Add support for adding children at specific index

See #51.
meyfa · Mar 21, 2018 · 9e50562 · 9e50562
1 parent 770f1e8
commit 9e50562
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Showing 2 changed files with 22 additions and 6 deletions.
diff --git a/src/Nodes/SVGNodeContainer.php b/src/Nodes/SVGNodeContainer.php
@@ -28,14 +28,16 @@ public function __construct()
     }
 
     /**
-     * Adds an SVGNode instance to the end of this container's child list.
-     * Does nothing if it already exists.
+     * Inserts an SVGNode instance at the given index, or, if no index is given,
+     * at the end of the child list.
+     * Does nothing if the node already exists in this container.
      *
-     * @param SVGNode $node The node to add to this container's children.
+     * @param SVGNode $node  The node to add to this container's children.
+     * @param int     $index The position to insert at (optional).
      *
      * @return $this This node instance, for call chaining.
      */
-    public function addChild(SVGNode $node)
+    public function addChild(SVGNode $node, $index = null)
     {
         if ($node === $this || $node->parent === $this) {
             return $this;
@@ -45,8 +47,11 @@ public function addChild(SVGNode $node)
             $node->parent->removeChild($node);
         }
 
-        $this->children[] = $node;
-        $node->parent     = $this;
+        $index = ($index !== null) ? $index : count($this->children);
+
+        // insert and set new parent
+        array_splice($this->children, $index, 0, array($node));
+        $node->parent = $this;
 
         if ($node instanceof SVGStyle) {
             // if node is SVGStyle then add rules to container's style

diff --git a/tests/Nodes/SVGNodeContainerTest.php b/tests/Nodes/SVGNodeContainerTest.php
@@ -19,7 +19,10 @@ public function testAddChild()
     {
         $obj = new SVGNodeContainerSubclass();
         $obj2 = new SVGNodeContainerSubclass();
+
         $child = new SVGNodeContainerSubclass();
+        $child2 = new SVGNodeContainerSubclass();
+        $child3 = new SVGNodeContainerSubclass();
 
         // should add the child
         $obj->addChild($child);
@@ -45,6 +48,14 @@ public function testAddChild()
         $this->assertSame($obj, $obj->addChild($child));
         $this->assertSame($obj, $obj->addChild($child));
         $this->assertSame($obj, $obj->addChild($obj));
+
+        // should add at the given position
+        $obj->addChild($child, 0);
+        $obj->addChild($child2, 0);
+        $obj->addChild($child3, 2);
+        $this->assertSame($child2, $obj->getChild(0));
+        $this->assertSame($child, $obj->getChild(1));
+        $this->assertSame($child3, $obj->getChild(2));
     }
 
     public function testRemoveChild()