Restore distance-based ordering

class MapView_QuasiDistanceOrdering {
    /**
     * Set up a listener to potentially re-order location based search results.
     */
    public function __construct() {
        add_action( 'tribe_events_before_view', array( $this, 'listen' ) );
    }

    /**
     * We can only reorder by distance if the query results contain distance/geodata
     * for each result.
     *
     * @param $template
     */
    public function listen( $template ) {
        global $wp_query;

        if ( empty( $wp_query->posts ) ) return;
        if ( ! $this->are_distances_assigned() ) return;

        $this->quick_sort( $wp_query->posts );
    }

    protected function are_distances_assigned() {
        global $wp_query;
        $posts_copy = $wp_query->posts;
        $test_post = array_shift( $posts_copy );
        return isset( $test_post->distance );
    }

    /**
     * Borrows quick sort implementation from previous incarnation
     * of TribeEventsGeoLoc, in turn this borrows from the referenced
     * answer on StackOverflow.
     *
     * @see http://stackoverflow.com/questions/1462503/sort-array-by-object-property-in-php
     * @param $array
     */
    protected function quick_sort( &$array ) {
        $cur           = 1;
        $stack[1]['l'] = 0;
        $stack[1]['r'] = count( $array ) - 1;

        do {
            $l = $stack[$cur]['l'];
            $r = $stack[$cur]['r'];
            $cur --;

            do {
                $i   = $l;
                $j   = $r;
                $tmp = $array[(int) ( ( $l + $r ) / 2 )];

                do {
                    /* Divide... */
                    while ( $array[$i]->distance < $tmp->distance ) {
                        $i ++;
                    }

                    while ( $tmp->distance < $array[$j]->distance ) {
                        $j --;
                    }

                    /* ...and conquer! */
                    if ( $i <= $j ) {
                        $w         = $array[$i];
                        $array[$i] = $array[$j];
                        $array[$j] = $w;

                        $i ++;
                        $j --;
                    }

                } while ( $i <= $j );

                if ( $i < $r ) {
                    $cur ++;
                    $stack[$cur]['l'] = $i;
                    $stack[$cur]['r'] = $r;
                }
                $r = $j;

            } while ( $l < $r );

        } while ( $cur != 0 );
    }
}

new MapView_QuasiDistanceOrdering;