src/tui/app/machine/browse_state.rs

@@ -1,7 +1,7 @@
 use crate::tui::app::{
     machine::{App, AppInner, AppMachine},
-    selection::{Delta, ListSelection},
-    AppPublicState, AppState, IAppInteractBrowse,
+    selection::ListSelection,
+    AppPublicState, AppState, IAppInteractBrowse, Delta
 };
 
 pub struct BrowseState;

src/tui/app/machine/match_state.rs

@@ -9,8 +9,8 @@ use musichoard::collection::{
 use crate::tui::{
     app::{
         machine::{fetch_state::FetchState, input::Input, App, AppInner, AppMachine},
-        AlbumMatches, AppPublicState, AppState, ArtistMatches, IAppInteractMatch, ListOption,
-        MatchOption, MatchStateInfo, MatchStatePublic, WidgetState,
+        AlbumMatches, AppPublicState, AppState, ArtistMatches, Delta, IAppInteractMatch,
+        ListOption, MatchOption, MatchStateInfo, MatchStatePublic, WidgetState,
     },
     lib::interface::musicbrainz::api::{Lookup, Match},
 };
@@ -243,19 +243,19 @@ impl<'a> From<&'a mut MatchState> for AppPublicState<'a> {
 impl IAppInteractMatch for AppMachine<MatchState> {
     type APP = App;
 
-    fn prev_match(mut self) -> Self::APP {
+    fn decrement_match(mut self, delta: Delta) -> Self::APP {
         if let Some(index) = self.state.state.list.selected() {
-            let result = index.saturating_sub(1);
+            let result = index.saturating_sub(delta.as_usize(&self.state.state));
             self.state.state.list.select(Some(result));
         }
 
         self.into()
     }
 
-    fn next_match(mut self) -> Self::APP {
+    fn increment_match(mut self, delta: Delta) -> Self::APP {
         let index = self.state.state.list.selected().unwrap();
         let to = cmp::min(
-            index.saturating_add(1),
+            index.saturating_add(delta.as_usize(&self.state.state)),
             self.state.current.len().saturating_sub(1),
         );
         self.state.state.list.select(Some(to));
@@ -473,38 +473,38 @@ mod tests {
         assert_eq!(matches.state.current, matches_info);
         assert_eq!(matches.state.state, widget_state);
 
-        let matches = matches.prev_match().unwrap_match();
+        let matches = matches.decrement_match(Delta::Line).unwrap_match();
 
         assert_eq!(matches.state.current, matches_info);
         assert_eq!(matches.state.state.list.selected(), Some(0));
 
         let mut matches = matches;
         for ii in 1..len {
-            matches = matches.next_match().unwrap_match();
+            matches = matches.increment_match(Delta::Line).unwrap_match();
 
             assert_eq!(matches.state.current, matches_info);
             assert_eq!(matches.state.state.list.selected(), Some(ii));
         }
 
         // Next is CannotHaveMBID
-        let matches = matches.next_match().unwrap_match();
+        let matches = matches.increment_match(Delta::Line).unwrap_match();
 
         assert_eq!(matches.state.current, matches_info);
         assert_eq!(matches.state.state.list.selected(), Some(len));
 
         // Next is ManualInputMbid
-        let matches = matches.next_match().unwrap_match();
+        let matches = matches.increment_match(Delta::Line).unwrap_match();
 
         assert_eq!(matches.state.current, matches_info);
         assert_eq!(matches.state.state.list.selected(), Some(len + 1));
 
-        let matches = matches.next_match().unwrap_match();
+        let matches = matches.increment_match(Delta::Line).unwrap_match();
 
         assert_eq!(matches.state.current, matches_info);
         assert_eq!(matches.state.state.list.selected(), Some(len + 1));
 
         // Go prev_match first as selecting on manual input does not go back to fetch.
-        let matches = matches.prev_match().unwrap_match();
+        let matches = matches.decrement_match(Delta::Line).unwrap_match();
         matches.select().unwrap_fetch();
     }
 
@@ -619,10 +619,10 @@ mod tests {
             AppMachine::match_state(inner(music_hoard(vec![])), match_state(album_match()));
 
         // album_match has two matches which means that the fourth option should be manual input.
-        let matches = matches.next_match().unwrap_match();
-        let matches = matches.next_match().unwrap_match();
-        let matches = matches.next_match().unwrap_match();
-        let matches = matches.next_match().unwrap_match();
+        let matches = matches.increment_match(Delta::Line).unwrap_match();
+        let matches = matches.increment_match(Delta::Line).unwrap_match();
+        let matches = matches.increment_match(Delta::Line).unwrap_match();
+        let matches = matches.increment_match(Delta::Line).unwrap_match();
 
         let app = matches.select();
 
@@ -657,8 +657,8 @@ mod tests {
         );
 
         // There are no matches which means that the second option should be manual input.
-        let matches = matches.next_match().unwrap_match();
-        let matches = matches.next_match().unwrap_match();
+        let matches = matches.increment_match(Delta::Line).unwrap_match();
+        let matches = matches.increment_match(Delta::Line).unwrap_match();
 
         let mut app = matches.select();
         app = input_mbid(app);
@@ -691,8 +691,8 @@ mod tests {
         );
 
         // There are no matches which means that the second option should be manual input.
-        let matches = matches.next_match().unwrap_match();
-        let matches = matches.next_match().unwrap_match();
+        let matches = matches.increment_match(Delta::Line).unwrap_match();
+        let matches = matches.increment_match(Delta::Line).unwrap_match();
 
         let mut app = matches.select();
         app = input_mbid(app);

src/tui/app/mod.rs

@@ -2,7 +2,8 @@ mod machine;
 mod selection;
 
 pub use machine::App;
-pub use selection::{Category, Delta, Selection, WidgetState};
+use ratatui::widgets::ListState;
+pub use selection::{Category, Selection};
 
 use musichoard::collection::{
     album::AlbumMeta,
@@ -124,8 +125,8 @@ pub trait IAppEventFetch {
 pub trait IAppInteractMatch {
     type APP: IApp;
 
-    fn prev_match(self) -> Self::APP;
-    fn next_match(self) -> Self::APP;
+    fn decrement_match(self, delta: Delta) -> Self::APP;
+    fn increment_match(self, delta: Delta) -> Self::APP;
     fn select(self) -> Self::APP;
 
     fn abort(self) -> Self::APP;
@@ -159,6 +160,40 @@ pub trait IAppInteractError {
     fn dismiss_error(self) -> Self::APP;
 }
 
+#[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)
+    }
+}
+
+impl WidgetState {
+    #[must_use]
+    pub const fn with_selected(mut self, selected: Option<usize>) -> Self {
+        self.list = self.list.with_selected(selected);
+        self
+    }
+}
+
+pub enum Delta {
+    Line,
+    Page,
+}
+
+impl Delta {
+    fn as_usize(&self, state: &WidgetState) -> usize {
+        match self {
+            Delta::Line => 1,
+            Delta::Page => state.height.saturating_sub(1),
+        }
+    }
+}
+
 // It would be preferable to have a getter for each field separately. However, the selection field
 // needs to be mutably accessible requiring a mutable borrow of the entire struct if behind a trait.
 // This in turn complicates simultaneous field access since only a single mutable borrow is allowed.

src/tui/app/selection/album.rs

@@ -5,9 +5,11 @@ use musichoard::collection::{
     track::Track,
 };
 
-use crate::tui::app::selection::{
-    track::{KeySelectTrack, TrackSelection},
-    Delta, SelectionState, WidgetState,
+use crate::tui::app::{
+    selection::{
+        track::{KeySelectTrack, TrackSelection},
+        SelectionState,
+    }, Delta, WidgetState
 };
 
 #[derive(Clone, Debug, PartialEq)]

src/tui/app/selection/artist.rs

@@ -6,9 +6,11 @@ use musichoard::collection::{
     track::Track,
 };
 
-use crate::tui::app::selection::{
-    album::{AlbumSelection, KeySelectAlbum},
-    Delta, SelectionState, WidgetState,
+use crate::tui::app::{
+    selection::{
+        album::{AlbumSelection, KeySelectAlbum},
+        SelectionState,
+    }, Delta, WidgetState
 };
 
 #[derive(Clone, Debug, PartialEq)]

src/tui/app/selection/mod.rs

@@ -5,7 +5,10 @@ mod track;
 use musichoard::collection::{album::Album, artist::Artist, track::Track, Collection};
 use ratatui::widgets::ListState;
 
-use artist::{ArtistSelection, KeySelectArtist};
+use crate::tui::app::{
+    selection::artist::{ArtistSelection, KeySelectArtist},
+    Delta, WidgetState,
+};
 
 #[derive(Copy, Clone, Debug, PartialEq, Eq)]
 pub enum Category {
@@ -24,40 +27,6 @@ pub struct SelectionState<'a, T> {
     pub index: usize,
 }
 
-#[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)
-    }
-}
-
-impl WidgetState {
-    #[must_use]
-    pub const fn with_selected(mut self, selected: Option<usize>) -> Self {
-        self.list = self.list.with_selected(selected);
-        self
-    }
-}
-
-pub enum Delta {
-    Line,
-    Page,
-}
-
-impl Delta {
-    fn as_usize(&self, state: &WidgetState) -> usize {
-        match self {
-            Delta::Line => 1,
-            Delta::Page => state.height.saturating_sub(1),
-        }
-    }
-}
-
 impl Selection {
     pub fn new(artists: &[Artist]) -> Self {
         Selection {

src/tui/app/selection/track.rs

@@ -2,7 +2,7 @@ use std::cmp;
 
 use musichoard::collection::track::{Track, TrackId, TrackNum};
 
-use crate::tui::app::selection::{Delta, SelectionState, WidgetState};
+use crate::tui::app::{selection::SelectionState, Delta, WidgetState};
 
 #[derive(Clone, Debug, PartialEq)]
 pub struct TrackSelection {

src/tui/handler.rs

@@ -212,8 +212,10 @@ impl<APP: IApp> IEventHandlerPrivate<APP> for EventHandler {
             // Abort.
             KeyCode::Esc | KeyCode::Char('q') | KeyCode::Char('Q') => app.abort(),
             // Select.
-            KeyCode::Up => app.prev_match(),
-            KeyCode::Down => app.next_match(),
+            KeyCode::Up => app.decrement_match(Delta::Line),
+            KeyCode::Down => app.increment_match(Delta::Line),
+            KeyCode::PageUp => app.decrement_match(Delta::Page),
+            KeyCode::PageDown => app.increment_match(Delta::Page),
             KeyCode::Enter => app.select(),
             // Othey keys.
             _ => app.no_op(),