Correctly position the contrast level bar

src/contrast_level.rs

@@ -93,7 +93,6 @@ impl ChartBarWidget {
         let column = widget.upcast::<gtk::Widget>();
         let column = column.downcast::<gtk::Container>().unwrap();
         column.add(overlay);
-        column.set_margin_bottom(24);
         column.show();
 
         let weak_instance = Rc::downgrade(&s).clone();
@@ -166,6 +165,7 @@ impl ContrastLevelBar {
 
     fn init(&mut self) {
         self.widget.set_halign(gtk::Align::Fill);
+        self.widget.set_valign(gtk::Align::Center);
         self.widget.set_vexpand(true);
         self.widget.get_style_context().add_class("level-box");
 
@@ -177,6 +177,7 @@ impl ContrastLevelBar {
 
         self.level_label.get_style_context().add_class("level-label");
         self.level_label.set_halign(gtk::Align::Center);
+        self.level_label.set_valign(gtk::Align::Start);
         self.level_label.show();
         self.widget.pack_start(&self.level_label, false, false, 0);
 

src/window.rs

@@ -144,8 +144,8 @@ impl Window {
         entries_container.show();
         self.headerbar.set_custom_title(Some(&entries_container));
 
-        container.pack_start(&self.preview.borrow().widget, true, true, 18);
-        container.pack_start(&self.levelbar.borrow().widget, false, false, 18);
+        container.pack_start(&self.preview.borrow().widget, true, true, 24);
+        container.pack_start(&self.levelbar.borrow().widget, true, true, 24);
 
         self.widget.add(&container);
         // Restore state