How to create a new G Signal ?

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Hello,

My attempt to answer the question :

define("g_signal_id", 0);// hack to assign dynamic value to invariant const ZOOMED

class MyObject extends GObject {
	/**
	 * @g_signal_new("zoomed",
	 *               self,
	 *               G_SIGNAL_RUN_LAST,
	 *               NULL, NULL, NULL,
	 *               G_TYPE_INT, 1, G_TYPE_INT)
	 */
	const ZOOMED = g_signal_id;// internal hack : change constant ZOOMED value
	protected $zoom = 100;

	function setZoom($value) {
		$this->zoom = $value;
		g_signal_emit($this, self::ZOOMED, 0, $ret);
	}
}

$object = new MyObject();
g_object_connect($object, "signal::zoomed", function(int):int{ echo "callback"; return 0;}, NULL, NULL);
//g_signal_connect($object, "zoomed", function(int):int{ echo "callback"; return 0;}, NULL);
$object->setZoom(51);

Output:
callback

What do you think ?