Save the views as their original widgets

This allows me to directly reference functions that occur on those
widgets without losing them behind a gtk::Widget upcast or needing to
later downcast them.

fitnesstrax/app/src/app_window.rs

@@ -87,7 +87,7 @@ impl AppWindow {
         let initial_view = View::Placeholder(PlaceholderView::new().upcast());
 
         layout.append(&header);
-        layout.append(initial_view.widget());
+        layout.append(&initial_view.widget());
 
         window.set_content(Some(&layout));
         window.present();
@@ -130,9 +130,9 @@ impl AppWindow {
     // position.
     fn swap_main(&self, view: View) {
         let mut current_widget = self.current_view.borrow_mut();
-        self.layout.remove(&*current_widget.widget());
+        self.layout.remove(&current_widget.widget());
         *current_widget = view;
-        self.layout.append(&*current_widget.widget());
+        self.layout.append(&current_widget.widget());
     }
 
     fn construct_view(&self, view: ViewName) -> View {

fitnesstrax/app/src/views/mod.rs

@@ -14,6 +14,8 @@ General Public License for more details.
 You should have received a copy of the GNU General Public License along with FitnessTrax. If not, see <https://www.gnu.org/licenses/>.
 */
 
+use gtk::prelude::*;
+
 mod historical_view;
 pub use historical_view::HistoricalView;
 
@@ -30,17 +32,17 @@ pub enum ViewName {
 }
 
 pub enum View {
-    Placeholder(gtk::Widget),
-    Welcome(gtk::Widget),
-    Historical(gtk::Widget),
+    Placeholder(PlaceholderView),
+    Welcome(WelcomeView),
+    Historical(HistoricalView),
 }
 
 impl View {
-    pub fn widget<'a>(&'a self) -> &'a gtk::Widget {
+    pub fn widget(&self) -> gtk::Widget {
         match self {
-            View::Placeholder(widget) => widget,
-            View::Welcome(widget) => widget,
-            View::Historical(widget) => widget,
+            View::Placeholder(widget) => widget.clone().upcast::<gtk::Widget>(),
+            View::Welcome(widget) => widget.clone().upcast::<gtk::Widget>(),
+            View::Historical(widget) => widget.clone().upcast::<gtk::Widget>(),
         }
     }
 }