File: pymailgui-products/unzipped/PyMailGui-PP4E/ListWindows.py

"""
###############################################################################
Implementation of mail-server and save-file message list main windows:
one class per kind.  Code is factored here for reuse: server and file
list windows are customized versions of the PyMailCommon list window class;
the server window maps actions to mail transferred from a server, and the
file window applies actions to a local file.  

List windows create View, Write, Reply, and Forward windows on user actions.
The server list window is the main window opened on program startup by the 
top-level file;  file list windows are opened on demand via server and file 
list window "Open".  Msgnums may be temporarily out of sync with server if 
POP inbox changes (triggers full reload here).

Changes here in 2.1:
-now checks on deletes and loads to see if msg nums in sync with server
-added up to N attachment direct-access buttons on view windows
-threaded save-mail file loads, to avoid N-second pause for big files
-also threads save-mail file deletes so file write doesn't pause GUI

TBD:
-save-mail file saves still not threaded: may pause GUI briefly, but
 uncommon - unlike load and delete, save/send only appends the local file.
-implementation of local save-mail files as text files with separators
 is mostly a prototype: it loads all full mails into memory, and so limits
 the practical size of these files; better alternative: use 2 DBM keyed
 access files for hdrs and fulltext, plus a list to map keys to position;
 in this scheme save-mail files become directories, no longer readable.
###############################################################################
"""

from SharedNames import *     # program-wide global objects
from ViewWindows import ViewWindow, WriteWindow, ReplyWindow, ForwardWindow


###############################################################################
# main frame - general structure for both file and server message lists
###############################################################################


class PyMailCommon(mailtools.MailParser):
    """
    an abstract widget package, with main mail listbox;
    mixed in with a Tk, Toplevel, or Frame by top-level window classes;
    must be customized in mode-specific subclass with actions() and other;
    creates view and write windows on demand: they serve as MailSenders;
    """
    # class attrs shared by all list windows
    # [4.1] queueChecksPerSecond 20=>5; 20 was too much CPU % on macos
    threadLoopStarted = False                     # started by first window
    queueChecksPerSecond = 5                      # tweak if CPU use too high
    queueDelay = 1000 // queueChecksPerSecond     # min msecs between timer events 
    queueBatch = 200  # oct15 (feb14 100: was 5)  # max callbacks per timer event

    # all windows use same dialogs: remember last dirs
    # [4.0] Mac: use message (title ignored for open dialogs, but not saves)
    # [4.0] extend 'Mail' to 'Saved-Mail', else this seems too ambiguous
    opendlgtitle = appname + ': Open Saved-Mail File'
    savedlgtitle = appname + ': Append Saved-Mail File'
    if sys.platform.startswith('darwin'):
        opendlgkargs = dict(message=opendlgtitle)  # Mac ignores title
    else:
        opendlgkargs = dict(title=opendlgtitle)    # Windows+Linux
    openDialog = Open(**opendlgkargs)
    saveDialog = SaveAs(title=savedlgtitle)

    # 3.0: avoid downloading (fetching) same message in parallel
    beingFetched = set()

    def __init__(self, withdrawn=False):
        """
        build GUI, start thread poll loop, plus subclass extensions
        [4.0] window now hidden/unhidden for build, to avoid any GUI
        flashes (for more details see ViewWindows, which does too);
        this did not seem to help much with the fewer flashes here;
        """
        # draw my contents: list, tools, help?
        self.makeWidgets()
            
        if not PyMailCommon.threadLoopStarted: 

            #-------------------------------------------------------------------
            # start thread-exit check timer loop
            # a timer-event polling loop that dispatches queued GUI callbacks;
            # just one loop for all windows: server,file,views can all thread;
            # 3.0/4E: added queue delay/batch for progress speedup: ~100x/sec;
            #
            # [4.0] Tk's widget.after() method requires that widget not be
            # destroyed before the timer expires, else no callback occurs; we
            # satisfy this here because the first window created by PyMalGUI
            # is a list window that inherits from Tk(), and endures for the
            # entire session; this window also winds up being the implicit
            # parent of all popped-up windows, so none are destroyed silently;
            # otherwise, may need to use tkinter's _default_root (see PyEdit);
            #
            # Dec2015, caveat: after() can be thrown off by changes to system's
            # clock (e.g., on dst); if queue appears to hang, reset your clock;
            # see http://learning-python.com/books/pp4e-updates.html#tkinterafter
            #--------------------------------------------------------------------
            
            PyMailCommon.threadLoopStarted = True
            threadtools.threadChecker(self, self.queueDelay, self.queueBatch)

        # unhide window now if hidden during build
        if withdrawn: 
            self.deiconify()

    def refocusList(self):
        """
        [4.0] call after standard dialog closes to restore focus on the
        mail-list component, else user must click on Mac to reset active
        style (at least under ActiveState's possibly-buggy Tk 8.5);  see
        PyEdit for more on this requirement: it spans all programs;
        """
        self.listBox.focus_force()

    def makeWidgets(self):
        """
        build the common portions of a ListWindow (server subclass adds Help)
        """
        # add all/none checkbtn at bottom
        tools = Frame(self, relief=SUNKEN, bd=2, cursor='hand2')    # 3.0: configs
        tools.pack(side=BOTTOM, fill=X)
        self.allModeVar = IntVar()
        chk = Checkbutton(tools, text="All")
        chk.config(variable=self.allModeVar, command=self.onCheckAll)
        chk.pack(side=RIGHT)

        # add main buttons at bottom toolbar
        for (title, callback) in self.actions():
            if not callback:
                sep = Label(tools, text=title)                # 3.0: separator
                sep.pack(side=LEFT, expand=YES, fill=BOTH)    # expands with window
            else:
                Button(tools, text=title, command=callback).pack(side=LEFT)

        # add multiselect listbox with scrollbars
        listwide = mailconfig.listWidth  or 74    # 3.0: config start size 
        listhigh = mailconfig.listHeight or 15    # wide=chars, high=lines
        mails    = Frame(self)
        vscroll  = Scrollbar(mails)
        hscroll  = Scrollbar(mails, orient='horizontal')
        fontsz   = (sys.platform[:3] == 'win' and 8) or 10      # defaults
        listbg   = mailconfig.listbg   or 'white'
        listfg   = mailconfig.listfg   or 'black'
        listfont = mailconfig.listfont or ('courier', fontsz, 'normal')
        listbox  = Listbox(mails, bg=listbg, fg=listfg, font=listfont)
        listbox.config(selectmode=EXTENDED)
        listbox.config(width=listwide, height=listhigh) # 3.0: init wider
        listbox.bind('<Double-1>', (lambda event: self.onViewRawMail()))

        # crosslink listbox and scrollbars
        vscroll.config(command=listbox.yview, relief=SUNKEN)
        hscroll.config(command=listbox.xview, relief=SUNKEN)
        listbox.config(yscrollcommand=vscroll.set, relief=SUNKEN)
        listbox.config(xscrollcommand=hscroll.set)

        # pack last = clip first
        mails.pack(side=TOP, expand=YES, fill=BOTH)
        vscroll.pack(side=RIGHT,  fill=BOTH)
        hscroll.pack(side=BOTTOM, fill=BOTH)
        listbox.pack(side=LEFT, expand=YES, fill=BOTH)
        self.listBox = listbox

    #################
    # event handlers
    #################

    def onCheckAll(self):
        # all or none click         
        if self.allModeVar.get():
            self.listBox.select_set(0, END)
        else:
            self.listBox.select_clear(0, END)

    def onViewRawMail(self):
        # possibly threaded: view selected messages - raw text headers, body
        msgnums = self.verifySelectedMsgs()
        if msgnums:
            self.getMessages(msgnums, after=lambda: self.contViewRaw(msgnums))

    def contViewRaw(self, msgnums, pyedit=True):     # do we need full TextEditor?
        for msgnum in msgnums:                       # could be a nested def
            fulltext = self.getMessage(msgnum)       # fulltext is Unicode decoded
            if not pyedit:
                # display in a scrolledtext
                from tkinter.scrolledtext import ScrolledText
                window  = windows.QuietPopupWindow(appname, 'raw message viewer')
                browser = ScrolledText(window)
                browser.insert('0.0', fixTkBMP(fulltext))    # [4.0] replace bad Unicode chars
                browser.pack(expand=YES, fill=BOTH)
            else:    
                # 3.0/4E: more useful PyEdit text editor
                wintitle = 'raw message text'
                browser = textEditor.TextEditorMainPopup(
                                       parent=None,          # [4.0] don't close with self
                                       winTitle=wintitle)
                browser.update()
                browser.setAllText(fixTkBMP(fulltext))       # [4.0] replace bad Unicode chars
                browser.clearModified()                      # caveat: PyEdit now does so too 

    def onViewFormatMail(self):
        """
        possibly threaded: view selected messages - pop up formatted display
        not threaded if in savefile list, or messages are already loaded
        the after action runs only if getMessages prefetch allowed and worked
        """
        msgnums = self.verifySelectedMsgs()
        if msgnums:
            self.getMessages(msgnums, after=lambda: self.contViewFmt(msgnums))

    def contViewFmt(self, msgnums):
        """
        finish View: extract main text, popup view window(s) to display;
        extracts plain text from html text if required, wraps text lines;
        html mails: show extracted text, then save in temp file and open
        in web browser;  part can also be opened manually from view window
        Split or part button;  if non-multipart, other: part must be opened
        manually with Split or part button;  verify html open per mailconfig;

        3.0: for html-only mails, main text is str here, but save its raw
        bytes in binary mode to finesse encodings;  worth the effort because 
        many mails are just html today;  this first tried N encoding guesses 
        (utf-8, latin-1, platform dflt), but now gets and saves raw bytes to
        minimize any fidelity loss;  if a part is later opened on demand, it 
        is saved in a binary file as raw bytes in the same way;

        caveat: the spawned web browser won't have any original email headers:
        it may still have to guess or be told the encoding, unless the html 
        already has its own encoding headers (these take the form of <meta>
        html tags within <head> sections if present; none are inserted in the 
        html here, as some well-formed html parts have them);  IE seems to 
        handle most html part files anyhow;  always encoding html parts to 
        utf-8 may suffice too: this encoding can handle most types of text;  
        """
        for msgnum in msgnums:
            fulltext = self.getMessage(msgnum)             # 3.0: str for parser
            message  = self.parseMessage(fulltext)
            type, content = self.findMainText(message)     # 3.0: Unicode decoded 
            if type in ['text/html', 'text/xml']:          # 3.0: get plain text
                content = html2text.html2text(content)
            content  = wraplines.wrapText1(content, mailconfig.wrapsz)
            ViewWindow(headermap   = message,
                       showtext    = content,            
                       origmessage = message)              # 3.0: decodes headers

            # non-multipart, content-type text/HTML (rude but true!)
            if type == 'text/html':
                if ((not mailconfig.verifyHTMLTextOpen) or
                    askyesno(appname, 'Open message text in browser?')):
                
                    # 3.0: get post mime decode, pre unicode decode bytes
                    type, asbytes = self.findMainText(message, asStr=False)
                    try:
                        from tempfile import gettempdir # or a Tk HTML viewer?
                        tempname = os.path.join(gettempdir(), 'pymailgui.html')
                        tmp = open(tempname, 'wb')      # already encoded
                        tmp.write(asbytes); tmp.close() # flush output now
                        webbrowser.open_new('file://' + tempname)
                    except:
                        showerror(appname, 'Cannot open in browser')

    def onWriteMail(self):
        """
        compose a new email from scratch, without fetching others;
        nothing to quote here, but adds sig, and prefills Bcc with the
        sender's address if this optional header enabled in mailconfig;
        From may be i18N encoded in mailconfig: view window will decode;
        """
        starttext = '\n'                         # use auto signature text
        if mailconfig.mysignature:
            starttext += '%s\n' % mailconfig.mysignature
        From  = mailconfig.myaddress
        WriteWindow(starttext = starttext,
                    headermap = dict(From=From, Bcc=From))    # 3.0: prefill bcc

    def onReplyMail(self):
        # possibly threaded: reply to selected emails
        msgnums = self.verifySelectedMsgs()         
        if msgnums:
            self.getMessages(msgnums, after=lambda: self.contReply(msgnums))

    def contReply(self, msgnums):
        """
        finish Reply: drop attachments, quote with '>', add signature;
        presets initial to/from values from mail or config module;
        don't use original To for From: may be many or a listname;
        To keeps name+<addr> format even if ',' separator in name;
        Uses original From for To, ignores reply-to header if any;
        3.0: replies also copy to all original recipients by default;

        3.0: now uses getaddresses/parseaddr full parsing to separate 
        addrs on commas, and handle any commas that appear nested in 
        email name parts;  multiple addresses are separated by comma 
        in GUI, we copy comma separators when displaying headers, and 
        we use getaddresses to split addrs as needed;  ',' is required 
        by servers for separator;  no longer uses parseaddr to get 1st
        name/addr pair of getaddresses result: use full From for To;

        3.0: we decode the Subject header here because we need its text,
        but the view window superclass of edit windows performs decoding
        on all displayed headers (the extra Subject decode is a no-op);
        on sends, all non-ASCII hdrs and hdr email names are in decoded
        form in the GUI, but are encoded within the mailtools package;
        quoteOrigText also decodes the initial headers it inserts into
        the quoted text block, and index lists decode for display;

        [4.1] To and Reply-To are both still i18m encoded here:
        they will be later decoded on ReplyWindow() for display, and 
        reencoded on sends by mailtools.MailSender; 'referid' here is
        the message-id of the received message, and is assumed to be 
        unencoded (though it's likely moot - just moved between hdrs);
        """
        for msgnum in msgnums:
            fulltext = self.getMessage(msgnum)
            message  = self.parseMessage(fulltext)         # may fail: error obj
            maintext = self.formatQuotedMainText(message)  # same as forward

            # from and to are decoded by view window
            From = mailconfig.myaddress                    # not original To
            To   = message.get('From', '')                 # 3.0: ',' sept [tbd: Reply-To]
            Cc   = self.replyCopyTo(message)               # 3.0: cc all recipients?
            Subj = message.get('Subject', '(no subject)')
            Subj = self.decodeHeader(Subj)                 # deocde for str
            if Subj[:4].lower() != 're: ':                 # 3.0: unify case
                Subj = 'Re: ' + Subj
            Ref  = message.get('Message-ID', None)         # [4.1] m-id iff has
            To   = message.get('Reply-To', None) or To     # [4.1] reply-to alt
            ReplyWindow(starttext = maintext,
                        referid   = Ref,
                        headermap = 
                            dict(From=From, To=To, Cc=Cc, Subject=Subj, Bcc=From))

    def onFwdMail(self):
        # possibly threaded: forward selected emails
        msgnums = self.verifySelectedMsgs()
        if msgnums:
            self.getMessages(msgnums, after=lambda: self.contFwd(msgnums))

    def contFwd(self, msgnums):
        """
        finish Forward: drop attachments, quote with '>', add signature;
        see notes about headers decoding in the Reply action methods;
        view window superclass will decode the From header we pass here;
        """
        for msgnum in msgnums:
            fulltext = self.getMessage(msgnum)
            message  = self.parseMessage(fulltext)
            maintext = self.formatQuotedMainText(message)  # same as reply

            # initial From value from config, not mail
            From = mailconfig.myaddress                    # encoded or not
            Subj = message.get('Subject', '(no subject)')
            Subj = self.decodeHeader(Subj)                 # 3.0: send encodes
            if Subj[:5].lower() != 'fwd: ':                # 3.0: unify case
                Subj = 'Fwd: ' + Subj
            Ref1 = message.get('Message-ID', None)         # [4.1], multiple refs?
            Ref2 = message.get('References', None)         # convoluted: use just one
            Ref3 = message.get('In-Reply-To', None)
            """
            if Ref2:
                Ref = Ref2 + (('\n ' + Ref1) if Ref1 else '')
            elif Ref3:
                Ref = Ref3 + (('\n ' + Ref1) if Ref1 else '')
            else:
                Ref = Ref1
            """
            Ref = Ref1    # punt: else may require smart splits and joins (and moot)
            ForwardWindow(starttext = maintext,
                          referid   = Ref,
                          headermap = dict(From=From, Subject=Subj, Bcc=From))

    def onSaveMailFile(self):
        """
        save selected emails to file for offline viewing;
        disabled if target file load/delete is in progress;
        disabled by getMessages if self is a busy file too;
        contSave not threaded: disables all other actions;
        """
        # Oct2011, examples 1.3: test for blocking action before fileselect 
        # dialog, else action's exit callback might invalidate selected message
        # numbers while file select dialog is open; getMessages blocks other 
        # changes later, with modal nature of this code; see also onDelete below;  

        if self.okayToSave():     # subclass specific test and error popup
            msgnums = self.selectedMsgs()
            if not msgnums:
                showerror(appname, 'No message selected')
            else:
                # caveat: dialog warns about replacing file
                filename = self.saveDialog.show()            # shared class attr
                if filename:                                 # don't verify num msgs
                    filename = os.path.abspath(filename)     # normalize / to \
                    self.getMessages(msgnums,
                            after=lambda: self.contSave(msgnums, filename))
        self.refocusList()                                   # [4.0] Mac hack

    def contSave(self, msgnums, filename):
        # test busy now, after poss srvr msgs load
        if (filename in openSaveFiles.keys() and           # viewing this file?
            openSaveFiles[filename].openFileBusy):         # load/del occurring?
            showerror(appname, 'Target file busy - cannot save')
            self.refocusList()                             # [4.0] Mac hack
        else:
            try:                                           # caveat:not threaded
                fulltextlist = []                          # 3.0: use encoding
                mailfile = open(filename, 'a', encoding=mailconfig.fetchEncoding)
                for msgnum in msgnums:                     # < 1sec for N megs
                    fulltext = self.getMessage(msgnum)     # but poss many msgs
                    if fulltext[-1] != '\n': fulltext += '\n'
                    mailfile.write(saveMailSeparator)
                    mailfile.write(fulltext)
                    fulltextlist.append(fulltext)
                mailfile.close()
            except:
                showerror(appname, 'Error during save')
                self.refocusList()                         # [4.0] Mac hack
                printStack(sys.exc_info())
            else:                                          # why .keys(): EIBTI
                if filename in openSaveFiles.keys():       # viewing this file?
                    window = openSaveFiles[filename]       # update list, raise
                    window.addSavedMails(fulltextlist)     # avoid file reload
                    #window.loadMailFileThread()           # this was very slow

    def onOpenMailFile(self, filename=None):
        # process saved mail offline
        filename = filename or self.openDialog.show()      # shared class attr
        self.refocusList()                                 # [4.0] Mac hack
        if filename:
            filename = os.path.abspath(filename)           # match on full name
            if filename in openSaveFiles.keys():           # only 1 win per file
                openSaveFiles[filename].lift()             # raise file's window
                showinfo(appname, 'File already open')     # else deletes odd
            else:
                from PyMailGui import PyMailFileWindow     # avoid duplicate win
                popup = PyMailFileWindow(filename)         # new list window
                openSaveFiles[filename] = popup            # removed in quit
                popup.loadMailFileThread()                 # try load in thread

    def onDeleteMail(self):
        """
        delete selected mails from server or file
        """
        # Oct2011, examples 1.3: test for delete-in-progress before verification
        # pupup, else a prior delete's exit action may be run from an after() timer
        # event callback between pressing Delete and the verification dialog's OK, 
        # invalidating selected message numbers (and possibly deleting wrong mails!);
        # a similar timing issue for the file selection dialog in Save was patched 
        # too, but it seems much less harmful to save than delete incorrect mails;

        if self.okayToDelete():     # subclass specific test and error popup
            msgnums = self.selectedMsgs()                      # subclass: fillIndex
            if not msgnums:                                    # always verify here
                showerror(appname, 'No message selected')
            else:
                if askyesno(appname, 'Verify delete %d mails?' % len(msgnums)):
                    self.doDelete(msgnums)
        self.refocusList()                                     # [4.0] Mac hack

    ##################
    # utility methods
    ##################

    def selectedMsgs(self):
        # get messages selected in main listbox
        selections = self.listBox.curselection()  # tuple of digit strs, 0..N-1
        return [int(x)+1 for x in selections]     # convert to ints, make 1..N

    warningLimit = 15
    def verifySelectedMsgs(self):
        msgnums = self.selectedMsgs()
        if not msgnums:
            showerror(appname, 'No message selected')
        else:
            numselects = len(msgnums)             
            if numselects > self.warningLimit:
                if not askyesno(appname, 'Open %d selections?' % numselects):
                    msgnums = []
        self.refocusList()                        # [4.0] Mac hack
        return msgnums

    def fillIndex(self, maxhdrsize=25):
        """
        fill all of main listbox from message header mappings;
        3.0: decode headers per email/mime/unicode here if encoded;
        3.0: caveat: large chinese characters can break '|' alignment;  
        """
        def makeTimeLocal(origTimeStr):
            """
            Oct2011, examples 1.3: display sent-time relative to local 
            timezone; must do after decode and for header size calc too; 
            runs: formatdate(mktime_tz(parsedate_tz(there)), localtime=True)
            """
            from email.utils import formatdate   
            from email._parseaddr import parsedate_tz, mktime_tz
            if origTimeStr in [' ', '']: 
                return origTimeStr  # common case: parser fails

            try:
                timeTuple    = parsedate_tz(origTimeStr)
                utcTimeNum   = mktime_tz(timeTuple)
                localTimeStr = formatdate(utcTimeNum, localtime=True)
                return localTimeStr
            except:
                #import traceback; traceback.print_exc()
                #print('Local time failed:', sys.exc_info()[0], sys.exc_info()[1])
                return origTimeStr  # use orig date-time text if anything fails

        hdrmaps  = self.headersMaps()                   # may be empty
        showhdrs = ('Subject', 'From', 'Date', 'To')    # default hdrs to show
        if hasattr(mailconfig, 'listheaders'):          # mailconfig customizes
            showhdrs = mailconfig.listheaders or showhdrs
        addrhdrs = ('From', 'To', 'Cc', 'Bcc')    # 3.0: decode i18n specially

        # compute max field sizes <= hdrsize
        maxsize = {}
        for key in showhdrs:
            allLens = []                                # too big for a list comp!
            for msg in hdrmaps:
                keyval = msg.get(key, ' ')
                if key == 'Date': 
                    allLens.append(len(makeTimeLocal(self.decodeHeader(keyval))))
                elif key not in addrhdrs:
                    allLens.append(len(self.decodeHeader(keyval)))
                else:
                    allLens.append(len(self.decodeAddrHeader(keyval)))
            if not allLens: allLens = [1]
            maxsize[key] = min(maxhdrsize, max(allLens))

        # populate listbox with fixed-width left-justified fields
        self.listBox.delete(0, END)                     # show multiparts with *
        for (ix, msg) in enumerate(hdrmaps):            # via content-type hdr
            msgtype = msg.get_content_maintype()        # no is_multipart yet
            msgline = (msgtype == 'multipart' and '*') or ' '
            msgline += '%03d' % (ix+1)
            for key in showhdrs:
                mysize  = maxsize[key]
                if key == 'Date':
                    keytext = makeTimeLocal(self.decodeHeader(msg.get(key, ' ')))
                elif key not in addrhdrs:
                    keytext = self.decodeHeader(msg.get(key, ' '))
                else:
                    keytext = self.decodeAddrHeader(msg.get(key, ' '))
                msgline += ' | %-*s' % (mysize, keytext[:mysize])
            msgline += '| %.1fK' % (self.mailSize(ix+1) / 1024)   # 3.0: .0 optional

            #-------------------------------------------------------------------------------------
            # Jun2015, 1.5: bad unicode char in hdr lines too (not just body): prevent thread exit gui
            # _tkinter.TclError: character U+1f48a is above the range (U+0000-U+FFFF) allowed
            #
            #try:
            #    self.listBox.insert(END, msgline)
            #except:
            #    showerror(appname, 'Error setting text in list window')
            #    printStack(sys.exc_info())
            #    self.listBox.insert(END, ('?%03d' % (ix+1)) +
            #                        ' | **bad unicode char in header line**')
            #-------------------------------------------------------------------------------------
            # [4.0] instead, replace chars outside BMP range with Unicode replacement char
            #-------------------------------------------------------------------------------------

            self.listBox.insert(END, fixTkBMP(msgline))

        self.listBox.see(END)         # show most recent mail=last line

    def replyCopyTo(self, message):
        """
        3.0: replies copy all original recipients, by prefilling
        Cc header with all addreses in original To and Cc after 
        removing duplicates and new sender;  could decode i18n addrs 
        here, but the view window will decode to display (and send
        will reencode) and the unique set filtering here will work 
        either way, though a sender's i18n address is assumed to be 
        in encoded form in mailconfig (else it is not removed here);
        empty To or Cc headers are okay: split returns empty lists;
        """
        if not mailconfig.repliesCopyToAll:
            # reply to sender only
            Cc = ''
        else:
            # copy all original recipients (3.0)
            allRecipients = (self.splitAddresses(message.get('To', '')) + 
                             self.splitAddresses(message.get('Cc', ''))) 
            uniqueOthers  = set(allRecipients) - set([mailconfig.myaddress])
            Cc = ', '.join(uniqueOthers)
        return Cc or '?'

    def formatQuotedMainText(self, message):
        """
        3.0: factor out common code shared by Reply and Forward:
        fetch decoded text, extract text if html, line wrap, add > quote
        """
        type, maintext = self.findMainText(message)       # 3.0: decoded str
        if type in ['text/html', 'text/xml']:             # 3.0: get plain text
            maintext = html2text.html2text(maintext)
        maintext = wraplines.wrapText1(maintext, mailconfig.wrapsz-2) # 2 = '> '
        maintext = self.quoteOrigText(maintext, message)              # add hdrs, >
        if mailconfig.mysignature:
            maintext = ('\n%s\n' % mailconfig.mysignature) + maintext
        return maintext

    def quoteOrigText(self, maintext, message):
        """
        3.0: we need to decode any i18n (internationalized) headers here too,
        or they show up in email+MIME encoded form in the quoted text block;
        decodeAddrHeader works on one addr or all in a comma-separated list;
        this may trigger full text encoding on sends, but the main text is 
        also already in fully decoded form: could be in any Unicode scheme;
        """
        quoted = '\n-----Original Message-----\n'
        for hdr in ('From', 'To', 'Subject', 'Date'):
            rawhdr = message.get(hdr, '?')
            if hdr not in ('From', 'To'):
                dechdr = self.decodeHeader(rawhdr)       # full value
            else:
                dechdr = self.decodeAddrHeader(rawhdr)   # name parts only
            quoted += '%s: %s\n' % (hdr, dechdr)
        quoted += '\n' + maintext
        quoted  = '\n' + quoted.replace('\n', '\n> ')
        return quoted

    ########################
    # subclass requirements
    ########################

    def getMessages(self, msgnums, after):        # used by view,save,reply,fwd
        after()                                   # redef if cache, thread test

    # plus okayToQuit?, okayToDelete?, okayToSave?, any unique actions
    def getMessage(self, msgnum): assert False    # used by many: full mail text
    def headersMaps(self): assert False           # fillIndex: hdr mappings list
    def mailSize(self, msgnum): assert False      # fillIndex: size of msgnum
    def doDelete(self): assert False              # onDeleteMail: delete button


###############################################################################
# main window - when viewing messages in local save file (or sent-mail file)
###############################################################################


class PyMailFile(PyMailCommon):
    """
    customize PyMailCommon for viewing saved-mail file offline;
    mixed with a Tk, Toplevel, or Frame, adds main mail listbox;
    maps load, fetch, delete actions to local text file storage;
    file opens and deletes here run in threads for large files;

    save and send not threaded, because only append to file; save 
    is disabled if source or target file busy with load/delete; 
    save disables load, delete, save just because it is not run 
    in a thread (blocks GUI);

    TBD: may need thread and O/S file locks if saves ever do run in
    threads: saves could disable other threads with openFileBusy, but
    file may not be open in GUI;  file locks not sufficient, because 
    GUI updated too;  TBD: appends to sent-mail file may require O/S 
    locks: as is, user gets error pop up if sent during load/del;

    3.0: mail save files are now Unicode text, encoded per an encoding
    name setting in the mailconfig module; this may not support worst 
    case scenarios of unusual or mixed encodings, but most full mail 
    text is ascii, and the Python 3.1 email package is partly broken;
    """
    def actions(self):
        return [ ('Open',   self.onOpenMailFile),
                 ('Write',  self.onWriteMail),
                 ('  ',     None),                           # 3.0:  separators
                 ('View',   self.onViewFormatMail),
                 ('Reply',  self.onReplyMail),
                 ('Fwd',    self.onFwdMail),
                 ('Save',   self.onSaveMailFile),
                 ('Delete', self.onDeleteMail),
                 ('  ',     None),
                 ('Quit',   self.quit) ]

    def __init__(self, filename, withdrawn=False):
        # caller: do loadMailFileThread next
        PyMailCommon.__init__(self, withdrawn)
        self.filename = filename
        self.openFileBusy = threadtools.ThreadCounter()      # one per window

        # [4.0] reset root's menu lost on PyEdit popups (see module: Tk bug?)
        # the server window's menu is app root menu, created in PyMailGgu.py
        from PP4E.Gui.Tools import guimaker
        guimaker.fixAppleMenuBarChild(self)
        
    def loadMailFileThread(self):
        """
        load or reload file and update window index list;
        called on Open, startup, and possibly on Send if
        sent-mail file appended is currently open;  there
        is always a bogus first item after the text split;
        alt: [self.parseHeaders(m) for m in self.msglist];
        could pop up a busy dialog, but quick for small files;

        2.1: this is now threaded--else runs < 1sec for N meg
        files, but can pause GUI N seconds if very large file;
        Save now uses addSavedMails to append msg lists for
        speed, not this reload;  still called from Send just
        because msg text unavailable - requires refactoring;
        delete threaded too: prevent open and delete overlap;
        """
        if self.openFileBusy:
            # don't allow parallel open/delete changes
            errmsg = 'Cannot load, file is busy:\n"%s"' % self.filename
            showerror(appname, fixTkBMP(errmsg))
            self.refocusList()                           # [4.0] Mac hack
        else:
            #self.listBox.insert(END, 'loading...')      # error if user clicks
            savetitle = self.title()                     # set by window class
            self.title(appname + ' - ' + 'Loading...')
            self.openFileBusy.incr()
            threadtools.startThread(
                action   = self.loadMailFile,
                args     = (),
                context  = (savetitle,),
                onExit   = self.onLoadMailFileExit,
                onFail   = self.onLoadMailFileFail)

    def loadMailFile(self):
        # run in a thread while GUI is active
        # open, read, parser may all raise excs: caught in thread utility
        file = open(self.filename, 'r', encoding=mailconfig.fetchEncoding)   # 3.0
        allmsgs = file.read()
        self.msglist  = allmsgs.split(saveMailSeparator)[1:]       # full text
        self.hdrlist  = list(map(self.parseHeaders, self.msglist)) # msg objects

    def onLoadMailFileExit(self, savetitle):
        # on thread success
        self.title(savetitle)         # reset window title to filename
        self.fillIndex()              # updates GUI: do in main thread
        self.lift()                   # raise my window
        self.openFileBusy.decr()

    def onLoadMailFileFail(self, exc_info, savetitle):
        # on thread exception
        showerror(appname, fixTkBMP('Error opening "%s"\n%s\n%s' %
                           ((self.filename,) +  exc_info[:2]) ))
        printStack(exc_info)
        self.destroy()                # always close my window?
        self.openFileBusy.decr()      # not needed if destroy

    def addSavedMails(self, fulltextlist):
        """
        optimization: extend loaded file lists for mails
        newly saved to this window's file; in past called
        loadMailThread to reload entire file on save - slow;
        must be called in main GUI thread only: updates GUI;
        sends still reloads sent file if open: no msg text;
        """
        self.msglist.extend(fulltextlist)
        self.hdrlist.extend(map(self.parseHeaders, fulltextlist))  # 3.x iter ok
        self.fillIndex()
        self.lift()

    def okayToSave(self):
        # Oct2011: test before file selection popup
        if self.openFileBusy:
            # dont allow parallel open/delete changes
            errmsg = 'Cannot save, file is busy:\n"%s"' % self.filename
            showerror(appname, fixTkBMP(errmsg))
            return False
        else:
            return True

    def okayToDelete(self):
        # Oct2011: test before verification popup too
        if self.openFileBusy:
            # dont allow parallel open/delete changes
            errmsg = 'Cannot delete, file is busy:\n"%s"' % self.filename
            showerror(appname, fixTkBMP(errmsg))
            return False
        else:
            return True

    def doDelete(self, msgnums):
        """
        simple-minded, but sufficient: rewrite all
        nondeleted mails to file; can't just delete
        from self.msglist in-place: changes item indexes;
        Py2.3 enumerate(L) same as zip(range(len(L)), L)
        2.1: now threaded, else N sec pause for large files
        """
        if self.openFileBusy:   # test probably not needed here too, but harmless
            # dont allow parallel open/delete changes
            errmsg = 'Cannot delete, file is busy:\n"%s"' % self.filename
            showerror(appname, fixTkBMP(errmsg))
            self.refocusList()            # [4.0] Mac hack
        else:
            savetitle = self.title()
            self.title(appname + ' - ' + 'Deleting...')
            self.openFileBusy.incr()
            threadtools.startThread(
                action   = self.deleteMailFile,
                args     = (msgnums,),
                context  = (savetitle,),
                onExit   = self.onDeleteMailFileExit,
                onFail   = self.onDeleteMailFileFail)

    def deleteMailFile(self, msgnums):
        # run in a thread while GUI active
        indexed = enumerate(self.msglist)
        keepers = [msg for (ix, msg) in indexed if ix+1 not in msgnums]
        allmsgs = saveMailSeparator.join([''] + keepers)
        file = open(self.filename, 'w', encoding=mailconfig.fetchEncoding)   # 3.0
        file.write(allmsgs)
        self.msglist = keepers
        self.hdrlist = list(map(self.parseHeaders, self.msglist))

    def onDeleteMailFileExit(self, savetitle):
        self.title(savetitle)
        self.fillIndex()              # updates GUI: do in main thread
        self.lift()                   # reset my title, raise my window
        self.openFileBusy.decr()

    def onDeleteMailFileFail(self, exc_info, savetitle):
        showerror(appname, fixTkBMP('Error deleting "%s"\n%s\n%s' %
                           ((self.filename,) +  exc_info[:2]) ))
        printStack(exc_info)
        self.destroy()                # always close my window?
        self.openFileBusy.decr()      # not needed if destroy

    def getMessages(self, msgnums, after):
        """
        used by view,save,reply,fwd: file load and delete
        threads may change the msg and hdr lists, so disable
        all other operations that depend on them to be safe;
        this test is for self: saves also test target file;
        """
        if self.openFileBusy:
            errmsg = 'Cannot fetch, file is busy:\n"%s"' % self.filename
            showerror(appname, fixTkBMP(errmsg))
            self.refocusList()           # [4.0] Mac hack
        else:
            after()                      # mail already loaded

    def getMessage(self, msgnum):
        return self.msglist[msgnum-1]    # full text of 1 mail

    def headersMaps(self):
        return self.hdrlist              # email.message.Message objects

    def mailSize(self, msgnum):
        return len(self.msglist[msgnum-1])
        
    def quit(self):
        """
        [4.0] close just this window, which is parent to none: no need
        to check for unsaved changes in PyEdit popups or components;
        """
        # don't destroy during update: fillIndex next
        if self.openFileBusy:
            showerror(appname, 'Cannot quit during load or delete')
            self.refocusList()        # [4.0] Mac hack
        else:
            if askyesno(appname, 'Verify Window Close?'):
                # delete file from open list
                del openSaveFiles[self.filename]
                Toplevel.destroy(self)
            else:
                self.refocusList()    # [4.0] Mac hack


###############################################################################
# main window - when viewing messages on the mail server
###############################################################################


class PyMailServer(PyMailCommon):
    """
    customize PyMailCommon for viewing mail still on server;
    mixed with a Tk, Toplevel, or Frame, adds main mail listbox;
    maps load, fetch, delete actions to email server inbox;
    embeds a MessageCache => which is a mailtools MailFetcher;
    this is a MailParser, and ViewWindows may be MailSenders;
    """
    def actions(self):
        return [ ('Load',   self.onLoadServer),
                 ('Open',   self.onOpenMailFile),
                 ('Write',  self.onWriteMail),
                 ('  ',     None),                           # 3.0:  separators
                 ('View',   self.onViewFormatMail),
                 ('Reply',  self.onReplyMail),
                 ('Fwd',    self.onFwdMail),
                 ('Save',   self.onSaveMailFile),
                 ('Delete', self.onDeleteMail),
                 ('  ',     None),
                 ('Quit',   self.quit) ]

    def __init__(self, withdrawn=False):
        # Dec2015: never ask for pop password again after first successful load
        PyMailCommon.__init__(self, withdrawn)
        self.cache = messagecache.GuiMessageCache()    # embedded, not inherited
        self.loadedOnce = False
       #self.listBox.insert(END, 'Press Load to fetch mail')

    def makeWidgets(self):                             # help bar: main win only
        self.addHelpBar()
        PyMailCommon.makeWidgets(self)

    def addHelpBar(self):
        msg = 'PyMailGUI—a Python/tkinter email client  (☒=Help)'

        # [4.0] Mac OS X Tk doesn't do Button bg colors (white-on-white!)
        if sys.platform.startswith('darwin'):
            # Macs: substitute a label + bind event
            title = Label(self, text=msg)
            title.config(bg='steelblue', fg='white', relief=RIDGE)
            title.bind('<Button-1>', lambda event: self.onShowHelp())
        else:
            # Windows and Linux: as before
            title = Button(self, text=msg)
            title.config(bg='steelblue', fg='white', relief=RIDGE)
            title.config(command=self.onShowHelp)
        
        title.pack(fill=X)
        # Dec2015: allow help bar's colors to be changed too (an oversight)
        if getattr(mailconfig, 'helpfg', ''): title.config(fg=mailconfig.helpfg)
        if getattr(mailconfig, 'helpbg', ''): title.config(bg=mailconfig.helpbg)

    def onShowHelp(self):
        """
        load,show text block string;
        3.0: now uses HTML and webbrowser module here too;
        user setting in mailconfig selects text, HTML, or both;
        always displays one or the other: html if both false;
        Dec2015: recoded to support 3rd help option - standalone readme;
        [4.0] now invoked from both help bar and Mac app-menu and Dock;
        """
        texthelp = mailconfig.showHelpAsText
        htmlhelp = mailconfig.showHelpAsHTML
        newhelp  = getattr(mailconfig, 'showStandaloneHelp', True)    # not (set & False)

        if not (texthelp or htmlhelp or newhelp):
            #newhelp = True   # always do something on click?
            pass              # no: allow disabling (bar is too easy to hit)

        if texthelp:
            # original: text-based GUI popup 
            from PyMailGuiHelp import helptext
            popuputil.HelpPopup(appname, helptext, showsource=self.onShowMySource)
            
        if htmlhelp:
            # 3.0: HTML version without source file links
            self.update()
            from PyMailGuiHelp import showHtmlHelp
            showHtmlHelp()
            
        if newhelp:
            # Dec2015: HTML help file for standalone release (links to older)
            self.update()
            updir  = os.path.abspath('..')
            readme = os.path.join(updir, 'UserGuide.html')
            if htmlhelp:
                # pause if showing both htmls, else some browsers show just one (IE, FF)
                import time; time.sleep(1.0)              
            webbrowser.open('file://' + readme)

    def onShowMySource(self, showAsMail=False):
        """
        display my sourcecode file, plus imported modules here & elsewhere
        """
        import PyMailGui, ListWindows, ViewWindows, SharedNames, textConfig
        from PP4E.Internet.Email.mailtools import (    # mailtools now a pkg
             mailSender, mailFetcher, mailParser)      # can't use * in def
        mymods = (
            PyMailGui, ListWindows, ViewWindows, SharedNames,
            PyMailGuiHelp, popuputil, messagecache, wraplines, html2text,
            mailtools, mailFetcher, mailSender, mailParser,
            mailconfig, textConfig, threadtools, windows, textEditor)
        for mod in mymods:
            source = mod.__file__
            if source.endswith('.pyc'):
                source = source[:-4] + '.py'       # assume a .py in same dir
            if showAsMail:
                # this is a bit cheesey...
                code   = open(source).read()       # 3.0: platform encoding
                user   = mailconfig.myaddress
                hdrmap = {'From': appname, 'To': user, 'Subject': mod.__name__}
                ViewWindow(showtext=code,
                           headermap=hdrmap,
                           origmessage=email.message.Message())
            else:                 
                # more useful PyEdit text editor
                # 4E: assume in UTF8 Unicode encoding (else PeEdit may ask!)
                # [4.0] use parent=None=Tk root: don't close with self
                wintitle = mod.__name__
                textEditor.TextEditorMainPopup(None, source, wintitle, 'utf-8')

    def onLoadServer(self, forceReload=False):
        """
        threaded: load or reload mail headers list on request;
        Exit,Fail,Progress run by threadChecker after callback via queue;
        load may overlap with sends, but disables all but send;
        could overlap with loadingMsgs, but may change msg cache list;
        forceReload on delete/synch fail, else loads recent arrivals only;

        2.1: cache.loadHeaders may do quick check to see if msgnums
        in synch with server, if we are loading just newly arrived hdrs;

        Dec2015 note: loads preclude other actions and can never overlap,
        so one load's exit cannot change password switches set by another;
        """
        if loadingHdrsBusy or deletingBusy or loadingMsgsBusy:
            showerror(appname, 'Cannot load headers during load or delete')
            self.refocusList()                             # [4.0] Mac hack
        else:
            loadingHdrsBusy.incr()
            if not self.loadedOnce:                        # Dec2015: if not 1st load ok
                # [4.0] pass self for transient+geometry on Linux and Mac - modal
                self.cache.setPopPassword(appname, self)   # don't do GUI in the thread!

            # [4.0] do NOT pass self for geometry - can be covered by parent
            popup = popuputil.BusyBoxNowait(appname, 'Loading message headers')

            threadtools.startThread(
                action     = self.cache.loadHeaders,
                args       = (forceReload,),
                context    = (popup,),
                onExit     = self.onLoadHdrsExit,
                onFail     = self.onLoadHdrsFail,
                onProgress = self.onLoadHdrsProgress)

    def onLoadHdrsExit(self, popup):
        self.fillIndex()
        popup.quit()
        self.lift()
        loadingHdrsBusy.decr()     # allow other actions to run
        self.loadedOnce = True     # Dec2015: never ask for pop password again 

    def onLoadHdrsFail(self, exc_info, popup):
        popup.quit()
        showerror(appname, fixTkBMP('Load failed: \n%s\n%s' % exc_info[:2]))
        self.refocusList()                         # [4.0] Mac hack
        printStack(exc_info)                       # send stack trace to stdout
        loadingHdrsBusy.decr()
        if exc_info[0] == mailtools.MessageSynchError:    # synch inbox/index
            self.onLoadServer(forceReload=True)           # new thread: reload
        elif not self.loadedOnce:                  # Dec2015: unless loaded ok,
            self.cache.popPassword = None          # force re-input next time

    def onLoadHdrsProgress(self, i, n, popup):
        popup.changeText('%d of %d' % (i, n))

    def okayToSave(self):
        # Oct2011: test before file selection popup
        if loadingHdrsBusy or deletingBusy or loadingMsgsBusy:
            showerror(appname, 'Cannot save during load or delete')
            return False
        else:
            return True

    def okayToDelete(self):
        # Oct2011: test before verification popup too
        if loadingHdrsBusy or deletingBusy or loadingMsgsBusy:
            showerror(appname, 'Cannot delete during load or delete')
            return False
        else:
            return True

    def doDelete(self, msgnumlist):
        """
        threaded: delete from server now - changes msg nums;
        may overlap with sends only, disables all except sends;

        2.1: cache.deleteMessages now checks TOP result to see
        if headers match selected mails, in case msgnums out of
        synch with mail server: poss if mail deleted by other client,
        or server deletes inbox mail automatically - some ISPs may
        move a mail from inbox to undeliverable on load failure;

        Dec2015 note: no need to set pswd or clear it on failure here:
        a failure doesn't invalidate pswd, and pswd now never cleared
        after first good load (which happened, else no mails to delete);
        """
        if loadingHdrsBusy or deletingBusy or loadingMsgsBusy:  # retest is harmless
            showerror(appname, 'Cannot delete during load or delete')
            self.refocusList()                                  # [4.0] Mac hack
        else:
            deletingBusy.incr()
            # [4.0] do NOT pass self for geometry - can be covered by parent
            popup = popuputil.BusyBoxNowait(appname, 'Deleting selected mails')
            threadtools.startThread(
                action     = self.cache.deleteMessages,
                args       = (msgnumlist,),
                context    = (popup,),
                onExit     = self.onDeleteExit,
                onFail     = self.onDeleteFail,
                onProgress = self.onDeleteProgress)

    def onDeleteExit(self, popup):
        self.fillIndex()                     # no need to reload from server
        popup.quit()                         # refill index with updated cache
        self.lift()                          # raise index window, release lock
        deletingBusy.decr()

    def onDeleteFail(self, exc_info, popup):
        popup.quit()
        showerror(appname, fixTkBMP('Delete failed: \n%s\n%s' % exc_info[:2]))
        self.refocusList()                   # [4.0] Mac hack
        printStack(exc_info)
        deletingBusy.decr()                  # delete or synch check failure
        self.onLoadServer(forceReload=True)  # new thread: some msgnums changed

    def onDeleteProgress(self, i, n, popup):
        popup.changeText('%d of %d' % (i, n))

    def getMessages(self, msgnums, after):
        """
        threaded: prefetch all selected messages into cache now;
        used by save, view, reply, and forward to prefill cache;
        may overlap with other loadmsgs and sends, disables delete,load;
        only runs "after" action if the fetch allowed and successful;

        2.1: cache.getMessages tests if index in synch with server,
        but we only test if we have to go to server, not if cached;

        3.0: see messagecache note: now avoids potential fetch of mail
        currently being fetched, if user clicks again while in progress;
        any message being fetched by any other request in progress must
        disable entire toLoad batch: else, need to wait for N other loads;
        fetches are still allowed to overlap in time, as long as disjoint;

        Dec2015 note: no need to set pswd or clear it on failure here:
        a failure doesn't invalidate pswd, and pswd now never cleared
        after first good load (which happened, else no mails to fetch);
        """
        if loadingHdrsBusy or deletingBusy:
            showerror(appname, 'Cannot fetch message during load or delete')
            self.refocusList()                        # [4.0] Mac hack
        else:
            toLoad = [num for num in msgnums if not self.cache.isLoaded(num)]
            if not toLoad:
                after()         # all already loaded
                return          # process now, no wait pop up
            else:
                if set(toLoad) & self.beingFetched:   # 3.0: any in progress?
                    showerror(appname, 'Cannot fetch any message being fetched')
                    self.refocusList()                # [4.0] Mac hack
                else: 
                    self.beingFetched |= set(toLoad)
                    loadingMsgsBusy.incr()
                    from popuputil import BusyBoxNowait
                    # [4.0] do NOT pass self for geometry - can be covered by parent
                    popup = BusyBoxNowait(appname, 'Fetching message contents')
                    threadtools.startThread(
                        action     = self.cache.getMessages,
                        args       = (toLoad,),
                        context    = (after, popup, toLoad),
                        onExit     = self.onLoadMsgsExit,
                        onFail     = self.onLoadMsgsFail,
                        onProgress = self.onLoadMsgsProgress)

    def onLoadMsgsExit(self, after, popup, toLoad):
        self.beingFetched -= set(toLoad)
        popup.quit()
        after()
        loadingMsgsBusy.decr()    # allow other actions after onExit done

    def onLoadMsgsFail(self, exc_info, after, popup, toLoad):
        self.beingFetched -= set(toLoad)
        popup.quit()
        showerror(appname, fixTkBMP('Fetch failed: \n%s\n%s' % exc_info[:2]))
        self.refocusList()                                  # [4.0] Mac hack
        printStack(exc_info)
        loadingMsgsBusy.decr()
        if exc_info[0] == mailtools.MessageSynchError:      # synch inbox/index
            self.onLoadServer(forceReload=True)             # new thread: reload

    def onLoadMsgsProgress(self, i, n, after, popup, toLoad):
        popup.changeText('%d of %d' % (i, n))

    def getMessage(self, msgnum):
        return self.cache.getMessage(msgnum)                # full mail text

    def headersMaps(self):
        # list of email.message.Message objects, 3.x requires list() if map()
        # return [self.parseHeaders(h) for h in self.cache.allHdrs()]
        return list(map(self.parseHeaders, self.cache.allHdrs()))

    def mailSize(self, msgnum):
        return self.cache.getSize(msgnum)

    def okayToQuit(self):
        # any threads still running?
        filesbusy = [win for win in openSaveFiles.values() if win.openFileBusy]
        busy = loadingHdrsBusy or deletingBusy or sendingBusy or loadingMsgsBusy
        busy = busy or filesbusy
        return not busy

    def quit(self):
        """
        [4.0] extend window class method to notify of changed text in
        any open PyEdit popup window or view window component widget;
        self is the app root Tk: its quit will auto-close all others;
        super could be __class__.__bases__[1], but other mixins unused;
        [4.0] now invoked for both window quit button and toolbar quit,
        plus Mac's global top-of-screen app-menu and Dock Quits;
        [4.0] also raise any/all changed windows if user cancels quit,
        or simply refocus on this list window if no changes were found;
        """
        changed = textEditor.TextEditor.anyWindowsModified()
        if not changed:
            notice = ''
        else:
            notice = "%d window%s ha%s unsaved text changes.\n\n"
            notice %= ((len(changed),) +
                      (('', 's') if len(changed) == 1 else ('s', 've')))

        # quit, focus, or raise, if allowed
        windows.MainWindow.quit(self, notice,
                    onNo=
                        self.refocusList if not changed else
                        lambda: textEditor.TextEditor.liftWindows(changed))



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