[Backport][ShaderGraph][2021.2][1357648] Fix bug that prevents switching to Graph Settings tab in Inspector when multiple nodes and edge are selected

com.unity.shadergraph/CHANGELOG.md

@@ -55,6 +55,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 - Changed "Create Node" action in ShaderGraph stack separator context menu to "Add Block Node" and added it to main stack context menu
 
 ### Fixed
+- Fixed bug where it was not possible to switch to Graph Settings tab in Inspector if multiple nodes and an edge was selected [1357648] (https://fogbugz.unity3d.com/f/cases/1357648/)
 - Fixed an issue where fog node density was incorrectly calculated.
 - Fixed inspector property header styling
 - Added padding to the blackboard window to prevent overlapping of resize region and scrollbars interfering with user interaction

com.unity.shadergraph/Editor/Drawing/Blackboard/SGBlackboardCategory.cs

@@ -690,15 +690,8 @@ public void AddToSelection(ISelectable selectable)
                 return;
             }
 
-            if (selectable != this)
-                Inspector.InspectorView.forceNodeView = true;
-
             var materialGraphView = m_ViewModel.parentView.GetFirstAncestorOfType<MaterialGraphView>();
             materialGraphView?.AddToSelection(selectable);
-
-            if (materialGraphView.selection.OfType<SGBlackboardCategory>().Any())
-                // Turns off the inspector being forced to trigger so user can still use Graph Settings tab if they want, on category selection
-                Inspector.InspectorView.forceNodeView = false;
         }
 
         public void RemoveFromSelection(ISelectable selectable)

com.unity.shadergraph/Editor/Drawing/Inspector/InspectorView.cs

@@ -15,10 +15,14 @@ class InspectorView : GraphSubWindow
         const float k_InspectorUpdateInterval = 0.25f;
         const int k_InspectorElementLimit = 20;
 
+        bool m_GraphSettingsTabFocused = false;
+
         int m_CurrentlyInspectedElementsCount = 0;
 
         readonly List<Type> m_PropertyDrawerList = new List<Type>();
 
+        HashSet<IInspectable> cachedInspectables = new();
+
         // There's persistent data that is stored in the graph settings property drawer that we need to hold onto between interactions
         IPropertyDrawer m_graphSettingsPropertyDrawer = new GraphDataPropertyDrawer();
         public override string windowTitle => "Graph Inspector";
@@ -34,8 +38,6 @@ class InspectorView : GraphSubWindow
 
         Label m_MaxItemsMessageLabel;
 
-        internal static bool forceNodeView = true;
-
         void RegisterPropertyDrawer(Type newPropertyDrawerType)
         {
             if (typeof(IPropertyDrawer).IsAssignableFrom(newPropertyDrawerType) == false)
@@ -83,8 +85,8 @@ public InspectorView(InspectorViewModel viewModel) : base(viewModel)
             m_MaxItemsMessageLabel = m_GraphInspectorView.Q<Label>("maxItemsMessageLabel");
             m_ContentContainer.Add(m_GraphInspectorView);
             m_ScrollView = this.Q<ScrollView>();
-            m_GraphInspectorView.Q<TabButton>("GraphSettingsButton").OnSelect += SetScrollModeHorizontal;
-            m_GraphInspectorView.Q<TabButton>("NodeSettingsButton").OnSelect += SetScrollModeHorizontalVertical;
+            m_GraphInspectorView.Q<TabButton>("GraphSettingsButton").OnSelect += GraphSettingsTabClicked;
+            m_GraphInspectorView.Q<TabButton>("NodeSettingsButton").OnSelect += NodeSettingsTabClicked;
 
             isWindowScrollable = true;
             isWindowResizable = true;
@@ -100,13 +102,15 @@ public InspectorView(InspectorViewModel viewModel) : base(viewModel)
             m_GraphInspectorView.Activate(m_GraphInspectorView.Q<TabButton>("GraphSettingsButton"));
         }
 
-        void SetScrollModeHorizontal(TabButton button)
+        void GraphSettingsTabClicked(TabButton button)
         {
+            m_GraphSettingsTabFocused = true;
             m_ScrollView.mode = ScrollViewMode.Vertical;
         }
 
-        void SetScrollModeHorizontalVertical(TabButton button)
+        void NodeSettingsTabClicked(TabButton button)
         {
+            m_GraphSettingsTabFocused = false;
             m_ScrollView.mode = ScrollViewMode.VerticalAndHorizontal;
         }
 
@@ -130,28 +134,41 @@ public void Update()
             ShowGraphSettings_Internal(m_GraphSettingsContainer);
 
             m_NodeSettingsContainer.Clear();
-            m_CurrentlyInspectedElementsCount = 0;
 
             try
             {
                 bool anySelectables = false;
+                int currentInspectablesCount = 0;
+                var currentInspectables = new HashSet<IInspectable>();
                 foreach (var selectable in selection)
                 {
                     if (selectable is IInspectable inspectable)
                     {
                         DrawInspectable(m_NodeSettingsContainer, inspectable);
-                        m_CurrentlyInspectedElementsCount++;
+                        currentInspectablesCount++;
                         anySelectables = true;
+                        currentInspectables.Add(inspectable);
                     }
 
-                    if (m_CurrentlyInspectedElementsCount == k_InspectorElementLimit)
+                    if (currentInspectablesCount == k_InspectorElementLimit)
                     {
                         m_NodeSettingsContainer.Add(m_MaxItemsMessageLabel);
                         m_MaxItemsMessageLabel.style.visibility = Visibility.Visible;
                         break;
                     }
                 }
-                if (anySelectables && forceNodeView)
+
+                // If we have changed our inspector selection while the graph settings tab was focused, we want to switch back to the node settings tab, so invalidate the flag
+                foreach (var currentInspectable in currentInspectables)
+                {
+                    if (cachedInspectables.Contains(currentInspectable) == false)
+                        m_GraphSettingsTabFocused = false;
+                }
+
+                cachedInspectables = currentInspectables;
+                m_CurrentlyInspectedElementsCount = currentInspectablesCount;
+
+                if (anySelectables && !m_GraphSettingsTabFocused)
                 {
                     // Anything selectable in the graph (GraphSettings not included) is only ever interacted with through the
                     // Node Settings tab so we can make the assumption they want to see that tab
@@ -180,9 +197,20 @@ void DrawInspectable(
         internal void HandleGraphChanges()
         {
             float timePassed = (float)(EditorApplication.timeSinceStartup % k_InspectorUpdateInterval);
+
+            int currentInspectablesCount = 0;
+            foreach (var selectable in selection)
+            {
+                if (selectable is IInspectable)
+                    currentInspectablesCount++;
+            }
+
             // Don't update for selections beyond a certain amount as they are no longer visible in the inspector past a certain point and only cost performance as the user performs operations
-            if (timePassed < 0.01f && selection.Count < k_InspectorElementLimit && selection.Count != m_CurrentlyInspectedElementsCount)
+            if (timePassed < 0.01f && selection.Count < k_InspectorElementLimit && currentInspectablesCount != m_CurrentlyInspectedElementsCount)
+            {
+                m_GraphSettingsTabFocused = false;
                 Update();
+            }
         }
 
         void TriggerInspectorUpdate()

com.unity.shadergraph/Editor/Drawing/Views/MaterialGraphView.cs

@@ -111,10 +111,7 @@ void ChangeTargetSettings()
 
             graph.UpdateActiveBlocks(activeBlocks);
             this.m_PreviewManagerUpdateDelegate();
-            //Quick bugfix for 1327208. Can be fixed properly with GTF
-            Inspector.InspectorView.forceNodeView = false;
             this.m_InspectorUpdateDelegate();
-            Inspector.InspectorView.forceNodeView = true;
         }
 
         void ChangePrecision(GraphPrecision newGraphDefaultPrecision)