"""MultiCall - a class which inherits its methods from a Tkinter widget (Text, forexample), but enables multiple calls of functions per virtual event - allmatching events will be called, not only the most specific one. This is doneby wrapping the event functions - event_add, event_delete and event_info.MultiCall recognizes only a subset of legal event sequences. Sequences whichare not recognized are treated by the original Tk handling mechanism. Amore-specific event will be called before a less-specific event. The recognized sequences are complete one-event sequences (no emacs-styleCtrl-X Ctrl-C, no shortcuts like <3>), for all types of events.Key/Button Press/Release events can have modifiers.The recognized modifiers are Shift, Control, Option and Command for Mac, andControl, Alt, Shift, Meta/M for other platforms. For all events which were handled by MultiCall, a new member is added to theevent instance passed to the binded functions - mc_type. This is one of theevent type constants defined in this module (such as MC_KEYPRESS).For Key/Button events (which are handled by MultiCall and may receivemodifiers), another member is added - mc_state. This member gives the stateof the recognized modifiers, as a combination of the modifier constantsalso defined in this module (for example, MC_SHIFT).Using these members is absolutely portable. The order by which events are called is defined by these rules:1. A more-specific event will be called before a less-specific event.2. A recently-binded event will be called before a previously-binded event,   unless this conflicts with the first rule.Each function will be called at most once for each event.""" import sysimport osimport stringimport reimport Tkinter # the event type constants, which define the meaning of mc_typeMC_KEYPRESS=0; MC_KEYRELEASE=1; MC_BUTTONPRESS=2; MC_BUTTONRELEASE=3;MC_ACTIVATE=4; MC_CIRCULATE=5; MC_COLORMAP=6; MC_CONFIGURE=7;MC_DEACTIVATE=8; MC_DESTROY=9; MC_ENTER=10; MC_EXPOSE=11; MC_FOCUSIN=12;MC_FOCUSOUT=13; MC_GRAVITY=14; MC_LEAVE=15; MC_MAP=16; MC_MOTION=17;MC_MOUSEWHEEL=18; MC_PROPERTY=19; MC_REPARENT=20; MC_UNMAP=21; MC_VISIBILITY=22;# the modifier state constants, which define the meaning of mc_stateMC_SHIFT = 1<<0; MC_CONTROL = 1<<2; MC_ALT = 1<<3; MC_META = 1<<5MC_OPTION = 1<<6; MC_COMMAND = 1<<7 # define the list of modifiers, to be used in complex event types.if sys.platform == "darwin" and sys.executable.count(".app"):    _modifiers = (("Shift",), ("Control",), ("Option",), ("Command",))    _modifier_masks = (MC_SHIFT, MC_CONTROL, MC_OPTION, MC_COMMAND)else:    _modifiers = (("Control",), ("Alt",), ("Shift",), ("Meta", "M"))    _modifier_masks = (MC_CONTROL, MC_ALT, MC_SHIFT, MC_META) # a dictionary to map a modifier name into its number_modifier_names = dict([(name, number)                         for number in range(len(_modifiers))                         for name in _modifiers[number]]) # A binder is a class which binds functions to one type of event. It has two# methods: bind and unbind, which get a function and a parsed sequence, as# returned by _parse_sequence(). There are two types of binders:# _SimpleBinder handles event types with no modifiers and no detail.# No Python functions are called when no events are binded.# _ComplexBinder handles event types with modifiers and a detail.# A Python function is called each time an event is generated. class _SimpleBinder:    def __init__(self, type, widget, widgetinst):        self.type = type        self.sequence = '<'+_types[type][0]+'>'        self.widget = widget        self.widgetinst = widgetinst        self.bindedfuncs = []        self.handlerid = None     def bind(self, triplet, func):        if not self.handlerid:            def handler(event, l = self.bindedfuncs, mc_type = self.type):                event.mc_type = mc_type                wascalled = {}                for i in range(len(l)-1, -1, -1):                    func = l[i]                    if func not in wascalled:                        wascalled[func] = True                        r = func(event)                        if r:                            return r            self.handlerid = self.widget.bind(self.widgetinst,                                              self.sequence, handler)        self.bindedfuncs.append(func)     def unbind(self, triplet, func):        self.bindedfuncs.remove(func)        if not self.bindedfuncs:            self.widget.unbind(self.widgetinst, self.sequence, self.handlerid)            self.handlerid = None     def __del__(self):        if self.handlerid:            self.widget.unbind(self.widgetinst, self.sequence, self.handlerid) # An int in range(1 << len(_modifiers)) represents a combination of modifiers# (if the least significent bit is on, _modifiers[0] is on, and so on).# _state_subsets gives for each combination of modifiers, or *state*,# a list of the states which are a subset of it. This list is ordered by the# number of modifiers is the state - the most specific state comes first._states = range(1 << len(_modifiers))_state_names = [reduce(lambda x, y: x + y,                       [_modifiers[i][0]+'-' for i in range(len(_modifiers))                        if (1 << i) & s],                       "")                for s in _states]_state_subsets = map(lambda i: filter(lambda j: not (j & (~i)), _states),                      _states)for l in _state_subsets:    l.sort(lambda a, b, nummod = lambda x: len(filter(lambda i: (1<<i) & x,                                                      range(len(_modifiers)))):           nummod(b) - nummod(a))# _state_codes gives for each state, the portable code to be passed as mc_state_state_codes = [reduce(lambda x, y: x | y,                       [_modifier_masks[i] for i in range(len(_modifiers))                        if (1 << i) & s],                       0)                for s in _states] class _ComplexBinder:    # This class binds many functions, and only unbinds them when it is deleted.    # self.handlerids is the list of seqs and ids of binded handler functions.    # The binded functions sit in a dictionary of lists of lists, which maps    # a detail (or None) and a state into a list of functions.    # When a new detail is discovered, handlers for all the possible states    # are binded.     def __create_handler(self, lists, mc_type, mc_state):        def handler(event, lists = lists,                    mc_type = mc_type, mc_state = mc_state,                    ishandlerrunning = self.ishandlerrunning,                    doafterhandler = self.doafterhandler):            ishandlerrunning[:] = [True]            event.mc_type = mc_type            event.mc_state = mc_state            wascalled = {}            r = None            for l in lists:                for i in range(len(l)-1, -1, -1):                    func = l[i]                    if func not in wascalled:                        wascalled[func] = True                        r = l[i](event)                        if r:                            break                if r:                    break            ishandlerrunning[:] = []            # Call all functions in doafterhandler and remove them from list            while doafterhandler:                doafterhandler.pop()()            if r:                return r        return handler     def __init__(self, type, widget, widgetinst):        self.type = type        self.typename = _types[type][0]        self.widget = widget        self.widgetinst = widgetinst        self.bindedfuncs = {None: [[] for s in _states]}        self.handlerids = []        # we don't want to change the lists of functions while a handler is        # running - it will mess up the loop and anyway, we usually want the        # change to happen from the next event. So we have a list of functions        # for the handler to run after it finishes calling the binded functions.        # It calls them only once.        # ishandlerrunning is a list. An empty one means no, otherwise - yes.        # this is done so that it would be mutable.        self.ishandlerrunning = []        self.doafterhandler = []        for s in _states:            lists = [self.bindedfuncs[None][i] for i in _state_subsets[s]]            handler = self.__create_handler(lists, type, _state_codes[s])            seq = '<'+_state_names[s]+self.typename+'>'            self.handlerids.append((seq, self.widget.bind(self.widgetinst,                                                          seq, handler)))     def bind(self, triplet, func):        if not self.bindedfuncs.has_key(triplet[2]):            self.bindedfuncs[triplet[2]] = [[] for s in _states]            for s in _states:                lists = [ self.bindedfuncs[detail][i]                          for detail in (triplet[2], None)                          for i in _state_subsets[s]       ]                handler = self.__create_handler(lists, self.type,                                                _state_codes[s])                seq = "<%s%s-%s>"% (_state_names[s], self.typename, triplet[2])                self.handlerids.append((seq, self.widget.bind(self.widgetinst,                                                              seq, handler)))        doit = lambda: self.bindedfuncs[triplet[2]][triplet[0]].append(func)        if not self.ishandlerrunning:            doit()        else:            self.doafterhandler.append(doit)     def unbind(self, triplet, func):        doit = lambda: self.bindedfuncs[triplet[2]][triplet[0]].remove(func)        if not self.ishandlerrunning:            doit()        else:            self.doafterhandler.append(doit)     def __del__(self):        for seq, id in self.handlerids:            self.widget.unbind(self.widgetinst, seq, id) # define the list of event types to be handled by MultiEvent. the order is# compatible with the definition of event type constants._types = (    ("KeyPress", "Key"), ("KeyRelease",), ("ButtonPress", "Button"),    ("ButtonRelease",), ("Activate",), ("Circulate",), ("Colormap",),    ("Configure",), ("Deactivate",), ("Destroy",), ("Enter",), ("Expose",),    ("FocusIn",), ("FocusOut",), ("Gravity",), ("Leave",), ("Map",),    ("Motion",), ("MouseWheel",), ("Property",), ("Reparent",), ("Unmap",),    ("Visibility",),) # which binder should be used for every event type?_binder_classes = (_ComplexBinder,) * 4 + (_SimpleBinder,) * (len(_types)-4) # A dictionary to map a type name into its number_type_names = dict([(name, number)                     for number in range(len(_types))                     for name in _types[number]]) _keysym_re = re.compile(r"^\w+$")_button_re = re.compile(r"^[1-5]$")def _parse_sequence(sequence):    """Get a string which should describe an event sequence. If it is    successfully parsed as one, return a tuple containing the state (as an int),    the event type (as an index of _types), and the detail - None if none, or a    string if there is one. If the parsing is unsuccessful, return None.    """    if not sequence or sequence[0] != '<' or sequence[-1] != '>':        return None    words = string.split(sequence[1:-1], '-')     modifiers = 0    while words and words[0] in _modifier_names:        modifiers |= 1 << _modifier_names[words[0]]        del words[0]     if words and words[0] in _type_names:        type = _type_names[words[0]]        del words[0]    else:        return None     if _binder_classes[type] is _SimpleBinder:        if modifiers or words:            return None        else:            detail = None    else:        # _ComplexBinder        if type in [_type_names[s] for s in ("KeyPress", "KeyRelease")]:            type_re = _keysym_re        else:            type_re = _button_re         if not words:            detail = None        elif len(words) == 1 and type_re.match(words[0]):            detail = words[0]        else:            return None     return modifiers, type, detail def _triplet_to_sequence(triplet):    if triplet[2]:        return '<'+_state_names[triplet[0]]+_types[triplet[1]][0]+'-'+ \               triplet[2]+'>'    else:        return '<'+_state_names[triplet[0]]+_types[triplet[1]][0]+'>' _multicall_dict = {}def MultiCallCreator(widget):    """Return a MultiCall class which inherits its methods from the    given widget class (for example, Tkinter.Text). This is used    instead of a templating mechanism.    """    if widget in _multicall_dict:        return _multicall_dict[widget]     class MultiCall (widget):        assert issubclass(widget, Tkinter.Misc)         def __init__(self, *args, **kwargs):            apply(widget.__init__, (self,)+args, kwargs)            # a dictionary which maps a virtual event to a tuple with:            #  0. the function binded            #  1. a list of triplets - the sequences it is binded to            self.__eventinfo = {}            self.__binders = [_binder_classes[i](i, widget, self)                              for i in range(len(_types))]         def bind(self, sequence=None, func=None, add=None):            #print "bind(%s, %s, %s) called." % (sequence, func, add)            if type(sequence) is str and len(sequence) > 2 and \               sequence[:2] == "<<" and sequence[-2:] == ">>":                if sequence in self.__eventinfo:                    ei = self.__eventinfo[sequence]                    if ei[0] is not None:                        for triplet in ei[1]:                            self.__binders[triplet[1]].unbind(triplet, ei[0])                    ei[0] = func                    if ei[0] is not None:                        for triplet in ei[1]:                            self.__binders[triplet[1]].bind(triplet, func)                else:                    self.__eventinfo[sequence] = [func, []]            return widget.bind(self, sequence, func, add)         def unbind(self, sequence, funcid=None):            if type(sequence) is str and len(sequence) > 2 and \               sequence[:2] == "<<" and sequence[-2:] == ">>" and \               sequence in self.__eventinfo:                func, triplets = self.__eventinfo[sequence]                if func is not None:                    for triplet in triplets:                        self.__binders[triplet[1]].unbind(triplet, func)                    self.__eventinfo[sequence][0] = None            return widget.unbind(self, sequence, funcid)         def event_add(self, virtual, *sequences):            #print "event_add(%s,%s) was called"%(repr(virtual),repr(sequences))            if virtual not in self.__eventinfo:                self.__eventinfo[virtual] = [None, []]             func, triplets = self.__eventinfo[virtual]            for seq in sequences:                triplet = _parse_sequence(seq)                if triplet is None:                    #print >> sys.stderr, "Seq. %s was added by Tkinter."%seq                    widget.event_add(self, virtual, seq)                else:                    if func is not None:                        self.__binders[triplet[1]].bind(triplet, func)                    triplets.append(triplet)         def event_delete(self, virtual, *sequences):            if virtual not in self.__eventinfo:                return            func, triplets = self.__eventinfo[virtual]            for seq in sequences:                triplet = _parse_sequence(seq)                if triplet is None:                    #print >> sys.stderr, "Seq. %s was deleted by Tkinter."%seq                    widget.event_delete(self, virtual, seq)                else:                    if func is not None:                        self.__binders[triplet[1]].unbind(triplet, func)                    triplets.remove(triplet)         def event_info(self, virtual=None):            if virtual is None or virtual not in self.__eventinfo:                return widget.event_info(self, virtual)            else:                return tuple(map(_triplet_to_sequence,                                 self.__eventinfo[virtual][1])) + \                       widget.event_info(self, virtual)         def __del__(self):            for virtual in self.__eventinfo:                func, triplets = self.__eventinfo[virtual]                if func:                    for triplet in triplets:                        self.__binders[triplet[1]].unbind(triplet, func)      _multicall_dict[widget] = MultiCall    return MultiCall if __name__ == "__main__":    # Test    root = Tkinter.Tk()    text = MultiCallCreator(Tkinter.Text)(root)    text.pack()    def bindseq(seq, n=[0]):        def handler(event):            print seq        text.bind("<<handler%d>>"%n[0], handler)        text.event_add("<<handler%d>>"%n[0], seq)        n[0] += 1    bindseq("<Key>")    bindseq("<Control-Key>")    bindseq("<Alt-Key-a>")    bindseq("<Control-Key-a>")    bindseq("<Alt-Control-Key-a>")    bindseq("<Key-b>")    bindseq("<Control-Button-1>")    bindseq("<Alt-Button-1>")    bindseq("<FocusOut>")    bindseq("<Enter>")    bindseq("<Leave>")    root.mainloop()