[gtkmm] Gtk::Widget: reparent() takes a Container&

[Kjell Ahlstedt <kjellahl src gnome org>]

commit 24059c5adf1cc990b5c006eeb2dfd23d4d4ea98f
Author: Kjell Ahlstedt <kjell ahlstedt bredband net>
Date:   Sun Nov 13 15:46:17 2016 +0100

    Gtk::Widget: reparent() takes a Container&

 gtk/src/widget.ccg |   16 ++++++----------
 gtk/src/widget.hg  |    5 ++---
 2 files changed, 8 insertions(+), 13 deletions(-)
---
diff --git a/gtk/src/widget.ccg b/gtk/src/widget.ccg
index b96e44a..a1ff8cb 100644
--- a/gtk/src/widget.ccg
+++ b/gtk/src/widget.ccg
@@ -277,20 +277,16 @@ void Widget_Class::measure_vfunc_callback(GtkWidget* self, GtkOrientation orient
 Widget::~Widget() noexcept
 {}
 
-void Widget::reparent(Widget& new_parent)
+void Widget::reparent(Container& new_parent)
 {
-  //TODO: When 'Widget& new_parent' is changed to 'Container& new_parent',
-  // remove the next two statements.
-  auto new_container = dynamic_cast<Container*>(&new_parent);
-  g_return_if_fail(new_container != nullptr); // if new_parent is not a Container
-  auto old_container = get_parent();
-  g_return_if_fail(old_container != nullptr); // if the widget is not in a Container
-
-  if (old_container != new_container)
+  auto old_parent = get_parent();
+  g_return_if_fail(old_parent != nullptr); // if the widget is not in a Container
+
+  if (old_parent != &new_parent)
   {
     reference();
-    old_container->remove(*this);
-    new_container->add(*this);
+    old_parent->remove(*this);
+    new_parent.add(*this);
     unreference();
   }
 }
diff --git a/gtk/src/widget.hg b/gtk/src/widget.hg
index 3aa1f3c..748c1b8 100644
--- a/gtk/src/widget.hg
+++ b/gtk/src/widget.hg
@@ -162,14 +162,13 @@ public:
   _WRAP_METHOD(bool send_focus_change(GdkEvent* gdk_event), gtk_widget_send_focus_change)
   _WRAP_METHOD(bool activate(), gtk_widget_activate)
 
-  //TODO: When we can break ABI/API, change to void reparent(Container& new_parent).
-  // gtk_widget_reparent() is deprecated, but we want to keep Gtk::Widget::reparent().
+  // gtk_widget_reparent() has been removed, but we want to keep Gtk::Widget::reparent().
   /** Moves a widget from one Gtk::Container to another, handling reference
    * count issues to avoid destroying the widget.
    *
    * @param new_parent A Gtk::Container to move the widget into.
    */
-  void reparent(Widget& new_parent);
+  void reparent(Container& new_parent);
 
   bool intersect(const Gdk::Rectangle& area) const;
   _WRAP_METHOD(bool intersect(const Gdk::Rectangle& area, Gdk::Rectangle& intersection) const, 
gtk_widget_intersect)