src/core/database/json/testmod.rs

@@ -26,6 +26,11 @@ pub static DATABASE_JSON: &str = "[\
     \"id\":{\"number\":3,\"title\":\"track a.a.3\"},\
     \"artist\":[\"artist a.a.3\"],\
     \"quality\":{\"format\":\"Flac\",\"bitrate\":1061}\
+    },\
+    {\
+    \"id\":{\"number\":4,\"title\":\"track a.a.4\"},\
+    \"artist\":[\"artist a.a.4\"],\
+    \"quality\":{\"format\":\"Flac\",\"bitrate\":1042}\
     }\
     ]\
     },\
@@ -88,6 +93,36 @@ pub static DATABASE_JSON: &str = "[\
     \"quality\":{\"format\":\"Mp3\",\"bitrate\":320}\
     }\
     ]\
+    },\
+    {\
+    \"id\":{\"year\":2009,\"title\":\"album_title b.c\"},\
+    \"tracks\":[\
+    {\
+    \"id\":{\"number\":1,\"title\":\"track b.c.1\"},\
+    \"artist\":[\"artist b.c.1\"],\
+    \"quality\":{\"format\":\"Mp3\",\"bitrate\":190}\
+    },\
+    {\
+    \"id\":{\"number\":2,\"title\":\"track b.c.2\"},\
+    \"artist\":[\"artist b.c.2.1\",\"artist b.c.2.2\"],\
+    \"quality\":{\"format\":\"Mp3\",\"bitrate\":120}\
+    }\
+    ]\
+    },\
+    {\
+    \"id\":{\"year\":2015,\"title\":\"album_title b.d\"},\
+    \"tracks\":[\
+    {\
+    \"id\":{\"number\":1,\"title\":\"track b.d.1\"},\
+    \"artist\":[\"artist b.d.1\"],\
+    \"quality\":{\"format\":\"Mp3\",\"bitrate\":190}\
+    },\
+    {\
+    \"id\":{\"number\":2,\"title\":\"track b.d.2\"},\
+    \"artist\":[\"artist b.d.2.1\",\"artist b.d.2.2\"],\
+    \"quality\":{\"format\":\"Mp3\",\"bitrate\":120}\
+    }\
+    ]\
     }\
     ]\
     },\
@@ -132,5 +167,47 @@ pub static DATABASE_JSON: &str = "[\
     ]\
     }\
     ]\
+    },\
+    {\
+    \"id\":{\"name\":\"album_artist d\"},\
+    \"sort\":null,\
+    \"properties\":{\
+    \"musicbrainz\":null,\
+    \"musicbutler\":[],\
+    \"bandcamp\":[],\
+    \"qobuz\":null\
+    },\
+    \"albums\":[\
+    {\
+    \"id\":{\"year\":1995,\"title\":\"album_title d.a\"},\
+    \"tracks\":[\
+    {\
+    \"id\":{\"number\":1,\"title\":\"track d.a.1\"},\
+    \"artist\":[\"artist d.a.1\"],\
+    \"quality\":{\"format\":\"Mp3\",\"bitrate\":120}\
+    },\
+    {\
+    \"id\":{\"number\":2,\"title\":\"track d.a.2\"},\
+    \"artist\":[\"artist d.a.2.1\",\"artist d.a.2.2\"],\
+    \"quality\":{\"format\":\"Mp3\",\"bitrate\":120}\
+    }\
+    ]\
+    },\
+    {\
+    \"id\":{\"year\":2028,\"title\":\"album_title d.b\"},\
+    \"tracks\":[\
+    {\
+    \"id\":{\"number\":1,\"title\":\"track d.b.1\"},\
+    \"artist\":[\"artist d.b.1\"],\
+    \"quality\":{\"format\":\"Flac\",\"bitrate\":841}\
+    },\
+    {\
+    \"id\":{\"number\":2,\"title\":\"track d.b.2\"},\
+    \"artist\":[\"artist d.b.2.1\",\"artist d.b.2.2\"],\
+    \"quality\":{\"format\":\"Flac\",\"bitrate\":756}\
+    }\
+    ]\
+    }\
+    ]\
     }\
     ]";

src/core/library/beets/testmod.rs

@@ -5,15 +5,24 @@ pub static LIBRARY_BEETS: Lazy<Vec<String>> = Lazy::new(|| -> Vec<String> {
         String::from("album_artist a -*^-  -*^- 1998 -*^- album_title a.a -*^- 1 -*^- track a.a.1 -*^- artist a.a.1 -*^- FLAC -*^- 992"),
         String::from("album_artist a -*^-  -*^- 1998 -*^- album_title a.a -*^- 2 -*^- track a.a.2 -*^- artist a.a.2.1; artist a.a.2.2 -*^- MP3 -*^- 320"),
         String::from("album_artist a -*^-  -*^- 1998 -*^- album_title a.a -*^- 3 -*^- track a.a.3 -*^- artist a.a.3 -*^- FLAC -*^- 1061"),
+        String::from("album_artist a -*^-  -*^- 1998 -*^- album_title a.a -*^- 4 -*^- track a.a.4 -*^- artist a.a.4 -*^- FLAC -*^- 1042"),
         String::from("album_artist a -*^-  -*^- 2015 -*^- album_title a.b -*^- 1 -*^- track a.b.1 -*^- artist a.b.1 -*^- FLAC -*^- 1004"),
         String::from("album_artist a -*^-  -*^- 2015 -*^- album_title a.b -*^- 2 -*^- track a.b.2 -*^- artist a.b.2 -*^- FLAC -*^- 1077"),
         String::from("album_artist b -*^-  -*^- 2003 -*^- album_title b.a -*^- 1 -*^- track b.a.1 -*^- artist b.a.1 -*^- MP3 -*^- 190"),
         String::from("album_artist b -*^-  -*^- 2003 -*^- album_title b.a -*^- 2 -*^- track b.a.2 -*^- artist b.a.2.1; artist b.a.2.2 -*^- MP3 -*^- 120"),
         String::from("album_artist b -*^-  -*^- 2008 -*^- album_title b.b -*^- 1 -*^- track b.b.1 -*^- artist b.b.1 -*^- FLAC -*^- 1077"),
         String::from("album_artist b -*^-  -*^- 2008 -*^- album_title b.b -*^- 2 -*^- track b.b.2 -*^- artist b.b.2.1; artist b.b.2.2 -*^- MP3 -*^- 320"),
+        String::from("album_artist b -*^-  -*^- 2009 -*^- album_title b.c -*^- 1 -*^- track b.c.1 -*^- artist b.c.1 -*^- MP3 -*^- 190"),
+        String::from("album_artist b -*^-  -*^- 2009 -*^- album_title b.c -*^- 2 -*^- track b.c.2 -*^- artist b.c.2.1; artist b.c.2.2 -*^- MP3 -*^- 120"),
+        String::from("album_artist b -*^-  -*^- 2015 -*^- album_title b.d -*^- 1 -*^- track b.d.1 -*^- artist b.d.1 -*^- MP3 -*^- 190"),
+        String::from("album_artist b -*^-  -*^- 2015 -*^- album_title b.d -*^- 2 -*^- track b.d.2 -*^- artist b.d.2.1; artist b.d.2.2 -*^- MP3 -*^- 120"),
         String::from("album_artist c -*^-  -*^- 1985 -*^- album_title c.a -*^- 1 -*^- track c.a.1 -*^- artist c.a.1 -*^- MP3 -*^- 320"),
         String::from("album_artist c -*^-  -*^- 1985 -*^- album_title c.a -*^- 2 -*^- track c.a.2 -*^- artist c.a.2.1; artist c.a.2.2 -*^- MP3 -*^- 120"),
         String::from("album_artist c -*^-  -*^- 2018 -*^- album_title c.b -*^- 1 -*^- track c.b.1 -*^- artist c.b.1 -*^- FLAC -*^- 1041"),
-        String::from("album_artist c -*^-  -*^- 2018 -*^- album_title c.b -*^- 2 -*^- track c.b.2 -*^- artist c.b.2.1; artist c.b.2.2 -*^- FLAC -*^- 756")
+        String::from("album_artist c -*^-  -*^- 2018 -*^- album_title c.b -*^- 2 -*^- track c.b.2 -*^- artist c.b.2.1; artist c.b.2.2 -*^- FLAC -*^- 756"),
+        String::from("album_artist d -*^-  -*^- 1995 -*^- album_title d.a -*^- 1 -*^- track d.a.1 -*^- artist d.a.1 -*^- MP3 -*^- 120"),
+        String::from("album_artist d -*^-  -*^- 1995 -*^- album_title d.a -*^- 2 -*^- track d.a.2 -*^- artist d.a.2.1; artist d.a.2.2 -*^- MP3 -*^- 120"),
+        String::from("album_artist d -*^-  -*^- 2028 -*^- album_title d.b -*^- 1 -*^- track d.b.1 -*^- artist d.b.1 -*^- FLAC -*^- 841"),
+        String::from("album_artist d -*^-  -*^- 2028 -*^- album_title d.b -*^- 2 -*^- track d.b.2 -*^- artist d.b.2.1; artist d.b.2.2 -*^- FLAC -*^- 756")
     ]
 });

src/core/library/testmod.rs

@@ -40,6 +40,17 @@ pub static LIBRARY_ITEMS: Lazy<Vec<Item>> = Lazy::new(|| -> Vec<Item> {
             track_format: Format::Flac,
             track_bitrate: 1061,
         },
+        Item {
+            album_artist: String::from("album_artist a"),
+            album_artist_sort: None,
+            album_year: 1998,
+            album_title: String::from("album_title a.a"),
+            track_number: 4,
+            track_title: String::from("track a.a.4"),
+            track_artist: vec![String::from("artist a.a.4")],
+            track_format: Format::Flac,
+            track_bitrate: 1042,
+        },
         Item {
             album_artist: String::from("album_artist a"),
             album_artist_sort: None,
@@ -112,6 +123,56 @@ pub static LIBRARY_ITEMS: Lazy<Vec<Item>> = Lazy::new(|| -> Vec<Item> {
             track_format: Format::Mp3,
             track_bitrate: 320,
         },
+        Item {
+            album_artist: String::from("album_artist b"),
+            album_artist_sort: None,
+            album_year: 2009,
+            album_title: String::from("album_title b.c"),
+            track_number: 1,
+            track_title: String::from("track b.c.1"),
+            track_artist: vec![String::from("artist b.c.1")],
+            track_format: Format::Mp3,
+            track_bitrate: 190,
+        },
+        Item {
+            album_artist: String::from("album_artist b"),
+            album_artist_sort: None,
+            album_year: 2009,
+            album_title: String::from("album_title b.c"),
+            track_number: 2,
+            track_title: String::from("track b.c.2"),
+            track_artist: vec![
+                String::from("artist b.c.2.1"),
+                String::from("artist b.c.2.2"),
+            ],
+            track_format: Format::Mp3,
+            track_bitrate: 120,
+        },
+        Item {
+            album_artist: String::from("album_artist b"),
+            album_artist_sort: None,
+            album_year: 2015,
+            album_title: String::from("album_title b.d"),
+            track_number: 1,
+            track_title: String::from("track b.d.1"),
+            track_artist: vec![String::from("artist b.d.1")],
+            track_format: Format::Mp3,
+            track_bitrate: 190,
+        },
+        Item {
+            album_artist: String::from("album_artist b"),
+            album_artist_sort: None,
+            album_year: 2015,
+            album_title: String::from("album_title b.d"),
+            track_number: 2,
+            track_title: String::from("track b.d.2"),
+            track_artist: vec![
+                String::from("artist b.d.2.1"),
+                String::from("artist b.d.2.2"),
+            ],
+            track_format: Format::Mp3,
+            track_bitrate: 120,
+        },
         Item {
             album_artist: String::from("album_artist c"),
             album_artist_sort: None,
@@ -162,5 +223,55 @@ pub static LIBRARY_ITEMS: Lazy<Vec<Item>> = Lazy::new(|| -> Vec<Item> {
             track_format: Format::Flac,
             track_bitrate: 756,
         },
+        Item {
+            album_artist: String::from("album_artist d"),
+            album_artist_sort: None,
+            album_year: 1995,
+            album_title: String::from("album_title d.a"),
+            track_number: 1,
+            track_title: String::from("track d.a.1"),
+            track_artist: vec![String::from("artist d.a.1")],
+            track_format: Format::Mp3,
+            track_bitrate: 120,
+        },
+        Item {
+            album_artist: String::from("album_artist d"),
+            album_artist_sort: None,
+            album_year: 1995,
+            album_title: String::from("album_title d.a"),
+            track_number: 2,
+            track_title: String::from("track d.a.2"),
+            track_artist: vec![
+                String::from("artist d.a.2.1"),
+                String::from("artist d.a.2.2"),
+            ],
+            track_format: Format::Mp3,
+            track_bitrate: 120,
+        },
+        Item {
+            album_artist: String::from("album_artist d"),
+            album_artist_sort: None,
+            album_year: 2028,
+            album_title: String::from("album_title d.b"),
+            track_number: 1,
+            track_title: String::from("track d.b.1"),
+            track_artist: vec![String::from("artist d.b.1")],
+            track_format: Format::Flac,
+            track_bitrate: 841,
+        },
+        Item {
+            album_artist: String::from("album_artist d"),
+            album_artist_sort: None,
+            album_year: 2028,
+            album_title: String::from("album_title d.b"),
+            track_number: 2,
+            track_title: String::from("track d.b.2"),
+            track_artist: vec![
+                String::from("artist d.b.2.1"),
+                String::from("artist d.b.2.2"),
+            ],
+            track_format: Format::Flac,
+            track_bitrate: 756,
+        },
     ]
 });

src/tests.rs

@@ -55,6 +55,17 @@ macro_rules! library_collection {
                                     bitrate: 1061,
                                 },
                             },
+                            Track {
+                                id: TrackId {
+                                    number: 4,
+                                    title: "track a.a.4".to_string(),
+                                },
+                                artist: vec!["artist a.a.4".to_string()],
+                                quality: Quality {
+                                    format: Format::Flac,
+                                    bitrate: 1042,
+                                },
+                            },
                         ],
                     },
                     Album {
@@ -167,6 +178,72 @@ macro_rules! library_collection {
                             },
                         ],
                     },
+                    Album {
+                        id: AlbumId {
+                            year: 2009,
+                            title: "album_title b.c".to_string(),
+                        },
+                        tracks: vec![
+                            Track {
+                                id: TrackId {
+                                    number: 1,
+                                    title: "track b.c.1".to_string(),
+                                },
+                                artist: vec!["artist b.c.1".to_string()],
+                                quality: Quality {
+                                    format: Format::Mp3,
+                                    bitrate: 190,
+                                },
+                            },
+                            Track {
+                                id: TrackId {
+                                    number: 2,
+                                    title: "track b.c.2".to_string(),
+                                },
+                                artist: vec![
+                                    "artist b.c.2.1".to_string(),
+                                    "artist b.c.2.2".to_string(),
+                                ],
+                                quality: Quality {
+                                    format: Format::Mp3,
+                                    bitrate: 120,
+                                },
+                            },
+                        ],
+                    },
+                    Album {
+                        id: AlbumId {
+                            year: 2015,
+                            title: "album_title b.d".to_string(),
+                        },
+                        tracks: vec![
+                            Track {
+                                id: TrackId {
+                                    number: 1,
+                                    title: "track b.d.1".to_string(),
+                                },
+                                artist: vec!["artist b.d.1".to_string()],
+                                quality: Quality {
+                                    format: Format::Mp3,
+                                    bitrate: 190,
+                                },
+                            },
+                            Track {
+                                id: TrackId {
+                                    number: 2,
+                                    title: "track b.d.2".to_string(),
+                                },
+                                artist: vec![
+                                    "artist b.d.2.1".to_string(),
+                                    "artist b.d.2.2".to_string(),
+                                ],
+                                quality: Quality {
+                                    format: Format::Mp3,
+                                    bitrate: 120,
+                                },
+                            },
+                        ],
+                    },
                 ],
             },
             Artist {
@@ -249,6 +326,86 @@ macro_rules! library_collection {
                     },
                 ],
             },
+            Artist {
+                id: ArtistId {
+                    name: "album_artist d".to_string(),
+                },
+                sort: None,
+                properties: ArtistProperties {
+                    musicbrainz: None,
+                    musicbutler: vec![],
+                    bandcamp: vec![],
+                    qobuz: None,
+                },
+                albums: vec![
+                    Album {
+                        id: AlbumId {
+                            year: 1995,
+                            title: "album_title d.a".to_string(),
+                        },
+                        tracks: vec![
+                            Track {
+                                id: TrackId {
+                                    number: 1,
+                                    title: "track d.a.1".to_string(),
+                                },
+                                artist: vec!["artist d.a.1".to_string()],
+                                quality: Quality {
+                                    format: Format::Mp3,
+                                    bitrate: 120,
+                                },
+                            },
+                            Track {
+                                id: TrackId {
+                                    number: 2,
+                                    title: "track d.a.2".to_string(),
+                                },
+                                artist: vec![
+                                    "artist d.a.2.1".to_string(),
+                                    "artist d.a.2.2".to_string(),
+                                ],
+                                quality: Quality {
+                                    format: Format::Mp3,
+                                    bitrate: 120,
+                                },
+                            },
+                        ],
+                    },
+                    Album {
+                        id: AlbumId {
+                            year: 2028,
+                            title: "album_title d.b".to_string(),
+                        },
+                        tracks: vec![
+                            Track {
+                                id: TrackId {
+                                    number: 1,
+                                    title: "track d.b.1".to_string(),
+                                },
+                                artist: vec!["artist d.b.1".to_string()],
+                                quality: Quality {
+                                    format: Format::Flac,
+                                    bitrate: 841,
+                                },
+                            },
+                            Track {
+                                id: TrackId {
+                                    number: 2,
+                                    title: "track d.b.2".to_string(),
+                                },
+                                artist: vec![
+                                    "artist d.b.2.1".to_string(),
+                                    "artist d.b.2.2".to_string(),
+                                ],
+                                quality: Quality {
+                                    format: Format::Flac,
+                                    bitrate: 756,
+                                },
+                            },
+                        ],
+                    },
+                ],
+            },
         ]
     };
 }
@@ -318,6 +475,8 @@ macro_rules! full_collection {
             qobuz: None,
         };
 
+        // Nothing for artist_d
+
         collection
     }};
 }

src/tui/app/app.rs

@@ -3,7 +3,7 @@
 use musichoard::collection::Collection;
 
 use crate::tui::{
-    app::selection::{ActiveSelection, Selection},
+    app::selection::{ActiveSelection, Delta, Selection},
     lib::IMusicHoard,
 };
 
@@ -50,8 +50,8 @@ pub trait IAppInteract {
 pub trait IAppInteractBrowse {
     fn increment_category(&mut self);
     fn decrement_category(&mut self);
-    fn increment_selection(&mut self);
+    fn increment_selection(&mut self, delta: Delta);
-    fn decrement_selection(&mut self);
+    fn decrement_selection(&mut self, delta: Delta);
 
     fn show_info_overlay(&mut self);
 
@@ -160,14 +160,14 @@ impl<MH: IMusicHoard> IAppInteractBrowse for App<MH> {
         self.selection.decrement_category();
     }
 
-    fn increment_selection(&mut self) {
+    fn increment_selection(&mut self, delta: Delta) {
         self.selection
-            .increment_selection(self.music_hoard.get_collection());
+            .increment_selection(self.music_hoard.get_collection(), delta);
     }
 
-    fn decrement_selection(&mut self) {
+    fn decrement_selection(&mut self, delta: Delta) {
         self.selection
-            .decrement_selection(self.music_hoard.get_collection());
+            .decrement_selection(self.music_hoard.get_collection(), delta);
     }
 
     fn show_info_overlay(&mut self) {
@@ -362,87 +362,126 @@ mod tests {
         assert!(app.is_running());
 
         assert_eq!(app.selection.active, Category::Artist);
-        assert_eq!(app.selection.artist.state.selected(), Some(0));
+        assert_eq!(app.selection.artist.state.list.selected(), Some(0));
-        assert_eq!(app.selection.artist.album.state.selected(), Some(0));
+        assert_eq!(app.selection.artist.album.state.list.selected(), Some(0));
-        assert_eq!(app.selection.artist.album.track.state.selected(), Some(0));
+        assert_eq!(
+            app.selection.artist.album.track.state.list.selected(),
+            Some(0)
+        );
 
-        app.increment_selection();
+        app.increment_selection(Delta::Line);
         assert_eq!(app.selection.active, Category::Artist);
-        assert_eq!(app.selection.artist.state.selected(), Some(1));
+        assert_eq!(app.selection.artist.state.list.selected(), Some(1));
-        assert_eq!(app.selection.artist.album.state.selected(), Some(0));
+        assert_eq!(app.selection.artist.album.state.list.selected(), Some(0));
-        assert_eq!(app.selection.artist.album.track.state.selected(), Some(0));
+        assert_eq!(
+            app.selection.artist.album.track.state.list.selected(),
+            Some(0)
+        );
 
         app.increment_category();
         assert_eq!(app.selection.active, Category::Album);
-        assert_eq!(app.selection.artist.state.selected(), Some(1));
+        assert_eq!(app.selection.artist.state.list.selected(), Some(1));
-        assert_eq!(app.selection.artist.album.state.selected(), Some(0));
+        assert_eq!(app.selection.artist.album.state.list.selected(), Some(0));
-        assert_eq!(app.selection.artist.album.track.state.selected(), Some(0));
+        assert_eq!(
+            app.selection.artist.album.track.state.list.selected(),
+            Some(0)
+        );
 
-        app.increment_selection();
+        app.increment_selection(Delta::Line);
         assert_eq!(app.selection.active, Category::Album);
-        assert_eq!(app.selection.artist.state.selected(), Some(1));
+        assert_eq!(app.selection.artist.state.list.selected(), Some(1));
-        assert_eq!(app.selection.artist.album.state.selected(), Some(1));
+        assert_eq!(app.selection.artist.album.state.list.selected(), Some(1));
-        assert_eq!(app.selection.artist.album.track.state.selected(), Some(0));
+        assert_eq!(
+            app.selection.artist.album.track.state.list.selected(),
+            Some(0)
+        );
 
         app.increment_category();
         assert_eq!(app.selection.active, Category::Track);
-        assert_eq!(app.selection.artist.state.selected(), Some(1));
+        assert_eq!(app.selection.artist.state.list.selected(), Some(1));
-        assert_eq!(app.selection.artist.album.state.selected(), Some(1));
+        assert_eq!(app.selection.artist.album.state.list.selected(), Some(1));
-        assert_eq!(app.selection.artist.album.track.state.selected(), Some(0));
+        assert_eq!(
+            app.selection.artist.album.track.state.list.selected(),
+            Some(0)
+        );
 
-        app.increment_selection();
+        app.increment_selection(Delta::Line);
         assert_eq!(app.selection.active, Category::Track);
-        assert_eq!(app.selection.artist.state.selected(), Some(1));
+        assert_eq!(app.selection.artist.state.list.selected(), Some(1));
-        assert_eq!(app.selection.artist.album.state.selected(), Some(1));
+        assert_eq!(app.selection.artist.album.state.list.selected(), Some(1));
-        assert_eq!(app.selection.artist.album.track.state.selected(), Some(1));
+        assert_eq!(
+            app.selection.artist.album.track.state.list.selected(),
+            Some(1)
+        );
 
         app.increment_category();
         assert_eq!(app.selection.active, Category::Track);
-        assert_eq!(app.selection.artist.state.selected(), Some(1));
+        assert_eq!(app.selection.artist.state.list.selected(), Some(1));
-        assert_eq!(app.selection.artist.album.state.selected(), Some(1));
+        assert_eq!(app.selection.artist.album.state.list.selected(), Some(1));
-        assert_eq!(app.selection.artist.album.track.state.selected(), Some(1));
+        assert_eq!(
+            app.selection.artist.album.track.state.list.selected(),
+            Some(1)
+        );
 
-        app.decrement_selection();
+        app.decrement_selection(Delta::Line);
         assert_eq!(app.selection.active, Category::Track);
-        assert_eq!(app.selection.artist.state.selected(), Some(1));
+        assert_eq!(app.selection.artist.state.list.selected(), Some(1));
-        assert_eq!(app.selection.artist.album.state.selected(), Some(1));
+        assert_eq!(app.selection.artist.album.state.list.selected(), Some(1));
-        assert_eq!(app.selection.artist.album.track.state.selected(), Some(0));
+        assert_eq!(
+            app.selection.artist.album.track.state.list.selected(),
+            Some(0)
+        );
 
-        app.increment_selection();
+        app.increment_selection(Delta::Line);
         app.decrement_category();
         assert_eq!(app.selection.active, Category::Album);
-        assert_eq!(app.selection.artist.state.selected(), Some(1));
+        assert_eq!(app.selection.artist.state.list.selected(), Some(1));
-        assert_eq!(app.selection.artist.album.state.selected(), Some(1));
+        assert_eq!(app.selection.artist.album.state.list.selected(), Some(1));
-        assert_eq!(app.selection.artist.album.track.state.selected(), Some(1));
+        assert_eq!(
+            app.selection.artist.album.track.state.list.selected(),
+            Some(1)
+        );
 
-        app.decrement_selection();
+        app.decrement_selection(Delta::Line);
         assert_eq!(app.selection.active, Category::Album);
-        assert_eq!(app.selection.artist.state.selected(), Some(1));
+        assert_eq!(app.selection.artist.state.list.selected(), Some(1));
-        assert_eq!(app.selection.artist.album.state.selected(), Some(0));
+        assert_eq!(app.selection.artist.album.state.list.selected(), Some(0));
-        assert_eq!(app.selection.artist.album.track.state.selected(), Some(0));
+        assert_eq!(
+            app.selection.artist.album.track.state.list.selected(),
+            Some(0)
+        );
 
-        app.increment_selection();
+        app.increment_selection(Delta::Line);
         app.decrement_category();
         assert_eq!(app.selection.active, Category::Artist);
-        assert_eq!(app.selection.artist.state.selected(), Some(1));
+        assert_eq!(app.selection.artist.state.list.selected(), Some(1));
-        assert_eq!(app.selection.artist.album.state.selected(), Some(1));
+        assert_eq!(app.selection.artist.album.state.list.selected(), Some(1));
-        assert_eq!(app.selection.artist.album.track.state.selected(), Some(0));
+        assert_eq!(
+            app.selection.artist.album.track.state.list.selected(),
+            Some(0)
+        );
 
-        app.decrement_selection();
+        app.decrement_selection(Delta::Line);
         assert_eq!(app.selection.active, Category::Artist);
-        assert_eq!(app.selection.artist.state.selected(), Some(0));
+        assert_eq!(app.selection.artist.state.list.selected(), Some(0));
-        assert_eq!(app.selection.artist.album.state.selected(), Some(0));
+        assert_eq!(app.selection.artist.album.state.list.selected(), Some(0));
-        assert_eq!(app.selection.artist.album.track.state.selected(), Some(0));
+        assert_eq!(
+            app.selection.artist.album.track.state.list.selected(),
+            Some(0)
+        );
 
         app.increment_category();
-        app.increment_selection();
+        app.increment_selection(Delta::Line);
         app.decrement_category();
-        app.decrement_selection();
+        app.decrement_selection(Delta::Line);
         app.decrement_category();
         assert_eq!(app.selection.active, Category::Artist);
-        assert_eq!(app.selection.artist.state.selected(), Some(0));
+        assert_eq!(app.selection.artist.state.list.selected(), Some(0));
-        assert_eq!(app.selection.artist.album.state.selected(), Some(1));
+        assert_eq!(app.selection.artist.album.state.list.selected(), Some(1));
-        assert_eq!(app.selection.artist.album.track.state.selected(), Some(0));
+        assert_eq!(
+            app.selection.artist.album.track.state.list.selected(),
+            Some(0)
+        );
     }
 
     #[test]
@@ -454,24 +493,24 @@ mod tests {
         assert!(app.is_running());
 
         assert_eq!(app.selection.active, Category::Artist);
-        assert_eq!(app.selection.artist.state.selected(), Some(0));
+        assert_eq!(app.selection.artist.state.list.selected(), Some(0));
-        assert_eq!(app.selection.artist.album.state.selected(), Some(0));
+        assert_eq!(app.selection.artist.album.state.list.selected(), Some(0));
-        assert_eq!(app.selection.artist.album.track.state.selected(), None);
+        assert_eq!(app.selection.artist.album.track.state.list.selected(), None);
 
         app.increment_category();
         app.increment_category();
 
-        app.increment_selection();
+        app.increment_selection(Delta::Line);
         assert_eq!(app.selection.active, Category::Track);
-        assert_eq!(app.selection.artist.state.selected(), Some(0));
+        assert_eq!(app.selection.artist.state.list.selected(), Some(0));
-        assert_eq!(app.selection.artist.album.state.selected(), Some(0));
+        assert_eq!(app.selection.artist.album.state.list.selected(), Some(0));
-        assert_eq!(app.selection.artist.album.track.state.selected(), None);
+        assert_eq!(app.selection.artist.album.track.state.list.selected(), None);
 
-        app.decrement_selection();
+        app.decrement_selection(Delta::Line);
         assert_eq!(app.selection.active, Category::Track);
-        assert_eq!(app.selection.artist.state.selected(), Some(0));
+        assert_eq!(app.selection.artist.state.list.selected(), Some(0));
-        assert_eq!(app.selection.artist.album.state.selected(), Some(0));
+        assert_eq!(app.selection.artist.album.state.list.selected(), Some(0));
-        assert_eq!(app.selection.artist.album.track.state.selected(), None);
+        assert_eq!(app.selection.artist.album.track.state.list.selected(), None);
     }
 
     #[test]
@@ -483,37 +522,37 @@ mod tests {
         assert!(app.is_running());
 
         assert_eq!(app.selection.active, Category::Artist);
-        assert_eq!(app.selection.artist.state.selected(), Some(0));
+        assert_eq!(app.selection.artist.state.list.selected(), Some(0));
-        assert_eq!(app.selection.artist.album.state.selected(), None);
+        assert_eq!(app.selection.artist.album.state.list.selected(), None);
-        assert_eq!(app.selection.artist.album.track.state.selected(), None);
+        assert_eq!(app.selection.artist.album.track.state.list.selected(), None);
 
         app.increment_category();
 
-        app.increment_selection();
+        app.increment_selection(Delta::Line);
         assert_eq!(app.selection.active, Category::Album);
-        assert_eq!(app.selection.artist.state.selected(), Some(0));
+        assert_eq!(app.selection.artist.state.list.selected(), Some(0));
-        assert_eq!(app.selection.artist.album.state.selected(), None);
+        assert_eq!(app.selection.artist.album.state.list.selected(), None);
-        assert_eq!(app.selection.artist.album.track.state.selected(), None);
+        assert_eq!(app.selection.artist.album.track.state.list.selected(), None);
 
-        app.decrement_selection();
+        app.decrement_selection(Delta::Line);
         assert_eq!(app.selection.active, Category::Album);
-        assert_eq!(app.selection.artist.state.selected(), Some(0));
+        assert_eq!(app.selection.artist.state.list.selected(), Some(0));
-        assert_eq!(app.selection.artist.album.state.selected(), None);
+        assert_eq!(app.selection.artist.album.state.list.selected(), None);
-        assert_eq!(app.selection.artist.album.track.state.selected(), None);
+        assert_eq!(app.selection.artist.album.track.state.list.selected(), None);
 
         app.increment_category();
 
-        app.increment_selection();
+        app.increment_selection(Delta::Line);
         assert_eq!(app.selection.active, Category::Track);
-        assert_eq!(app.selection.artist.state.selected(), Some(0));
+        assert_eq!(app.selection.artist.state.list.selected(), Some(0));
-        assert_eq!(app.selection.artist.album.state.selected(), None);
+        assert_eq!(app.selection.artist.album.state.list.selected(), None);
-        assert_eq!(app.selection.artist.album.track.state.selected(), None);
+        assert_eq!(app.selection.artist.album.track.state.list.selected(), None);
 
-        app.decrement_selection();
+        app.decrement_selection(Delta::Line);
         assert_eq!(app.selection.active, Category::Track);
-        assert_eq!(app.selection.artist.state.selected(), Some(0));
+        assert_eq!(app.selection.artist.state.list.selected(), Some(0));
-        assert_eq!(app.selection.artist.album.state.selected(), None);
+        assert_eq!(app.selection.artist.album.state.list.selected(), None);
-        assert_eq!(app.selection.artist.album.track.state.selected(), None);
+        assert_eq!(app.selection.artist.album.track.state.list.selected(), None);
     }
 
     #[test]
@@ -522,49 +561,49 @@ mod tests {
         assert!(app.is_running());
 
         assert_eq!(app.selection.active, Category::Artist);
-        assert_eq!(app.selection.artist.state.selected(), None);
+        assert_eq!(app.selection.artist.state.list.selected(), None);
-        assert_eq!(app.selection.artist.album.state.selected(), None);
+        assert_eq!(app.selection.artist.album.state.list.selected(), None);
-        assert_eq!(app.selection.artist.album.track.state.selected(), None);
+        assert_eq!(app.selection.artist.album.track.state.list.selected(), None);
 
-        app.increment_selection();
+        app.increment_selection(Delta::Line);
         assert_eq!(app.selection.active, Category::Artist);
-        assert_eq!(app.selection.artist.state.selected(), None);
+        assert_eq!(app.selection.artist.state.list.selected(), None);
-        assert_eq!(app.selection.artist.album.state.selected(), None);
+        assert_eq!(app.selection.artist.album.state.list.selected(), None);
-        assert_eq!(app.selection.artist.album.track.state.selected(), None);
+        assert_eq!(app.selection.artist.album.track.state.list.selected(), None);
 
-        app.decrement_selection();
+        app.decrement_selection(Delta::Line);
         assert_eq!(app.selection.active, Category::Artist);
-        assert_eq!(app.selection.artist.state.selected(), None);
+        assert_eq!(app.selection.artist.state.list.selected(), None);
-        assert_eq!(app.selection.artist.album.state.selected(), None);
+        assert_eq!(app.selection.artist.album.state.list.selected(), None);
-        assert_eq!(app.selection.artist.album.track.state.selected(), None);
+        assert_eq!(app.selection.artist.album.track.state.list.selected(), None);
 
         app.increment_category();
 
-        app.increment_selection();
+        app.increment_selection(Delta::Line);
         assert_eq!(app.selection.active, Category::Album);
-        assert_eq!(app.selection.artist.state.selected(), None);
+        assert_eq!(app.selection.artist.state.list.selected(), None);
-        assert_eq!(app.selection.artist.album.state.selected(), None);
+        assert_eq!(app.selection.artist.album.state.list.selected(), None);
-        assert_eq!(app.selection.artist.album.track.state.selected(), None);
+        assert_eq!(app.selection.artist.album.track.state.list.selected(), None);
 
-        app.decrement_selection();
+        app.decrement_selection(Delta::Line);
         assert_eq!(app.selection.active, Category::Album);
-        assert_eq!(app.selection.artist.state.selected(), None);
+        assert_eq!(app.selection.artist.state.list.selected(), None);
-        assert_eq!(app.selection.artist.album.state.selected(), None);
+        assert_eq!(app.selection.artist.album.state.list.selected(), None);
-        assert_eq!(app.selection.artist.album.track.state.selected(), None);
+        assert_eq!(app.selection.artist.album.track.state.list.selected(), None);
 
         app.increment_category();
 
-        app.increment_selection();
+        app.increment_selection(Delta::Line);
         assert_eq!(app.selection.active, Category::Track);
-        assert_eq!(app.selection.artist.state.selected(), None);
+        assert_eq!(app.selection.artist.state.list.selected(), None);
-        assert_eq!(app.selection.artist.album.state.selected(), None);
+        assert_eq!(app.selection.artist.album.state.list.selected(), None);
-        assert_eq!(app.selection.artist.album.track.state.selected(), None);
+        assert_eq!(app.selection.artist.album.track.state.list.selected(), None);
 
-        app.decrement_selection();
+        app.decrement_selection(Delta::Line);
         assert_eq!(app.selection.active, Category::Track);
-        assert_eq!(app.selection.artist.state.selected(), None);
+        assert_eq!(app.selection.artist.state.list.selected(), None);
-        assert_eq!(app.selection.artist.album.state.selected(), None);
+        assert_eq!(app.selection.artist.album.state.list.selected(), None);
-        assert_eq!(app.selection.artist.album.track.state.selected(), None);
+        assert_eq!(app.selection.artist.album.track.state.list.selected(), None);
     }
 
     #[test]

src/tui/app/selection.rs

@@ -13,43 +13,51 @@ pub enum Category {
     Track,
 }
 
+#[derive(Clone, Debug, Default)]
+pub struct WidgetState {
+    pub list: ListState,
+    pub height: usize,
+}
+
+impl PartialEq for WidgetState {
+    fn eq(&self, other: &Self) -> bool {
+        self.list.selected().eq(&other.list.selected()) && self.height.eq(&other.height)
+    }
+}
+
 pub struct Selection {
     pub active: Category,
     pub artist: ArtistSelection,
 }
 
-#[derive(Clone, Debug)]
+#[derive(Clone, Debug, PartialEq)]
 pub struct ArtistSelection {
-    pub state: ListState,
+    pub state: WidgetState,
     pub album: AlbumSelection,
 }
 
-impl PartialEq for ArtistSelection {
+#[derive(Clone, Debug, PartialEq)]
-    fn eq(&self, other: &Self) -> bool {
-        self.state.selected().eq(&other.state.selected()) && self.album.eq(&other.album)
-    }
-}
-
-#[derive(Clone, Debug)]
 pub struct AlbumSelection {
-    pub state: ListState,
+    pub state: WidgetState,
     pub track: TrackSelection,
 }
 
-impl PartialEq for AlbumSelection {
+#[derive(Clone, Debug, PartialEq)]
-    fn eq(&self, other: &Self) -> bool {
-        self.state.selected().eq(&other.state.selected()) && self.track.eq(&other.track)
-    }
-}
-
-#[derive(Clone, Debug)]
 pub struct TrackSelection {
-    pub state: ListState,
+    pub state: WidgetState,
 }
 
-impl PartialEq for TrackSelection {
+pub enum Delta {
-    fn eq(&self, other: &Self) -> bool {
+    Line,
-        self.state.selected().eq(&other.state.selected())
+    Page,
+}
+
+impl Delta {
+    fn as_usize(&self, state: &WidgetState) -> usize {
+        match self {
+            Delta::Line => 1,
+            Delta::Page => state.height.saturating_sub(1),
+        }
     }
 }
 
@@ -81,51 +89,51 @@ impl Selection {
         };
     }
 
-    pub fn increment_selection(&mut self, collection: &Collection) {
+    pub fn increment_selection(&mut self, collection: &Collection, delta: Delta) {
         match self.active {
-            Category::Artist => self.increment_artist(collection),
+            Category::Artist => self.increment_artist(collection, delta),
-            Category::Album => self.increment_album(collection),
+            Category::Album => self.increment_album(collection, delta),
-            Category::Track => self.increment_track(collection),
+            Category::Track => self.increment_track(collection, delta),
         }
     }
 
-    pub fn decrement_selection(&mut self, collection: &Collection) {
+    pub fn decrement_selection(&mut self, collection: &Collection, delta: Delta) {
         match self.active {
-            Category::Artist => self.decrement_artist(collection),
+            Category::Artist => self.decrement_artist(collection, delta),
-            Category::Album => self.decrement_album(collection),
+            Category::Album => self.decrement_album(collection, delta),
-            Category::Track => self.decrement_track(collection),
+            Category::Track => self.decrement_track(collection, delta),
         }
     }
 
-    fn increment_artist(&mut self, artists: &[Artist]) {
+    fn increment_artist(&mut self, artists: &[Artist], delta: Delta) {
-        self.artist.increment(artists);
+        self.artist.increment(artists, delta);
     }
 
-    fn decrement_artist(&mut self, artists: &[Artist]) {
+    fn decrement_artist(&mut self, artists: &[Artist], delta: Delta) {
-        self.artist.decrement(artists);
+        self.artist.decrement(artists, delta);
     }
 
-    fn increment_album(&mut self, artists: &[Artist]) {
+    fn increment_album(&mut self, artists: &[Artist], delta: Delta) {
-        self.artist.increment_album(artists);
+        self.artist.increment_album(artists, delta);
     }
 
-    fn decrement_album(&mut self, artists: &[Artist]) {
+    fn decrement_album(&mut self, artists: &[Artist], delta: Delta) {
-        self.artist.decrement_album(artists);
+        self.artist.decrement_album(artists, delta);
     }
 
-    fn increment_track(&mut self, artists: &[Artist]) {
+    fn increment_track(&mut self, artists: &[Artist], delta: Delta) {
-        self.artist.increment_track(artists);
+        self.artist.increment_track(artists, delta);
     }
 
-    fn decrement_track(&mut self, artists: &[Artist]) {
+    fn decrement_track(&mut self, artists: &[Artist], delta: Delta) {
-        self.artist.decrement_track(artists);
+        self.artist.decrement_track(artists, delta);
     }
 }
 
 impl ArtistSelection {
     fn initialise(artists: &[Artist]) -> Self {
         let mut selection = ArtistSelection {
-            state: ListState::default(),
+            state: WidgetState::default(),
             album: AlbumSelection::initialise(&[]),
         };
         selection.reinitialise(artists, None);
@@ -151,60 +159,71 @@ impl ArtistSelection {
         active_album: Option<ActiveAlbum>,
     ) {
         if artists.is_empty() {
-            self.state.select(None);
+            self.state.list.select(None);
             self.album = AlbumSelection::initialise(&[]);
         } else if index >= artists.len() {
             let end = artists.len() - 1;
-            self.state.select(Some(end));
+            self.state.list.select(Some(end));
             self.album = AlbumSelection::initialise(&artists[end].albums);
         } else {
-            self.state.select(Some(index));
+            self.state.list.select(Some(index));
             self.album
                 .reinitialise(&artists[index].albums, active_album);
         }
     }
 
-    fn increment(&mut self, artists: &[Artist]) {
+    fn increment_by(&mut self, artists: &[Artist], by: usize) {
-        if let Some(index) = self.state.selected() {
+        if let Some(index) = self.state.list.selected() {
-            if let Some(result) = index.checked_add(1) {
+            let mut result = index.saturating_add(by);
-                if result < artists.len() {
+            if result >= artists.len() {
-                    self.state.select(Some(result));
+                result = artists.len() - 1;
-                    self.album = AlbumSelection::initialise(&artists[result].albums);
-                }
             }
-        }
+            if self.state.list.selected() != Some(result) {
-    }
+                self.state.list.select(Some(result));
-
-    fn increment_album(&mut self, artists: &[Artist]) {
-        if let Some(index) = self.state.selected() {
-            self.album.increment(&artists[index].albums);
-        }
-    }
-
-    fn increment_track(&mut self, artists: &[Artist]) {
-        if let Some(index) = self.state.selected() {
-            self.album.increment_track(&artists[index].albums);
-        }
-    }
-
-    fn decrement(&mut self, artists: &[Artist]) {
-        if let Some(index) = self.state.selected() {
-            if let Some(result) = index.checked_sub(1) {
-                self.state.select(Some(result));
                 self.album = AlbumSelection::initialise(&artists[result].albums);
             }
         }
     }
 
-    fn decrement_album(&mut self, artists: &[Artist]) {
+    fn increment(&mut self, artists: &[Artist], delta: Delta) {
-        if let Some(index) = self.state.selected() {
+        self.increment_by(artists, delta.as_usize(&self.state));
-            self.album.decrement(&artists[index].albums);
+    }
+
+    fn increment_album(&mut self, artists: &[Artist], delta: Delta) {
+        if let Some(index) = self.state.list.selected() {
+            self.album.increment(&artists[index].albums, delta);
         }
     }
 
-    fn decrement_track(&mut self, artists: &[Artist]) {
+    fn increment_track(&mut self, artists: &[Artist], delta: Delta) {
-        if let Some(index) = self.state.selected() {
+        if let Some(index) = self.state.list.selected() {
-            self.album.decrement_track(&artists[index].albums);
+            self.album.increment_track(&artists[index].albums, delta);
+        }
+    }
+
+    fn decrement_by(&mut self, artists: &[Artist], by: usize) {
+        if let Some(index) = self.state.list.selected() {
+            let result = index.saturating_sub(by);
+            if self.state.list.selected() != Some(result) {
+                self.state.list.select(Some(result));
+                self.album = AlbumSelection::initialise(&artists[result].albums);
+            }
+        }
+    }
+
+    fn decrement(&mut self, artists: &[Artist], delta: Delta) {
+        self.decrement_by(artists, delta.as_usize(&self.state));
+    }
+
+    fn decrement_album(&mut self, artists: &[Artist], delta: Delta) {
+        if let Some(index) = self.state.list.selected() {
+            self.album.decrement(&artists[index].albums, delta);
+        }
+    }
+
+    fn decrement_track(&mut self, artists: &[Artist], delta: Delta) {
+        if let Some(index) = self.state.list.selected() {
+            self.album.decrement_track(&artists[index].albums, delta);
         }
     }
 }
@@ -212,7 +231,7 @@ impl ArtistSelection {
 impl AlbumSelection {
     fn initialise(albums: &[Album]) -> Self {
         let mut selection = AlbumSelection {
-            state: ListState::default(),
+            state: WidgetState::default(),
             track: TrackSelection::initialise(&[]),
         };
         selection.reinitialise(albums, None);
@@ -238,47 +257,58 @@ impl AlbumSelection {
         active_track: Option<ActiveTrack>,
     ) {
         if albums.is_empty() {
-            self.state.select(None);
+            self.state.list.select(None);
             self.track = TrackSelection::initialise(&[]);
         } else if index >= albums.len() {
             let end = albums.len() - 1;
-            self.state.select(Some(end));
+            self.state.list.select(Some(end));
             self.track = TrackSelection::initialise(&albums[end].tracks);
         } else {
-            self.state.select(Some(index));
+            self.state.list.select(Some(index));
             self.track.reinitialise(&albums[index].tracks, active_track);
         }
     }
 
-    fn increment(&mut self, albums: &[Album]) {
+    fn increment_by(&mut self, albums: &[Album], by: usize) {
-        if let Some(index) = self.state.selected() {
+        if let Some(index) = self.state.list.selected() {
-            if let Some(result) = index.checked_add(1) {
+            let mut result = index.saturating_add(by);
-                if result < albums.len() {
+            if result >= albums.len() {
-                    self.state.select(Some(result));
+                result = albums.len() - 1;
-                    self.track = TrackSelection::initialise(&albums[result].tracks);
-                }
             }
-        }
+            if self.state.list.selected() != Some(result) {
-    }
+                self.state.list.select(Some(result));
-
-    fn increment_track(&mut self, albums: &[Album]) {
-        if let Some(index) = self.state.selected() {
-            self.track.increment(&albums[index].tracks);
-        }
-    }
-
-    fn decrement(&mut self, albums: &[Album]) {
-        if let Some(index) = self.state.selected() {
-            if let Some(result) = index.checked_sub(1) {
-                self.state.select(Some(result));
                 self.track = TrackSelection::initialise(&albums[result].tracks);
             }
         }
     }
 
-    fn decrement_track(&mut self, albums: &[Album]) {
+    fn increment(&mut self, albums: &[Album], delta: Delta) {
-        if let Some(index) = self.state.selected() {
+        self.increment_by(albums, delta.as_usize(&self.state));
-            self.track.decrement(&albums[index].tracks);
+    }
+
+    fn increment_track(&mut self, albums: &[Album], delta: Delta) {
+        if let Some(index) = self.state.list.selected() {
+            self.track.increment(&albums[index].tracks, delta);
+        }
+    }
+
+    fn decrement_by(&mut self, albums: &[Album], by: usize) {
+        if let Some(index) = self.state.list.selected() {
+            let result = index.saturating_sub(by);
+            if self.state.list.selected() != Some(result) {
+                self.state.list.select(Some(result));
+                self.track = TrackSelection::initialise(&albums[result].tracks);
+            }
+        }
+    }
+
+    fn decrement(&mut self, albums: &[Album], delta: Delta) {
+        self.decrement_by(albums, delta.as_usize(&self.state));
+    }
+
+    fn decrement_track(&mut self, albums: &[Album], delta: Delta) {
+        if let Some(index) = self.state.list.selected() {
+            self.track.decrement(&albums[index].tracks, delta);
         }
     }
 }
@@ -286,7 +316,7 @@ impl AlbumSelection {
 impl TrackSelection {
     fn initialise(tracks: &[Track]) -> Self {
         let mut selection = TrackSelection {
-            state: ListState::default(),
+            state: WidgetState::default(),
         };
         selection.reinitialise(tracks, None);
         selection
@@ -305,31 +335,42 @@ impl TrackSelection {
 
     fn reinitialise_with_index(&mut self, tracks: &[Track], index: usize) {
         if tracks.is_empty() {
-            self.state.select(None);
+            self.state.list.select(None);
         } else if index >= tracks.len() {
-            self.state.select(Some(tracks.len() - 1));
+            self.state.list.select(Some(tracks.len() - 1));
         } else {
-            self.state.select(Some(index));
+            self.state.list.select(Some(index));
         }
     }
 
-    fn increment(&mut self, tracks: &[Track]) {
+    fn increment_by(&mut self, tracks: &[Track], by: usize) {
-        if let Some(index) = self.state.selected() {
+        if let Some(index) = self.state.list.selected() {
-            if let Some(result) = index.checked_add(1) {
+            let mut result = index.saturating_add(by);
-                if result < tracks.len() {
+            if result >= tracks.len() {
-                    self.state.select(Some(result));
+                result = tracks.len() - 1;
-                }
+            }
+            if self.state.list.selected() != Some(result) {
+                self.state.list.select(Some(result));
             }
         }
     }
 
-    fn decrement(&mut self, _tracks: &[Track]) {
+    fn increment(&mut self, tracks: &[Track], delta: Delta) {
-        if let Some(index) = self.state.selected() {
+        self.increment_by(tracks, delta.as_usize(&self.state));
-            if let Some(result) = index.checked_sub(1) {
+    }
-                self.state.select(Some(result));
+
+    fn decrement_by(&mut self, _tracks: &[Track], by: usize) {
+        if let Some(index) = self.state.list.selected() {
+            let result = index.saturating_sub(by);
+            if self.state.list.selected() != Some(result) {
+                self.state.list.select(Some(result));
             }
         }
     }
+
+    fn decrement(&mut self, tracks: &[Track], delta: Delta) {
+        self.decrement_by(tracks, delta.as_usize(&self.state));
+    }
 }
 
 pub struct ActiveSelection {
@@ -360,7 +401,7 @@ impl ActiveSelection {
 
 impl ActiveArtist {
     fn get(artists: &[Artist], selection: &ArtistSelection) -> Option<Self> {
-        selection.state.selected().map(|index| {
+        selection.state.list.selected().map(|index| {
             let artist = &artists[index];
             ActiveArtist {
                 artist_id: artist.get_sort_key().clone(),
@@ -372,7 +413,7 @@ impl ActiveArtist {
 
 impl ActiveAlbum {
     fn get(albums: &[Album], selection: &AlbumSelection) -> Option<Self> {
-        selection.state.selected().map(|index| {
+        selection.state.list.selected().map(|index| {
             let album = &albums[index];
             ActiveAlbum {
                 album_id: album.get_sort_key().clone(),
@@ -384,7 +425,7 @@ impl ActiveAlbum {
 
 impl ActiveTrack {
     fn get(tracks: &[Track], selection: &TrackSelection) -> Option<Self> {
-        selection.state.selected().map(|index| {
+        selection.state.list.selected().map(|index| {
             let track = &tracks[index];
             ActiveTrack {
                 track_id: track.get_sort_key().clone(),
@@ -405,24 +446,62 @@ mod tests {
         assert!(tracks.len() > 1);
 
         let empty = TrackSelection::initialise(&[]);
-        assert_eq!(empty.state.selected(), None);
+        assert_eq!(empty.state.list.selected(), None);
 
         let mut sel = TrackSelection::initialise(tracks);
-        assert_eq!(sel.state.selected(), Some(0));
+        assert_eq!(sel.state.list.selected(), Some(0));
 
-        sel.decrement(tracks);
+        sel.decrement(tracks, Delta::Line);
-        assert_eq!(sel.state.selected(), Some(0));
+        assert_eq!(sel.state.list.selected(), Some(0));
 
-        sel.increment(tracks);
+        sel.increment(tracks, Delta::Line);
-        assert_eq!(sel.state.selected(), Some(1));
+        assert_eq!(sel.state.list.selected(), Some(1));
 
-        sel.decrement(tracks);
+        sel.decrement(tracks, Delta::Line);
-        assert_eq!(sel.state.selected(), Some(0));
+        assert_eq!(sel.state.list.selected(), Some(0));
 
         for _ in 0..(tracks.len() + 5) {
-            sel.increment(tracks);
+            sel.increment(tracks, Delta::Line);
         }
-        assert_eq!(sel.state.selected(), Some(tracks.len() - 1));
+        assert_eq!(sel.state.list.selected(), Some(tracks.len() - 1));
+    }
+
+    #[test]
+    fn track_delta_page() {
+        let tracks = &COLLECTION[0].albums[0].tracks;
+        assert!(tracks.len() > 1);
+
+        let empty = TrackSelection::initialise(&[]);
+        assert_eq!(empty.state.list.selected(), None);
+
+        let mut sel = TrackSelection::initialise(tracks);
+        assert_eq!(sel.state.list.selected(), Some(0));
+
+        assert!(tracks.len() >= 4);
+        sel.state.height = 3;
+
+        sel.decrement(tracks, Delta::Page);
+        assert_eq!(sel.state.list.selected(), Some(0));
+
+        sel.increment(tracks, Delta::Page);
+        assert_eq!(sel.state.list.selected(), Some(2));
+
+        sel.decrement(tracks, Delta::Page);
+        assert_eq!(sel.state.list.selected(), Some(0));
+
+        for _ in 0..(tracks.len() + 5) {
+            sel.increment(tracks, Delta::Page);
+        }
+        assert_eq!(sel.state.list.selected(), Some(tracks.len() - 1));
+    }
+
+    #[test]
+    fn track_reinitialise() {
+        let tracks = &COLLECTION[0].albums[0].tracks;
+        assert!(tracks.len() > 1);
+
+        let mut sel = TrackSelection::initialise(tracks);
+        sel.state.list.select(Some(tracks.len() - 1));
 
         // Re-initialise.
         let expected = sel.clone();
@@ -432,7 +511,7 @@ mod tests {
 
         // Re-initialise out-of-bounds.
         let mut expected = sel.clone();
-        expected.decrement(tracks);
+        expected.decrement(tracks, Delta::Line);
         let active_track = ActiveTrack::get(tracks, &sel);
         sel.reinitialise(&tracks[..(tracks.len() - 1)], active_track);
         assert_eq!(sel, expected);
@@ -442,13 +521,6 @@ mod tests {
         let active_track = ActiveTrack::get(tracks, &sel);
         sel.reinitialise(&[], active_track);
         assert_eq!(sel, expected);
-
-        // Artifical test case to verify upper limit.
-        sel.state.select(Some(std::usize::MAX));
-        assert_eq!(sel.state.selected(), Some(std::usize::MAX));
-
-        sel.increment(&[]);
-        assert_eq!(sel.state.selected(), Some(std::usize::MAX));
     }
 
     #[test]
@@ -457,43 +529,101 @@ mod tests {
         assert!(albums.len() > 1);
 
         let empty = AlbumSelection::initialise(&[]);
-        assert_eq!(empty.state.selected(), None);
+        assert_eq!(empty.state.list.selected(), None);
 
         let mut sel = AlbumSelection::initialise(albums);
-        assert_eq!(sel.state.selected(), Some(0));
+        assert_eq!(sel.state.list.selected(), Some(0));
-        assert_eq!(sel.track.state.selected(), Some(0));
+        assert_eq!(sel.track.state.list.selected(), Some(0));
 
-        sel.increment_track(albums);
+        sel.increment_track(albums, Delta::Line);
-        assert_eq!(sel.state.selected(), Some(0));
+        assert_eq!(sel.state.list.selected(), Some(0));
-        assert_eq!(sel.track.state.selected(), Some(1));
+        assert_eq!(sel.track.state.list.selected(), Some(1));
 
         // Verify that decrement that doesn't change index does not reset track.
-        sel.decrement(albums);
+        sel.decrement(albums, Delta::Line);
-        assert_eq!(sel.state.selected(), Some(0));
+        assert_eq!(sel.state.list.selected(), Some(0));
-        assert_eq!(sel.track.state.selected(), Some(1));
+        assert_eq!(sel.track.state.list.selected(), Some(1));
 
-        sel.increment(albums);
+        sel.increment(albums, Delta::Line);
-        assert_eq!(sel.state.selected(), Some(1));
+        assert_eq!(sel.state.list.selected(), Some(1));
-        assert_eq!(sel.track.state.selected(), Some(0));
+        assert_eq!(sel.track.state.list.selected(), Some(0));
 
-        sel.decrement(albums);
+        sel.decrement(albums, Delta::Line);
-        assert_eq!(sel.state.selected(), Some(0));
+        assert_eq!(sel.state.list.selected(), Some(0));
-        assert_eq!(sel.track.state.selected(), Some(0));
+        assert_eq!(sel.track.state.list.selected(), Some(0));
 
         for _ in 0..(albums.len() + 5) {
-            sel.increment(albums);
+            sel.increment(albums, Delta::Line);
         }
-        assert_eq!(sel.state.selected(), Some(albums.len() - 1));
+        assert_eq!(sel.state.list.selected(), Some(albums.len() - 1));
-        assert_eq!(sel.track.state.selected(), Some(0));
+        assert_eq!(sel.track.state.list.selected(), Some(0));
 
-        sel.increment_track(albums);
+        sel.increment_track(albums, Delta::Line);
-        assert_eq!(sel.state.selected(), Some(albums.len() - 1));
+        assert_eq!(sel.state.list.selected(), Some(albums.len() - 1));
-        assert_eq!(sel.track.state.selected(), Some(1));
+        assert_eq!(sel.track.state.list.selected(), Some(1));
 
         // Verify that increment that doesn't change index does not reset track.
-        sel.increment(albums);
+        sel.increment(albums, Delta::Line);
-        assert_eq!(sel.state.selected(), Some(albums.len() - 1));
+        assert_eq!(sel.state.list.selected(), Some(albums.len() - 1));
-        assert_eq!(sel.track.state.selected(), Some(1));
+        assert_eq!(sel.track.state.list.selected(), Some(1));
+    }
+
+    #[test]
+    fn album_delta_page() {
+        let albums = &COLLECTION[1].albums;
+        assert!(albums.len() > 1);
+
+        let empty = AlbumSelection::initialise(&[]);
+        assert_eq!(empty.state.list.selected(), None);
+
+        let mut sel = AlbumSelection::initialise(albums);
+        assert_eq!(sel.state.list.selected(), Some(0));
+        assert_eq!(sel.track.state.list.selected(), Some(0));
+
+        assert!(albums.len() >= 4);
+        sel.state.height = 3;
+
+        sel.increment_track(albums, Delta::Line);
+        assert_eq!(sel.state.list.selected(), Some(0));
+        assert_eq!(sel.track.state.list.selected(), Some(1));
+
+        // Verify that decrement that doesn't change index does not reset track.
+        sel.decrement(albums, Delta::Page);
+        assert_eq!(sel.state.list.selected(), Some(0));
+        assert_eq!(sel.track.state.list.selected(), Some(1));
+
+        sel.increment(albums, Delta::Page);
+        assert_eq!(sel.state.list.selected(), Some(2));
+        assert_eq!(sel.track.state.list.selected(), Some(0));
+
+        sel.decrement(albums, Delta::Page);
+        assert_eq!(sel.state.list.selected(), Some(0));
+        assert_eq!(sel.track.state.list.selected(), Some(0));
+
+        for _ in 0..(albums.len() + 5) {
+            sel.increment(albums, Delta::Page);
+        }
+        assert_eq!(sel.state.list.selected(), Some(albums.len() - 1));
+        assert_eq!(sel.track.state.list.selected(), Some(0));
+
+        sel.increment_track(albums, Delta::Line);
+        assert_eq!(sel.state.list.selected(), Some(albums.len() - 1));
+        assert_eq!(sel.track.state.list.selected(), Some(1));
+
+        // Verify that increment that doesn't change index does not reset track.
+        sel.increment(albums, Delta::Page);
+        assert_eq!(sel.state.list.selected(), Some(albums.len() - 1));
+        assert_eq!(sel.track.state.list.selected(), Some(1));
+    }
+
+    #[test]
+    fn album_reinitialise() {
+        let albums = &COLLECTION[0].albums;
+        assert!(albums.len() > 1);
+
+        let mut sel = AlbumSelection::initialise(albums);
+        sel.state.list.select(Some(albums.len() - 1));
+        sel.track.state.list.select(Some(1));
 
         // Re-initialise.
         let expected = sel.clone();
@@ -503,7 +633,7 @@ mod tests {
 
         // Re-initialise out-of-bounds.
         let mut expected = sel.clone();
-        expected.decrement(albums);
+        expected.decrement(albums, Delta::Line);
         let active_album = ActiveAlbum::get(albums, &sel);
         sel.reinitialise(&albums[..(albums.len() - 1)], active_album);
         assert_eq!(sel, expected);
@@ -513,16 +643,6 @@ mod tests {
         let active_album = ActiveAlbum::get(albums, &sel);
         sel.reinitialise(&[], active_album);
         assert_eq!(sel, expected);
-
-        // Artifical test case to verify upper limit.
-        sel.state.select(Some(std::usize::MAX));
-        sel.track.state.select(Some(1));
-        assert_eq!(sel.state.selected(), Some(std::usize::MAX));
-        assert_eq!(sel.track.state.selected(), Some(1));
-
-        sel.increment(&[]);
-        assert_eq!(sel.state.selected(), Some(std::usize::MAX));
-        assert_eq!(sel.track.state.selected(), Some(1));
     }
 
     #[test]
@@ -531,43 +651,101 @@ mod tests {
         assert!(artists.len() > 1);
 
         let empty = ArtistSelection::initialise(&[]);
-        assert_eq!(empty.state.selected(), None);
+        assert_eq!(empty.state.list.selected(), None);
 
         let mut sel = ArtistSelection::initialise(artists);
-        assert_eq!(sel.state.selected(), Some(0));
+        assert_eq!(sel.state.list.selected(), Some(0));
-        assert_eq!(sel.album.state.selected(), Some(0));
+        assert_eq!(sel.album.state.list.selected(), Some(0));
 
-        sel.increment_album(artists);
+        sel.increment_album(artists, Delta::Line);
-        assert_eq!(sel.state.selected(), Some(0));
+        assert_eq!(sel.state.list.selected(), Some(0));
-        assert_eq!(sel.album.state.selected(), Some(1));
+        assert_eq!(sel.album.state.list.selected(), Some(1));
 
         // Verify that decrement that doesn't change index does not reset album.
-        sel.decrement(artists);
+        sel.decrement(artists, Delta::Line);
-        assert_eq!(sel.state.selected(), Some(0));
+        assert_eq!(sel.state.list.selected(), Some(0));
-        assert_eq!(sel.album.state.selected(), Some(1));
+        assert_eq!(sel.album.state.list.selected(), Some(1));
 
-        sel.increment(artists);
+        sel.increment(artists, Delta::Line);
-        assert_eq!(sel.state.selected(), Some(1));
+        assert_eq!(sel.state.list.selected(), Some(1));
-        assert_eq!(sel.album.state.selected(), Some(0));
+        assert_eq!(sel.album.state.list.selected(), Some(0));
 
-        sel.decrement(artists);
+        sel.decrement(artists, Delta::Line);
-        assert_eq!(sel.state.selected(), Some(0));
+        assert_eq!(sel.state.list.selected(), Some(0));
-        assert_eq!(sel.album.state.selected(), Some(0));
+        assert_eq!(sel.album.state.list.selected(), Some(0));
 
         for _ in 0..(artists.len() + 5) {
-            sel.increment(artists);
+            sel.increment(artists, Delta::Line);
         }
-        assert_eq!(sel.state.selected(), Some(artists.len() - 1));
+        assert_eq!(sel.state.list.selected(), Some(artists.len() - 1));
-        assert_eq!(sel.album.state.selected(), Some(0));
+        assert_eq!(sel.album.state.list.selected(), Some(0));
 
-        sel.increment_album(artists);
+        sel.increment_album(artists, Delta::Line);
-        assert_eq!(sel.state.selected(), Some(artists.len() - 1));
+        assert_eq!(sel.state.list.selected(), Some(artists.len() - 1));
-        assert_eq!(sel.album.state.selected(), Some(1));
+        assert_eq!(sel.album.state.list.selected(), Some(1));
 
         // Verify that increment that doesn't change index does not reset album.
-        sel.increment(artists);
+        sel.increment(artists, Delta::Line);
-        assert_eq!(sel.state.selected(), Some(artists.len() - 1));
+        assert_eq!(sel.state.list.selected(), Some(artists.len() - 1));
-        assert_eq!(sel.album.state.selected(), Some(1));
+        assert_eq!(sel.album.state.list.selected(), Some(1));
+    }
+
+    #[test]
+    fn artist_delta_page() {
+        let artists = &COLLECTION;
+        assert!(artists.len() > 1);
+
+        let empty = ArtistSelection::initialise(&[]);
+        assert_eq!(empty.state.list.selected(), None);
+
+        let mut sel = ArtistSelection::initialise(artists);
+        assert_eq!(sel.state.list.selected(), Some(0));
+        assert_eq!(sel.album.state.list.selected(), Some(0));
+
+        assert!(artists.len() >= 4);
+        sel.state.height = 3;
+
+        sel.increment_album(artists, Delta::Line);
+        assert_eq!(sel.state.list.selected(), Some(0));
+        assert_eq!(sel.album.state.list.selected(), Some(1));
+
+        // Verify that decrement that doesn't change index does not reset album.
+        sel.decrement(artists, Delta::Page);
+        assert_eq!(sel.state.list.selected(), Some(0));
+        assert_eq!(sel.album.state.list.selected(), Some(1));
+
+        sel.increment(artists, Delta::Page);
+        assert_eq!(sel.state.list.selected(), Some(2));
+        assert_eq!(sel.album.state.list.selected(), Some(0));
+
+        sel.decrement(artists, Delta::Page);
+        assert_eq!(sel.state.list.selected(), Some(0));
+        assert_eq!(sel.album.state.list.selected(), Some(0));
+
+        for _ in 0..(artists.len() + 5) {
+            sel.increment(artists, Delta::Page);
+        }
+        assert_eq!(sel.state.list.selected(), Some(artists.len() - 1));
+        assert_eq!(sel.album.state.list.selected(), Some(0));
+
+        sel.increment_album(artists, Delta::Line);
+        assert_eq!(sel.state.list.selected(), Some(artists.len() - 1));
+        assert_eq!(sel.album.state.list.selected(), Some(1));
+
+        // Verify that increment that doesn't change index does not reset album.
+        sel.increment(artists, Delta::Page);
+        assert_eq!(sel.state.list.selected(), Some(artists.len() - 1));
+        assert_eq!(sel.album.state.list.selected(), Some(1));
+    }
+
+    #[test]
+    fn artist_reinitialise() {
+        let artists = &COLLECTION;
+        assert!(artists.len() > 1);
+
+        let mut sel = ArtistSelection::initialise(artists);
+        sel.state.list.select(Some(artists.len() - 1));
+        sel.album.state.list.select(Some(1));
 
         // Re-initialise.
         let expected = sel.clone();
@@ -577,7 +755,7 @@ mod tests {
 
         // Re-initialise out-of-bounds.
         let mut expected = sel.clone();
-        expected.decrement(artists);
+        expected.decrement(artists, Delta::Line);
         let active_artist = ActiveArtist::get(artists, &sel);
         sel.reinitialise(&artists[..(artists.len() - 1)], active_artist);
         assert_eq!(sel, expected);
@@ -587,15 +765,5 @@ mod tests {
         let active_artist = ActiveArtist::get(artists, &sel);
         sel.reinitialise(&[], active_artist);
         assert_eq!(sel, expected);
-
-        // Artifical test case to verify upper limit.
-        sel.state.select(Some(std::usize::MAX));
-        sel.album.state.select(Some(1));
-        assert_eq!(sel.state.selected(), Some(std::usize::MAX));
-        assert_eq!(sel.album.state.selected(), Some(1));
-
-        sel.increment(&[]);
-        assert_eq!(sel.state.selected(), Some(std::usize::MAX));
-        assert_eq!(sel.album.state.selected(), Some(1));
     }
 }

src/tui/handler.rs

@@ -4,9 +4,12 @@ use crossterm::event::{KeyCode, KeyEvent, KeyModifiers};
 use mockall::automock;
 
 use crate::tui::{
-    app::app::{
+    app::{
-        AppState, IAppInteract, IAppInteractBrowse, IAppInteractError, IAppInteractInfo,
+        app::{
-        IAppInteractReload,
+            AppState, IAppInteract, IAppInteractBrowse, IAppInteractError, IAppInteractInfo,
+            IAppInteractReload,
+        },
+        selection::Delta,
     },
     event::{Event, EventError, EventReceiver},
 };
@@ -83,8 +86,10 @@ impl<APP: IAppInteract> IEventHandlerPrivate<APP> for EventHandler {
             KeyCode::Left => app.decrement_category(),
             KeyCode::Right => app.increment_category(),
             // Selection change.
-            KeyCode::Up => app.decrement_selection(),
+            KeyCode::Up => app.decrement_selection(Delta::Line),
-            KeyCode::Down => app.increment_selection(),
+            KeyCode::Down => app.increment_selection(Delta::Line),
+            KeyCode::PageUp => app.decrement_selection(Delta::Page),
+            KeyCode::PageDown => app.increment_selection(Delta::Page),
             // Toggle overlay.
             KeyCode::Char('m') | KeyCode::Char('M') => app.show_info_overlay(),
             // Toggle Reload

src/tui/ui.rs

@@ -14,7 +14,7 @@ use ratatui::{
 
 use crate::tui::app::{
     app::{AppState, IAppAccess},
-    selection::{Category, Selection},
+    selection::{Category, Selection, WidgetState},
 };
 
 pub trait IUi {
@@ -159,11 +159,11 @@ impl OverlayBuilder {
 struct ArtistState<'a, 'b> {
     active: bool,
     list: List<'a>,
-    state: &'b mut ListState,
+    state: &'b mut WidgetState,
 }
 
 impl<'a, 'b> ArtistState<'a, 'b> {
-    fn new(active: bool, artists: &'a [Artist], state: &'b mut ListState) -> ArtistState<'a, 'b> {
+    fn new(active: bool, artists: &'a [Artist], state: &'b mut WidgetState) -> ArtistState<'a, 'b> {
         let list = List::new(
             artists
                 .iter()
@@ -234,12 +234,12 @@ impl<'a> ArtistOverlay<'a> {
 struct AlbumState<'a, 'b> {
     active: bool,
     list: List<'a>,
-    state: &'b mut ListState,
+    state: &'b mut WidgetState,
     info: Paragraph<'a>,
 }
 
 impl<'a, 'b> AlbumState<'a, 'b> {
-    fn new(active: bool, albums: &'a [Album], state: &'b mut ListState) -> AlbumState<'a, 'b> {
+    fn new(active: bool, albums: &'a [Album], state: &'b mut WidgetState) -> AlbumState<'a, 'b> {
         let list = List::new(
             albums
                 .iter()
@@ -247,7 +247,7 @@ impl<'a, 'b> AlbumState<'a, 'b> {
                 .collect::<Vec<ListItem>>(),
         );
 
-        let album = state.selected().map(|i| &albums[i]);
+        let album = state.list.selected().map(|i| &albums[i]);
         let info = Paragraph::new(format!(
             "Title: {}\n\
              Year: {}",
@@ -267,12 +267,12 @@ impl<'a, 'b> AlbumState<'a, 'b> {
 struct TrackState<'a, 'b> {
     active: bool,
     list: List<'a>,
-    state: &'b mut ListState,
+    state: &'b mut WidgetState,
     info: Paragraph<'a>,
 }
 
 impl<'a, 'b> TrackState<'a, 'b> {
-    fn new(active: bool, tracks: &'a [Track], state: &'b mut ListState) -> TrackState<'a, 'b> {
+    fn new(active: bool, tracks: &'a [Track], state: &'b mut WidgetState) -> TrackState<'a, 'b> {
         let list = List::new(
             tracks
                 .iter()
@@ -280,7 +280,7 @@ impl<'a, 'b> TrackState<'a, 'b> {
                 .collect::<Vec<ListItem>>(),
         );
 
-        let track = state.selected().map(|i| &tracks[i]);
+        let track = state.list.selected().map(|i| &tracks[i]);
         let info = Paragraph::new(format!(
             "Track: {}\n\
              Title: {}\n\
@@ -342,7 +342,7 @@ impl Ui {
     fn render_list_widget<B: Backend>(
         title: &str,
         list: List,
-        list_state: &mut ListState,
+        state: &mut WidgetState,
         active: bool,
         area: Rect,
         frame: &mut Frame<'_, B>,
@@ -353,8 +353,9 @@ impl Ui {
                 .style(Self::style(active, false))
                 .block(Self::block(title, active, false)),
             area,
-            list_state,
+            &mut state.list,
         );
+        state.height = area.height.saturating_sub(2) as usize;
     }
 
     fn render_info_widget<B: Backend>(
@@ -422,6 +423,7 @@ impl Ui {
         let no_albums: Vec<Album> = vec![];
         let albums = artist_selection
             .state
+            .list
             .selected()
             .map(|i| &artists[i].albums)
             .unwrap_or_else(|| &no_albums);
@@ -437,6 +439,7 @@ impl Ui {
         let no_tracks: Vec<Track> = vec![];
         let tracks = album_selection
             .state
+            .list
             .selected()
             .map(|i| &albums[i].tracks)
             .unwrap_or_else(|| &no_tracks);
@@ -458,7 +461,7 @@ impl Ui {
         let area = OverlayBuilder::default().build(frame.size());
 
         let artist_selection = &mut selection.artist;
-        let artist_overlay = ArtistOverlay::new(artists, &artist_selection.state);
+        let artist_overlay = ArtistOverlay::new(artists, &artist_selection.state.list);
 
         Self::render_overlay_widget("Artist", artist_overlay.properties, area, false, frame);
     }
@@ -510,7 +513,11 @@ impl IUi for Ui {
 
 #[cfg(test)]
 mod tests {
-    use crate::tui::{app::app::AppPublic, testmod::COLLECTION, tests::terminal};
+    use crate::tui::{
+        app::{app::AppPublic, selection::Delta},
+        testmod::COLLECTION,
+        tests::terminal,
+    };
 
     use super::*;
 
@@ -564,14 +571,14 @@ mod tests {
         // Change the track (which has a different track format).
         selection.increment_category();
         selection.increment_category();
-        selection.increment_selection(artists);
+        selection.increment_selection(artists, Delta::Line);
 
         draw_test_suite(artists, &mut selection);
 
         // Change the artist (which has a multi-link entry).
         selection.decrement_category();
         selection.decrement_category();
-        selection.increment_selection(artists);
+        selection.increment_selection(artists, Delta::Line);
 
         draw_test_suite(artists, &mut selection);
     }