Walker::paged_walk( array $elements, int $max_depth, int $page_num, int $per_page, mixed $args ): string

292	public function paged_walk( $elements, $max_depth, $page_num, $per_page, ...$args ) {293		$output = '';294 295		$max_depth = (int) $max_depth;296 297		if ( empty( $elements ) || $max_depth < -1 ) {298			return $output;299		}300 301		$parent_field = $this->db_fields['parent'];302 303		$count = -1;304		if ( -1 === $max_depth ) {305			$total_top = count( $elements );306		}307		if ( $page_num < 1 || $per_page < 0 ) {308			// No paging.309			$paging = false;310			$start  = 0;311			if ( -1 === $max_depth ) {312				$end = $total_top;313			}314			$this->max_pages = 1;315		} else {316			$paging = true;317			$start  = ( (int) $page_num - 1 ) * (int) $per_page;318			$end    = $start + $per_page;319			if ( -1 === $max_depth ) {320				$this->max_pages = (int) ceil( $total_top / $per_page );321			}322		}323 324		// Flat display.325		if ( -1 === $max_depth ) {326			if ( ! empty( $args[0]['reverse_top_level'] ) ) {327				$elements = array_reverse( $elements );328				$oldstart = $start;329				$start    = $total_top - $end;330				$end      = $total_top - $oldstart;331			}332 333			$empty_array = array();334			foreach ( $elements as $e ) {335				++$count;336				if ( $count < $start ) {337					continue;338				}339				if ( $count >= $end ) {340					break;341				}342				$this->display_element( $e, $empty_array, 1, 0, $args, $output );343			}344			return $output;345		}346 347		/*348		 * Separate elements into two buckets: top level and children elements.349		 * Children_elements is two dimensional array, e.g.350		 * $children_elements[10][] contains all sub-elements whose parent is 10.351		 */352		$top_level_elements = array();353		$children_elements  = array();354		foreach ( $elements as $e ) {355			if ( empty( $e->$parent_field ) ) {356				$top_level_elements[] = $e;357			} else {358				$children_elements[ $e->$parent_field ][] = $e;359			}360		}361 362		$total_top = count( $top_level_elements );363		if ( $paging ) {364			$this->max_pages = (int) ceil( $total_top / $per_page );365		} else {366			$end = $total_top;367		}368 369		if ( ! empty( $args[0]['reverse_top_level'] ) ) {370			$top_level_elements = array_reverse( $top_level_elements );371			$oldstart           = $start;