Only expand one album at a time

src/elekf/library.gleam

@@ -13,6 +13,9 @@ pub type Library {
   )
 }
 
+/// An ID that can never match any library item
+pub const invalid_id = -1
+
 /// Gets an empty library for use as a default value.
 pub fn empty() {
   Library(albums: map.new(), artists: map.new(), tracks: map.new())

src/elekf/utils/misc.gleam

@@ -0,0 +1,10 @@
+//// Miscellaneous utilities that do not fit anywhere else.
+
+/// Toggle a value with a new value - if the new value is the same as the
+/// previous, returns the "null" value. Otherwise returns the new value.
+pub fn toggle(prev: a, new: a, null: a) {
+  case new == prev {
+    True -> null
+    False -> new
+  }
+}

src/elekf/web/components/library_views/albums_view.gleam

@@ -3,7 +3,6 @@
 import gleam/string
 import gleam/list
 import gleam/map
-import gleam/set
 import gleam/option
 import gleam/dynamic
 import gleam/result
@@ -11,7 +10,7 @@ import lustre
 import lustre/effect
 import lustre/attribute
 import lustre/element
-import elekf/utils/set as set_utils
+import elekf/utils/misc
 import elekf/library.{type Library}
 import elekf/library/album.{type Album}
 import elekf/library/album_utils
@@ -23,7 +22,7 @@ import elekf/web/common
 const component_name = "albums-view"
 
 type Model {
-  Model(library_view: library_view.Model(Album), expanded_albums: set.Set(Int))
+  Model(library_view: library_view.Model(Album), expanded_album: Int)
 }
 
 type Msg {
@@ -62,7 +61,7 @@ fn init() {
     library_view.init(library.empty(), data_getter, shuffler)
 
   #(
-    Model(library_view: lib_m, expanded_albums: set.new()),
+    Model(library_view: lib_m, expanded_album: library.invalid_id),
     effect.map(lib_e, LibraryViewMsg),
   )
 }
@@ -73,7 +72,11 @@ fn update(model: Model, msg) {
       #(
         Model(
           ..model,
-          expanded_albums: set_utils.toggle(model.expanded_albums, album.0),
+          expanded_album: misc.toggle(
+            model.expanded_album,
+            album.0,
+            library.invalid_id,
+          ),
         ),
         effect.none(),
       )
@@ -116,6 +119,6 @@ fn view(model: Model, item: LibraryItem(Album)) {
     model.library_view.library,
     model.library_view.settings,
     item,
-    set.contains(model.expanded_albums, item.0),
+    item.0 == model.expanded_album,
   )
 }

src/elekf/web/components/library_views/single_artist_view.gleam

@@ -3,7 +3,6 @@
 import gleam/string
 import gleam/list
 import gleam/map
-import gleam/set
 import gleam/option
 import gleam/dynamic
 import gleam/result
@@ -12,7 +11,7 @@ import lustre/element/html.{div, header}
 import lustre/element.{text}
 import lustre/attribute
 import lustre/effect
-import elekf/utils/set as set_utils
+import elekf/utils/misc
 import elekf/library.{type Library}
 import elekf/library/album.{type Album}
 import elekf/library/album_utils
@@ -28,7 +27,7 @@ type Model {
   Model(
     library_view: library_view.Model(Album),
     artist: option.Option(LibraryItem(Artist)),
-    expanded_albums: set.Set(Int),
+    expanded_album: Int,
   )
 }
 
@@ -85,7 +84,11 @@ fn init() {
     )
 
   #(
-    Model(artist: option.None, expanded_albums: set.new(), library_view: lib_m),
+    Model(
+      artist: option.None,
+      expanded_album: library.invalid_id,
+      library_view: lib_m,
+    ),
     effect.map(lib_e, LibraryViewMsg),
   )
 }
@@ -95,7 +98,7 @@ fn update(model: Model, msg) {
     ArtistUpdated(option.Some(artist)) -> #(
       Model(
         artist: option.Some(artist),
-        expanded_albums: set.new(),
+        expanded_album: library.invalid_id,
         library_view: library_view.Model(
           ..model.library_view,
           data: data_getter(model.library_view.library, artist),
@@ -106,7 +109,7 @@ fn update(model: Model, msg) {
     ArtistUpdated(option.None) -> #(
       Model(
         artist: option.None,
-        expanded_albums: set.new(),
+        expanded_album: library.invalid_id,
         library_view: library_view.Model(..model.library_view, data: []),
       ),
       effect.none(),
@@ -114,7 +117,11 @@ fn update(model: Model, msg) {
     LibraryViewMsg(AlbumExpandToggled(album)) -> #(
       Model(
         ..model,
-        expanded_albums: set_utils.toggle(model.expanded_albums, album.0),
+        expanded_album: misc.toggle(
+          model.expanded_album,
+          album.0,
+          library.invalid_id,
+        ),
       ),
       effect.none(),
     )
@@ -186,7 +193,7 @@ fn album_view(model: Model, item: LibraryItem(Album)) {
     model.library_view.library,
     model.library_view.settings,
     item,
-    set.contains(model.expanded_albums, item.0),
+    item.0 == model.expanded_album,
   )
 }