SceneGraph: added Object::move().

doc/changelog.dox

@@ -66,6 +66,10 @@ See also:
 -   Added @ref Math::fmod() (see [mosra/magnum#454](https://github.com/mosra/magnum/pull/454))
 -   Added @ref Math::binomialCoefficient() (see [mosra/magnum#461](https://github.com/mosra/magnum/pull/461))
 
+@subsubsection changelog-latest-new-scenegraph SceneGraph library
+
+-   Added @ref SceneGraph::Object::move()
+
 @subsection changelog-latest-changes Changes and improvements
 
 @subsubsection changelog-latest-changes-gl GL library

src/Magnum/SceneGraph/Object.h

@@ -157,6 +157,23 @@ template<class Transformation> class Object: public AbstractObject<Transformatio
             return Containers::LinkedListItem<Object<Transformation>, Object<Transformation>>::list();
         }
 
+        /**
+         * @brief Move a child object before another
+         * @return Reference to self (for method chaining)
+         * @m_since_latest
+         *
+         * Doesn't have any effect on draw order, only on the child order when
+         * iterating through @ref children(). The @p child is expected to be a
+         * child of this object, @p before is either a child of this object or
+         * @cpp nullptr @ce in which case the @p child is moved to the last
+         * position in the child list.
+         * @see @ref Corrade::Containers::LinkedList::move()
+         */
+        Object<Transformation>& move(Object<Transformation>& child, Object<Transformation>* before) {
+            Containers::LinkedList<Object<Transformation>>::move(&child, before);
+            return *this;
+        }
+
         /** @brief Previous sibling object or `nullptr`, if this is the first object */
         Object<Transformation>* previousSibling() {
             return Containers::LinkedListItem<Object<Transformation>, Object<Transformation>>::previous();

src/Magnum/SceneGraph/Test/ObjectTest.cpp

@@ -40,6 +40,7 @@ struct ObjectTest: TestSuite::Tester {
 
     void parenting();
     void addChild();
+    void move();
     void scene();
     void setParentKeepTransformation();
     void setParentKeepTransformationInvalid();
@@ -78,6 +79,7 @@ ObjectTest::ObjectTest() {
 
               &ObjectTest::parenting,
               &ObjectTest::addChild,
+              &ObjectTest::move,
               &ObjectTest::scene,
               &ObjectTest::setParentKeepTransformation,
               &ObjectTest::setParentKeepTransformationInvalid,
@@ -154,6 +156,27 @@ void ObjectTest::addChild() {
     CORRADE_COMPARE(p.parent(), &o);
 }
 
+void ObjectTest::move() {
+    Scene3D scene;
+    Object3D* a = new Object3D{&scene};
+    Object3D* b = new Object3D{&scene};
+    Object3D* c = new Object3D{&scene};
+
+    CORRADE_COMPARE(a->nextSibling(), b);
+    CORRADE_COMPARE(b->nextSibling(), c);
+    CORRADE_COMPARE(c->nextSibling(), nullptr);
+
+    scene.move(*a, c);
+    CORRADE_COMPARE(b->nextSibling(), a);
+    CORRADE_COMPARE(a->nextSibling(), c);
+    CORRADE_COMPARE(c->nextSibling(), nullptr);
+
+    scene.move(*a, nullptr);
+    CORRADE_COMPARE(b->nextSibling(), c);
+    CORRADE_COMPARE(c->nextSibling(), a);
+    CORRADE_COMPARE(a->nextSibling(), nullptr);
+}
+
 void ObjectTest::scene() {
     Scene3D scene;
     CORRADE_VERIFY(scene.scene() == &scene);