lib: Add Data/Tree/Node.php

library/Icinga/Data/Tree/Node.php

@@ -0,0 +1,62 @@
+<?php
+// {{{ICINGA_LICENSE_HEADER}}}
+// {{{ICINGA_LICENSE_HEADER}}}
+
+namespace Icinga\Data\Tree;
+
+use RecursiveIteratorIterator;
+use RuntimeException;
+use SplDoublyLinkedList;
+
+class Node extends SplDoublyLinkedList implements NodeInterface
+{
+    protected $value;
+
+    public function __construct($value = null)
+    {
+        $this->value = $value;
+    }
+
+    public function getValue()
+    {
+        return $this->value;
+    }
+
+    public function appendChild($value)
+    {
+        $child = new static($value);
+        $this->push($child);
+        return $child;
+    }
+
+    public function hasChildren()
+    {
+        $current = $this->current();
+        if ($current === null) {;
+            $current = $this;
+        }
+        return ! $current->isEmpty();
+    }
+
+    public function getChildren()
+    {
+        $current = $this->current();
+        if ($current === null) {;
+            $current = $this;
+        }
+        return $current;
+    }
+
+    public function findNodeBy($callback)
+    {
+        if (! is_callable($callback)) {
+            throw new RuntimeException();
+        }
+        foreach (new RecursiveIteratorIterator($this, RecursiveIteratorIterator::SELF_FIRST) as $node) {
+            if (call_user_func($callback, $node)) {
+                return $node;
+            }
+        }
+        return null;
+    }
+}