Add Has Goal decorator to BT

Source/Editor/CustomEditors/Editors/BehaviorKnowledgeSelectorEditor.cs

@@ -2,6 +2,7 @@
 
 using System;
 using System.Collections.Generic;
+using System.Linq;
 using FlaxEditor.GUI;
 using FlaxEditor.GUI.Tree;
 using FlaxEditor.Scripting;
@@ -89,6 +90,15 @@ namespace FlaxEditor.CustomEditors.Editors
                 typed = new ScriptType(valueType.GenericTypeArguments[0]);
             }
 
+            // Get customization options
+            var attributes = Values.GetAttributes();
+            var attribute = (BehaviorKnowledgeSelectorAttribute)attributes?.FirstOrDefault(x => x is BehaviorKnowledgeSelectorAttribute);
+            bool isGoalSelector = false;
+            if (attribute != null)
+            {
+                isGoalSelector = attribute.IsGoalSelector;
+            }
+
             // Create menu with tree-like structure and search box
             var menu = Utilities.Utils.CreateSearchPopup(out var searchBox, out var tree, 0, true);
             var selected = Path;
@@ -111,8 +121,11 @@ namespace FlaxEditor.CustomEditors.Editors
             if (string.IsNullOrEmpty(selected))
                 tree.Select(noneNode);
 
+            if (!isGoalSelector)
+            {
                 // Blackboard
                 SetupPickerTypeItems(tree, typed, selected, "Blackboard", "Blackboard/", rootNode.BlackboardType);
+            }
 
             // Goals
             var goalTypes = rootNode.GoalTypes;
@@ -129,7 +142,7 @@ namespace FlaxEditor.CustomEditors.Editors
                     var goalType = TypeUtils.GetType(goalTypeName);
                     if (goalType == null)
                         continue;
-                    var goalTypeNode = SetupPickerTypeItems(tree, typed, selected, goalType.Name, "Goal/" + goalTypeName + "/", goalTypeName);
+                    var goalTypeNode = SetupPickerTypeItems(tree, typed, selected, goalType.Name, "Goal/" + goalTypeName + "/", goalTypeName, !isGoalSelector);
                     goalTypeNode.Parent = goalsNode;
                 }
                 goalsNode.ExpandAll(true);
@@ -138,12 +151,11 @@ namespace FlaxEditor.CustomEditors.Editors
             menu.Show(_label, new Float2(0, _label.Height));
         }
 
-        private TreeNode SetupPickerTypeItems(Tree tree, ScriptType typed, string selected, string text, string typePath, string typeName)
+        private TreeNode SetupPickerTypeItems(Tree tree, ScriptType typed, string selected, string text, string typePath, string typeName, bool addItems = true)
         {
             var type = TypeUtils.GetType(typeName);
             if (type == null)
                 return null;
-            var items = GenericEditor.GetItemsForType(type, type.IsClass, true);
             var typeNode = new TreeNode
             {
                 Text = text,
@@ -155,6 +167,9 @@ namespace FlaxEditor.CustomEditors.Editors
                 typeNode.Tag = null;
             if (string.Equals(selected, (string)typeNode.Tag, StringComparison.Ordinal))
                 tree.Select(typeNode);
+            if (addItems)
+            {
+                var items = GenericEditor.GetItemsForType(type, type.IsClass, true);
                 foreach (var item in items)
                 {
                     if (typed && !typed.IsAssignableFrom(item.Info.ValueType))
@@ -172,6 +187,7 @@ namespace FlaxEditor.CustomEditors.Editors
                     // TODO: add support for nested items (eg. field from blackboard structure field)
                 }
                 typeNode.Expand(true);
+            }
             return typeNode;
         }
     }

Source/Engine/AI/BehaviorKnowledge.cpp

@@ -19,9 +19,11 @@ bool AccessVariant(Variant& instance, const StringAnsiView& member, Variant& val
     if (member.IsEmpty())
     {
         // Whole blackboard value
-        CHECK_RETURN(instance.Type == value.Type, false);
         if (set)
+        {
+            CHECK_RETURN(instance.Type == value.Type, false);
             instance = value;
+        }
         else
             value = instance;
         return true;

Source/Engine/AI/BehaviorKnowledgeSelector.cs

@@ -4,6 +4,28 @@ using System;
 
 namespace FlaxEngine
 {
+    /// <summary>
+    /// Customizes editor of <see cref="BehaviorKnowledgeSelector{T}"/> or <see cref="BehaviorKnowledgeSelectorAny"/>.
+    /// </summary>
+    /// <seealso cref="System.Attribute" />
+    [AttributeUsage(AttributeTargets.Field | AttributeTargets.Property)]
+    public sealed class BehaviorKnowledgeSelectorAttribute : Attribute
+    {
+        /// <summary>
+        /// Changes selector editor to allow to pick only whole goals.
+        /// </summary>
+        public bool IsGoalSelector;
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="BehaviorKnowledgeSelectorAttribute"/> structure.
+        /// </summary>
+        /// <param name="isGoalSelector">Changes selector editor to allow to pick only whole goals.</param>
+        public BehaviorKnowledgeSelectorAttribute(bool isGoalSelector = false)
+        {
+            IsGoalSelector = isGoalSelector;
+        }
+    }
+
 #if FLAX_EDITOR
     [CustomEditor(typeof(FlaxEditor.CustomEditors.Editors.BehaviorKnowledgeSelectorEditor))]
 #endif

Source/Engine/AI/BehaviorTreeNodes.cpp

@@ -456,3 +456,9 @@ bool BehaviorTreeHasTagDecorator::CanUpdate(const BehaviorUpdateContext& context
     result ^= Invert;
     return result;
 }
+
+bool BehaviorTreeHasGoalDecorator::CanUpdate(const BehaviorUpdateContext& context)
+{
+    Variant value; // TODO: use HasGoal in Knowledge to optimize this (goal struct is copied by selector accessor)
+    return Goal.TryGet(context.Knowledge, value);
+}

Source/Engine/AI/BehaviorTreeNodes.h

@@ -374,3 +374,20 @@ public:
     // [BehaviorTreeNode]
     bool CanUpdate(const BehaviorUpdateContext& context) override;
 };
+
+/// <summary>
+/// Checks if certain goal has been added to Behavior knowledge.
+/// </summary>
+API_CLASS(Sealed) class FLAXENGINE_API BehaviorTreeHasGoalDecorator : public BehaviorTreeDecorator
+{
+    DECLARE_SCRIPTING_TYPE_WITH_CONSTRUCTOR_IMPL(BehaviorTreeHasGoalDecorator, BehaviorTreeDecorator);
+    API_AUTO_SERIALIZATION();
+
+    // The goal type to check.
+    API_FIELD(Attributes="EditorOrder(0), BehaviorKnowledgeSelector(IsGoalSelector = true)")
+    BehaviorKnowledgeSelectorAny Goal;
+
+public:
+    // [BehaviorTreeNode]
+    bool CanUpdate(const BehaviorUpdateContext& context) override;
+};