LibGUI: Some more convenience functions for constructing widgets

This patch adds two new API's:

- WidgetType& GUI::Window::set_main_widget<WidgetType>();

  This creates a new main widget for a window, assigns it, and returns
  it to you as a WidgetType&.

- LayoutType& GUI::Widget::set_layout<LayoutType>();

  Same basic idea, creates a new layout, assigns it, and returns it to
  you as a LayoutType&.

1 files changed, 8 insertions, 0 deletions

diff --git a/Libraries/LibGUI/Window.h b/Libraries/LibGUI/Window.h
index 65db147a96..c056637c50 100644
--- a/Libraries/LibGUI/Window.h
+++ b/Libraries/LibGUI/Window.h
@@ -125,6 +125,14 @@ public:
     const Widget* main_widget() const { return m_main_widget; }
     void set_main_widget(Widget*);
 
+    template<class T, class... Args>
+    inline T& set_main_widget(Args&&... args)
+    {
+        auto widget = T::construct(forward<Args>(args)...);
+        set_main_widget(widget.ptr());
+        return *widget;
+    }
+
     Widget* focused_widget() { return m_focused_widget; }
     const Widget* focused_widget() const { return m_focused_widget; }
     void set_focused_widget(Widget*);