More intuitive navigation between groups

Silksong.ModMenu/Elements/AbstractGroup.cs

@@ -60,19 +60,19 @@ protected AbstractGroup()
     protected abstract IEnumerable<INavigable> GetNavigables(NavigationDirection direction);
 
     /// <inheritdoc/>
-    public virtual void ClearNeighbor(NavigationDirection direction)
+    public virtual void ClearNeighbors(NavigationDirection direction)
     {
         foreach (var navigable in GetNavigables(direction))
-            navigable.ClearNeighbor(direction);
+            navigable.ClearNeighbors(direction);
     }
 
     /// <inheritdoc/>
     public virtual void ClearNeighbors()
     {
-        ClearNeighbor(NavigationDirection.Up);
-        ClearNeighbor(NavigationDirection.Left);
-        ClearNeighbor(NavigationDirection.Right);
-        ClearNeighbor(NavigationDirection.Down);
+        ClearNeighbors(NavigationDirection.Up);
+        ClearNeighbors(NavigationDirection.Left);
+        ClearNeighbors(NavigationDirection.Right);
+        ClearNeighbors(NavigationDirection.Down);
     }
 
     /// <inheritdoc/>
@@ -85,9 +85,9 @@ public virtual void ClearNeighbors()
             .FirstOrDefault();
 
     /// <inheritdoc/>
-    public abstract bool GetSelectable(
+    public abstract bool GetSelectables(
         NavigationDirection direction,
-        [MaybeNullWhen(false)] out Selectable selectable
+        [MaybeNullWhen(false)] out IEnumerable<Selectable> selectables
     );
 
     private GameObject? gameObjectParent;
@@ -113,10 +113,13 @@ public virtual void ClearGameObjectParent()
     }
 
     /// <inheritdoc/>
-    public virtual void SetNeighbor(NavigationDirection direction, Selectable selectable)
+    public virtual void SetNeighbors(
+        NavigationDirection direction,
+        IEnumerable<Selectable> selectables
+    )
     {
         foreach (var navigable in GetNavigables(direction))
-            navigable.SetNeighbor(direction, selectable);
+            navigable.SetNeighbors(direction, selectables);
     }
 
     /// <inheritdoc/>

Silksong.ModMenu/Elements/FreeGroup.cs

@@ -88,15 +88,14 @@ private static float SortKey(NavigationDirection direction, Vector2 pos) =>
         };
 
     /// <inheritdoc/>
-    public override bool GetSelectable(
+    public override bool GetSelectables(
         NavigationDirection direction,
-        [MaybeNullWhen(false)] out Selectable selectable
+        [MaybeNullWhen(false)] out IEnumerable<Selectable> selectables
     )
     {
-        selectable = GetNavigables(direction)
-            .Select(n => n.GetSelectable(direction, out var s) ? s : null)
-            .FirstOrDefault();
-        return selectable != null;
+        selectables = GetNavigables(direction.Opposite())
+            .SelectMany(n => n.GetSelectables(direction, out var s) ? s : []);
+        return selectables.Any();
     }
 
     /// <inheritdoc/>

Silksong.ModMenu/Elements/GridGroup.cs

@@ -150,36 +150,30 @@ public override void Clear()
     }
 
     /// <inheritdoc/>
-    public override bool GetSelectable(
+    public override bool GetSelectables(
         NavigationDirection direction,
-        [MaybeNullWhen(false)] out Selectable selectable
+        [MaybeNullWhen(false)] out IEnumerable<Selectable> selectables
     )
     {
-        var navigable = direction switch
+        var navigables = direction switch
         {
-            // Last element.
-            NavigationDirection.Up => AllEntities()
-                .Where(e => e.VisibleSelf)
-                .OfType<INavigable>()
-                .LastOrDefault(),
-            // Rightmost element.
-            NavigationDirection.Left => GetColumns()
-                .SelectMany(col => col.WhereNonNull(e => e.VisibleSelf).OfType<INavigable>())
-                .LastOrDefault(),
-            // Leftmost element.
-            NavigationDirection.Right => GetColumns()
-                .SelectMany(col => col.WhereNonNull(e => e.VisibleSelf).OfType<INavigable>())
-                .FirstOrDefault(),
-            // First element.
-            NavigationDirection.Down => AllEntities()
-                .Where(e => e.VisibleSelf)
-                .OfType<INavigable>()
-                .FirstOrDefault(),
+            // Bottommost element of every column.
+            NavigationDirection.Up => GetColumns()
+                .Select(x => (INavigable?)x.LastOrDefault(e => e is INavigable && e.VisibleSelf))
+                .WhereNonNull(),
+            // Rightmost element of every row.
+            NavigationDirection.Left => GetNavigables(NavigationDirection.Right),
+            // Leftmost element of every row.
+            NavigationDirection.Right => GetNavigables(NavigationDirection.Left),
+            // Topmost element of every column.
+            NavigationDirection.Down => GetColumns()
+                .Select(x => (INavigable?)x.FirstOrDefault(e => e is INavigable && e.VisibleSelf))
+                .WhereNonNull(),
             _ => throw new ArgumentException($"{direction}"),
         };
 
-        selectable = default;
-        return navigable != null && navigable.GetSelectable(direction, out selectable);
+        selectables = navigables.SelectMany(x => x.GetSelectables(direction, out var s) ? s : []);
+        return selectables.Any();
     }
 
     /// <inheritdoc/>
@@ -216,7 +210,7 @@ static bool ClosestColumn(
                     INavigable?[] row,
                     NavigationDirection dir,
                     int column,
-                    [MaybeNullWhen(false)] out Selectable target
+                    [MaybeNullWhen(false)] out IEnumerable<Selectable> targets
                 )
                 {
                     int offset = 0;
@@ -235,12 +229,12 @@ static bool ClosestColumn(
                         if (
                             idx >= 0
                             && idx < row.Length
-                            && (row[idx]?.GetSelectable(dir, out target) ?? false)
+                            && (row[idx]?.GetSelectables(dir, out targets) ?? false)
                         )
                             return true;
                     }
 
-                    target = default;
+                    targets = default;
                     return false;
                 }
 
@@ -250,12 +244,12 @@ static bool ClosestColumn(
                         prevRow[i] != null
                         && ClosestColumn(nextRow, NavigationDirection.Down, i, out var s)
                     )
-                        prevRow[i]!.SetNeighborDown(s);
+                        prevRow[i]!.SetNeighborsDown(s);
                     if (
                         nextRow[i] != null
                         && ClosestColumn(prevRow, NavigationDirection.Up, i, out s)
                     )
-                        nextRow[i]!.SetNeighborUp(s);
+                        nextRow[i]!.SetNeighborsUp(s);
                 }
             }
             prevRow = nextRow;

Silksong.ModMenu/Elements/INavigable.cs

@@ -1,4 +1,6 @@
-using System.Diagnostics.CodeAnalysis;
+using System.Collections;
+using System.Collections.Generic;
+using System.Diagnostics.CodeAnalysis;
 using UnityEngine.UI;
 
 namespace Silksong.ModMenu.Elements;
@@ -14,25 +16,25 @@ public interface INavigable
     void ClearNeighbors();
 
     /// <summary>
-    /// Set the directional neighbor of this entity.
+    /// Set the directional neighbors of this entity to one or more of the given choices.
     /// </summary>
     /// <returns>False if this entity has no navigation to connect.</returns>
-    void SetNeighbor(NavigationDirection direction, Selectable selectable);
+    void SetNeighbors(NavigationDirection direction, IEnumerable<Selectable> selectables);
 
     /// <summary>
     /// Unset the given directional neighbor of this entity.
     /// </summary>
-    void ClearNeighbor(NavigationDirection direction);
+    void ClearNeighbors(NavigationDirection direction);
 
     /// <summary>
-    /// Get the Selectable to target if navigating to this element along 'direction'.
+    /// Get a set of choices for the Selectables to target if navigating to this element along 'direction'.
     ///
     /// In other words, typical usage would entail:
-    ///   if (foo.GetSelectable(dir, out var selectable))
-    ///       bar.SetNeighbor(dir, selectable);
+    ///   if (foo.GetSelectables(dir, out var selectables))
+    ///       bar.SetNeighbors(dir, selectables);
     /// </summary>
-    bool GetSelectable(
+    bool GetSelectables(
         NavigationDirection direction,
-        [MaybeNullWhen(false)] out Selectable selectable
+        [MaybeNullWhen(false)] out IEnumerable<Selectable> selectables
     );
 }