| 1 | <?php |
||
| 5 | class NodeWalker |
||
| 6 | { |
||
| 7 | /** |
||
| 8 | * @var Node |
||
| 9 | */ |
||
| 10 | private $root; |
||
| 11 | |||
| 12 | /** |
||
| 13 | * @var Node|null |
||
| 14 | */ |
||
| 15 | private $current; |
||
| 16 | |||
| 17 | /** |
||
| 18 | * @var bool |
||
| 19 | */ |
||
| 20 | private $entering; |
||
| 21 | |||
| 22 | /** |
||
| 23 | * @param Node $root |
||
| 24 | */ |
||
| 25 | 1941 | public function __construct(Node $root) |
|
| 31 | |||
| 32 | /** |
||
| 33 | * Returns an event which contains node and entering flag |
||
| 34 | * (entering is true when we enter a Node from a parent or sibling, |
||
| 35 | * and false when we reenter it from child) |
||
| 36 | * |
||
| 37 | * @return NodeWalkerEvent|null |
||
| 38 | */ |
||
| 39 | 1941 | public function next(): ?NodeWalkerEvent |
|
| 40 | { |
||
| 41 | 1941 | $current = $this->current; |
|
| 42 | 1941 | $entering = $this->entering; |
|
| 43 | 1941 | if (null === $current) { |
|
| 44 | 1941 | return null; |
|
| 45 | } |
||
| 46 | |||
| 47 | 1941 | if ($entering && $current->isContainer()) { |
|
| 48 | 1941 | if ($current->firstChild()) { |
|
| 49 | 1935 | $this->current = $current->firstChild(); |
|
| 50 | 1935 | $this->entering = true; |
|
| 51 | } else { |
||
| 52 | 1941 | $this->entering = false; |
|
| 53 | } |
||
| 54 | 1941 | } elseif ($current === $this->root) { |
|
| 55 | 1941 | $this->current = null; |
|
| 56 | 1935 | } elseif (null === $current->next()) { |
|
| 57 | 1935 | $this->current = $current->parent(); |
|
| 58 | 1935 | $this->entering = false; |
|
| 59 | } else { |
||
| 60 | 504 | $this->current = $current->next(); |
|
| 61 | 504 | $this->entering = true; |
|
| 62 | } |
||
| 63 | |||
| 64 | 1941 | return new NodeWalkerEvent($current, $entering); |
|
| 65 | } |
||
| 66 | |||
| 67 | /** |
||
| 68 | * Resets the iterator to resume at the specified node |
||
| 69 | * |
||
| 70 | * @param Node $node |
||
| 71 | * @param bool $entering |
||
| 72 | */ |
||
| 73 | public function resumeAt(Node $node, bool $entering = true) |
||
| 78 | } |
||
| 79 |