JezK
Edit File: multicall.py
""" 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 idlelib.idle_test.htest import run run(_multi_call)