LibCore: Make CObject reference-counted

Okay, I've spent a whole day on this now, and it finally kinda works!
With this patch, CObject and all of its derived classes are reference
counted instead of tree-owned.

The previous, Qt-like model was nice and familiar, but ultimately also
outdated and difficult to reason about.

CObject-derived types should now be stored in RefPtr/NonnullRefPtr and
each class can be constructed using the forwarding construct() helper:

    auto widget = GWidget::construct(parent_widget);

Note that construct() simply forwards all arguments to an existing
constructor. It is inserted into each class by the C_OBJECT macro,
see CObject.h to understand how that works.

CObject::delete_later() disappears in this patch, as there is no longer
a single logical owner of a CObject.

1 files changed, 1 insertions, 1 deletions

diff --git a/Demos/WidgetGallery/main.cpp b/Demos/WidgetGallery/main.cpp
index 3e7c9af88f..4e2c1c4017 100755
--- a/Demos/WidgetGallery/main.cpp
+++ b/Demos/WidgetGallery/main.cpp
@@ -66,7 +66,7 @@ int main(int argc, char** argv)
     auto spinbox2 = GSpinBox::construct(main_widget);
     spinbox2->set_enabled(false);
 
-    auto vertical_slider_container = GWidget::construct(main_widget);
+    auto vertical_slider_container = GWidget::construct(main_widget.ptr());
     vertical_slider_container->set_size_policy(SizePolicy::Fill, SizePolicy::Fixed);
     vertical_slider_container->set_preferred_size(0, 100);
     vertical_slider_container->set_layout(make<GBoxLayout>(Orientation::Horizontal));