zim.signals.SignalEmitter

class documentation

Replacement for GObject to make objects emit signals. API should be (mostly) compatible with API offered by GObject.

Supported signals need to be defined in the dict __signals__. For each signal a 3-tuple is provided where the first argument is either SIGNAL_RUN_FIRST or SIGNAL_RUN_LAST, the second is the return argument (or None for most signals) and the third is the argument spec for the signal.

When a signal is emitted all handlers are called one by one and exceptions in a handler are intercepted. If the class defines a method do_signalname() (where "signalname" is the name of the signal with "-" replaced by "_") this is considered a default handler that is automatically connected. The SIGNAL_RUN_FIRST and SIGNAL_RUN_LAST flags in the signal spec control where in the emission sequence this default handler is called: it either runs as the first or as the last handler. Typically the default handler is used to implement the change signalled by the signal. So if your signal name suggests something happened already (e.g. "changed"), probably you want to use SIGNAL_RUN_FIRST. However if the action is phrased as still happening (e.g. "change") and the handlers can influence this, you probably want SIGNAL_RUN_LAST.

Signals connected with connect_after() always run after all the normal handlers (which are connected with connect()) and after the default handler (even if the default handler is setup with SIGNAL_RUN_LAST).

If a signal defines a return type, emission should use either emit_return_first() or emit_return_iter() to handle return values.

(Also see the Glib documentation to understand the full system of which we implement a sub-set here.)

Method	`__new__`	Undocumented
Method	`block_signals`	Returns a context manager for blocking one or more signals
Method	`connect`	Register a handler for a specific object.
Method	`connect_after`	Like `connect()` but handler will be called after default handler
Method	`disconnect`	Undocumented
Method	`emit`	Undocumented
Method	`emit_return_first`	Emits a signal and stops emission on the first handler that returns a not-None value.
Method	`emit_return_iter`	Returns an generator that calls one handler on each iteration and yields the return values. This allows aggregating return values.
Class Variable	`__signals__`	Undocumented
Method	`_connect`	Undocumented
Method	`_setup_signal`	Undocumented
Method	`_teardown_signal`	Undocumented

def __new__(cls, *arg, **kwarg): (source)

Undocumented

def block_signals(self, *signals): (source)

Returns a context manager for blocking one or more signals

def connect(self, signal, handler): (source)

Note that connecting makes a hard reference to the connected object. So connecting an bound method will prevent the object the method belongs to to be destroyed until the signal is disconnected.

Parameters
signal	the signal name
handler	callback to be called upon the signal, first object to the callback will be the emitting object, other params are signal specific.
Returns
an id for the registered handler

def connect_after(self, signal, handler): (source)

Like connect() but handler will be called after default handler

def disconnect(self, handlerid): (source)

Undocumented

def emit(self, signal, *args): (source)

Undocumented

def emit_return_first(self, signal, *args): (source)

Emits a signal and stops emission on the first handler that returns a not-None value.

def emit_return_iter(self, signal, *args): (source)

Returns an generator that calls one handler on each iteration and yields the return values. This allows aggregating return values.

__signals__: dict = (source)

overridden in zim.config.dicts.ControlledDict, zim.config.manager.ConfigFile, zim.fs.FSObjectMonitor, zim.fs.FSSingletonClass, zim.gui.customtools.CustomToolManager, zim.history.History, zim.newfs.helpers.FileTreeWatcher, zim.newfs.helpers.FSObjectMonitor, zim.notebook.index.base.IndexerBase, zim.notebook.index.files.FilesIndexer, zim.notebook.index.Index, zim.notebook.index.IndexUpdateIter, zim.notebook.notebook.Notebook, zim.notebook.operations.NotebookOperation, zim.notebook.page.Page, zim.plugins.base.imagegenerator.ImageGeneratorModel, zim.plugins.ExtensionBase, zim.plugins.InsertedObjectTypeMap, zim.plugins.PluginManagerClass, zim.plugins.tableeditor.TableModel, zim.plugins.trayicon.AppIndicatorTrayIcon, zim.templates.Template

Undocumented

def _connect(self, category, signal, callback): (source)

Undocumented

def _setup_signal(self, signal): (source)

overridden in zim.fs.FSObjectMonitor, zim.newfs.helpers.FSObjectMonitor

Undocumented

def _teardown_signal(self, signal): (source)

overridden in zim.fs.FSObjectMonitor, zim.newfs.helpers.FSObjectMonitor

Undocumented