Refactor and finalize

1 files changed, 341 insertions, 309 deletions

diff --git a/src/main.rs b/src/main.rs
index 5c262bb..b363500 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,15 +1,247 @@
+// Copyright © 2021-2022 Jakob L. Kreuze <zerodaysfordays@sdf.org>
+//
+// This file is part of Tunes.
+//
+// Tunes is free software; you can redistribute it and/or modify it
+// under the terms of the GNU Affero General Public License as
+// published by the Free Software Foundation; either version 3 of the
+// License, or (at your option) any later version.
+//
+// Tunes is distributed in the hope that it will be useful, but WITHOUT
+// ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+// or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Affero General
+// Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public
+// License along with Tunes. If not, see <http://www.gnu.org/licenses/>.
+
 use futures::{channel::mpsc, StreamExt};
+use glib::clone;
 use gtk::prelude::*;
-use gtk::{gdk_pixbuf, gio, glib};
+use gtk::subclass::prelude::ObjectSubclassExt;
+use gtk::{gdk_pixbuf, gio, glib, pango};
 use libhandy::prelude::*;
 use libhandy::{ApplicationWindow, HeaderBar};
 use mpd::idle::Idle;
 use mpd::Client;
 
-struct TunesUI {
-    header_bar: HeaderBar,
-    // album_art: Image,
-    // queue_switcher: Notebook,
+const MPD_HOST: &str = "127.0.0.1:6600";
+
+fn main() {
+    let application = gtk::Application::builder()
+        .application_id("space.jakob.Tunes")
+        .build();
+
+    // We have to wait until the `activate` signal is fired before we can do our
+    // setup.
+    application.connect_activate(|app| {
+        // Our event-handling code will look a bit like what's common in SDL
+        // with their `SDLPollEvent` interface, in the sense that we'll have all
+        // of the different sub-systems of this application notify the main
+        // event loop by way of a channel.
+        let (sender, mut receiver) = mpsc::channel(1024);
+
+        // Load all of the mobile UI support code from `libhandy`.
+        libhandy::init();
+
+        // `mpd` will notify us of events. Let's spin up a thread to listen for
+        // those notifications, and shuttle them through a channel as they
+        // arrive.
+        std::thread::spawn(clone!(@strong sender => move || {
+            let mut conn = Client::connect(MPD_HOST).unwrap();
+            while let Ok(_subsystems) = conn.wait(&[mpd::idle::Subsystem::Player]) {
+                let mut sender = sender.clone();
+                sender
+                    .try_send(StateUpdateKind::MpdEvent)
+                    .expect("Couldn't notify thread");
+            }
+        }));
+
+        // We'll connect to the MPD daemon here so we can populate the UI with
+        // some information from the current state.
+        let mut conn = Client::connect(MPD_HOST).unwrap();
+
+        // We'll have two "views" in our application: one for viewing and
+        // manipulating the current `mpd` queue, and another for searching for
+        // songs to add to the queue. In GTK, we can handle switching between
+        // these different views using a Stack.
+        let stack = gtk::Stack::new();
+        stack.set_expand(true);
+
+        let song_info = SongInfo::new(sender.clone());
+        stack.add_named(song_info.as_ref(), "current_song");
+        stack.set_child_title(song_info.as_ref(), Some("Now Playing"));
+        stack.set_child_icon_name(song_info.as_ref(), Some("audio-speakers-symbolic"));
+
+        let query_info = QueryInfo::new(sender.clone());
+        stack.add_named(query_info.as_ref(), "query_songs");
+        stack.set_child_title(query_info.as_ref(), Some("Search Database"));
+        stack.set_child_icon_name(query_info.as_ref(), Some("system-search-symbolic"));
+
+        // The `HeaderBar` is a GTK concept that libhandy plays nicely with. On
+        // desktop, the elements for switching stack views will show up there.
+        // On mobile, it will show up in a `ViewSwitcherBar` at the bottom.
+        let header_bar = HeaderBar::builder()
+            .show_close_button(true)
+            .title(&header_title(&mut conn).unwrap())
+            .build();
+        let view_switcher_title = libhandy::ViewSwitcherTitle::builder()
+            .title("Tunes")
+            .stack(&stack)
+            .build();
+        header_bar.add(&view_switcher_title);
+        let view_switcher_bar = libhandy::ViewSwitcherBar::builder()
+            .visible(true)
+            .can_focus(false)
+            .stack(&stack)
+            .reveal(true)
+            .build();
+
+        // The window needs a single child, so we'll join the header bar, the
+        // stack, and the view switcher into a single box.
+        let content = gtk::Box::new(gtk::Orientation::Vertical, 0);
+        content.set_vexpand(true);
+        content.add(&header_bar);
+        content.add(&stack);
+        content.add(&view_switcher_bar);
+
+        // Finally, the window. It's tied to a child, which we made above, and
+        // the GtkApplication that we declared at the beginning of `main`.
+        let window = ApplicationWindow::builder()
+            .default_width(350)
+            .default_height(70)
+            .modal(true)
+            .child(&content)
+            .build();
+        window.set_application(Some(app));
+        window.show_all();
+
+        // This isn't perfect (it won't run when the window gets its initial
+        // size), but this is how we notify that the album art display should be
+        // resized.
+        window.connect_configure_event(clone!(@strong sender => move |_, _| {
+            let mut sender = sender.clone();
+            sender
+                .try_send(StateUpdateKind::WindowResizeEvent)
+                .expect("Couldn't notify thread");
+            false
+        }));
+
+        // Now that everything's been allocated a window, let's go ahead and
+        // update the widgets.
+        song_info
+            .update(&mut conn)
+            .expect("Couldn't update song info");
+
+        // The following code will fill the search view with every song in the
+        // database. If you have a music library as big as mine, it will
+        // negatively impact startup time. This could be done in, for example, a
+        // worker thread, but I've just omitted it because I don't want this
+        // example to be more complex than it has to be.
+        //
+        // let mut query = mpd::Query::new();
+        // query.and(mpd::Term::Any, "");
+        // let songs = conn.search(&query, (0, 65535));
+        // for song in songs.unwrap() {
+        //     query_info.model.insert(0, &SongObject::new(&song));
+        // }
+
+        // Finally, we'll start the "main event loop" we've been talking about
+        // in the main context of the application.
+        let main_context = gtk::glib::MainContext::default();
+        main_context.spawn_local(async move {
+            let mut conn = Client::connect(MPD_HOST).unwrap();
+            while let Some(event_type) = receiver.next().await {
+                match event_type {
+                    StateUpdateKind::MpdEvent => {
+                        if let Ok(title) = header_title(&mut conn) {
+                            header_bar.set_title(Some(&title));
+                            song_info
+                                .update(&mut conn)
+                                .expect("Couldn't update song info");
+                        }
+                    }
+                    StateUpdateKind::WindowResizeEvent => {
+                        song_info
+                            .update_album_art(&mut conn)
+                            .expect("Couldn't update album art");
+                    }
+                    StateUpdateKind::QueryUpdateEvent(query_string) => {
+                        // Let's not produce massive queries while the user is typing :)
+                        if query_string.len() <= 2 {
+                            continue;
+                        }
+
+                        // Start from a blank slate.
+                        query_info.model.remove_all();
+
+                        // Query on all fields, case-insensitively, for the text
+                        // that the user input.
+                        let mut query = mpd::Query::new();
+                        query.and(mpd::Term::Any, &query_string);
+                        let songs = conn.search(&query, (0, 65535));
+
+                        // Insert them all into the model. This is reversed,
+                        // which I don't consider to be a big deal. It's far
+                        // less complex than adding it in order, which you will
+                        // see below in the code that handles the queue.
+                        for song in songs.unwrap() {
+                            query_info.model.insert(0, &SongObject::new(&song));
+                        }
+                    }
+                    StateUpdateKind::QueueDeleteRequest(index) => {
+                        conn.delete(index).expect("Couldn't dequeue song");
+                    }
+                    StateUpdateKind::QueueAddRequest(filename) => {
+                        conn.push_str(filename).expect("Couldn't queue song");
+                    }
+                    StateUpdateKind::PlaybackStateChange(action) => {
+                        dispatch_playback_state_change(&mut conn, action)
+                            .expect("Couldn't queue action");
+                    }
+                }
+            }
+        });
+    });
+
+    application.run();
+}
+
+/// Take action on `conn` based on a `PlaybackStateChange` notification
+fn dispatch_playback_state_change(
+    conn: &mut mpd::Client,
+    action: PlaybackStateChange,
+) -> anyhow::Result<()> {
+    use PlaybackStateChange::*;
+    match action {
+        SkipBackwards => conn.prev()?,
+        SkipForwards => conn.next()?,
+        Start => conn.play()?,
+        Stop => conn.stop()?,
+        Pause => conn.pause(true)?,
+    }
+    Ok(())
+}
+
+/// Kind of event we can notify the UI future about
+#[derive(Debug)]
+enum StateUpdateKind {
+    MpdEvent,
+    WindowResizeEvent,
+    QueryUpdateEvent(String),
+    QueueAddRequest(String),
+    QueueDeleteRequest(u32),
+    PlaybackStateChange(PlaybackStateChange),
+}
+
+/// A simple action that affects playback state.
+#[derive(Debug)]
+enum PlaybackStateChange {
+    Start,
+    Stop,
+    Pause,
+    SkipBackwards,
+    SkipForwards,
 }
 
 /// Produce a short status line for the current state of `conn`.
@@ -47,6 +279,7 @@ impl SongInfo {
         let song_text = gtk::Label::new(None);
         song_text.set_justify(gtk::Justification::Center);
         song_text.set_line_wrap(true);
+        song_text.set_line_wrap_mode(pango::WrapMode::WordChar);
         container.add(&album_art);
         container.add(&song_text);
 
@@ -58,142 +291,132 @@ impl SongInfo {
             gtk::IconSize::SmallToolbar,
         );
         action_bar.add(&control_previous_song);
-        let sender1 = sender.clone();
-        control_previous_song.connect_clicked(move |_| {
-            let mut sender = sender1.clone();
+        control_previous_song.connect_clicked(clone!(@strong sender => move |_| {
+            let mut sender = sender.clone();
             sender
                 .try_send(StateUpdateKind::PlaybackStateChange(
                     PlaybackStateChange::SkipBackwards,
                 ))
                 .expect("Couldn't notify thread");
-        });
+        }));
 
         let control_start_song = gtk::Button::from_icon_name(
             Some("media-playback-start-symbolic"),
             gtk::IconSize::SmallToolbar,
         );
         action_bar.add(&control_start_song);
-        let sender1 = sender.clone();
-        control_start_song.connect_clicked(move |_| {
-            let mut sender = sender1.clone();
+        control_start_song.connect_clicked(clone!(@strong sender => move |_| {
+            let mut sender = sender.clone();
             sender
                 .try_send(StateUpdateKind::PlaybackStateChange(
-                    PlaybackStateChange::StartPlayback,
+                    PlaybackStateChange::Start,
                 ))
                 .expect("Couldn't notify thread");
-        });
+        }));
 
         let control_pause_song = gtk::Button::from_icon_name(
             Some("media-playback-pause-symbolic"),
             gtk::IconSize::SmallToolbar,
         );
         action_bar.add(&control_pause_song);
-        let sender1 = sender.clone();
-        control_pause_song.connect_clicked(move |_| {
-            let mut sender = sender1.clone();
+        control_pause_song.connect_clicked(clone!(@strong sender => move |_| {
+            let mut sender = sender.clone();
             sender
                 .try_send(StateUpdateKind::PlaybackStateChange(
-                    PlaybackStateChange::PausePlayback,
+                    PlaybackStateChange::Pause,
                 ))
                 .expect("Couldn't notify thread");
-        });
+        }));
 
         let control_stop_song = gtk::Button::from_icon_name(
             Some("media-playback-stop-symbolic"),
             gtk::IconSize::SmallToolbar,
         );
         action_bar.add(&control_stop_song);
-        let sender1 = sender.clone();
-        control_stop_song.connect_clicked(move |_| {
-            let mut sender = sender1.clone();
+        control_stop_song.connect_clicked(clone!(@strong sender => move |_| {
+            let mut sender = sender.clone();
             sender
                 .try_send(StateUpdateKind::PlaybackStateChange(
-                    PlaybackStateChange::StopPlayback,
+                    PlaybackStateChange::Stop,
                 ))
                 .expect("Couldn't notify thread");
-        });
+        }));
 
         let control_next_song = gtk::Button::from_icon_name(
             Some("media-skip-forward-symbolic"),
             gtk::IconSize::SmallToolbar,
         );
         action_bar.add(&control_next_song);
-        let sender1 = sender.clone();
-        control_next_song.connect_clicked(move |_| {
-            let mut sender = sender1.clone();
+        control_next_song.connect_clicked(clone!(@strong sender => move |_| {
+            let mut sender = sender.clone();
             sender
                 .try_send(StateUpdateKind::PlaybackStateChange(
                     PlaybackStateChange::SkipForwards,
                 ))
                 .expect("Couldn't notify thread");
-        });
+        }));
 
         let model = gio::ListStore::new(SongObject::static_type());
         let listbox = gtk::ListBox::new();
-        let sender1 = sender.clone();
-        listbox.bind_model(Some(&model), move |item| {
-            let sender = sender1.clone();
+        listbox.bind_model(
+            Some(&model),
+            clone!(@strong sender => move |item| {
+                let sender = sender.clone();
 
-            let box_ = gtk::ListBoxRow::new();
-            let item = item
-                .downcast_ref::<SongObject>()
-                .expect("Row data is of wrong type");
-
-            let grid = gtk::Grid::builder().column_homogeneous(true).build();
-
-            let remove_individual_song = gtk::Button::from_icon_name(
-                Some("list-remove-symbolic"),
-                gtk::IconSize::SmallToolbar,
-            );
-            remove_individual_song.set_visible(true);
-            let index = item.property::<u32>("index");
-            remove_individual_song.connect_clicked(move |_| {
-                let mut sender = sender.clone();
-                sender
-                    .try_send(StateUpdateKind::QueueDeleteRequest(index))
-                    .expect("Couldn't notify thread");
-
-                // We don't actually get notified by `mpd`, but we can pretend
-                // that we did!
-                sender
-                    .try_send(StateUpdateKind::MpdEvent)
-                    .expect("Couldn't notify thread");
-            });
-            grid.attach(&remove_individual_song, 0, 0, 1, 1);
-
-            let title_label = gtk::Label::new(None);
-            title_label.set_line_wrap(true);
-            item.bind_property("title", &title_label, "label")
-                .flags(glib::BindingFlags::DEFAULT | glib::BindingFlags::SYNC_CREATE)
-                .build();
-            grid.attach(&title_label, 1, 0, 1, 1);
+                let box_ = gtk::ListBoxRow::new();
+                let item = item
+                    .downcast_ref::<SongObject>()
+                    .expect("Row data is of wrong type");
 
-            title_label.set_visible(true); // why?
+                let grid = gtk::Grid::builder().column_homogeneous(true).build();
 
-            let album_label = gtk::Label::new(None);
-            album_label.set_line_wrap(true);
-            item.bind_property("album", &album_label, "label")
-                .flags(glib::BindingFlags::DEFAULT | glib::BindingFlags::SYNC_CREATE)
-                .build();
-            grid.attach(&album_label, 2, 0, 1, 1);
+                let remove_individual_song = gtk::Button::from_icon_name(
+                    Some("list-remove-symbolic"),
+                    gtk::IconSize::SmallToolbar,
+                );
+                let index = item.property::<u32>("index");
+                remove_individual_song.connect_clicked(move |_| {
+                    let mut sender = sender.clone();
+                    sender
+                        .try_send(StateUpdateKind::QueueDeleteRequest(index))
+                        .expect("Couldn't notify thread");
+                    sender
+                        .try_send(StateUpdateKind::MpdEvent)
+                        .expect("Couldn't notify thread");
+                });
+                grid.attach(&remove_individual_song, 0, 0, 1, 1);
 
-            album_label.set_visible(true); // why?
+                let title_label = gtk::Label::new(None);
+                title_label.set_line_wrap(true);
+                title_label.set_line_wrap_mode(pango::WrapMode::WordChar);
+                item.bind_property("title", &title_label, "label")
+                    .flags(glib::BindingFlags::DEFAULT | glib::BindingFlags::SYNC_CREATE)
+                    .build();
+                grid.attach(&title_label, 1, 0, 1, 1);
 
-            let artist_label = gtk::Label::new(None);
-            artist_label.set_line_wrap(true);
-            item.bind_property("artist", &artist_label, "label")
-                .flags(glib::BindingFlags::DEFAULT | glib::BindingFlags::SYNC_CREATE)
-                .build();
-            grid.attach(&artist_label, 3, 0, 1, 1);
 
-            artist_label.set_visible(true); // why?
+                let album_label = gtk::Label::new(None);
+                album_label.set_line_wrap(true);
+                album_label.set_line_wrap_mode(pango::WrapMode::WordChar);
+                item.bind_property("album", &album_label, "label")
+                    .flags(glib::BindingFlags::DEFAULT | glib::BindingFlags::SYNC_CREATE)
+                    .build();
+                grid.attach(&album_label, 2, 0, 1, 1);
 
-            grid.set_visible(true); // why?
 
-            box_.add(&grid);
+                let artist_label = gtk::Label::new(None);
+                artist_label.set_line_wrap(true);
+                artist_label.set_line_wrap_mode(pango::WrapMode::WordChar);
+                item.bind_property("artist", &artist_label, "label")
+                    .flags(glib::BindingFlags::DEFAULT | glib::BindingFlags::SYNC_CREATE)
+                    .build();
+                grid.attach(&artist_label, 3, 0, 1, 1);
 
-            box_.upcast::<gtk::Widget>()
-        });
+                grid.show_all();
+                box_.add(&grid);
+                box_.upcast::<gtk::Widget>()
+            }),
+        );
 
         let scrolled_window =
             gtk::ScrolledWindow::new(gtk::Adjustment::NONE, gtk::Adjustment::NONE);
@@ -202,7 +425,6 @@ impl SongInfo {
 
         container.add(&action_bar);
         container.add(&scrolled_window);
-
         container.show_all();
 
         SongInfo {
@@ -215,11 +437,11 @@ impl SongInfo {
 
     fn update_album_art(&self, conn: &mut mpd::Client) -> anyhow::Result<()> {
         if let Some(song) = conn.currentsong()? {
-            // If we've been allocated a window, pick the greatest dimension
-            // (width or height) and divide that dimension by two to get the
-            // size (in pixels) that we'll scale the album art to. Otherwise, we
-            // default to 128.
-            let album_art_size = std::cmp::max(
+            // If we've been allocated a window, pick the least dimension (width
+            // or height) and divide that dimension by two to get the size (in
+            // pixels) that we'll scale the album art to. Otherwise, we default
+            // to 128.
+            let album_art_size = std::cmp::min(
                 self.container
                     .window()
                     .map(|x| x.width() / 2)
@@ -252,16 +474,8 @@ impl SongInfo {
         self.update_album_art(conn)?;
 
         if let Some(song) = conn.currentsong()? {
-            let title = song
-                .title
-                .as_ref()
-                .map(|x| x.as_str())
-                .unwrap_or("[Unknown]");
-            let artist = song
-                .artist
-                .as_ref()
-                .map(|x| x.as_str())
-                .unwrap_or("[Unknown]");
+            let title = song.title.as_deref().unwrap_or("[Unknown]");
+            let artist = song.artist.as_deref().unwrap_or("[Unknown]");
             let album = song
                 .tags
                 .get("Album")
@@ -270,15 +484,14 @@ impl SongInfo {
             let text = format!("{}\n{} - {}", title, artist, album);
             self.song_text.set_text(&text);
 
+            // We'll use `pango` attributes to make the display look nice and
+            // pretty. Scale the title of the song the most, and still make the
+            // other info reasonably large.
             let attr_list = gtk::pango::AttrList::new();
-
-            // Scale the title of the song the most.
             let mut attr = gtk::pango::AttrFloat::new_scale(2.0);
             attr.set_start_index(0);
             attr.set_end_index(title.len() as u32);
             attr_list.insert(attr);
-
-            // And still make the other info reasonably large.
             let mut attr = gtk::pango::AttrFloat::new_scale(1.5);
             attr.set_start_index(title.len() as u32 + 1);
             attr_list.insert(attr);
@@ -288,9 +501,10 @@ impl SongInfo {
 
         self.model.remove_all();
         for (i, song) in conn.queue()?.iter().enumerate() {
-            let object = SongObject::new(&song);
-            object.set_index(i.try_into().unwrap());
-            self.model.insert(i.try_into().unwrap(), &object)
+            let index = i.try_into().unwrap();
+            let object = SongObject::new(song);
+            object.set_index(index);
+            self.model.insert(index, &object)
         }
 
         Ok(())
@@ -314,20 +528,18 @@ impl QueryInfo {
         let container = gtk::Box::new(gtk::Orientation::Vertical, 2);
 
         let query_input = gtk::Entry::builder().visible(true).build();
-        let sender1 = sender.clone();
-        query_input.connect_key_press_event(move |widget, _| {
-            let mut sender = sender1.clone(); // Interesting ownership puzzle :D
+        query_input.connect_key_press_event(clone!(@strong sender => move |widget, _| {
+            let mut sender = sender.clone();
             sender
                 .try_send(StateUpdateKind::QueryUpdateEvent(widget.text().into()))
                 .expect("Couldn't notify thread");
             gtk::Inhibit(false)
-        });
+        }));
 
         let model = gio::ListStore::new(SongObject::static_type());
         let listbox = gtk::ListBox::new();
-        let sender1 = sender.clone();
-        listbox.bind_model(Some(&model), move |item| {
-            let sender = sender1.clone();
+        listbox.bind_model(Some(&model), clone!(@strong sender => move |item| {
+            let sender = sender.clone();
 
             let box_ = gtk::ListBoxRow::new();
             let item = item
@@ -346,42 +558,40 @@ impl QueryInfo {
                 sender
                     .try_send(StateUpdateKind::QueueAddRequest(filename))
                     .expect("Couldn't notify thread");
+                sender
+                    .try_send(StateUpdateKind::MpdEvent)
+                    .expect("Couldn't notify thread");
             });
             grid.attach(&add_individual_song, 0, 0, 1, 1);
 
             let title_label = gtk::Label::new(None);
             title_label.set_line_wrap(true);
+            title_label.set_line_wrap_mode(pango::WrapMode::WordChar);
             item.bind_property("title", &title_label, "label")
                 .flags(glib::BindingFlags::DEFAULT | glib::BindingFlags::SYNC_CREATE)
                 .build();
             grid.attach(&title_label, 1, 0, 1, 1);
 
-            title_label.set_visible(true); // why?
-
             let album_label = gtk::Label::new(None);
             album_label.set_line_wrap(true);
+            album_label.set_line_wrap_mode(pango::WrapMode::WordChar);
             item.bind_property("album", &album_label, "label")
                 .flags(glib::BindingFlags::DEFAULT | glib::BindingFlags::SYNC_CREATE)
                 .build();
             grid.attach(&album_label, 2, 0, 1, 1);
 
-            album_label.set_visible(true); // why?
-
             let artist_label = gtk::Label::new(None);
             artist_label.set_line_wrap(true);
+            artist_label.set_line_wrap_mode(pango::WrapMode::WordChar);
             item.bind_property("artist", &artist_label, "label")
                 .flags(glib::BindingFlags::DEFAULT | glib::BindingFlags::SYNC_CREATE)
                 .build();
             grid.attach(&artist_label, 3, 0, 1, 1);
 
-            artist_label.set_visible(true); // why?
-
-            grid.set_visible(true); // why?
-
+            grid.show_all();
             box_.add(&grid);
-
             box_.upcast::<gtk::Widget>()
-        });
+        }));
 
         let scrolled_window =
             gtk::ScrolledWindow::new(gtk::Adjustment::NONE, gtk::Adjustment::NONE);
@@ -401,11 +611,13 @@ impl AsRef<gtk::Widget> for QueryInfo {
     }
 }
 
+// Unfortunately, to use the `ListStore` interface, we'll need to represent our
+// data as an actual `glib` object. This is a little hairy in Rust, involving a
+// fair bit of boilerplate, but not too terrible.
 glib::wrapper! {
     pub struct SongObject(ObjectSubclass<imp::SongObject>);
 }
 
-use gtk::subclass::prelude::ObjectSubclassExt;
 impl SongObject {
     pub fn new(song: &mpd::song::Song) -> Self {
         glib::Object::new(&[
@@ -415,7 +627,7 @@ impl SongObject {
                 &song
                     .title
                     .as_ref()
-                    .map(|x| x.clone())
+                    .cloned()
                     .unwrap_or_else(|| "[Untitled]".into()),
             ),
             (
@@ -423,7 +635,7 @@ impl SongObject {
                 &song
                     .artist
                     .as_ref()
-                    .map(|x| x.clone())
+                    .cloned()
                     .unwrap_or_else(|| "[No Artist]".into()),
             ),
             (
@@ -431,7 +643,7 @@ impl SongObject {
                 &song
                     .tags
                     .get("Album")
-                    .map(|x| x.clone())
+                    .cloned()
                     .unwrap_or_else(|| "[Untitled]".into()),
             ),
         ])
@@ -444,6 +656,8 @@ impl SongObject {
     }
 }
 
+// These class "implementations" are typically done in a separate
+// file/directory. I wanted to keep the example self-contained.
 mod imp {
     use std::cell::{Cell, RefCell};
 
@@ -531,185 +745,3 @@ mod imp {
         }
     }
 }
-
-/// Kind of event we can notify the UI future about
-enum StateUpdateKind {
-    MpdEvent,
-    WindowResizeEvent,
-    QueryUpdateEvent(String),
-    QueueAddRequest(String),
-    QueueDeleteRequest(u32),
-    PlaybackStateChange(PlaybackStateChange),
-}
-
-#[derive(Debug)]
-enum PlaybackStateChange {
-    SkipBackwards,
-    SkipForwards,
-    StartPlayback,
-    StopPlayback,
-    PausePlayback,
-}
-
-fn main() {
-    let application = gtk::Application::builder()
-        .application_id("space.jakob.Tunes")
-        .build();
-
-    application.connect_activate(|app| {
-        libhandy::init();
-
-        let mut conn = Client::connect("127.0.0.1:6600").unwrap();
-        let (sender, mut receiver) = mpsc::channel(1000);
-
-        let mut sender1 = sender.clone();
-        std::thread::spawn(move || loop {
-            let mut conn = Client::connect("127.0.0.1:6600").unwrap();
-            if let Ok(_subsystems) = conn.wait(&[mpd::idle::Subsystem::Player]) {
-                sender1
-                    .try_send(StateUpdateKind::MpdEvent)
-                    .expect("Couldn't notify thread");
-            } else {
-                break;
-            }
-        });
-
-        // conn.volume(100).unwrap();
-        // conn.load("My Lounge Playlist", ..).unwrap();
-        // conn.play().unwrap();
-
-        let stack = gtk::Stack::new();
-        stack.set_expand(true);
-
-        let song_info = SongInfo::new(sender.clone());
-        stack.add_named(song_info.as_ref(), "current_song");
-        stack.set_child_title(song_info.as_ref(), Some("Now Playing"));
-        stack.set_child_icon_name(song_info.as_ref(), Some("audio-speakers-symbolic"));
-
-        let query_info = QueryInfo::new(sender.clone());
-        stack.add_named(query_info.as_ref(), "query_songs");
-        stack.set_child_title(query_info.as_ref(), Some("Search Database"));
-        stack.set_child_icon_name(query_info.as_ref(), Some("system-search-symbolic"));
-
-        let header_bar = HeaderBar::builder()
-            .show_close_button(true)
-            .title(&header_title(&mut conn).unwrap())
-            .build();
-        let view_switcher_title = libhandy::ViewSwitcherTitle::builder()
-            .title("Tunes")
-            .stack(&stack)
-            .build();
-        header_bar.add(&view_switcher_title);
-
-        let view_switcher_bar = libhandy::ViewSwitcherBar::builder()
-            .visible(true)
-            .can_focus(false)
-            .stack(&stack)
-            .reveal(true)
-            .build();
-
-        let ui = TunesUI { header_bar };
-
-        // Combine the content in a box
-        let content = gtk::Box::new(gtk::Orientation::Vertical, 0);
-        content.set_vexpand(true);
-        // Handy's ApplicationWindow does not include a HeaderBar
-        content.add(&ui.header_bar);
-        content.add(&stack);
-        content.add(&view_switcher_bar);
-
-        let window = ApplicationWindow::builder()
-            .default_width(350)
-            .default_height(70)
-            .modal(true)
-            // add content to window
-            .child(&content)
-            .build();
-        window.set_application(Some(app));
-        window.show_all();
-
-        window.connect_size_allocate(move |_, _| {
-            let mut sender = sender.clone();
-            sender
-                .try_send(StateUpdateKind::WindowResizeEvent)
-                .expect("Couldn't notify thread");
-        });
-
-        // Now that everything's been allocated a window, let's go ahead and
-        // update the widgets.
-        song_info
-            .update(&mut conn)
-            .expect("Couldn't update song info");
-
-        let mut query = mpd::Query::new();
-        query.and(mpd::Term::Any, "");
-        let songs = conn.find(&mut query, (0, 65535));
-        // println!("{:?}", songs);
-        for song in songs.unwrap() {
-            query_info.model.insert(0, &SongObject::new(&song));
-        }
-
-        let main_context = gtk::glib::MainContext::default();
-        main_context.spawn_local(async move {
-            let mut conn = Client::connect("127.0.0.1:6600").unwrap();
-            while let Some(event_type) = receiver.next().await {
-                match event_type {
-                    StateUpdateKind::MpdEvent => {
-                        if let Ok(title) = header_title(&mut conn) {
-                            ui.header_bar.set_title(Some(&title));
-                            song_info
-                                .update(&mut conn)
-                                .expect("Couldn't update song info");
-                        }
-                    }
-                    StateUpdateKind::WindowResizeEvent => {
-                        song_info
-                            .update_album_art(&mut conn)
-                            .expect("Couldn't update album art");
-                    }
-                    StateUpdateKind::QueryUpdateEvent(query_string) => {
-                        // Let's not produce massive queries while the user is typing :)
-                        if query_string.len() <= 2 {
-                            continue;
-                        }
-                        query_info.model.remove_all();
-                        let mut query = mpd::Query::new();
-                        query.and(mpd::Term::Any, &query_string);
-                        let songs = conn.search(&mut query, (0, 65535));
-                        // println!("{:?}", songs);
-                        for song in songs.unwrap() {
-                            query_info.model.insert(0, &SongObject::new(&song));
-                        }
-                    }
-                    StateUpdateKind::QueueDeleteRequest(index) => {
-                        conn.delete(index).expect("Couldn't dequeue song");
-                    }
-                    StateUpdateKind::QueueAddRequest(filename) => {
-                        conn.push_str(filename).expect("Couldn't queue song");
-                    }
-                    StateUpdateKind::PlaybackStateChange(action) => {
-                        dispatch_playback_state_change(&mut conn, action)
-                            .expect("Couldn't queue action");
-                    }
-                }
-            }
-        });
-    });
-
-    application.run();
-}
-
-fn dispatch_playback_state_change(
-    conn: &mut mpd::Client,
-    action: PlaybackStateChange,
-) -> anyhow::Result<()> {
-    use PlaybackStateChange::*;
-    match action {
-        SkipBackwards => conn.prev()?,
-        SkipForwards => conn.next()?,
-        StartPlayback => conn.play()?,
-        StopPlayback => conn.stop()?,
-        PausePlayback => conn.pause(true)?,
-    }
-    Ok(())
-}