src/main.rs

@@ -20,7 +20,13 @@ use musichoard::{
     MusicHoardBuilder, NoDatabase, NoLibrary,
 };
 
-use tui::{event::EventChannel, handler::EventHandler, listener::EventListener, ui::Ui, Tui};
+use tui::{
+    event::EventChannel,
+    handler::EventHandler,
+    listener::EventListener,
+    ui::{render::Renderer, Ui},
+    Tui,
+};
 
 #[derive(StructOpt)]
 struct Opt {
@@ -68,9 +74,10 @@ fn with<LIB: ILibrary, DB: IDatabase>(builder: MusicHoardBuilder<LIB, DB>) {
     let handler = EventHandler::new(channel.receiver());
 
     let ui = Ui::new(music_hoard).expect("failed to initialise ui");
+    let renderer = Renderer;
 
     // Run the TUI application.
-    Tui::run(terminal, ui, handler, listener).expect("failed to run tui");
+    Tui::run(terminal, ui, renderer, handler, listener).expect("failed to run tui");
 }
 
 fn with_database<LIB: ILibrary>(db_opt: DbOpt, builder: MusicHoardBuilder<LIB, NoDatabase>) {

src/tui/mod.rs

@@ -15,7 +15,7 @@ use std::marker::PhantomData;
 use self::event::EventError;
 use self::handler::IEventHandler;
 use self::listener::IEventListener;
-use self::ui::IUi;
+use self::ui::{render::IRender, IUi};
 
 #[derive(Debug, PartialEq, Eq)]
 pub enum Error {
@@ -43,12 +43,12 @@ impl From<EventError> for Error {
     }
 }
 
-pub struct Tui<B: Backend, UI: IUi> {
+pub struct Tui<B: Backend, R: IRender, UI: IUi> {
     terminal: Terminal<B>,
-    _phantom: PhantomData<UI>,
+    _phantom: PhantomData<(R, UI)>,
 }
 
-impl<B: Backend, UI: IUi> Tui<B, UI> {
+impl<B: Backend, R: IRender, UI: IUi> Tui<B, R, UI> {
     fn init(&mut self) -> Result<(), Error> {
         self.terminal.hide_cursor()?;
         self.terminal.clear()?;
@@ -65,9 +65,14 @@ impl<B: Backend, UI: IUi> Tui<B, UI> {
         self.exit();
     }
 
-    fn main_loop(&mut self, mut ui: UI, handler: impl IEventHandler<UI>) -> Result<(), Error> {
+    fn main_loop(
+        &mut self,
+        mut ui: UI,
+        renderer: R,
+        handler: impl IEventHandler<UI>,
+    ) -> Result<(), Error> {
         while ui.is_running() {
-            self.terminal.draw(|frame| ui.render(frame))?;
+            self.terminal.draw(|frame| ui.render(&renderer, frame))?;
             handler.handle_next_event(&mut ui)?;
         }
 
@@ -77,6 +82,7 @@ impl<B: Backend, UI: IUi> Tui<B, UI> {
     fn main(
         term: Terminal<B>,
         ui: UI,
+        renderer: R,
         handler: impl IEventHandler<UI>,
         listener: impl IEventListener,
     ) -> Result<(), Error> {
@@ -88,7 +94,7 @@ impl<B: Backend, UI: IUi> Tui<B, UI> {
         tui.init()?;
 
         let listener_handle = listener.spawn();
-        let result = tui.main_loop(ui, handler);
+        let result = tui.main_loop(ui, renderer, handler);
 
         match result {
             Ok(_) => {
@@ -136,11 +142,12 @@ impl<B: Backend, UI: IUi> Tui<B, UI> {
     pub fn run(
         term: Terminal<B>,
         ui: UI,
+        renderer: R,
         handler: impl IEventHandler<UI>,
         listener: impl IEventListener,
     ) -> Result<(), Error> {
         Self::enable()?;
-        let result = Self::main(term, ui, handler, listener);
+        let result = Self::main(term, ui, renderer, handler, listener);
         match result {
             Ok(_) => {
                 Self::disable()?;
@@ -169,7 +176,10 @@ mod tests {
     use musichoard::collection::Collection;
 
     use crate::tui::{
-        handler::MockIEventHandler, lib::MockIMusicHoard, listener::MockIEventListener, ui::Ui,
+        handler::MockIEventHandler,
+        lib::MockIMusicHoard,
+        listener::MockIEventListener,
+        ui::{render::Renderer, Ui},
     };
 
     use super::*;
@@ -220,11 +230,12 @@ mod tests {
     fn run() {
         let terminal = terminal();
         let ui = ui(COLLECTION.to_owned());
+        let renderer = Renderer;
 
         let listener = listener();
         let handler = handler();
 
-        let result = Tui::main(terminal, ui, handler, listener);
+        let result = Tui::main(terminal, ui, renderer, handler, listener);
         assert!(result.is_ok());
     }
 
@@ -232,6 +243,7 @@ mod tests {
     fn event_error() {
         let terminal = terminal();
         let ui = ui(COLLECTION.to_owned());
+        let renderer = Renderer;
 
         let listener = listener();
 
@@ -240,7 +252,7 @@ mod tests {
             .expect_handle_next_event()
             .return_once(|_| Err(EventError::Recv));
 
-        let result = Tui::main(terminal, ui, handler, listener);
+        let result = Tui::main(terminal, ui, renderer, handler, listener);
         assert!(result.is_err());
         assert_eq!(
             result.unwrap_err(),
@@ -252,6 +264,7 @@ mod tests {
     fn listener_error() {
         let terminal = terminal();
         let ui = ui(COLLECTION.to_owned());
+        let renderer = Renderer;
 
         let error = EventError::Io(io::Error::new(io::ErrorKind::Interrupted, "error"));
         let listener_handle: thread::JoinHandle<EventError> = thread::spawn(|| error);
@@ -265,7 +278,7 @@ mod tests {
             .expect_handle_next_event()
             .return_once(|_| Err(EventError::Recv));
 
-        let result = Tui::main(terminal, ui, handler, listener);
+        let result = Tui::main(terminal, ui, renderer, handler, listener);
         assert!(result.is_err());
 
         let error = EventError::Io(io::Error::new(io::ErrorKind::Interrupted, "error"));
@@ -276,6 +289,7 @@ mod tests {
     fn listener_panic() {
         let terminal = terminal();
         let ui = ui(COLLECTION.to_owned());
+        let renderer = Renderer;
 
         let listener_handle: thread::JoinHandle<EventError> = thread::spawn(|| panic!());
         while !listener_handle.is_finished() {}
@@ -288,7 +302,7 @@ mod tests {
             .expect_handle_next_event()
             .return_once(|_| Err(EventError::Recv));
 
-        let result = Tui::main(terminal, ui, handler, listener);
+        let result = Tui::main(terminal, ui, renderer, handler, listener);
         assert!(result.is_err());
         assert_eq!(result.unwrap_err(), Error::ListenerPanic);
     }

src/tui/ui/mod.rs

@@ -1,20 +1,14 @@
+pub mod render;
+
 use std::fmt;
 
-use musichoard::collection::{
+use musichoard::collection::{album::Album, artist::Artist, track::Track, Collection};
-    album::Album,
+use ratatui::{backend::Backend, widgets::ListState, Frame};
-    artist::Artist,
-    track::{Format, Track},
-    Collection,
-};
-use ratatui::{
-    backend::Backend,
-    layout::{Alignment, Rect},
-    style::{Color, Style},
-    widgets::{Block, BorderType, Borders, Clear, List, ListItem, ListState, Paragraph, Wrap},
-    Frame,
-};
 
-use crate::tui::{lib::IMusicHoard, Error};
+use crate::tui::{
+    ui::render::IRender,
+    {lib::IMusicHoard, Error},
+};
 
 #[derive(Debug)]
 pub enum UiError {
@@ -73,7 +67,7 @@ pub trait IUi {
 
     fn state(&mut self) -> UiState<&mut Self::BS, &mut Self::IS, &mut Self::RS, &mut Self::ES>;
 
-    fn render<B: Backend>(&mut self, frame: &mut Frame<'_, B>);
+    fn render<R: IRender, B: Backend>(&mut self, renderer: &R, frame: &mut Frame<'_, B>);
 }
 
 pub trait IUiBrowse {
@@ -258,7 +252,7 @@ pub enum Category {
     Track,
 }
 
-struct Selection {
+pub struct Selection {
     active: Category,
     artist: ArtistSelection,
 }
@@ -328,292 +322,7 @@ impl Selection {
     }
 }
 
-struct ArtistArea {
+pub struct Ui<MH: IMusicHoard> {
-    list: Rect,
-}
-
-struct AlbumArea {
-    list: Rect,
-    info: Rect,
-}
-
-struct TrackArea {
-    list: Rect,
-    info: Rect,
-}
-
-struct FrameArea {
-    artist: ArtistArea,
-    album: AlbumArea,
-    track: TrackArea,
-}
-
-impl FrameArea {
-    fn new(frame: Rect) -> Self {
-        let width_one_third = frame.width / 3;
-        let height_one_third = frame.height / 3;
-
-        let panel_width = width_one_third;
-        let panel_width_last = frame.width - 2 * panel_width;
-        let panel_height_top = frame.height - height_one_third;
-        let panel_height_bottom = height_one_third;
-
-        let artist_list = Rect {
-            x: frame.x,
-            y: frame.y,
-            width: panel_width,
-            height: frame.height,
-        };
-
-        let album_list = Rect {
-            x: artist_list.x + artist_list.width,
-            y: frame.y,
-            width: panel_width,
-            height: panel_height_top,
-        };
-
-        let album_info = Rect {
-            x: album_list.x,
-            y: album_list.y + album_list.height,
-            width: album_list.width,
-            height: panel_height_bottom,
-        };
-
-        let track_list = Rect {
-            x: album_list.x + album_list.width,
-            y: frame.y,
-            width: panel_width_last,
-            height: panel_height_top,
-        };
-
-        let track_info = Rect {
-            x: track_list.x,
-            y: track_list.y + track_list.height,
-            width: track_list.width,
-            height: panel_height_bottom,
-        };
-
-        FrameArea {
-            artist: ArtistArea { list: artist_list },
-            album: AlbumArea {
-                list: album_list,
-                info: album_info,
-            },
-            track: TrackArea {
-                list: track_list,
-                info: track_info,
-            },
-        }
-    }
-}
-
-enum OverlaySize {
-    MarginFactor(u16),
-    Value(u16),
-}
-
-impl Default for OverlaySize {
-    fn default() -> Self {
-        OverlaySize::MarginFactor(8)
-    }
-}
-
-impl OverlaySize {
-    fn get(&self, full: u16) -> (u16, u16) {
-        match self {
-            OverlaySize::MarginFactor(margin_factor) => {
-                let margin = full / margin_factor;
-                (margin, full - (2 * margin))
-            }
-            OverlaySize::Value(value) => {
-                let margin = (full - value) / 2;
-                (margin, *value)
-            }
-        }
-    }
-}
-
-#[derive(Default)]
-struct OverlayBuilder {
-    width: OverlaySize,
-    height: OverlaySize,
-}
-
-impl OverlayBuilder {
-    fn with_width(mut self, width: OverlaySize) -> OverlayBuilder {
-        self.width = width;
-        self
-    }
-
-    fn with_height(mut self, height: OverlaySize) -> OverlayBuilder {
-        self.height = height;
-        self
-    }
-
-    fn build(self, frame: Rect) -> Rect {
-        let (x, width) = self.width.get(frame.width);
-        let (y, height) = self.height.get(frame.height);
-
-        Rect {
-            x,
-            y,
-            width,
-            height,
-        }
-    }
-}
-
-struct ArtistState<'a, 'b> {
-    active: bool,
-    list: List<'a>,
-    state: &'b mut ListState,
-}
-
-impl<'a, 'b> ArtistState<'a, 'b> {
-    fn new(active: bool, artists: &'a [Artist], state: &'b mut ListState) -> ArtistState<'a, 'b> {
-        let list = List::new(
-            artists
-                .iter()
-                .map(|a| ListItem::new(a.id.name.as_str()))
-                .collect::<Vec<ListItem>>(),
-        );
-
-        ArtistState {
-            active,
-            list,
-            state,
-        }
-    }
-}
-
-struct ArtistOverlay<'a> {
-    properties: Paragraph<'a>,
-}
-
-impl<'a> ArtistOverlay<'a> {
-    fn opt_opt_to_str<S: AsRef<str>>(opt: Option<Option<&S>>) -> &str {
-        opt.flatten().map(|item| item.as_ref()).unwrap_or("")
-    }
-
-    fn opt_vec_to_string<S: AsRef<str>>(opt_vec: Option<&Vec<S>>, indent: &str) -> String {
-        opt_vec
-            .map(|vec| {
-                if vec.len() < 2 {
-                    vec.first()
-                        .map(|item| item.as_ref())
-                        .unwrap_or("")
-                        .to_string()
-                } else {
-                    let indent = format!("\n{indent}");
-                    let list = vec
-                        .iter()
-                        .map(|item| item.as_ref())
-                        .collect::<Vec<&str>>()
-                        .join(&indent);
-                    format!("{indent}{list}")
-                }
-            })
-            .unwrap_or_else(|| String::from(""))
-    }
-
-    fn new(artists: &'a [Artist], state: &ListState) -> ArtistOverlay<'a> {
-        let artist = state.selected().map(|i| &artists[i]);
-
-        let item_indent = "   ";
-        let list_indent = "     - ";
-        let properties = Paragraph::new(format!(
-            "Artist: {}\n\n{item_indent}\
-             MusicBrainz: {}\n{item_indent}\
-             MusicButler: {}\n{item_indent}\
-             Bandcamp: {}\n{item_indent}\
-             Qobuz: {}",
-            artist.map(|a| a.id.name.as_str()).unwrap_or(""),
-            Self::opt_opt_to_str(artist.map(|a| a.properties.musicbrainz.as_ref())),
-            Self::opt_vec_to_string(artist.map(|a| &a.properties.musicbutler), list_indent),
-            Self::opt_vec_to_string(artist.map(|a| &a.properties.bandcamp), list_indent),
-            Self::opt_opt_to_str(artist.map(|a| a.properties.qobuz.as_ref())),
-        ));
-
-        ArtistOverlay { properties }
-    }
-}
-
-struct AlbumState<'a, 'b> {
-    active: bool,
-    list: List<'a>,
-    state: &'b mut ListState,
-    info: Paragraph<'a>,
-}
-
-impl<'a, 'b> AlbumState<'a, 'b> {
-    fn new(active: bool, albums: &'a [Album], state: &'b mut ListState) -> AlbumState<'a, 'b> {
-        let list = List::new(
-            albums
-                .iter()
-                .map(|a| ListItem::new(a.id.title.as_str()))
-                .collect::<Vec<ListItem>>(),
-        );
-
-        let album = state.selected().map(|i| &albums[i]);
-        let info = Paragraph::new(format!(
-            "Title: {}\n\
-             Year: {}",
-            album.map(|a| a.id.title.as_str()).unwrap_or(""),
-            album.map(|a| a.id.year.to_string()).unwrap_or_default(),
-        ));
-
-        AlbumState {
-            active,
-            list,
-            state,
-            info,
-        }
-    }
-}
-
-struct TrackState<'a, 'b> {
-    active: bool,
-    list: List<'a>,
-    state: &'b mut ListState,
-    info: Paragraph<'a>,
-}
-
-impl<'a, 'b> TrackState<'a, 'b> {
-    fn new(active: bool, tracks: &'a [Track], state: &'b mut ListState) -> TrackState<'a, 'b> {
-        let list = List::new(
-            tracks
-                .iter()
-                .map(|tr| ListItem::new(tr.id.title.as_str()))
-                .collect::<Vec<ListItem>>(),
-        );
-
-        let track = state.selected().map(|i| &tracks[i]);
-        let info = Paragraph::new(format!(
-            "Track: {}\n\
-             Title: {}\n\
-             Artist: {}\n\
-             Quality: {}",
-            track.map(|t| t.id.number.to_string()).unwrap_or_default(),
-            track.map(|t| t.id.title.as_str()).unwrap_or(""),
-            track.map(|t| t.artist.join("; ")).unwrap_or_default(),
-            track
-                .map(|t| match t.quality.format {
-                    Format::Flac => "FLAC".to_string(),
-                    Format::Mp3 => format!("MP3 {}kbps", t.quality.bitrate),
-                })
-                .unwrap_or_default(),
-        ));
-
-        TrackState {
-            active,
-            list,
-            state,
-            info,
-        }
-    }
-}
-
-pub struct Ui<MH> {
     running: bool,
     music_hoard: MH,
     selection: Selection,
@@ -622,6 +331,7 @@ pub struct Ui<MH> {
 
 impl<MH: IMusicHoard> Ui<MH> {
     pub fn new(mut music_hoard: MH) -> Result<Self, Error> {
+        // FIXME: if either returns an error start in an error state
         music_hoard.load_from_database()?;
         music_hoard.rescan_library()?;
         let selection = Selection::new(Some(music_hoard.get_collection()));
@@ -632,182 +342,6 @@ impl<MH: IMusicHoard> Ui<MH> {
             state: UiState::Browse(()),
         })
     }
-
-    fn style(_active: bool) -> Style {
-        Style::default().fg(Color::White).bg(Color::Black)
-    }
-
-    fn block_style(active: bool) -> Style {
-        Self::style(active)
-    }
-
-    fn highlight_style(active: bool) -> Style {
-        if active {
-            Style::default().fg(Color::White).bg(Color::DarkGray)
-        } else {
-            Self::style(false)
-        }
-    }
-
-    fn block<'a>(title: &str, active: bool) -> Block<'a> {
-        Block::default()
-            .title_alignment(Alignment::Center)
-            .borders(Borders::ALL)
-            .border_type(BorderType::Rounded)
-            .style(Self::block_style(active))
-            .title(format!(" {title} "))
-    }
-
-    fn render_list_widget<B: Backend>(
-        title: &str,
-        list: List,
-        list_state: &mut ListState,
-        active: bool,
-        area: Rect,
-        frame: &mut Frame<'_, B>,
-    ) {
-        frame.render_stateful_widget(
-            list.highlight_style(Self::highlight_style(active))
-                .highlight_symbol(">> ")
-                .style(Self::style(active))
-                .block(Self::block(title, active)),
-            area,
-            list_state,
-        );
-    }
-
-    fn render_info_widget<B: Backend>(
-        title: &str,
-        paragraph: Paragraph,
-        active: bool,
-        area: Rect,
-        frame: &mut Frame<'_, B>,
-    ) {
-        frame.render_widget(
-            paragraph
-                .style(Self::style(active))
-                .block(Self::block(title, active)),
-            area,
-        );
-    }
-
-    fn render_overlay_widget<B: Backend>(
-        title: &str,
-        paragraph: Paragraph,
-        area: Rect,
-        frame: &mut Frame<'_, B>,
-    ) {
-        frame.render_widget(Clear, area);
-        frame.render_widget(
-            paragraph
-                .style(Self::style(true))
-                .block(Self::block(title, true)),
-            area,
-        );
-    }
-
-    fn render_artist_column<B: Backend>(st: ArtistState, ar: ArtistArea, fr: &mut Frame<'_, B>) {
-        Self::render_list_widget("Artists", st.list, st.state, st.active, ar.list, fr);
-    }
-
-    fn render_album_column<B: Backend>(st: AlbumState, ar: AlbumArea, fr: &mut Frame<'_, B>) {
-        Self::render_list_widget("Albums", st.list, st.state, st.active, ar.list, fr);
-        Self::render_info_widget("Album info", st.info, st.active, ar.info, fr);
-    }
-
-    fn render_track_column<B: Backend>(st: TrackState, ar: TrackArea, fr: &mut Frame<'_, B>) {
-        Self::render_list_widget("Tracks", st.list, st.state, st.active, ar.list, fr);
-        Self::render_info_widget("Track info", st.info, st.active, ar.info, fr);
-    }
-
-    fn render_collection<B: Backend>(
-        artists: &Collection,
-        selection: &mut Selection,
-        frame: &mut Frame<'_, B>,
-    ) {
-        let active = selection.active;
-        let areas = FrameArea::new(frame.size());
-
-        let artist_selection = &mut selection.artist;
-        let artist_state = ArtistState::new(
-            active == Category::Artist,
-            artists,
-            &mut artist_selection.state,
-        );
-
-        Self::render_artist_column(artist_state, areas.artist, frame);
-
-        let no_albums: Vec<Album> = vec![];
-        let albums = artist_selection
-            .state
-            .selected()
-            .map(|i| &artists[i].albums)
-            .unwrap_or_else(|| &no_albums);
-        let album_selection = &mut artist_selection.album;
-        let album_state = AlbumState::new(
-            active == Category::Album,
-            albums,
-            &mut album_selection.state,
-        );
-
-        Self::render_album_column(album_state, areas.album, frame);
-
-        let no_tracks: Vec<Track> = vec![];
-        let tracks = album_selection
-            .state
-            .selected()
-            .map(|i| &albums[i].tracks)
-            .unwrap_or_else(|| &no_tracks);
-        let track_selection = &mut album_selection.track;
-        let track_state = TrackState::new(
-            active == Category::Track,
-            tracks,
-            &mut track_selection.state,
-        );
-
-        Self::render_track_column(track_state, areas.track, frame);
-    }
-
-    fn render_info_overlay<B: Backend>(
-        artists: &Collection,
-        selection: &mut Selection,
-        frame: &mut Frame<'_, B>,
-    ) {
-        let area = OverlayBuilder::default().build(frame.size());
-
-        let artist_selection = &mut selection.artist;
-        let artist_overlay = ArtistOverlay::new(artists, &artist_selection.state);
-
-        Self::render_overlay_widget("Artist", artist_overlay.properties, area, frame);
-    }
-
-    fn render_reload_overlay<B: Backend>(frame: &mut Frame<'_, B>) {
-        let area = OverlayBuilder::default()
-            .with_width(OverlaySize::Value(39))
-            .with_height(OverlaySize::Value(4))
-            .build(frame.size());
-
-        let reload_text = Paragraph::new(
-            "d: database\n\
-             l: library",
-        )
-        .alignment(Alignment::Center);
-
-        Self::render_overlay_widget("Reload", reload_text, area, frame);
-    }
-
-    fn render_error_overlay<S: AsRef<str>, B: Backend>(msg: S, frame: &mut Frame<'_, B>) {
-        let area = OverlayBuilder::default()
-            .with_height(OverlaySize::Value(4))
-            .build(frame.size());
-
-        let error_text = Paragraph::new(msg.as_ref())
-            .alignment(Alignment::Center)
-            .wrap(Wrap { trim: true });
-
-        // FIXME: highlight with red
-        Self::render_overlay_widget("Error", error_text, area, frame);
-    }
 }
 
 impl<MH: IMusicHoard> IUi for Ui<MH> {
@@ -837,15 +371,18 @@ impl<MH: IMusicHoard> IUi for Ui<MH> {
         }
     }
 
-    fn render<B: Backend>(&mut self, frame: &mut Frame<'_, B>) {
+    // FIXME: rendering logic should be in render.rs - reverse Renderer/Ui relationship so that TUI
+    // calls are renderer.render(ui, frame); Then rename ui -> app and render -> ui as it used to be
+    // originally.
+    fn render<R: IRender, B: Backend>(&mut self, _: &R, frame: &mut Frame<'_, B>) {
         let collection: &Collection = &self.music_hoard.get_collection();
         let selection: &mut Selection = &mut self.selection;
 
-        Self::render_collection(collection, selection, frame);
+        R::render_collection(collection, selection, frame);
         match self.state {
-            UiState::Info(_) => Self::render_info_overlay(collection, selection, frame),
+            UiState::Info(_) => R::render_info_overlay(collection, selection, frame),
-            UiState::Reload(_) => Self::render_reload_overlay(frame),
+            UiState::Reload(_) => R::render_reload_overlay(frame),
-            UiState::Error(ref msg) => Self::render_error_overlay(msg, frame),
+            UiState::Error(ref msg) => R::render_error_overlay(msg, frame),
             _ => {}
         }
     }
@@ -934,6 +471,7 @@ mod tests {
     use crate::tui::lib::MockIMusicHoard;
     use crate::tui::testmod::COLLECTION;
     use crate::tui::tests::{terminal, ui};
+    use crate::tui::ui::render::Renderer;
 
     use super::*;
 
@@ -954,7 +492,7 @@ mod tests {
     }
 
     #[test]
-    fn test_track_selection() {
+    fn track_selection() {
         let tracks = &COLLECTION[0].albums[0].tracks;
         assert!(tracks.len() > 1);
 
@@ -990,7 +528,7 @@ mod tests {
     }
 
     #[test]
-    fn test_album_selection() {
+    fn album_selection() {
         let albums = &COLLECTION[0].albums;
         assert!(albums.len() > 1);
 
@@ -1048,7 +586,7 @@ mod tests {
     }
 
     #[test]
-    fn test_artist_selection() {
+    fn artist_selection() {
         let artists = &COLLECTION;
         assert!(artists.len() > 1);
 
@@ -1106,7 +644,7 @@ mod tests {
     }
 
     #[test]
-    fn ui_running() {
+    fn running() {
         let mut ui = Ui::new(music_hoard(COLLECTION.to_owned())).unwrap();
         assert!(ui.is_running());
 
@@ -1115,7 +653,7 @@ mod tests {
     }
 
     #[test]
-    fn ui_save() {
+    fn save() {
         let mut music_hoard = music_hoard(COLLECTION.to_owned());
 
         music_hoard
@@ -1130,7 +668,7 @@ mod tests {
     }
 
     #[test]
-    fn ui_modifiers() {
+    fn modifiers() {
         let mut ui = Ui::new(music_hoard(COLLECTION.to_owned())).unwrap();
         assert!(ui.is_running());
 
@@ -1219,7 +757,7 @@ mod tests {
     }
 
     #[test]
-    fn app_no_tracks() {
+    fn no_tracks() {
         let mut collection = COLLECTION.to_owned();
         collection[0].albums[0].tracks = vec![];
 
@@ -1248,7 +786,7 @@ mod tests {
     }
 
     #[test]
-    fn app_no_albums() {
+    fn no_albums() {
         let mut collection = COLLECTION.to_owned();
         collection[0].albums = vec![];
 
@@ -1290,7 +828,7 @@ mod tests {
     }
 
     #[test]
-    fn app_no_artists() {
+    fn no_artists() {
         let mut app = Ui::new(music_hoard(vec![])).unwrap();
         assert!(app.is_running());
 
@@ -1343,50 +881,120 @@ mod tests {
     // This is UI so the only sensible unit test is to run the code through various app states.
 
     #[test]
-    fn empty() {
+    fn info_overlay() {
         let mut terminal = terminal();
-        let mut ui = ui(vec![]);
+        let renderer = Renderer;
 
-        terminal.draw(|frame| ui.render(frame)).unwrap();
-    }
-
-    #[test]
-    fn collection() {
-        let mut terminal = terminal();
-        let mut ui = ui(COLLECTION.to_owned());
-
-        terminal.draw(|frame| ui.render(frame)).unwrap();
-
-        // Change the track (which has a different track format).
-        ui.increment_category();
-        ui.increment_category();
-        ui.increment_selection();
-
-        terminal.draw(|frame| ui.render(frame)).unwrap();
-    }
-
-    #[test]
-    fn overlay() {
-        let mut terminal = terminal();
         let mut ui = ui(COLLECTION.to_owned());
         assert!(ui.state().is_browse());
-
+        terminal.draw(|frame| ui.render(&renderer, frame)).unwrap();
-        terminal.draw(|frame| ui.render(frame)).unwrap();
 
         ui.show_info_overlay();
         assert!(ui.state().is_info());
-
+        terminal.draw(|frame| ui.render(&renderer, frame)).unwrap();
-        terminal.draw(|frame| ui.render(frame)).unwrap();
 
         // Change the artist (which has a multi-link entry).
         ui.increment_selection();
-
+        terminal.draw(|frame| ui.render(&renderer, frame)).unwrap();
-        terminal.draw(|frame| ui.render(frame)).unwrap();
 
         ui.hide_info_overlay();
         assert!(ui.state().is_browse());
+        terminal.draw(|frame| ui.render(&renderer, frame)).unwrap();
+    }
 
-        terminal.draw(|frame| ui.render(frame)).unwrap();
+    #[test]
+    fn reload_go_back() {
+        let mut terminal = terminal();
+        let renderer = Renderer;
+        let music_hoard = music_hoard(COLLECTION.to_owned());
+
+        let mut ui = Ui::new(music_hoard).unwrap();
+        assert!(ui.state().is_browse());
+        terminal.draw(|frame| ui.render(&renderer, frame)).unwrap();
+
+        ui.show_reload_menu();
+        assert!(ui.state().is_reload());
+        terminal.draw(|frame| ui.render(&renderer, frame)).unwrap();
+
+        ui.go_back();
+        assert!(ui.state().is_browse());
+        terminal.draw(|frame| ui.render(&renderer, frame)).unwrap();
+    }
+
+    #[test]
+    fn reload_database() {
+        let mut terminal = terminal();
+        let renderer = Renderer;
+        let mut music_hoard = music_hoard(COLLECTION.to_owned());
+
+        music_hoard
+            .expect_load_from_database()
+            .times(1)
+            .return_once(|| Ok(()));
+
+        let mut ui = Ui::new(music_hoard).unwrap();
+        assert!(ui.state().is_browse());
+        terminal.draw(|frame| ui.render(&renderer, frame)).unwrap();
+
+        ui.show_reload_menu();
+        assert!(ui.state().is_reload());
+        terminal.draw(|frame| ui.render(&renderer, frame)).unwrap();
+
+        ui.reload_database();
+        assert!(ui.state().is_browse());
+        terminal.draw(|frame| ui.render(&renderer, frame)).unwrap();
+    }
+
+    #[test]
+    fn reload_library() {
+        let mut terminal = terminal();
+        let renderer = Renderer;
+        let mut music_hoard = music_hoard(COLLECTION.to_owned());
+
+        music_hoard
+            .expect_rescan_library()
+            .times(1)
+            .return_once(|| Ok(()));
+
+        let mut ui = Ui::new(music_hoard).unwrap();
+        assert!(ui.state().is_browse());
+        terminal.draw(|frame| ui.render(&renderer, frame)).unwrap();
+
+        ui.show_reload_menu();
+        assert!(ui.state().is_reload());
+        terminal.draw(|frame| ui.render(&renderer, frame)).unwrap();
+
+        ui.reload_library();
+        assert!(ui.state().is_browse());
+        terminal.draw(|frame| ui.render(&renderer, frame)).unwrap();
+    }
+
+    #[test]
+    fn reload_error() {
+        let mut terminal = terminal();
+        let renderer = Renderer;
+        let mut music_hoard = music_hoard(COLLECTION.to_owned());
+
+        music_hoard
+            .expect_load_from_database()
+            .times(1)
+            .return_once(|| Err(musichoard::Error::DatabaseError(String::from("get rekt"))));
+
+        let mut ui = Ui::new(music_hoard).unwrap();
+        assert!(ui.state().is_browse());
+        terminal.draw(|frame| ui.render(&renderer, frame)).unwrap();
+
+        ui.show_reload_menu();
+        assert!(ui.state().is_reload());
+        terminal.draw(|frame| ui.render(&renderer, frame)).unwrap();
+
+        ui.reload_database();
+        assert!(ui.state().is_error());
+        terminal.draw(|frame| ui.render(&renderer, frame)).unwrap();
+
+        ui.dismiss_error();
+        assert!(ui.state().is_browse());
+        terminal.draw(|frame| ui.render(&renderer, frame)).unwrap();
     }
 
     #[test]

src/tui/ui/render.rs

@@ -0,0 +1,573 @@
+use musichoard::collection::{
+    album::Album,
+    artist::Artist,
+    track::{Format, Track},
+    Collection,
+};
+use ratatui::{
+    backend::Backend,
+    layout::{Alignment, Rect},
+    style::{Color, Style},
+    widgets::{Block, BorderType, Borders, Clear, List, ListItem, ListState, Paragraph, Wrap},
+    Frame,
+};
+
+use crate::tui::ui::{Category, Selection};
+
+pub trait IRender {
+    fn render_collection<B: Backend>(
+        artists: &Collection,
+        selection: &mut Selection,
+        frame: &mut Frame<'_, B>,
+    );
+    fn render_info_overlay<B: Backend>(
+        artists: &Collection,
+        selection: &mut Selection,
+        frame: &mut Frame<'_, B>,
+    );
+    fn render_reload_overlay<B: Backend>(frame: &mut Frame<'_, B>);
+    fn render_error_overlay<S: AsRef<str>, B: Backend>(msg: S, frame: &mut Frame<'_, B>);
+}
+
+struct ArtistArea {
+    list: Rect,
+}
+
+struct AlbumArea {
+    list: Rect,
+    info: Rect,
+}
+
+struct TrackArea {
+    list: Rect,
+    info: Rect,
+}
+
+struct FrameArea {
+    artist: ArtistArea,
+    album: AlbumArea,
+    track: TrackArea,
+}
+
+impl FrameArea {
+    fn new(frame: Rect) -> Self {
+        let width_one_third = frame.width / 3;
+        let height_one_third = frame.height / 3;
+
+        let panel_width = width_one_third;
+        let panel_width_last = frame.width - 2 * panel_width;
+        let panel_height_top = frame.height - height_one_third;
+        let panel_height_bottom = height_one_third;
+
+        let artist_list = Rect {
+            x: frame.x,
+            y: frame.y,
+            width: panel_width,
+            height: frame.height,
+        };
+
+        let album_list = Rect {
+            x: artist_list.x + artist_list.width,
+            y: frame.y,
+            width: panel_width,
+            height: panel_height_top,
+        };
+
+        let album_info = Rect {
+            x: album_list.x,
+            y: album_list.y + album_list.height,
+            width: album_list.width,
+            height: panel_height_bottom,
+        };
+
+        let track_list = Rect {
+            x: album_list.x + album_list.width,
+            y: frame.y,
+            width: panel_width_last,
+            height: panel_height_top,
+        };
+
+        let track_info = Rect {
+            x: track_list.x,
+            y: track_list.y + track_list.height,
+            width: track_list.width,
+            height: panel_height_bottom,
+        };
+
+        FrameArea {
+            artist: ArtistArea { list: artist_list },
+            album: AlbumArea {
+                list: album_list,
+                info: album_info,
+            },
+            track: TrackArea {
+                list: track_list,
+                info: track_info,
+            },
+        }
+    }
+}
+
+enum OverlaySize {
+    MarginFactor(u16),
+    Value(u16),
+}
+
+impl Default for OverlaySize {
+    fn default() -> Self {
+        OverlaySize::MarginFactor(8)
+    }
+}
+
+impl OverlaySize {
+    fn get(&self, full: u16) -> (u16, u16) {
+        match self {
+            OverlaySize::MarginFactor(margin_factor) => {
+                let margin = full / margin_factor;
+                (margin, full - (2 * margin))
+            }
+            OverlaySize::Value(value) => {
+                let margin = (full - value) / 2;
+                (margin, *value)
+            }
+        }
+    }
+}
+
+#[derive(Default)]
+struct OverlayBuilder {
+    width: OverlaySize,
+    height: OverlaySize,
+}
+
+impl OverlayBuilder {
+    fn with_width(mut self, width: OverlaySize) -> OverlayBuilder {
+        self.width = width;
+        self
+    }
+
+    fn with_height(mut self, height: OverlaySize) -> OverlayBuilder {
+        self.height = height;
+        self
+    }
+
+    fn build(self, frame: Rect) -> Rect {
+        let (x, width) = self.width.get(frame.width);
+        let (y, height) = self.height.get(frame.height);
+
+        Rect {
+            x,
+            y,
+            width,
+            height,
+        }
+    }
+}
+
+struct ArtistState<'a, 'b> {
+    active: bool,
+    list: List<'a>,
+    state: &'b mut ListState,
+}
+
+impl<'a, 'b> ArtistState<'a, 'b> {
+    fn new(active: bool, artists: &'a [Artist], state: &'b mut ListState) -> ArtistState<'a, 'b> {
+        let list = List::new(
+            artists
+                .iter()
+                .map(|a| ListItem::new(a.id.name.as_str()))
+                .collect::<Vec<ListItem>>(),
+        );
+
+        ArtistState {
+            active,
+            list,
+            state,
+        }
+    }
+}
+
+struct ArtistOverlay<'a> {
+    properties: Paragraph<'a>,
+}
+
+impl<'a> ArtistOverlay<'a> {
+    fn opt_opt_to_str<S: AsRef<str>>(opt: Option<Option<&S>>) -> &str {
+        opt.flatten().map(|item| item.as_ref()).unwrap_or("")
+    }
+
+    fn opt_vec_to_string<S: AsRef<str>>(opt_vec: Option<&Vec<S>>, indent: &str) -> String {
+        opt_vec
+            .map(|vec| {
+                if vec.len() < 2 {
+                    vec.first()
+                        .map(|item| item.as_ref())
+                        .unwrap_or("")
+                        .to_string()
+                } else {
+                    let indent = format!("\n{indent}");
+                    let list = vec
+                        .iter()
+                        .map(|item| item.as_ref())
+                        .collect::<Vec<&str>>()
+                        .join(&indent);
+                    format!("{indent}{list}")
+                }
+            })
+            .unwrap_or_else(|| String::from(""))
+    }
+
+    fn new(artists: &'a [Artist], state: &ListState) -> ArtistOverlay<'a> {
+        let artist = state.selected().map(|i| &artists[i]);
+
+        let item_indent = "   ";
+        let list_indent = "     - ";
+        let properties = Paragraph::new(format!(
+            "Artist: {}\n\n{item_indent}\
+             MusicBrainz: {}\n{item_indent}\
+             MusicButler: {}\n{item_indent}\
+             Bandcamp: {}\n{item_indent}\
+             Qobuz: {}",
+            artist.map(|a| a.id.name.as_str()).unwrap_or(""),
+            Self::opt_opt_to_str(artist.map(|a| a.properties.musicbrainz.as_ref())),
+            Self::opt_vec_to_string(artist.map(|a| &a.properties.musicbutler), list_indent),
+            Self::opt_vec_to_string(artist.map(|a| &a.properties.bandcamp), list_indent),
+            Self::opt_opt_to_str(artist.map(|a| a.properties.qobuz.as_ref())),
+        ));
+
+        ArtistOverlay { properties }
+    }
+}
+
+struct AlbumState<'a, 'b> {
+    active: bool,
+    list: List<'a>,
+    state: &'b mut ListState,
+    info: Paragraph<'a>,
+}
+
+impl<'a, 'b> AlbumState<'a, 'b> {
+    fn new(active: bool, albums: &'a [Album], state: &'b mut ListState) -> AlbumState<'a, 'b> {
+        let list = List::new(
+            albums
+                .iter()
+                .map(|a| ListItem::new(a.id.title.as_str()))
+                .collect::<Vec<ListItem>>(),
+        );
+
+        let album = state.selected().map(|i| &albums[i]);
+        let info = Paragraph::new(format!(
+            "Title: {}\n\
+             Year: {}",
+            album.map(|a| a.id.title.as_str()).unwrap_or(""),
+            album.map(|a| a.id.year.to_string()).unwrap_or_default(),
+        ));
+
+        AlbumState {
+            active,
+            list,
+            state,
+            info,
+        }
+    }
+}
+
+struct TrackState<'a, 'b> {
+    active: bool,
+    list: List<'a>,
+    state: &'b mut ListState,
+    info: Paragraph<'a>,
+}
+
+impl<'a, 'b> TrackState<'a, 'b> {
+    fn new(active: bool, tracks: &'a [Track], state: &'b mut ListState) -> TrackState<'a, 'b> {
+        let list = List::new(
+            tracks
+                .iter()
+                .map(|tr| ListItem::new(tr.id.title.as_str()))
+                .collect::<Vec<ListItem>>(),
+        );
+
+        let track = state.selected().map(|i| &tracks[i]);
+        let info = Paragraph::new(format!(
+            "Track: {}\n\
+             Title: {}\n\
+             Artist: {}\n\
+             Quality: {}",
+            track.map(|t| t.id.number.to_string()).unwrap_or_default(),
+            track.map(|t| t.id.title.as_str()).unwrap_or(""),
+            track.map(|t| t.artist.join("; ")).unwrap_or_default(),
+            track
+                .map(|t| match t.quality.format {
+                    Format::Flac => "FLAC".to_string(),
+                    Format::Mp3 => format!("MP3 {}kbps", t.quality.bitrate),
+                })
+                .unwrap_or_default(),
+        ));
+
+        TrackState {
+            active,
+            list,
+            state,
+            info,
+        }
+    }
+}
+
+pub struct Renderer;
+
+impl Renderer {
+    fn style(_active: bool) -> Style {
+        Style::default().fg(Color::White).bg(Color::Black)
+    }
+
+    fn block_style(active: bool) -> Style {
+        Self::style(active)
+    }
+
+    fn highlight_style(active: bool) -> Style {
+        if active {
+            Style::default().fg(Color::White).bg(Color::DarkGray)
+        } else {
+            Self::style(false)
+        }
+    }
+
+    fn block<'a>(title: &str, active: bool) -> Block<'a> {
+        Block::default()
+            .title_alignment(Alignment::Center)
+            .borders(Borders::ALL)
+            .border_type(BorderType::Rounded)
+            .style(Self::block_style(active))
+            .title(format!(" {title} "))
+    }
+
+    fn render_list_widget<B: Backend>(
+        title: &str,
+        list: List,
+        list_state: &mut ListState,
+        active: bool,
+        area: Rect,
+        frame: &mut Frame<'_, B>,
+    ) {
+        frame.render_stateful_widget(
+            list.highlight_style(Self::highlight_style(active))
+                .highlight_symbol(">> ")
+                .style(Self::style(active))
+                .block(Self::block(title, active)),
+            area,
+            list_state,
+        );
+    }
+
+    fn render_info_widget<B: Backend>(
+        title: &str,
+        paragraph: Paragraph,
+        active: bool,
+        area: Rect,
+        frame: &mut Frame<'_, B>,
+    ) {
+        frame.render_widget(
+            paragraph
+                .style(Self::style(active))
+                .block(Self::block(title, active)),
+            area,
+        );
+    }
+
+    fn render_overlay_widget<B: Backend>(
+        title: &str,
+        paragraph: Paragraph,
+        area: Rect,
+        frame: &mut Frame<'_, B>,
+    ) {
+        frame.render_widget(Clear, area);
+        frame.render_widget(
+            paragraph
+                .style(Self::style(true))
+                .block(Self::block(title, true)),
+            area,
+        );
+    }
+
+    fn render_artist_column<B: Backend>(st: ArtistState, ar: ArtistArea, fr: &mut Frame<'_, B>) {
+        Self::render_list_widget("Artists", st.list, st.state, st.active, ar.list, fr);
+    }
+
+    fn render_album_column<B: Backend>(st: AlbumState, ar: AlbumArea, fr: &mut Frame<'_, B>) {
+        Self::render_list_widget("Albums", st.list, st.state, st.active, ar.list, fr);
+        Self::render_info_widget("Album info", st.info, st.active, ar.info, fr);
+    }
+
+    fn render_track_column<B: Backend>(st: TrackState, ar: TrackArea, fr: &mut Frame<'_, B>) {
+        Self::render_list_widget("Tracks", st.list, st.state, st.active, ar.list, fr);
+        Self::render_info_widget("Track info", st.info, st.active, ar.info, fr);
+    }
+}
+
+impl IRender for Renderer {
+    fn render_collection<B: Backend>(
+        artists: &Collection,
+        selection: &mut Selection,
+        frame: &mut Frame<'_, B>,
+    ) {
+        let active = selection.active;
+        let areas = FrameArea::new(frame.size());
+
+        let artist_selection = &mut selection.artist;
+        let artist_state = ArtistState::new(
+            active == Category::Artist,
+            artists,
+            &mut artist_selection.state,
+        );
+
+        Self::render_artist_column(artist_state, areas.artist, frame);
+
+        let no_albums: Vec<Album> = vec![];
+        let albums = artist_selection
+            .state
+            .selected()
+            .map(|i| &artists[i].albums)
+            .unwrap_or_else(|| &no_albums);
+        let album_selection = &mut artist_selection.album;
+        let album_state = AlbumState::new(
+            active == Category::Album,
+            albums,
+            &mut album_selection.state,
+        );
+
+        Self::render_album_column(album_state, areas.album, frame);
+
+        let no_tracks: Vec<Track> = vec![];
+        let tracks = album_selection
+            .state
+            .selected()
+            .map(|i| &albums[i].tracks)
+            .unwrap_or_else(|| &no_tracks);
+        let track_selection = &mut album_selection.track;
+        let track_state = TrackState::new(
+            active == Category::Track,
+            tracks,
+            &mut track_selection.state,
+        );
+
+        Self::render_track_column(track_state, areas.track, frame);
+    }
+
+    fn render_info_overlay<B: Backend>(
+        artists: &Collection,
+        selection: &mut Selection,
+        frame: &mut Frame<'_, B>,
+    ) {
+        let area = OverlayBuilder::default().build(frame.size());
+
+        let artist_selection = &mut selection.artist;
+        let artist_overlay = ArtistOverlay::new(artists, &artist_selection.state);
+
+        Self::render_overlay_widget("Artist", artist_overlay.properties, area, frame);
+    }
+
+    fn render_reload_overlay<B: Backend>(frame: &mut Frame<'_, B>) {
+        let area = OverlayBuilder::default()
+            .with_width(OverlaySize::Value(39))
+            .with_height(OverlaySize::Value(4))
+            .build(frame.size());
+
+        let reload_text = Paragraph::new(
+            "d: database\n\
+             l: library",
+        )
+        .alignment(Alignment::Center);
+
+        Self::render_overlay_widget("Reload", reload_text, area, frame);
+    }
+
+    fn render_error_overlay<S: AsRef<str>, B: Backend>(msg: S, frame: &mut Frame<'_, B>) {
+        let area = OverlayBuilder::default()
+            .with_height(OverlaySize::Value(4))
+            .build(frame.size());
+
+        let error_text = Paragraph::new(msg.as_ref())
+            .alignment(Alignment::Center)
+            .wrap(Wrap { trim: true });
+
+        // FIXME: highlight with red
+        Self::render_overlay_widget("Error", error_text, area, frame);
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::tui::{testmod::COLLECTION, tests::terminal};
+
+    use super::*;
+
+    fn draw_test_suite(artists: &Collection, selection: &mut Selection) {
+        let mut terminal = terminal();
+
+        terminal
+            .draw(|frame| Renderer::render_collection(artists, selection, frame))
+            .unwrap();
+
+        terminal
+            .draw(|frame| Renderer::render_info_overlay(artists, selection, frame))
+            .unwrap();
+
+        terminal
+            .draw(|frame| {
+                Renderer::render_collection(artists, selection, frame);
+                Renderer::render_info_overlay(artists, selection, frame);
+            })
+            .unwrap();
+
+        terminal
+            .draw(|frame| {
+                Renderer::render_collection(artists, selection, frame);
+                Renderer::render_reload_overlay(frame);
+            })
+            .unwrap();
+
+        terminal
+            .draw(|frame| {
+                Renderer::render_collection(artists, selection, frame);
+                Renderer::render_error_overlay("get rekt scrub", frame);
+            })
+            .unwrap();
+    }
+
+    #[test]
+    fn stateless() {
+        let mut terminal = terminal();
+
+        terminal
+            .draw(|frame| Renderer::render_reload_overlay(frame))
+            .unwrap();
+
+        terminal
+            .draw(|frame| Renderer::render_error_overlay("get rekt scrub", frame))
+            .unwrap();
+    }
+
+    #[test]
+    fn empty() {
+        let artists: Vec<Artist> = vec![];
+        let mut selection = Selection::new(Some(&artists));
+
+        draw_test_suite(&artists, &mut selection);
+    }
+
+    #[test]
+    fn collection() {
+        let artists: &Collection = &COLLECTION;
+        let mut selection = Selection::new(Some(artists));
+
+        draw_test_suite(&artists, &mut selection);
+
+        // Change the track (which has a different track format).
+        selection.increment_category();
+        selection.increment_category();
+        selection.increment_selection(artists);
+
+        draw_test_suite(&artists, &mut selection);
+    }
+}