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, 1 insertions, 2 deletions

diff --git a/Applications/Calculator/main.cpp b/Applications/Calculator/main.cpp
index 6b166c5e25..772564f4a4 100644
--- a/Applications/Calculator/main.cpp
+++ b/Applications/Calculator/main.cpp
@@ -60,8 +60,7 @@ int main(int argc, char** argv)
     window->set_resizable(false);
     window->set_rect({ 300, 200, 254, 213 });
 
-    auto calc_widget = CalculatorWidget::construct();
-    window->set_main_widget(calc_widget);
+    window->set_main_widget<CalculatorWidget>();
 
     window->show();
     window->set_icon(Gfx::Bitmap::load_from_file("/res/icons/16x16/app-calculator.png"));