don't save empty records in asset editor

TLM/TLM/Lifecycle/AssetDataExtension.cs

@@ -43,7 +43,7 @@ public static void OnAssetSavedImpl(string name, object asset, out Dictionary<st
                 Log.Info("AssetDataExtension.OnAssetSavedImpl():  prefab is " + prefab);
                 var assetData = AssetData.GetAssetData(prefab);
                 if (assetData == null) {
-                    Log._Debug("AssetDataExtension.OnAssetSavedImpl(): No segments to record.");
+                    Log._Debug("AssetDataExtension.OnAssetSavedImpl(): Nothing to record.");
                 } else {
                     Log._Debug("AssetDataExtension.OnAssetSavedImpl(): assetData=" + assetData);
                     userData = new Dictionary<string, byte[]>();

TLM/TLM/Manager/Impl/JunctionRestrictionsManager.cs

@@ -855,6 +855,19 @@ public bool ClearSegmentEnd(ushort segmentId, bool startNode) {
             return ret;
         }
 
+        public bool ClearNode(ushort nodeId) {
+            bool ret = false;
+            ref NetNode node = ref nodeId.ToNode();
+            for (int segmentIndex = 0; segmentIndex < Constants.MAX_SEGMENTS_OF_NODE; ++segmentIndex) {
+                ushort segmentId = node.GetSegment(segmentIndex);
+                if (segmentId != 0) {
+                    bool startNode = segmentId.ToSegment().IsStartNode(nodeId);
+                    ret |= ClearSegmentEnd(segmentId, startNode);
+                }
+            }
+            return ret;
+        }
+
         private void SetSegmentJunctionRestrictions(ushort segmentId, bool startNode, JunctionRestrictions restrictions) {
             if (restrictions.HasValue(JunctionRestrictionFlags.AllowUTurn)) {
                 SetUturnAllowed(segmentId, startNode, restrictions.GetValueOrDefault(JunctionRestrictionFlags.AllowUTurn));

TLM/TLM/Manager/Impl/TrafficLightManager.cs

@@ -11,6 +11,7 @@ namespace TrafficManager.Manager.Impl {
     using TrafficManager.Util.Extensions;
     using ColossalFramework;
     using TrafficManager.TrafficLight.Impl;
+    using TrafficManager.API.Traffic.Data;
 
     /// <summary>
     /// Manages traffic light toggling
@@ -129,6 +130,43 @@ public bool ToggleTrafficLight(ushort nodeId, ref NetNode node, out ToggleTraffi
             return SetTrafficLight(nodeId, !HasTrafficLight(nodeId, ref node), ref node, out reason);
         }
 
+        public void ResetTrafficLightAndPrioritySignsFromNode(ushort nodeId) {
+            if (!Shortcuts.InSimulationThread()) {
+                SimulationManager.instance.AddAction(() => ResetTrafficLightAndPrioritySignsFromNode(nodeId));
+                return;
+            }
+
+            ref NetNode netNode = ref nodeId.ToNode();
+            if (!netNode.IsValid())
+                return;
+            if (netNode.m_flags.IsFlagSet(NetNode.Flags.CustomTrafficLights) &&
+                (this as ITrafficLightManager).CanToggleTrafficLight(nodeId)) {
+                TrafficPriorityManager.Instance.RemovePrioritySignsFromNode(nodeId);
+
+                // if CustomTrafficLights is not set, UpdateNodeFlags() resets traffic lights.
+                netNode.m_flags &= ~NetNode.Flags.CustomTrafficLights;
+                NetManager.instance.UpdateNodeFlags(nodeId);
+
+                Constants.ManagerFactory.GeometryManager.MarkAsUpdated(nodeId, true);
+                Notifier.Instance.OnNodeModified(nodeId, this);
+            }
+        }
+
+        public bool? GetHasTrafficLight(ushort nodeId) {
+            NetNode.Flags flags = nodeId.ToNode().m_flags;
+            return flags.IsFlagSet(NetNode.Flags.CustomTrafficLights)
+                ? HasTrafficLight(nodeId)
+                : null;
+        }
+
+        public void SetHasTrafficLight(ushort nodeId, bool? value) {
+            if (value == null) {
+                ResetTrafficLightAndPrioritySignsFromNode(nodeId);
+            } else {
+                SetTrafficLight(nodeId, value.Value, ref nodeId.ToNode());
+            }
+        }
+
         bool ITrafficLightManager.CanToggleTrafficLight(ushort nodeId) {
             ref NetNode netNode = ref nodeId.ToNode();
             return netNode.IsValid() &&

TLM/TLM/State/Asset/AssetData.cs

@@ -37,10 +37,14 @@ public static AssetData GetAssetData(BuildingInfo prefab) {
             if (!HasPaths(prefab)) {
                 return null;
             }
-
+            var record = RecordAll();
+            if (record == null || record.IsDefault()) {
+                return null;
+            }
+
             return new AssetData {
                 Version = VersionUtil.ModVersion,
-                Record = RecordAll(),
+                Record = record,
                 PathNetworkIDs = GetPathsNetworkIDs(prefab),
             };
         }

TLM/TLM/UI/MainMenu/OSD/OnscreenDisplay.cs

@@ -22,14 +22,6 @@ private static void Hide() {
             }
         }
 
-        /// <summary>Clear the OSD panel and display the idle hint.</summary>
-        public static void DisplayIdle() {
-            var items = new List<OsdItem>();
-            items.Add(new MainMenu.OSD.Label(
-                          localizedText: Translation.Menu.Get("Onscreen.Idle:Choose a tool")));
-            Display(items);
-        }
-
         /// <summary>
         /// On Screen Display feature:
         /// Clear, and hide the keybind panel.

TLM/TLM/UI/SubTools/JunctionRestrictionsTool.cs

@@ -34,17 +34,9 @@ public JunctionRestrictionsTool(TrafficManagerTool mainTool)
 
         public override void OnToolGUI(Event e) {
             // handle delete
+            // TODO: #568 provide unified delete key for all managers.
             if (KeybindSettingsBase.RestoreDefaultsKey.KeyDown(e)) {
-                ref NetNode node = ref SelectedNodeId.ToNode();
-
-                for (int segmentIndex = 0; segmentIndex < Constants.MAX_SEGMENTS_OF_NODE; ++segmentIndex) {
-                    ushort segmentId = node.GetSegment(segmentIndex);
-                    if (segmentId != 0) {
-                        // TODO: #568 provide unified delete key for all managers.
-                        bool startNode = segmentId.ToSegment().IsStartNode(SelectedNodeId);
-                        JunctionRestrictionsManager.Instance.ClearSegmentEnd(segmentId, startNode);
-                    }
-                }
+                JunctionRestrictionsManager.Instance.ClearNode(SelectedNodeId);
             }
         }
 

TLM/TLM/UI/TrafficManagerTool.cs

@@ -44,6 +44,8 @@ public class TrafficManagerTool
         // activate when we know the mechinism.
         private bool ReadjustPathMode => false; //ShiftIsPressed;
 
+        private bool NodeSelectionMode => AltIsPressed;
+
         // /// <summary>Set this to true to once call <see cref="RequestOnscreenDisplayUpdate"/>.</summary>
         // public bool InvalidateOnscreenDisplayFlag { get; set; }
 
@@ -346,7 +348,7 @@ public void SetToolMode(ToolMode newToolMode) {
                 toolMode_ = ToolMode.None;
 
                 Log._Debug($"SetToolMode: reset because toolmode not found {newToolMode}");
-                OnscreenDisplay.DisplayIdle();
+                ScreenDisplay();
                 ModUI.Instance?.MainMenu?.UpdateButtons();
                 return;
             }
@@ -493,10 +495,6 @@ void DefaultRenderOverlay(RenderManager.CameraInfo cameraInfo)
                 base.RenderOverlay(cameraInfo); // render path.
             }
 
-            if (HoveredSegmentId == 0) {
-                return;
-            }
-
             var netAdjust = NetManager.instance?.NetAdjust;
 
             if (netAdjust == null) {
@@ -507,8 +505,14 @@ void DefaultRenderOverlay(RenderManager.CameraInfo cameraInfo)
             ref NetSegment segment = ref HoveredSegmentId.ToSegment();
             var color = ToolsModifierControl.toolController.m_validColorInfo;
             float alpha = 1f;
-            NetTool.CheckOverlayAlpha(ref segment, ref alpha);
+            if (HoveredSegmentId != 0) {
+                NetTool.CheckOverlayAlpha(ref segment, ref alpha);
+            }
+
             color.a *= alpha;
+            if (SelectedNodeId != 0) {
+                Highlight.DrawNodeCircle(cameraInfo, SelectedNodeId, color);
+            }
 
             if (ReadjustPathMode) {
                 if (Input.GetMouseButton(0)) {
@@ -531,6 +535,10 @@ void DefaultRenderOverlay(RenderManager.CameraInfo cameraInfo)
                         importantColor: color,
                         nonImportantColor: color);
                 }
+            } else if (NodeSelectionMode) {
+                if (HoveredNodeId != SelectedNodeId && HoveredNodeId != 0) {
+                    Highlight.DrawNodeCircle(cameraInfo, HoveredNodeId, color);
+                }
             } else {
                 NetTool.RenderOverlay(cameraInfo, ref segment, color, color);
             }
@@ -593,8 +601,11 @@ protected override void OnToolUpdate() {
                     if(secondaryMouseClicked) {
                         if(GetToolMode() == ToolMode.None) {
                             RoadSelectionPanels roadSelectionPanels = UIView.GetAView().GetComponent<RoadSelectionPanels>();
-                            if(roadSelectionPanels && roadSelectionPanels.RoadWorldInfoPanelExt && roadSelectionPanels.RoadWorldInfoPanelExt.isVisible) {
+                            if (roadSelectionPanels && roadSelectionPanels.RoadWorldInfoPanelExt && roadSelectionPanels.RoadWorldInfoPanelExt.isVisible) {
                                 RoadSelectionPanels.RoadWorldInfoPanel.Hide();
+                            } else if (SelectedNodeId != 0) {
+                                SelectedNodeId = 0;
+                                RequestOnscreenDisplayUpdate();
                             } else {
                                 ModUI.Instance.CloseMainMenu();
                             }
@@ -680,38 +691,46 @@ public void OnToolGUIImpl(Event e) {
             }
         }
 
-        void DefaultOnToolGUI(Event e) {
+        private void DefaultOnToolGUI(Event e) {
             if (!TMPELifecycle.PlayMode) {
                 return; // world info view panels are not availble in edit mode
             }
             if (e.type == EventType.MouseDown && e.button == 0) {
-                bool isRoad = HoveredSegmentId != 0 && HoveredSegmentId.ToSegment().Info.m_netAI is RoadBaseAI;
-                if (!isRoad)
-                    return;
-
-                if (ReadjustPathMode) {
-                    bool isRoundabout = RoundaboutMassEdit.Instance.TraverseLoop(HoveredSegmentId, out var segmentList);
-                    if (!isRoundabout) {
-                        var segments = SegmentTraverser.Traverse(
-                            HoveredSegmentId,
-                            TraverseDirection.AnyDirection,
-                            TraverseSide.Straight,
-                            SegmentStopCriterion.None,
-                            (_) => true);
-                        segmentList = new List<ushort>(segments);
+                if (NodeSelectionMode) {
+                    SelectedNodeId = HoveredNodeId;
+                    RequestOnscreenDisplayUpdate();
+                } else {
+                    bool isRoad = HoveredSegmentId != 0 && HoveredSegmentId.ToSegment().Info.m_netAI is RoadBaseAI;
+                    if (!isRoad)
+                        return;
+
+                    if (ReadjustPathMode) {
+                        bool isRoundabout = RoundaboutMassEdit.Instance.TraverseLoop(HoveredSegmentId, out var segmentList);
+                        if (!isRoundabout) {
+                            var segments = SegmentTraverser.Traverse(
+                                HoveredSegmentId,
+                                TraverseDirection.AnyDirection,
+                                TraverseSide.Straight,
+                                SegmentStopCriterion.None,
+                                (_) => true);
+                            segmentList = new List<ushort>(segments);
+                        }
+                        RoadSelectionUtil.SetRoad(HoveredSegmentId, segmentList);
                     }
-                    RoadSelectionUtil.SetRoad(HoveredSegmentId, segmentList);
-                }
 
-                InstanceID instanceID = new InstanceID {
-                    NetSegment = HoveredSegmentId,
-                };
+                    InstanceID instanceID = new InstanceID {
+                        NetSegment = HoveredSegmentId,
+                    };
 
-                SimulationManager.instance.m_ThreadingWrapper.QueueMainThread(() => {
-                    OpenWorldInfoPanel(
-                        instanceID,
-                        HitPos);
-                });
+                    SimulationManager.instance.m_ThreadingWrapper.QueueMainThread(() => {
+                        OpenWorldInfoPanel(
+                            instanceID,
+                            HitPos);
+                    });
+                }
+            } else if (SelectedNodeId != 0 && KeybindSettingsBase.RestoreDefaultsKey.KeyDown(e)) {
+                ushort nodeId = SelectedNodeId;
+                SimulationManager.instance.AddAction(() => PriorityRoad.EraseAllTrafficRoadsForNode(nodeId));
             }
         }
 
@@ -1612,9 +1631,49 @@ public void RequestOnscreenDisplayUpdate() {
 
             if (activeOsd == null && activeLegacyOsd == null) {
                 // No tool hint support was available means we have to show the default
-                OnscreenDisplay.DisplayIdle();
+                ScreenDisplay();
+            }
+        }
+
+        /// <summary>Clear the OSD panel and display the idle hint.</summary>
+        public void ScreenDisplay() {
+            var items = new List<OsdItem>();
+            items.Add(new MainMenu.OSD.Label(
+                          localizedText: Translation.Menu.Get("Onscreen.Idle:Choose a tool")));
+            items.Add(new MainMenu.OSD.HardcodedMouseShortcut(
+                button: ColossalFramework.UI.UIMouseButton.Left,
+                shift: false,
+                ctrl: false,
+                alt: false,
+                localizedText: "Onscreen.Default:Select a road")); // select a road to set as main road.
+            items.Add(new MainMenu.OSD.HardcodedMouseShortcut(
+                button: ColossalFramework.UI.UIMouseButton.Left,
+                shift: false,
+                ctrl: false,
+                alt: true,
+                localizedText: "Onscreen.Default:Select a node")); // select a node to erase all traffic rules.
+
+            if (SelectedNodeId != 0) {
+                items.Add(new MainMenu.OSD.Shortcut(
+                    keybindSetting: KeybindSettingsBase.RestoreDefaultsKey,
+                    localizedText: "Onscreen.Default:Erase")); // Erase all traffic rules from selected node.
+                items.Add(new MainMenu.OSD.HardcodedMouseShortcut(
+                    button: ColossalFramework.UI.UIMouseButton.Right,
+                    shift: false,
+                    ctrl: false,
+                    alt: false,
+                    localizedText: "Onscreen.Default:Deselect node"));
             }
+
+            items.Add(new MainMenu.OSD.HoldModifier(
+                shift: false,
+                ctrl: true,
+                alt: false,
+                localizedText: "Onscreen.Default:Show traffic rules")); // show traffic rules for high priority roads
+
+            OnscreenDisplay.Display(items);
         }
+
         public void AddUUIButton() {
             try {
                 var hotkeys = new UUIHotKeys { ActivationKey = KeybindSettingsBase.ToggleMainMenu.Key };

TLM/TLM/Util/PriorityRoad.cs

@@ -674,5 +674,16 @@ public static IRecordable RecordRoad(List<ushort> segmentList) {
             record.Record();
             return record;
         }
+
+        public static void EraseAllTrafficRoadsForNode(ushort nodeId) {
+            try {
+                TrafficLightManager.Instance.ResetTrafficLightAndPrioritySignsFromNode(nodeId);
+                LaneConnectionManager.Instance.RemoveLaneConnectionsFromNode(nodeId);
+                LaneArrowManager.Instance.ResetNodeLaneArrows(nodeId);
+                JunctionRestrictionsManager.Instance.ClearNode(nodeId);
+            } catch (Exception ex) {
+                ex.LogException();
+            }
+        }
     } //end class
 }

TLM/TLM/Util/Record/IRecordable.cs

@@ -1,4 +1,4 @@
-using System;
+using System.Linq;
 using System.Collections.Generic;
 
 namespace TrafficManager.Util.Record {
@@ -19,6 +19,18 @@ public interface IRecordable {
         /// <param name="map">maps old Instance IDs to new Instance IDs</param>
         void Transfer(Dictionary<InstanceID, InstanceID> map);
 
+        /// <summary>
+        /// Detects if record is empty to help releasing empty records from memory.
+        /// </summary>
+        /// <returns>true if record stores only default values. false if record stores any useful information.</returns>
+        bool IsDefault();
+
         byte[] Serialize();
     }
+
+    public static class RecordUtil {
+        public static bool AreDefault<T>(this IEnumerable<T> records)
+            where T : IRecordable =>
+            records == null || records.All(record => record.IsDefault());
+    }
 }

TLM/TLM/Util/Record/LaneArrowsRecord.cs

@@ -17,6 +17,8 @@ public void Record() {
             arrows_ = Flags.GetLaneArrowFlags(LaneId);
         }
 
+        public bool IsDefault() => arrows_ == null;
+
         public void Restore() => Transfer(LaneId);
 
         public void Transfer(Dictionary<InstanceID, InstanceID> map) =>

TLM/TLM/Util/Record/LaneConnectionRecord.cs

@@ -48,6 +48,11 @@ private void RestoreImpl(LaneConnectionSubManager man, uint[] connections) {
             }
         }
 
+        public bool IsDefault() =>
+            connections_.IsNullOrEmpty() &&
+            roadConnections_.IsNullOrEmpty() &&
+            trackConnections_.IsNullOrEmpty();
+
         public void Restore() {
             if (connections_ != null) {
                 // legacy