Fixed dropdowns with some non-selectable children failing to navigate when using gamepad controls

CHANGELOG.md

@@ -60,6 +60,9 @@ Fixes
 - Fixed auto-navigating panels not scrolling to the center of elements properly
 - Fixed UiControls allowing for non-selectable or non-mouseable elements to be marked as selected or moused
 - Fixed buttons and checkboxes changing their CanBeSelected and CanBePressed values when being disabled
+- Fixed children of Panel scroll bars also being scrolled
+- Fixed RootElement.CanSelectContent and Element.IsSelected returning incorrect results when CanBeSelected changes
+- Fixed dropdowns with some non-selectable children failing to navigate when using gamepad controls
 
 Removals
 - Marked StyleProp equality members as obsolete

MLEM.Ui/Elements/Dropdown.cs

@@ -63,10 +63,10 @@ namespace MLEM.Ui.Elements {
                 if (dir == Direction2.Left || dir == Direction2.Right)
                     return null;
                 if (dir == Direction2.Up) {
-                    var prev = element.GetOlderSibling();
+                    var prev = element.GetOlderSibling(e => e.CanBeSelected);
                     return prev ?? this;
                 } else if (dir == Direction2.Down) {
-                    return element.GetSiblings(e => e.GetOlderSibling() == element).FirstOrDefault();
+                    return element.GetSiblings(e => e.CanBeSelected && e.GetOlderSibling(s => s.CanBeSelected) == element).FirstOrDefault();
                 }
                 return usualNext;
             };

MLEM.Ui/Elements/Element.cs

@@ -241,9 +241,9 @@ namespace MLEM.Ui.Elements {
         /// </summary>
         public bool IsMouseOver { get; protected set; }
         /// <summary>
-        /// Stores whether this element is its <see cref="Root"/>'s <see cref="RootElement.SelectedElement"/>.
+        /// Returns whether this element is its <see cref="Root"/>'s <see cref="RootElement.SelectedElement"/>.
         /// </summary>
-        public bool IsSelected { get; protected set; }
+        public bool IsSelected => this.Root.SelectedElement == this;
         /// <summary>
         /// Returns whether this element's <see cref="SetAreaDirty"/> method has been recently called and its area has not been updated since then using <see cref="UpdateAreaIfDirty"/> or <see cref="ForceUpdateArea"/>.
         /// </summary>
@@ -436,8 +436,6 @@ namespace MLEM.Ui.Elements {
             this.OnMouseExit += element => this.IsMouseOver = false;
             this.OnTouchEnter += element => this.IsMouseOver = true;
             this.OnTouchExit += element => this.IsMouseOver = false;
-            this.OnSelected += element => this.IsSelected = true;
-            this.OnDeselected += element => this.IsSelected = false;
             this.GetTabNextElement += (backward, next) => next;
             this.GetGamepadNextElement += (dir, next) => next;
 

MLEM.Ui/Elements/Panel.cs

@@ -119,7 +119,8 @@ namespace MLEM.Ui.Elements {
             if (!this.scrollOverflow)
                 return;
             var offset = new Vector2(0, -this.ScrollBar.CurrentValue);
-            foreach (var child in this.GetChildren(c => c != this.ScrollBar, true)) {
+            // we ignore false grandchildren so that the children of the scroll bar stay in place
+            foreach (var child in this.GetChildren(c => c != this.ScrollBar, true, true)) {
                 if (!child.ScrollOffset.Equals(offset, Epsilon)) {
                     child.ScrollOffset = offset;
                     this.relevantChildrenDirty = true;

MLEM.Ui/UiControls.cs

@@ -156,7 +156,7 @@ namespace MLEM.Ui {
         public virtual void Update() {
             if (this.IsInputOurs)
                 this.Input.Update();
-            this.ActiveRoot = this.System.GetRootElements().FirstOrDefault(root => root.CanSelectContent && !root.Element.IsHidden);
+            this.ActiveRoot = this.System.GetRootElements().FirstOrDefault(root => !root.Element.IsHidden && root.CanSelectContent);
 
             // MOUSE INPUT
             if (this.HandleMouse) {
@@ -274,7 +274,7 @@ namespace MLEM.Ui {
         /// <param name="element">The element to select, or null to deselect the selected element.</param>
         /// <param name="autoNav">Whether automatic navigation should be forced on</param>
         public void SelectElement(RootElement root, Element element, bool? autoNav = null) {
-            if (root == null || !root.CanSelectContent)
+            if (root == null)
                 return;
             if (element != null && !element.CanBeSelected)
                 return;
@@ -337,7 +337,7 @@ namespace MLEM.Ui {
         /// <param name="root">The root element whose selected element to return</param>
         /// <returns>The given root's selected element, or null if the root doesn't exist, or if there is no selected element for that root.</returns>
         public Element GetSelectedElement(RootElement root) {
-            if (root == null || !root.CanSelectContent)
+            if (root == null)
                 return null;
             this.selectedElements.TryGetValue(root.Name, out var element);
             if (element != null && !element.CanBeSelected)

MLEM.Ui/UiSystem.cs

@@ -535,7 +535,7 @@ namespace MLEM.Ui {
         /// Determines whether this root element contains any children that <see cref="Elements.Element.CanBeSelected"/>.
         /// This value is automatically calculated.
         /// </summary>
-        public bool CanSelectContent { get; private set; }
+        public bool CanSelectContent => this.Element.CanBeSelected || this.Element.GetChildren(c => c.CanBeSelected, true).Any();
 
         /// <summary>
         /// Event that is invoked when a <see cref="Element"/> is added to this root element or any of its children.
@@ -558,21 +558,6 @@ namespace MLEM.Ui {
             this.Name = name;
             this.Element = element;
             this.System = system;
-
-            this.OnElementAdded += e => {
-                if (e.CanBeSelected)
-                    this.CanSelectContent = true;
-            };
-            this.OnElementRemoved += e => {
-                if (e.CanBeSelected) {
-                    // check if removing this element removed all other selectable elements
-                    foreach (var c in this.Element.GetChildren(regardGrandchildren: true)) {
-                        if (c.CanBeSelected)
-                            return;
-                    }
-                    this.CanSelectContent = false;
-                }
-            };
         }
 
         /// <summary>