<?php

/** Internal class for Object, ignore this **/
class Connection
{
    public $slot;
    public $receiver;
}

/** Implements the signalling system */
abstract class FwObject
{
    private $signalsBlocked = false;

    // holds connections for this.
    private $connections = array();

    public function __construct()
    {
    }

    /**
     * Emit the signal.
     *
     * No guarantee on which order slots are called in.
     */
    public function emit( $signal )
    {
        // check if any signals exist and that signals are not blocked
        if( $this->signalsBlocked === false && isset( $this->connections[$signal] ) )
        {
            // fetch parameters, remove the signal part
            $args = func_get_args();
            unset( $args[0] );

            foreach( $this->connections[$signal] as $c )
            {
                call_user_func_array( array( $c->receiver, $c->slot ), $args );
            }
        }
    }

    /**
     * Connects a signal to a slot.
     *
     * TODO: add some sort of type safety to this system
     * also add check that the slot really exists.
     * if we want to check if the signal exists we need some system to
     * retrieve all the signals. Do we want that?
     */
    public function connect( $signal, Object $receiver, $slot )
    {
        if( !isset( $this->connections[$signal] ) )
        {
            $this->connections[$signal] = array();
        }
        $c = new Connection();
        $c->slot = $slot;
        $c->receiver = $receiver;
        $this->connections[$signal][] = $c;
    }

    public function disconnect( $signal, Object $receiver, $slot )
    {
        if( !isset( $this->connections[$signal] ) )
        {
            // TODO: warning, no such found
            return;
        }

        foreach( $this->connections[$signal] as $counter => $connection )
        {
            if( $slot == $connection->slot )
            {
                unset( $this->connections[$signal][$counter] );
                return;
            }
        }
        // TODO: warning, no such found
    }

    public function blockSignals( $blockSignals )
    {
        $this->signalsBlocked = $blockSignals;
    }

    public function signalsBlocked()
    {
        return $this->signalsBlocked;
    }
}

?>