Class Signals

java.lang.Object

org.javagi.gobject.types.Signals

@NullMarked
public class Signals
extends Object

Helper class to register signals in a new GType.

Field Summary

Fields

Modifier and Type	Field	Description
static final MethodHandle	g_signal_connect_data	The method handle for g_signal_connect_data is used by all generated signal-connection methods.
static final MethodHandle	g_signal_emit_by_name	The method handle for g_signal_emit_by_name is used by all generated signal-emission methods.

Constructor Summary

Constructors

Constructor	Description
Signals()

Method Summary

Modifier and Type	Method	Description
static @Nullable Object	emit(GObject gobject, String detailedSignal, Object... params)	Emits a signal from a GObject.
static Method	getSingleAbstractMethod(Class<?> cls)	Get the single abstract method (SAM) implementation of a functional interface.
static @Nullable Consumer<TypeClass>	installSignals(Class<?> cls)	If the provided class contains inner interface declarations with a @Signal-annotation, this function will return a class initializer that registers these declarations as GObject signals (using g_signal_newv) in the class initializer.

Methods inherited from class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

g_signal_connect_data

public static final MethodHandle g_signal_connect_data

The method handle for g_signal_connect_data is used by all generated signal-connection methods.

g_signal_emit_by_name

public static final MethodHandle g_signal_emit_by_name

The method handle for g_signal_emit_by_name is used by all generated signal-emission methods.

Constructor Details

Signals

public Signals()

Method Details

installSignals

public static @Nullable Consumer<TypeClass> installSignals(Class<?> cls)

If the provided class contains inner interface declarations with a @Signal-annotation, this function will return a class initializer that registers these declarations as GObject signals (using g_signal_newv) in the class initializer.

Parameters:

cls - the class that possibly contains @Signal annotations

Returns:

a class initializer that registers the signals

emit

public static @Nullable Object emit(GObject gobject,
 String detailedSignal,
 Object... params)

Emits a signal from a GObject.

Parameters:

gobject - the object that emits the signal

detailedSignal - a string of the form "signal-name::detail"

params - the parameters to emit for this signal

Returns:

the return value of the signal, or null if the signal has no return value

Throws:

IllegalArgumentException - if a signal with this name is not found for the object

getSingleAbstractMethod

public static Method getSingleAbstractMethod(Class<?> cls)
                                      throws IllegalArgumentException

Get the single abstract method (SAM) implementation of a functional interface. A functional interface has exactly one abstract method.

Parameters:

cls - a functional interface

Returns:

the Method reference to the method that implements the SAM

Throws:

IllegalArgumentException - if cls is not a functional interface