Fix bug where the layers panel doesn't init if it's not open when a sketch is loaded (#854)

* Wrong l10n ref for alt save button

* No reason for this to be public

* Move event handlers to awake/destroy

* Handle a potential edge case and add comments

Author: andybak

Assets/Prefabs/Panels/AdminPanel.prefab

@@ -420,7 +420,7 @@ MonoBehaviour:
     m_TableReference:
       m_TableCollectionName: GUID:c84355079ab3f3e4f8f3812258805f86
     m_TableEntryReference:
-      m_KeyId: 312729904472465408
+      m_KeyId: 312730512516521984
       m_Key: 
     m_FallbackState: 0
     m_WaitForCompletion: 0

Assets/Scripts/Layers/LayerUI_Manager.cs

@@ -29,8 +29,8 @@ public class LayerUI_Manager : MonoBehaviour
         [SerializeField] private LocalizedString m_AdditionalLayerName;
         [SerializeField] private NavButton m_PreviousPageButton;
         [SerializeField] private NavButton m_NextPageButton;
+        [SerializeField] private List<GameObject> m_Widgets;
 
-        public List<GameObject> m_Widgets;
         private List<CanvasScript> m_Canvases;
         private int m_StartingCanvasIndex;
         private bool m_RefreshNavButtons;
@@ -48,6 +48,9 @@ private void Start()
 
         private void ResetUI()
         {
+            // TODO: We're probably calling this too much during sketch load
+            // But it's not a huge performance hog so we'll leave it for now
+
             m_Canvases = App.Scene.LayerCanvases.ToList();
 
             for (int i = 0; i < m_Widgets.Count; i++)
@@ -97,14 +100,14 @@ private void OnLayerCanvasesUpdate()
         }
 
         // Subscribes to events
-        private void OnEnable()
+        private void Awake()
         {
             App.Scene.ActiveCanvasChanged += ActiveSceneChanged;
             App.Scene.LayerCanvasesUpdate += OnLayerCanvasesUpdate;
         }
 
         // Unsubscribes to events
-        private void OnDisable()
+        private void OnDestroy()
         {
             App.Scene.ActiveCanvasChanged -= ActiveSceneChanged;
             App.Scene.LayerCanvasesUpdate -= OnLayerCanvasesUpdate;

Assets/Scripts/Save/SketchWriter.cs

@@ -172,8 +172,16 @@ public static IEnumerable<AdjustedMemoryBrushStroke> EnumerateAdjustedSnapshots(
                     snapshot.layerIndex = canvasToIndexMap[stroke.Canvas];
                     yield return snapshot;
                 }
+                else if (stroke.IsGeometryEnabled && !canvasToIndexMap.ContainsKey(stroke.Canvas))
+                {
+                    // This shouldn't happen
+                    Debug.Log($"Skipping layerless stroke {stroke.m_BrushGuid}");
+                    snapshot.layerIndex = canvasToIndexMap[App.Scene.MainCanvas];
+                    yield return snapshot;
+                }
                 else
                 {
+                    Debug.Log($"Skipping inactive stroke {stroke.m_BrushGuid}");
                     // Effectively, if the lead stroke of group is inactive (erased), we promote
                     // subsequent strokes to lead until one such stroke is active.
                     resetGroupContinue = !snapshot.adjustedStrokeFlags.HasFlag(StrokeFlags.IsGroupContinue);