Emits a signal. Signal emission is done synchronously. The method will only return control after all handlers are called or signal emission was stopped.
g_signal_emit_valist() resets the return value to the default
if no handlers are connected, in contrast to g_signal_emitv().
This function is not directly available to language bindings.
The instance the signal is being emitted on.
The data is owned by the caller of the function.
The signal id.
A list of parameters to be passed to the signal, followed by a location for the return value. If the return type of the signal is
G_TYPE_NONE, the return value location can be omitted.