From 45afd9ac799a66c4c280a1cdae50da1f956e154f Mon Sep 17 00:00:00 2001
From: Ellpeck <me@ellpeck.de>
Date: Thu, 14 Apr 2022 17:54:25 +0200
Subject: [PATCH] Added Element.AutoNavGroup which allows forming groups for
 auto-navigation

---
 CHANGELOG.md                | 3 +++
 MLEM.Ui/Elements/Element.cs | 6 ++++++
 MLEM.Ui/UiControls.cs       | 8 ++++----
 3 files changed, 13 insertions(+), 4 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 6a56a10..1423c14 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -14,6 +14,9 @@ Additions
 - Added consuming variants of IsPressed methods to InputHandler
 
 ### MLEM.Ui
+Additions
+- Added Element.AutoNavGroup which allows forming groups for auto-navigation
+
 Fixes
 - Fixed auto-nav tooltip displaying on the selected element even when not in auto-nav mode
 - Fixed radio buttons not unchecking all other radio buttons with the same root element
diff --git a/MLEM.Ui/Elements/Element.cs b/MLEM.Ui/Elements/Element.cs
index db48ed3..378be87 100644
--- a/MLEM.Ui/Elements/Element.cs
+++ b/MLEM.Ui/Elements/Element.cs
@@ -249,6 +249,12 @@ namespace MLEM.Ui.Elements {
         /// 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>
         public bool AreaDirty { get; private set; }
+        /// <summary>
+        /// An optional string that represents a group of elements for automatic (keyboard and gamepad) navigation.
+        /// All elements that share the same auto-nav group will be able to be navigated between, and all other elements will not be reachable from elements of other groups.
+        /// Note that, if no element is previously selected and auto-navigation is invoked, this element can always be navigated to if it is the first one chosen by auto-navigation.
+        /// </summary>
+        public virtual string AutoNavGroup { get; set; }
 
         /// <summary>
         /// This Element's current <see cref="UiStyle"/>.
diff --git a/MLEM.Ui/UiControls.cs b/MLEM.Ui/UiControls.cs
index 5f5818d..5389702 100644
--- a/MLEM.Ui/UiControls.cs
+++ b/MLEM.Ui/UiControls.cs
@@ -353,15 +353,15 @@ namespace MLEM.Ui {
         protected virtual Element GetTabNextElement(bool backward) {
             if (this.ActiveRoot == null)
                 return null;
-            var children = this.ActiveRoot.Element.GetChildren(c => !c.IsHidden, true, true).Append(this.ActiveRoot.Element);
+            var children = this.ActiveRoot.Element.GetChildren(c => !c.IsHidden, true, true).Append(this.ActiveRoot.Element)
+                // we can't add these checks to GetChildren because it ignores false grandchildren
+                .Where(c => c.CanBeSelected && c.AutoNavGroup == this.SelectedElement?.AutoNavGroup);
             if (this.SelectedElement?.Root != this.ActiveRoot) {
-                return backward ? children.LastOrDefault(c => c.CanBeSelected) : children.FirstOrDefault(c => c.CanBeSelected);
+                return backward ? children.LastOrDefault() : children.FirstOrDefault();
             } else {
                 var foundCurr = false;
                 Element lastFound = null;
                 foreach (var child in children) {
-                    if (!child.CanBeSelected)
-                        continue;
                     if (child == this.SelectedElement) {
                         // when going backwards, return the last element found before the current one
                         if (backward)