"""
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 sys
import re
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):
root = tkinter.Tk()
root.title("Test MultiCall")
width, height, x, y = list(map(int, re.split('[x+]', parent.geometry())))
root.geometry("+%d+%d"%(x, y + 150))
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("<Button-2>")
bindseq("<Alt-Button-1>")
bindseq("<FocusOut>")
bindseq("<Enter>")
bindseq("<Leave>")
root.mainloop()
if __name__ == "__main__":
from idlelib.idle_test.htest import run
run(_multi_call)
