FIX: TreeView tracking of collapse/expanded states (ISX-1626) (#1775)

* enabled TreeView tracking of collapse/expanded states

* added changelog

Author: ritamerkl

Assets/Tests/InputSystem.Editor/SelectorsTests.cs

@@ -1,6 +1,8 @@
 // UITK TreeView is not supported in earlier versions
 // Therefore the UITK version of the InputActionAsset Editor is not available on earlier Editor versions either.
 #if UNITY_EDITOR && UNITY_INPUT_SYSTEM_PROJECT_WIDE_ACTIONS
+using System;
+using System.Collections.Generic;
 using System.Linq;
 using NUnit.Framework;
 using UnityEngine;
@@ -22,7 +24,7 @@ public void GetActionsAsTreeViewData_ReturnsActionsAndBindingsAsTreeViewData()
         var actionTwo = actionMap.AddAction("Action2", binding: "<Keyboard>/d");
 
 
-        var treeViewData = Selectors.GetActionsAsTreeViewData(TestData.EditorStateWithAsset(asset).Generate());
+        var treeViewData = Selectors.GetActionsAsTreeViewData(TestData.EditorStateWithAsset(asset).Generate(), new Dictionary<Guid, int>());
 
 
         Assert.That(treeViewData.Count, Is.EqualTo(2));

Packages/com.unity.inputsystem/CHANGELOG.md

@@ -33,6 +33,7 @@ however, it has to be formatted properly to pass verification tests.
 - Fixed case [ISXB-580](https://issuetracker.unity3d.com/product/unity/issues/guid/ISXB-580) (UI Submit / Cancel not working with Switch Pro controller) by adding "Submit" & "Cancel" usages to the Switch Pro controller input controls.
 - Fixed an issue where undoing deletion of Action Maps did not restore Actions correctly.
 - Fixed case [ISXB-628](https://issuetracker.unity3d.com/product/unity/issues/guid/ISXB-628) (OnIMECompositionChange does not return an empty string on accept when using Microsoft IME) by clarifying expectations and intended usage for the IME composition change event.
+- Fixed case [ISX-1626](https://jira.unity3d.com/browse/ISX-1626) where the expanded/collapsed state of items in the input action editor was not properly saved between rebuilds of the UI.
 - Fixed case [ISX-1668] (The Profiler shows incorrect data and spams the console with "Missing Profiler.EndSample" errors when there is an Input System Component in Scene).
 - Fixed [ISX-1661](https://jira.unity3d.com/browse/ISX-1661) where undoing duplications of action maps caused console errors
 - Fix for BindingSyntax `WithInteraction()` which was incorrectly using processors.

Packages/com.unity.inputsystem/InputSystem/Editor/UITKAssetEditor/SerializedInputAction.cs

@@ -12,6 +12,7 @@ public SerializedInputAction(SerializedProperty serializedProperty)
             // serialized fields and make sure they're present?
             wrappedProperty = serializedProperty ?? throw new ArgumentNullException(nameof(serializedProperty));
 
+            id = serializedProperty.FindPropertyRelative(nameof(InputAction.m_Id)).stringValue;
             name = serializedProperty.FindPropertyRelative(nameof(InputAction.m_Name)).stringValue;
             expectedControlType = ReadExpectedControlType(serializedProperty);
             type = (InputActionType)serializedProperty.FindPropertyRelative(nameof(InputAction.m_Type)).intValue;
@@ -22,6 +23,7 @@ public SerializedInputAction(SerializedProperty serializedProperty)
             expectedControlTypeTooltip = serializedProperty.FindPropertyRelative(nameof(InputAction.m_ExpectedControlType)).GetTooltip();
         }
 
+        public string id { get; }
         public string name { get; }
         public string expectedControlType { get; }
         public InputActionType type { get; }

Packages/com.unity.inputsystem/InputSystem/Editor/UITKAssetEditor/SerializedInputBinding.cs

@@ -18,6 +18,7 @@ public SerializedInputBinding(SerializedProperty serializedProperty)
         {
             wrappedProperty = serializedProperty ?? throw new ArgumentNullException(nameof(serializedProperty));
 
+            id = serializedProperty.FindPropertyRelative("m_Id").stringValue;
             name = serializedProperty.FindPropertyRelative("m_Name").stringValue;
             path = serializedProperty.FindPropertyRelative("m_Path").stringValue;
             interactions = serializedProperty.FindPropertyRelative("m_Interactions").stringValue;
@@ -38,6 +39,7 @@ public SerializedInputBinding(SerializedProperty serializedProperty)
         }
 
         public string name { get; }
+        public string id { get; }
         public string path { get; }
         public string interactions { get; }
         public string processors { get; }

Packages/com.unity.inputsystem/InputSystem/Editor/UITKAssetEditor/Views/ActionsTreeView.cs

@@ -22,12 +22,18 @@ internal class ActionsTreeView : ViewBase<ActionsTreeView.ViewState>
         private bool m_RenameOnActionAdded;
         private readonly CollectionViewSelectionChangeFilter m_ActionsTreeViewSelectionChangeFilter;
 
+        //save TreeView element id's of individual input actions and bindings to ensure saving of expanded state
+        private Dictionary<Guid, int> m_GuidToTreeViewId;
+
         public ActionsTreeView(VisualElement root, StateContainer stateContainer)
             : base(stateContainer)
         {
             m_Root = root;
 
             m_ActionsTreeView = m_Root.Q<TreeView>("actions-tree-view");
+            //assign unique viewDataKey to store treeView states like expanded/collapsed items - make it unique to avoid conflicts with other TreeViews
+            m_ActionsTreeView.viewDataKey = "InputActionTreeView " + stateContainer.GetState().serializedObject.targetObject.GetInstanceID();
+            m_GuidToTreeViewId = new Dictionary<Guid, int>();
             m_ActionsTreeView.selectionType = UIElements.SelectionType.Single;
             m_ActionsTreeView.makeItem = () => new InputActionsTreeViewItem();
             m_ActionsTreeView.bindItem = (e, i) =>
@@ -127,7 +133,7 @@ public ActionsTreeView(VisualElement root, StateContainer stateContainer)
             CreateSelector(Selectors.GetActionsForSelectedActionMap, Selectors.GetActionMapCount,
                 (_, count, state) =>
                 {
-                    var treeData = Selectors.GetActionsAsTreeViewData(state);
+                    var treeData = Selectors.GetActionsAsTreeViewData(state, m_GuidToTreeViewId);
                     return new ViewState
                     {
                         treeViewData = treeData,
@@ -305,7 +311,7 @@ public ActionOrBindingData(bool isAction, string name, int actionMapIndex, bool
 
     internal static partial class Selectors
     {
-        public static List<TreeViewItemData<ActionOrBindingData>> GetActionsAsTreeViewData(InputActionsEditorState state)
+        public static List<TreeViewItemData<ActionOrBindingData>> GetActionsAsTreeViewData(InputActionsEditorState state, Dictionary<Guid, int> idDictionary)
         {
             var actionMapIndex = state.selectedActionMapIndex;
             var controlSchemes = state.serializedObject.FindProperty(nameof(InputActionAsset.m_ControlSchemes));
@@ -323,16 +329,17 @@ public static List<TreeViewItemData<ActionOrBindingData>> GetActionsAsTreeViewDa
                 .Select(sp => new SerializedInputBinding(sp))
                 .ToList();
 
-            var id = 0;
             var actionItems = new List<TreeViewItemData<ActionOrBindingData>>();
             foreach (var action in actions)
             {
                 var actionBindings = bindings.Where(spb => spb.action == action.name).ToList();
                 var bindingItems = new List<TreeViewItemData<ActionOrBindingData>>();
+                var actionId = new Guid(action.id);
 
                 for (var i = 0; i < actionBindings.Count; i++)
                 {
                     var serializedInputBinding = actionBindings[i];
+                    var inputBindingId = new Guid(serializedInputBinding.id);
 
                     if (serializedInputBinding.isComposite)
                     {
@@ -343,8 +350,8 @@ public static List<TreeViewItemData<ActionOrBindingData>> GetActionsAsTreeViewDa
                             var isVisible = ShouldBindingBeVisible(nextBinding, state.selectedControlScheme);
                             if (isVisible)
                             {
-                                var name = GetHumanReadableCompositeName(nextBinding, state.selectedControlScheme, controlSchemes);
-                                compositeItems.Add(new TreeViewItemData<ActionOrBindingData>(id++,
+                                var name = GetHumanReadableCompositeName(nextBinding, state.selectedControlScheme, controlSchemes);                        var compositeBindingId = new Guid(nextBinding.id);
+                                compositeItems.Add(new TreeViewItemData<ActionOrBindingData>(GetIdForGuid(new Guid(nextBinding.id), idDictionary),
                                     new ActionOrBindingData(false, name, actionMapIndex, false,
                                         GetControlLayout(nextBinding.path), nextBinding.indexOfBinding)));
                             }
@@ -355,25 +362,35 @@ public static List<TreeViewItemData<ActionOrBindingData>> GetActionsAsTreeViewDa
                             nextBinding = actionBindings[i];
                         }
                         i--;
-                        bindingItems.Add(new TreeViewItemData<ActionOrBindingData>(id++,
+                        bindingItems.Add(new TreeViewItemData<ActionOrBindingData>(GetIdForGuid(inputBindingId, idDictionary),
                             new ActionOrBindingData(false, serializedInputBinding.name, actionMapIndex, true, action.expectedControlType, serializedInputBinding.indexOfBinding),
                             compositeItems.Count > 0 ? compositeItems : null));
                     }
                     else
                     {
                         var isVisible = ShouldBindingBeVisible(serializedInputBinding, state.selectedControlScheme);
                         if (isVisible)
-                            bindingItems.Add(new TreeViewItemData<ActionOrBindingData>(id++,
+                            bindingItems.Add(new TreeViewItemData<ActionOrBindingData>(GetIdForGuid(inputBindingId, idDictionary),
                                 new ActionOrBindingData(false, GetHumanReadableBindingName(serializedInputBinding, state.selectedControlScheme, controlSchemes), actionMapIndex,
                                     false, GetControlLayout(serializedInputBinding.path), serializedInputBinding.indexOfBinding)));
                     }
                 }
-                actionItems.Add(new TreeViewItemData<ActionOrBindingData>(id++,
+                actionItems.Add(new TreeViewItemData<ActionOrBindingData>(GetIdForGuid(actionId, idDictionary),
                     new ActionOrBindingData(true, action.name, actionMapIndex, false, action.expectedControlType), bindingItems.Count > 0 ? bindingItems : null));
             }
             return actionItems;
         }
 
+        private static int GetIdForGuid(Guid guid, Dictionary<Guid, int> idDictionary)
+        {
+            if (!idDictionary.TryGetValue(guid, out var id))
+            {
+                id = idDictionary.Values.Count > 0 ? idDictionary.Values.Max() + 1 : 0;
+                idDictionary.Add(guid, id);
+            }
+            return id;
+        }
+
         private static string GetHumanReadableBindingName(SerializedInputBinding serializedInputBinding, InputControlScheme? currentControlScheme, SerializedProperty allControlSchemes)
         {
             var name = InputControlPath.ToHumanReadableString(serializedInputBinding.path);