
+                  parent=self.text,
+                  initialvalue=self.indentwidth,
+                  minvalue=2,
+                  maxvalue=16)
+        if new and new != self.indentwidth and not self.usetabs:
+            self.indentwidth = new
+        return "break"
+
+    def get_region(self):
+        text = self.text
+        first, last = self.get_selection_indices()
+        if first and last:
+            head = text.index(first + " linestart")
+            tail = text.index(last + "-1c lineend +1c")
+        else:
+            head = text.index("insert linestart")
+            tail = text.index("insert lineend +1c")
+        chars = text.get(head, tail)
+        lines = chars.split("\n")
+        return head, tail, chars, lines
+
+    def set_region(self, head, tail, chars, lines):
+        text = self.text
+        newchars = "\n".join(lines)
+        if newchars == chars:
+            text.bell()
+            return
+        text.tag_remove("sel", "1.0", "end")
+        text.mark_set("insert", head)
+        text.undo_block_start()
+        text.delete(head, tail)
+        text.insert(head, newchars)
+        text.undo_block_stop()
+        text.tag_add("sel", head, "insert")
+
+    # Make string that displays as n leading blanks.
+
+    def _make_blanks(self, n):
+        if self.usetabs:
+            ntabs, nspaces = divmod(n, self.tabwidth)
+            return '\t' * ntabs + ' ' * nspaces
+        else:
+            return ' ' * n
+
+    # Delete from beginning of line to insert point, then reinsert
+    # column logical (meaning use tabs if appropriate) spaces.
+
+    def reindent_to(self, column):
+        text = self.text
+        text.undo_block_start()
+        if text.compare("insert linestart", "!=", "insert"):
+            text.delete("insert linestart", "insert")
+        if column:
+            text.insert("insert", self._make_blanks(column))
+        text.undo_block_stop()
+
+    def _asktabwidth(self):
+        return self.askinteger(
+            "Tab width",
+            "Columns per tab? (2-16)",
+            parent=self.text,
+            initialvalue=self.indentwidth,
+            minvalue=2,
+            maxvalue=16)
+
+    # Guess indentwidth from text content.
+    # Return guessed indentwidth.  This should not be believed unless
+    # it's in a reasonable range (e.g., it will be 0 if no indented
+    # blocks are found).
+
+    def guess_indent(self):
+        opener, indented = IndentSearcher(self.text, self.tabwidth).run()
+        if opener and indented:
+            raw, indentsmall = classifyws(opener, self.tabwidth)
+            raw, indentlarge = classifyws(indented, self.tabwidth)
+        else:
+            indentsmall = indentlarge = 0
+        return indentlarge - indentsmall
+
+# "line.col" -> line, as an int
+def index2line(index):
+    return int(float(index))
+
+# Look at the leading whitespace in s.
+# Return pair (# of leading ws characters,
+#              effective # of leading blanks after expanding
+#              tabs to width tabwidth)
+
+def classifyws(s, tabwidth):
+    raw = effective = 0
+    for ch in s:
+        if ch == ' ':
+            raw = raw + 1
+            effective = effective + 1
+        elif ch == '\t':
+            raw = raw + 1
+            effective = (effective // tabwidth + 1) * tabwidth
+        else:
+            break
+    return raw, effective
+
+import tokenize
+_tokenize = tokenize
+del tokenize
+
+class IndentSearcher(object):
+
+    # .run() chews over the Text widget, looking for a block opener
+    # and the stmt following it.  Returns a pair,
+    #     (line containing block opener, line containing stmt)
+    # Either or both may be None.
+
+    def __init__(self, text, tabwidth):
+        self.text = text
+        self.tabwidth = tabwidth
+        self.i = self.finished = 0
+        self.blkopenline = self.indentedline = None
+
+    def readline(self):
+        if self.finished:
+            return ""
+        i = self.i = self.i + 1
+        mark = repr(i) + ".0"
+        if self.text.compare(mark, ">=", "end"):
+            return ""
+        return self.text.get(mark, mark + " lineend+1c")
+
+    def tokeneater(self, type, token, start, end, line,
+                   INDENT=_tokenize.INDENT,
+                   NAME=_tokenize.NAME,
+                   OPENERS=('class', 'def', 'for', 'if', 'try', 'while')):
+        if self.finished:
+            pass
+        elif type == NAME and token in OPENERS:
+            self.blkopenline = line
+        elif type == INDENT and self.blkopenline:
+            self.indentedline = line
+            self.finished = 1
+
+    def run(self):
+        save_tabsize = _tokenize.tabsize
+        _tokenize.tabsize = self.tabwidth
+        try:
+            try:
+                tokens = _tokenize.generate_tokens(self.readline)
+                for token in tokens:
+                    self.tokeneater(*token)
+            except (_tokenize.TokenError, SyntaxError):
+                # since we cut off the tokenizer early, we can trigger
+                # spurious errors
+                pass
+        finally:
+            _tokenize.tabsize = save_tabsize
+        return self.blkopenline, self.indentedline
+
+### end autoindent code ###
+
+def prepstr(s):
+    # Helper to extract the underscore from a string, e.g.
+    # prepstr("Co_py") returns (2, "Copy").
+    i = s.find('_')
+    if i >= 0:
+        s = s[:i] + s[i+1:]
+    return i, s
+
+
+keynames = {
+ 'bracketleft': '[',
+ 'bracketright': ']',
+ 'slash': '/',
+}
+
+def get_accelerator(keydefs, eventname):
+    keylist = keydefs.get(eventname)
+    # issue10940: temporary workaround to prevent hang with OS X Cocoa Tk 8.5
+    # if not keylist:
+    if (not keylist) or (macosx.isCocoaTk() and eventname in {
+                            "<<open-module>>",
+                            "<<goto-line>>",
+                            "<<change-indentwidth>>"}):
+        return ""
+    s = keylist[0]
+    s = re.sub(r"-[a-z]\b", lambda m: m.group().upper(), s)
+    s = re.sub(r"\b\w+\b", lambda m: keynames.get(m.group(), m.group()), s)
+    s = re.sub("Key-", "", s)
+    s = re.sub("Cancel","Ctrl-Break",s)   # dscherer@cmu.edu
+    s = re.sub("Control-", "Ctrl-", s)
+    s = re.sub("-", "+", s)
+    s = re.sub("><", " ", s)
+    s = re.sub("<", "", s)
+    s = re.sub(">", "", s)
+    return s
+
+
+def fixwordbreaks(root):
+    # Make sure that Tk's double-click and next/previous word
+    # operations use our definition of a word (i.e. an identifier)
+    tk = root.tk
+    tk.call('tcl_wordBreakAfter', 'a b', 0) # make sure word.tcl is loaded
+    tk.call('set', 'tcl_wordchars', '[a-zA-Z0-9_]')
+    tk.call('set', 'tcl_nonwordchars', '[^a-zA-Z0-9_]')
+
+
+def _editor_window(parent):  # htest #
+    # error if close master window first - timer event, after script
+    root = parent
+    fixwordbreaks(root)
+    if sys.argv[1:]:
+        filename = sys.argv[1]
+    else:
+        filename = None
+    macosx.setupApp(root, None)
+    edit = EditorWindow(root=root, filename=filename)
+    edit.text.bind("<<close-all-windows>>", edit.close_event)
+    # Does not stop error, neither does following
+    # edit.text.bind("<<close-window>>", edit.close_event)
+
+if __name__ == '__main__':
+    import unittest
+    unittest.main('idlelib.idle_test.test_editor', verbosity=2, exit=False)
+
+    from idlelib.idle_test.htest import run
+    run(_editor_window)