<?php
class Signaler {
	private $_listeners = array();
	protected static $current = false;
	
	static public function connect(Signaler &$emitter, $signal, &$responder, $slot) {
		if( !is_object($responder) ) {
			return false;
		}
		elseif( !method_exists($responder, $slot) ) {
			return false;
		}
		if( !array_key_exists($signal, $emitter->_listeners) ) {
			$emitter->_listeners[$signal] = array();
		}
		$emitter->_listeners[$signal][] = array(
			'object' => &$responder,
			'method' => $slot
		);
	}
	protected function emit() {
		self::$current = &$this;
		$args = func_get_args();
		if( count($args)  == 0 ) {
			// Called without any arguments, raise an error
			return false;
		}
		$signal = array_shift($args);
		$sent = 0;
		if( array_key_exists($signal, $this->_listeners) ) {
			foreach( $this->_listeners[$signal] as $key => $listener ) {
				if(
					!is_object($listener['object'])
					|| !method_exists($listener['object'], $listener['method'])
				) {
					// Something happened to the object since it was connected,
					// and it is no longer usable. Drop it.
					unset($this->_listeners[$key]);
				} else {
					// Everything's good, set the callback loose.
					$result = call_user_func_array(array($listener['object'], $listener['method']), $args);
					if( $result !== false ) {
						$sent++;
					}
				}
			}
		}
		// Special signal for debugging purposes
		if( $signal !== '__emit' ) { $this->emit('__emit', $signal, $args); }
		return $sent;
	}
}
?>