"""
MultiCall - a class which inherits its methods from a Tkinter widget (Text, for
example), but enables multiple calls of functions per virtual event - all
matching events will be called, not only the most specific one. This is done
by wrapping the event functions - event_add, event_delete and event_info.
MultiCall recognizes only a subset of legal event sequences. Sequences which
are not recognized are treated by the original Tk handling mechanism. A
more-specific event will be called before a less-specific event.

The recognized sequences are complete one-event sequences (no emacs-style
Ctrl-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, and
Control, Alt, Shift, Meta/M for other platforms.

For all events which were handled by MultiCall, a new member is added to the
event instance passed to the binded functions - mc_type. This is one of the
event type constants defined in this module (such as MC_KEYPRESS).
For Key/Button events (which are handled by MultiCall and may receive
modifiers), another member is added - mc_state. This member gives the state
of the recognized modifiers, as a combination of the modifier constants
also 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 re
import sys

import tkinter

# the event type constants, which define the meaning of mc_type
MC_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_state
MC_SHIFT = 1<<0; MC_CONTROL = 1<<2; MC_ALT = 1<<3; MC_META = 1<<5
MC_OPTION = 1<<6; MC_COMMAND = 1<<7

# define the list of modifiers, to be used in complex event types.
if sys.platform == "darwin":
 _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]])

# In 3.4, if no shell window is ever open, the underlying Tk widget is
# destroyed before .__del__ methods here are called. The following
# is used to selectively ignore shutdown exceptions to avoid
# 'Exception ignored' messages. See http://bugs.python.org/issue20167
APPLICATION_GONE = "application has been destroyed"

# 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:
 try:
 self.widget.unbind(self.widgetinst, self.sequence,
 self.handlerid)
 except tkinter.TclError as e:
 if not APPLICATION_GONE in e.args[0]:
 raise

# An int in range(1 << len(_modifiers)) represents a combination of modifiers
# (if the least significant 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 = [''.join(m[0]+'-'
 for i, m in enumerate(_modifiers)
 if (1 << i) & s)
 for s in _states]

def expand_substates(states):
 '''For each item of states return a list containing all combinations of
 that item with individual bits reset, sorted by the number of set bits.
 '''
 def nbits(n):
 "number of bits set in n base 2"
 nb = 0
 while n:
 n, rem = divmod(n, 2)
 nb += rem
 return nb
 statelist = []
 for state in states:
 substates = list(set(state & x for x in states))
 substates.sort(key=nbits, reverse=True)
 statelist.append(substates)
 return statelist

_state_subsets = expand_substates(_states)

# _state_codes gives for each state, the portable code to be passed as mc_state
_state_codes = []
for s in _states:
 r = 0
 for i in range(len(_modifiers)):
 if (1 << i) & s:
 r |= _modifier_masks[i]
 _state_codes.append(r)

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
 for f in doafterhandler:
 f()
 doafterhandler[:] = []
 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 triplet[2] not in self.bindedfuncs:
 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:
 try:
 self.widget.unbind(self.widgetinst, seq, id)
 except tkinter.TclError as e:
 if not APPLICATION_GONE in e.args[0]:
 raise

# 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 = sequence[1:-1].split('-')
 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):
 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)" % (sequence, func, add),
 # file=sys.__stderr__)
 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)" % (repr(virtual), repr(sequences)),
 # file=sys.__stderr__)
 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("Tkinter event_add(%s)" % seq, file=sys.__stderr__)
 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("Tkinter event_delete: %s" % seq, file=sys.__stderr__)
 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:
 try:
 self.__binders[triplet[1]].unbind(triplet, func)
 except tkinter.TclError as e:
 if not APPLICATION_GONE in e.args[0]:
 raise

 _multicall_dict[widget] = MultiCall
 return MultiCall


def _multi_call(parent): # htest #
 top = tkinter.Toplevel(parent)
 top.title("Test MultiCall")
 x, y = map(int, parent.geometry().split('+')[1:])
 top.geometry("+%d+%d" % (x, y + 175))
 text = MultiCallCreator(tkinter.Text)(top)
 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("<Button-2>")
 bindseq("<Alt-Button-1>")
 bindseq("<FocusOut>")
 bindseq("<Enter>")
 bindseq("<Leave>")

if __name__ == "__main__":
 from unittest import main
 main('idlelib.idle_test.test_mainmenu', verbosity=2, exit=False)

 from idlelib.idle_test.htest import run
 run(_multi_call)