ShowsView: Retain vertical scrolling adjustment upon view refresh.

hammond-gtk/resources/gtk/shows_view.ui

@@ -3,16 +3,18 @@
 <interface>
   <requires lib="gtk+" version="3.20"/>
   <object class="GtkBox" id="fb_parent">
+    <property name="name">fb_parent</property>
     <property name="visible">True</property>
     <property name="can_focus">False</property>
     <property name="orientation">vertical</property>
     <child>
-      <object class="GtkScrolledWindow">
+      <object class="GtkScrolledWindow" id="scrolled_window">
+        <property name="name">scrolled_window</property>
         <property name="visible">True</property>
         <property name="can_focus">True</property>
         <property name="shadow_type">in</property>
         <child>
-          <object class="GtkViewport" id="viewport">
+          <object class="GtkViewport">
             <property name="visible">True</property>
             <property name="can_focus">False</property>
             <child>

hammond-gtk/src/content.rs

@@ -111,9 +111,31 @@ impl ShowStack {
 
     pub fn update_podcasts(&self) {
         let vis = self.stack.get_visible_child_name().unwrap();
-        let old = self.stack.get_child_by_name("podcasts").unwrap();
+
+        let old = self.stack
+            .get_child_by_name("podcasts")
+            // This is guaranted to exists, based on `ShowStack::new()`.
+            .unwrap()
+            .downcast::<gtk::Box>()
+            // This is guaranted to be a Box based on the `ShowsPopulated` impl.
+            .unwrap();
+        debug!("Name: {:?}", WidgetExt::get_name(&old));
+
+        let scrolled_window = old.get_children()
+            .first()
+            // This is guaranted to exist based on the show_widget.ui file.
+            .unwrap()
+            .clone()
+            .downcast::<gtk::ScrolledWindow>()
+            // This is guaranted based on the show_widget.ui file.
+            .unwrap();
+        debug!("Name: {:?}", WidgetExt::get_name(&scrolled_window));
 
         let pop = ShowsPopulated::new(Arc::new(self.clone()), self.sender.clone());
+        // Copy the vertical scrollbar adjustment from the old view into the new one.
+        scrolled_window
+            .get_vadjustment()
+            .map(|x| pop.set_vadjustment(&x));
 
         self.stack.remove(&old);
         self.stack.add_named(&pop.container, "podcasts");
@@ -132,10 +154,10 @@ impl ShowStack {
     pub fn replace_widget(&self, pd: &Podcast) {
         let old = self.stack
             .get_child_by_name("widget")
-            // This is guaranted to exists, based on ShowStack::new().
+            // This is guaranted to exists, based on `ShowStack::new()`.
             .unwrap()
             .downcast::<gtk::Box>()
-            // This is guaranted to be a Box based on the ShowWidget impl.
+            // This is guaranted to be a Box based on the `ShowWidget` impl.
             .unwrap();
         debug!("Name: {:?}", WidgetExt::get_name(&old));
 
@@ -218,10 +240,10 @@ impl EpisodeStack {
     pub fn update(&self) {
         let old = self.stack
             .get_child_by_name("episodes")
-            // This is guaranted to exists, based on EpisodeStack::new().
+            // This is guaranted to exists, based on `EpisodeStack::new()`.
             .unwrap()
             .downcast::<gtk::Box>()
-            // This is guaranted to be a Box based on the EpisodesView impl.
+            // This is guaranted to be a Box based on the `EpisodesView` impl.
             .unwrap();
         debug!("Name: {:?}", WidgetExt::get_name(&old));
 

hammond-gtk/src/views/shows.rs

@@ -15,21 +15,21 @@ use std::sync::Arc;
 #[derive(Debug, Clone)]
 pub struct ShowsPopulated {
     pub container: gtk::Box,
+    scrolled_window: gtk::ScrolledWindow,
     flowbox: gtk::FlowBox,
-    viewport: gtk::Viewport,
 }
 
 impl Default for ShowsPopulated {
     fn default() -> Self {
         let builder = gtk::Builder::new_from_resource("/org/gnome/hammond/gtk/shows_view.ui");
         let container: gtk::Box = builder.get_object("fb_parent").unwrap();
+        let scrolled_window: gtk::ScrolledWindow = builder.get_object("scrolled_window").unwrap();
         let flowbox: gtk::FlowBox = builder.get_object("flowbox").unwrap();
-        let viewport: gtk::Viewport = builder.get_object("viewport").unwrap();
 
         ShowsPopulated {
             container,
+            scrolled_window,
             flowbox,
-            viewport,
         }
     }
 }
@@ -74,6 +74,11 @@ impl ShowsPopulated {
     pub fn is_empty(&self) -> bool {
         self.flowbox.get_children().is_empty()
     }
+
+    /// Set scrolled window vertical adjustment.
+    pub fn set_vadjustment(&self, vadjustment: &gtk::Adjustment) {
+        self.scrolled_window.set_vadjustment(vadjustment)
+    }
 }
 
 #[derive(Debug)]