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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 | # -*- Mode: Python; py-indent-offset: 4 -*- # pygobject - Python bindings for the GObject library # Copyright (C) 2012 Simon Feltman # # gi/_signalhelper.py: GObject signal binding decorator object # # This library is free software; you can redistribute it and/or # modify it under the terms of the GNU Lesser General Public # License as published by the Free Software Foundation; either # version 2.1 of the License, or (at your option) any later version. # # This library is distributed in the hope that it will be useful, # but WITHOUT ANY WARRANTY; without even the implied warranty of # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU # Lesser General Public License for more details. # # You should have received a copy of the GNU Lesser General Public # License along with this library; if not, see <http://www.gnu.org/licenses/>. import sys from . import _gi # Callable went away in python 3.0 and came back in 3.2. # Use versioning to figure out when to define it, otherwise we have to deal with # the complexity of using __builtin__ or builtin between python versions to # check if callable exists which PyFlakes will also complain about. if (3, 0) <= sys.version_info < (3, 2): def callable(fn): return hasattr(fn, '__call__') class Signal(str): """Object which gives a nice API for creating and binding signals. :param name: Name of signal or callable closure when used as a decorator. :type name: str or callable :param callable func: Callable closure method. :param GObject.SignalFlags flags: Flags specifying when to run closure. :param type return_type: Return type of the Signal. :param list arg_types: List of argument types specifying the signals function signature :param str doc: Documentation of signal object. :param callable accumulator: Accumulator method with the signature: func(ihint, return_accu, handler_return, accu_data) -> boolean :param object accu_data: User data passed to the accumulator. :Example: .. code-block:: python class Spam(GObject.Object): velocity = 0 @GObject.Signal def pushed(self): self.velocity += 1 @GObject.Signal(flags=GObject.SignalFlags.RUN_LAST) def pulled(self): self.velocity -= 1 stomped = GObject.Signal('stomped', arg_types=(int,)) @GObject.Signal def annotated_signal(self, a:int, b:str): "Python3 annotation support for parameter types. def on_pushed(obj): print(obj) spam = Spam() spam.pushed.connect(on_pushed) spam.pushed.emit() """ class BoundSignal(str): """ Temporary binding object which can be used for connecting signals without specifying the signal name string to connect. """ def __new__(cls, name, *args, **kargs): return str.__new__(cls, name) def __init__(self, signal, gobj): str.__init__(self) self.signal = signal self.gobj = gobj def __repr__(self): return 'BoundSignal("%s")' % self def __call__(self, *args, **kargs): """Call the signals closure.""" return self.signal.func(self.gobj, *args, **kargs) def connect(self, callback, *args, **kargs): """Same as GObject.Object.connect except there is no need to specify the signal name.""" return self.gobj.connect(self, callback, *args, **kargs) def connect_detailed(self, callback, detail, *args, **kargs): """Same as GObject.Object.connect except there is no need to specify the signal name. In addition concats "::<detail>" to the signal name when connecting; for use with notifications like "notify" when a property changes. """ return self.gobj.connect(self + '::' + detail, callback, *args, **kargs) def disconnect(self, handler_id): """Same as GObject.Object.disconnect.""" self.instance.disconnect(handler_id) def emit(self, *args, **kargs): """Same as GObject.Object.emit except there is no need to specify the signal name.""" return self.gobj.emit(str(self), *args, **kargs) def __new__(cls, name='', *args, **kargs): if callable(name): name = name.__name__ return str.__new__(cls, name) def __init__(self, name='', func=None, flags=_gi.SIGNAL_RUN_FIRST, return_type=None, arg_types=None, doc='', accumulator=None, accu_data=None): if func and not name: name = func.__name__ elif callable(name): func = name name = func.__name__ if func and not doc: doc = func.__doc__ str.__init__(self) if func and not (return_type or arg_types): return_type, arg_types = get_signal_annotations(func) if arg_types is None: arg_types = tuple() self.func = func self.flags = flags self.return_type = return_type self.arg_types = arg_types self.__doc__ = doc self.accumulator = accumulator self.accu_data = accu_data def __get__(self, instance, owner=None): """Returns a BoundSignal when accessed on an object instance.""" if instance is None: return self return self.BoundSignal(self, instance) def __call__(self, obj, *args, **kargs): """Allows for instantiated Signals to be used as a decorator or calling of the underlying signal method.""" # If obj is a GObject, than we call this signal as a closure otherwise # it is used as a re-application of a decorator. if isinstance(obj, _gi.GObject): self.func(obj, *args, **kargs) else: # If self is already an allocated name, use it otherwise create a new named # signal using the closure name as the name. if str(self): name = str(self) else: name = obj.__name__ # Return a new value of this type since it is based on an immutable string. return type(self)(name=name, func=obj, flags=self.flags, return_type=self.return_type, arg_types=self.arg_types, doc=self.__doc__, accumulator=self.accumulator, accu_data=self.accu_data) def copy(self, newName=None): """Returns a renamed copy of the Signal.""" if newName is None: newName = self.name return type(self)(name=newName, func=self.func, flags=self.flags, return_type=self.return_type, arg_types=self.arg_types, doc=self.__doc__, accumulator=self.accumulator, accu_data=self.accu_data) def get_signal_args(self): """Returns a tuple of: (flags, return_type, arg_types, accumulator, accu_data)""" return (self.flags, self.return_type, self.arg_types, self.accumulator, self.accu_data) class SignalOverride(Signal): """Specialized sub-class of Signal which can be used as a decorator for overriding existing signals on GObjects. :Example: .. code-block:: python class MyWidget(Gtk.Widget): @GObject.SignalOverride def configure_event(self): pass """ def get_signal_args(self): """Returns the string 'override'.""" return 'override' def get_signal_annotations(func): """Attempt pulling python 3 function annotations off of 'func' for use as a signals type information. Returns an ordered nested tuple of (return_type, (arg_type1, arg_type2, ...)). If the given function does not have annotations then (None, tuple()) is returned. """ arg_types = tuple() return_type = None if hasattr(func, '__annotations__'): # import inspect only when needed because it takes ~10 msec to load import inspect spec = inspect.getfullargspec(func) arg_types = tuple(spec.annotations[arg] for arg in spec.args if arg in spec.annotations) if 'return' in spec.annotations: return_type = spec.annotations['return'] return return_type, arg_types def install_signals(cls): """Adds Signal instances on a GObject derived class into the '__gsignals__' dictionary to be picked up and registered as real GObject signals. """ gsignals = cls.__dict__.get('__gsignals__', {}) newsignals = {} for name, signal in cls.__dict__.items(): if isinstance(signal, Signal): signalName = str(signal) # Fixup a signal which is unnamed by using the class variable name. # Since Signal is based on string which immutable, # we must copy and replace the class variable. if not signalName: signalName = name signal = signal.copy(name) setattr(cls, name, signal) if signalName in gsignals: raise ValueError('Signal "%s" has already been registered.' % name) newsignals[signalName] = signal gsignals[signalName] = signal.get_signal_args() cls.__gsignals__ = gsignals # Setup signal closures by adding the specially named # method to the class in the form of "do_<signal_name>". for name, signal in newsignals.items(): if signal.func is not None: funcName = 'do_' + name.replace('-', '_') if not hasattr(cls, funcName): setattr(cls, funcName, signal.func)