Command pattern (Undo/Redo) system began. (Read desc)

I spent about 6 hours trying to fix this one specific bug involving the move undo. Turns out all I had to do was calm down and think logically instead of typing random bullshit for a few hours until it worked. I'm tired and I thank this for ruining my sleep schedule.

Assets/Scripts/LevelEditor/Commands.meta

@@ -0,0 +1,8 @@
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+folderAsset: yes
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+  userData: 
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Assets/Scripts/LevelEditor/Commands/CommandManager.cs

@@ -0,0 +1,75 @@
+using System.Collections;
+using System.Collections.Generic;
+using UnityEngine;
+
+using RhythmHeavenMania.Editor.Commands;
+
+namespace RhythmHeavenMania.Editor
+{
+    public class CommandManager : MonoBehaviour
+    {
+        private Stack<IAction> historyStack = new Stack<IAction>();
+        private Stack<IAction> redoHistoryStack = new Stack<IAction>();
+
+        int maxItems = 128;
+
+        public bool canUndo()
+        {
+            return historyStack.Count > 0;
+        }
+        public bool canRedo()
+        {
+            return redoHistoryStack.Count > 0;
+        }
+
+        public static CommandManager instance { get; private set; }
+
+        private void Awake()
+        {
+            instance = this;
+        }
+
+        public void Execute(IAction action)
+        {
+            action.Execute();
+            historyStack.Push(action);
+            redoHistoryStack.Clear();
+        }
+
+        public void Undo()
+        {
+            if (!canUndo()) return;
+
+            if (historyStack.Count > 0)
+            {
+                redoHistoryStack.Push(historyStack.Peek());
+                historyStack.Pop().Undo();
+            }
+        }
+
+        public void Redo()
+        {
+            if (!canRedo()) return;
+
+            if (redoHistoryStack.Count > 0)
+            {
+                historyStack.Push(redoHistoryStack.Peek());
+                redoHistoryStack.Pop().Redo();
+            }
+        }
+
+        // this is here as to not hog up memory, "max undos" basically
+        private void EnsureCapacity()
+        {
+            if (maxItems > 0)
+            {
+            }
+        }
+
+        private void Clear()
+        {
+            historyStack.Clear();
+            redoHistoryStack.Clear();
+        }
+    }
+}

Assets/Scripts/LevelEditor/Commands/CommandManager.cs.meta

@@ -0,0 +1,11 @@
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Assets/Scripts/LevelEditor/Commands/IAction.cs

@@ -0,0 +1,13 @@
+using System.Collections;
+using System.Collections.Generic;
+using UnityEngine;
+
+namespace RhythmHeavenMania.Editor.Commands
+{
+    public interface IAction
+    {
+        void Execute();
+        void Undo();
+        void Redo();
+    }
+}

Assets/Scripts/LevelEditor/Commands/IAction.cs.meta

@@ -0,0 +1,11 @@
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+guid: 64b35e3b4d623144a82ed956ee52a136
+MonoImporter:
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+  serializedVersion: 2
+  defaultReferences: []
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Assets/Scripts/LevelEditor/Commands/Selections.cs

@@ -0,0 +1,129 @@
+using System.Collections;
+using System.Collections.Generic;
+using System.Linq;
+using UnityEngine;
+
+namespace RhythmHeavenMania.Editor.Commands
+{
+    public class Selection : IAction
+    {
+        public void Execute()
+        {
+            throw new System.NotImplementedException();
+        }
+
+        public void Redo()
+        {
+            throw new System.NotImplementedException();
+        }
+
+        public void Undo()
+        {
+            throw new System.NotImplementedException();
+        }
+    }
+
+    // I spent 7 hours trying to fix this instead of sleeping, which would've probably worked better.
+    // I'll go fuck myself later I'm just glad it works
+    // I give massive props to people who code undo/redo systems
+    // -- Starpelly
+
+    public class Move : IAction
+    {
+        public List<Pos> pos = new List<Pos>();
+
+        public class Pos
+        {
+            public TimelineEventObj eventObj;
+
+            public Vector2 lastPos_;
+            public Vector3 previousPos;
+        }
+
+        public Move(List<TimelineEventObj> eventObjs)
+        {
+            pos.Clear();
+
+            for (int i = 0; i < eventObjs.Count; i++)
+            {
+                Pos p = new Pos();
+                p.eventObj = eventObjs[i];
+                p.lastPos_ = eventObjs[i].lastPos_;
+                p.previousPos = eventObjs[i].transform.localPosition;
+                this.pos.Add(p);
+            }
+        }
+
+        public void Execute()
+        {
+        }
+
+        public void Redo()
+        {
+            for (int i = 0; i < pos.Count; i++)
+            {
+                EnsureEventObj(i);
+                pos[i].eventObj.transform.localPosition = pos[i].previousPos;
+            }
+        }
+
+        public void Undo()
+        {
+
+            for (int i = 0; i < pos.Count; i++)
+            {
+                EnsureEventObj(i);
+                pos[i].eventObj.transform.localPosition = pos[i].lastPos_;
+            }
+        }
+
+        private void EnsureEventObj(int id)
+        {
+            if (pos[id].eventObj == null)
+            {
+                pos[id].eventObj = GameManager.instance.Beatmap.entities.Find(c => c.eventObj.eventObjID == pos[id].eventObj.eventObjID).eventObj;
+            }
+        }
+    }
+
+    public class Deletion : IAction
+    {
+        List<TimelineEventObj> eventObjs;
+
+        List<TimelineEventObj> deletedObjs;
+
+        public Deletion(List<TimelineEventObj> eventObjs)
+        {
+            this.eventObjs = eventObjs;
+        }
+
+        public void Execute()
+        {
+            deletedObjs = eventObjs;
+            for (int i = 0; i < eventObjs.Count; i++)
+            {
+                Selections.instance.Deselect(eventObjs[i]);
+                Timeline.instance.DestroyEventObject(eventObjs[i].entity);
+            }
+        }
+
+        public void Redo()
+        {
+            deletedObjs = eventObjs;
+            for (int i = 0; i < eventObjs.Count; i++)
+            {
+                Selections.instance.Deselect(eventObjs[i]);
+                Timeline.instance.DestroyEventObject(eventObjs[i].entity);
+            }
+        }
+
+        public void Undo()
+        {
+            for (int i = 0; i < deletedObjs.Count; i++)
+            {
+                Beatmap.Entity e = deletedObjs[i].entity;
+                eventObjs[i] = Timeline.instance.AddEventObject(e.datamodel, false, new Vector3(e.beat, -e.track * Timeline.instance.LayerHeight()), e, true, e.eventObj.eventObjID);
+            }
+        }
+    }
+}

Assets/Scripts/LevelEditor/Commands/Selections.cs.meta

@@ -0,0 +1,11 @@
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+guid: 8e13e41a59182b74ba7f0be1e3b58ff9
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Assets/Scripts/LevelEditor/Commands/TestCommand.cs

@@ -0,0 +1,34 @@
+using System.Collections;
+using System.Collections.Generic;
+using UnityEngine;
+
+using RhythmHeavenMania.Editor.Commands;
+
+public class TestCommand : IAction
+{
+    private GameObject prefab;
+    private Vector3 pos;
+
+    private GameObject spawnedgameObj;
+
+    public TestCommand(GameObject prefab, Vector3 pos)
+    {
+        this.prefab = prefab;
+        this.pos = pos;
+    }
+
+    public void Execute()
+    {
+        spawnedgameObj = GameObject.Instantiate(prefab, pos, Quaternion.identity);
+    }
+
+    public void Redo()
+    {
+        throw new System.NotImplementedException();
+    }
+
+    public void Undo()
+    {
+        GameObject.Destroy(spawnedgameObj);
+    }
+}

Assets/Scripts/LevelEditor/Commands/TestCommand.cs.meta

@@ -0,0 +1,11 @@
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+guid: 1e32a4a20b85d944aa030268410b0101
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+  externalObjects: {}
+  serializedVersion: 2
+  defaultReferences: []
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Assets/Scripts/LevelEditor/Editor.cs

@@ -6,6 +6,7 @@ using UnityEngine.UI;
 
 using Newtonsoft.Json;
 using TMPro;
+using Starpelly;
 
 namespace RhythmHeavenMania.Editor
 {
@@ -29,6 +30,8 @@ namespace RhythmHeavenMania.Editor
         [SerializeField] private Button NewBTN;
         [SerializeField] private Button OpenBTN;
         [SerializeField] private Button SaveBTN;
+        [SerializeField] private Button UndoBTN;
+        [SerializeField] private Button RedoBTN;
 
         public static List<TimelineEventObj> EventObjs = new List<TimelineEventObj>();
 
@@ -60,6 +63,8 @@ namespace RhythmHeavenMania.Editor
             Tooltip.AddTooltip(NewBTN.gameObject, "New");
             Tooltip.AddTooltip(OpenBTN.gameObject, "Open");
             Tooltip.AddTooltip(SaveBTN.gameObject, "Save");
+            Tooltip.AddTooltip(UndoBTN.gameObject, "Undo");
+            Tooltip.AddTooltip(RedoBTN.gameObject, "Redo");
         }
 
         public void Update()
@@ -77,6 +82,40 @@ namespace RhythmHeavenMania.Editor
                 GetComponent<Selector>().enabled = true;
                 GetComponent<BoxSelection>().enabled = true;
             }*/
+
+            if (Input.GetKeyDown(KeyCode.Delete))
+            {
+                List<TimelineEventObj> ev = new List<TimelineEventObj>();
+                for (int i = 0; i < Selections.instance.eventsSelected.Count; i++) ev.Add(Selections.instance.eventsSelected[i]);
+                CommandManager.instance.Execute(new Commands.Deletion(ev));
+            }
+
+            if (CommandManager.instance.canUndo())
+                UndoBTN.transform.GetChild(0).GetComponent<Image>().color = "BE72FF".Hex2RGB();
+            else
+                UndoBTN.transform.GetChild(0).GetComponent<Image>().color = Color.gray;
+
+            if (CommandManager.instance.canRedo())
+                RedoBTN.transform.GetChild(0).GetComponent<Image>().color = "7299FF".Hex2RGB();
+            else
+                RedoBTN.transform.GetChild(0).GetComponent<Image>().color = Color.gray;
+
+            if (Input.GetMouseButtonUp(0) && Timeline.instance.CheckIfMouseInTimeline())
+            {
+                List<TimelineEventObj> selectedEvents = Timeline.instance.eventObjs.FindAll(c => c.selected == true && c.eligibleToMove == true);
+
+                if (selectedEvents.Count > 0)
+                {
+                    List<TimelineEventObj> result = new List<TimelineEventObj>();
+
+                    for (int i = 0; i < selectedEvents.Count; i++)
+                    {
+                        result.Add(selectedEvents[i]);
+                        selectedEvents[i].OnUp();
+                    }
+                    CommandManager.instance.Execute(new Commands.Move(result));
+                }
+            }
         }
 
         public static Sprite GameIcon(string name)

Assets/Scripts/LevelEditor/EventSelector/GridGameSelector.cs

@@ -161,11 +161,11 @@ namespace RhythmHeavenMania.Editor
                 dragTimes++;
                 if (currentEventIndex == 0)
                 {
-                    Timeline.instance.AddEventObject($"gameManager/switchGame/{mg.name}", true, new Vector3(0, 0));
+                    Timeline.instance.AddEventObject($"gameManager/switchGame/{mg.name}", true, new Vector3(0, 0), null, true);
                 }
                 else
                 {
-                    Timeline.instance.AddEventObject(mg.name + "/" + mg.actions[currentEventIndex - 1].actionName, true, new Vector3(0, 0));
+                    Timeline.instance.AddEventObject(mg.name + "/" + mg.actions[currentEventIndex - 1].actionName, true, new Vector3(0, 0), null, true);
                 }
             }
         }

Assets/Scripts/LevelEditor/Selector.cs

@@ -1,6 +1,7 @@
 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
+using UnityEngine.EventSystems;
 
 namespace RhythmHeavenMania.Editor
 {
@@ -14,10 +15,5 @@ namespace RhythmHeavenMania.Editor
         {
             instance = this;
         }
-
-        private void Update()
-        {
-
-        }
     }
 }

Assets/Scripts/LevelEditor/Timeline.cs

@@ -51,7 +51,7 @@ namespace RhythmHeavenMania.Editor
                 var entity = GameManager.instance.Beatmap.entities[i];
                 var e = GameManager.instance.Beatmap.entities[i];
 
-                AddEventObject(e.datamodel, false, new Vector3(e.beat, -e.track * LayerHeight()), i);
+                AddEventObject(e.datamodel, false, new Vector3(e.beat, -e.track * LayerHeight()), e, false, Starpelly.Random.Strings.RandomString(Starpelly.Enums.Strings.StringType.Alphanumeric, 128));
             }
 
             TimelineSlider.GetChild(0).GetComponent<Image>().color = EditorTheme.theme.properties.BeatMarkerCol.Hex2RGB();
@@ -296,7 +296,7 @@ namespace RhythmHeavenMania.Editor
 
         #region Functions
 
-        public void AddEventObject(string eventName, bool dragNDrop = false, Vector3 pos = new Vector3(), int entityId = 0)
+        public TimelineEventObj AddEventObject(string eventName, bool dragNDrop = false, Vector3 pos = new Vector3(), Beatmap.Entity entity = null, bool addEvent = false, string eventId = "")
         {
             GameObject g = Instantiate(TimelineEventObjRef.gameObject, TimelineEventObjRef.parent);
             g.transform.localPosition = pos;
@@ -322,9 +322,9 @@ namespace RhythmHeavenMania.Editor
                 else
                 {
                     eventObj.resizable = true;
-                    if (gameAction.defaultLength != GameManager.instance.Beatmap.entities[entityId].length && dragNDrop == false)
+                    if (gameAction.defaultLength != entity.length && dragNDrop == false)
                     {
-                        g.GetComponent<RectTransform>().sizeDelta = new Vector2(GameManager.instance.Beatmap.entities[entityId].length, LayerHeight());
+                        g.GetComponent<RectTransform>().sizeDelta = new Vector2(entity.length, LayerHeight());
                     }
                     else
                     {
@@ -340,32 +340,46 @@ namespace RhythmHeavenMania.Editor
                 var mousePos = Camera.main.ScreenToWorldPoint(Input.mousePosition);
                 g.transform.position = new Vector3(mousePos.x, mousePos.y, 0);
 
-                Beatmap.Entity en = new Beatmap.Entity();
-                en.datamodel = eventName;
-                en.eventObj = eventObj;
-
-                GameManager.instance.Beatmap.entities.Add(en);
-                GameManager.instance.SortEventsList();
-
                 Selections.instance.ClickSelect(eventObj);
                 eventObj.moving = true;
             }
             else
             {
-                var entity = GameManager.instance.Beatmap.entities[entityId];
-
                 entity.eventObj = g.GetComponent<TimelineEventObj>();
                 entity.track = (int)(g.transform.localPosition.y / LayerHeight() * -1);
             }
 
+            if (addEvent)
+            {
+                if (entity == null)
+                {
+                    Beatmap.Entity en = new Beatmap.Entity();
+                    en.datamodel = eventName;
+                    en.eventObj = eventObj;
+
+                    GameManager.instance.Beatmap.entities.Add(en);
+                    GameManager.instance.SortEventsList();
+                }
+                else
+                {
+                    GameManager.instance.Beatmap.entities.Add(entity);
+                    GameManager.instance.SortEventsList();
+                }
+            }
+
             Editor.EventObjs.Add(eventObj);
             eventObjs.Add(eventObj);
+
+            eventObj.eventObjID = eventId;
+
+            return eventObj;
         }
 
         public void DestroyEventObject(Beatmap.Entity entity)
         {
             Editor.EventObjs.Remove(entity.eventObj);
             GameManager.instance.Beatmap.entities.Remove(entity);
+            Timeline.instance.eventObjs.Remove(entity.eventObj);
 
             Destroy(entity.eventObj.gameObject);
             GameManager.instance.SortEventsList();

Assets/Scripts/LevelEditor/TimelineEventObj.cs

@@ -14,6 +14,7 @@ namespace RhythmHeavenMania.Editor
         private float startPosY;
 
         private Vector3 lastPos;
+        public Vector2 lastPos_;
         private RectTransform rectTransform;
 
         [Header("Components")]
@@ -27,9 +28,9 @@ namespace RhythmHeavenMania.Editor
         [SerializeField] private RectTransform rightDrag;
 
         [Header("Properties")]
-        private Beatmap.Entity entity;
+        public Beatmap.Entity entity;
         public float length;
-        private bool eligibleToMove = false;
+        public bool eligibleToMove = false;
         private bool lastVisible;
         public bool selected;
         public bool mouseHovering;
@@ -39,18 +40,24 @@ namespace RhythmHeavenMania.Editor
         private bool resizingLeft;
         private bool resizingRight;
         private bool inResizeRegion;
+        public Vector2 lastMovePos;
+        public string eventObjID;
 
         [Header("Colors")]
         public Color NormalCol;
 
         private void Start()
         {
+            lastPos_ = transform.localPosition;
+
             rectTransform = GetComponent<RectTransform>();
 
             if (!resizable)
             {
                 Destroy(resizeGraphic.gameObject);
             }
+
+            lastMovePos = transform.localPosition;
         }
 
         private void Update()
@@ -89,8 +96,8 @@ namespace RhythmHeavenMania.Editor
             {
                 if (Input.GetKeyDown(KeyCode.Delete))
                 {
-                    Selections.instance.Deselect(this);
-                    Timeline.instance.DestroyEventObject(entity);
+                    /*Selections.instance.Deselect(this);
+                    Timeline.instance.DestroyEventObject(entity);*/
                 }
 
                 selectedImage.gameObject.SetActive(true);
@@ -119,18 +126,22 @@ namespace RhythmHeavenMania.Editor
                         }
                     }
 
-                    OnUp();
+                    // OnUp();
                 }
 
                 if (Timeline.instance.eventObjs.FindAll(c => c.moving).Count > 0 && selected)
                 {
                     Vector3 mousePos = Camera.main.ScreenToWorldPoint(Input.mousePosition);
 
+                    // lastPos_ = transform.localPosition;
+
                     this.transform.position = new Vector3(mousePos.x - startPosX, mousePos.y - startPosY - 0.40f, 0);
                     this.transform.localPosition = new Vector3(Mathf.Clamp(Mathp.Round2Nearest(this.transform.localPosition.x, 0.25f), 0, Mathf.Infinity), Timeline.instance.SnapToLayer(this.transform.localPosition.y));
 
                     if (lastPos != transform.localPosition)
+                    {
                         OnMove();
+                    }
 
                     lastPos = this.transform.localPosition;
                 }
@@ -148,7 +159,7 @@ namespace RhythmHeavenMania.Editor
 
                 rectTransform.sizeDelta = new Vector2(Mathp.Round2Nearest(sizeDelta.x, 0.25f), sizeDelta.y);
                 SetPivot(new Vector2(0, rectTransform.pivot.y));
-                OnComplete();
+                OnComplete(false);
             }
             else if (resizingRight)
             {
@@ -162,7 +173,7 @@ namespace RhythmHeavenMania.Editor
 
                 rectTransform.sizeDelta = new Vector2(Mathp.Round2Nearest(sizeDelta.x, 0.25f), sizeDelta.y);
                 SetPivot(new Vector2(0, rectTransform.pivot.y));
-                OnComplete();
+                OnComplete(false);
             }
 
             if (Input.GetMouseButtonUp(0))
@@ -203,6 +214,8 @@ namespace RhythmHeavenMania.Editor
         {
             if (selected)
             {
+                lastPos_ = transform.localPosition;
+
                 for (int i = 0; i < Timeline.instance.eventObjs.Count; i++)
                 {
                     Vector3 mousePos = Camera.main.ScreenToWorldPoint(Input.mousePosition);
@@ -211,22 +224,26 @@ namespace RhythmHeavenMania.Editor
                 }
 
                 moving = true;
-
-                OnComplete();
+                // lastMovePos = transform.localPosition;
+                // OnComplete();
             }
         }
 
         public void OnUp()
         {
+            // lastPos_ = this.lastPos_;
+            // previousPos = this.transform.localPosition;
+
             if (selected)
             {
-                moving = false;
-
                 if (eligibleToMove)
                 {
-                    OnComplete();
+
+                    OnComplete(true);
                 }
 
+                moving = false;
+
                 Cancel();
             }
         }
@@ -320,10 +337,10 @@ namespace RhythmHeavenMania.Editor
                 eligibleToMove = true;
             }
 
-            OnComplete();
+            OnComplete(true);
         }
 
-        private void OnComplete()
+        private void OnComplete(bool move)
         {
             entity.length = rectTransform.sizeDelta.x;
             entity.beat = this.transform.localPosition.x;

Assets/Scripts/WTF.cs

@@ -2,12 +2,20 @@ using UnityEngine;
 
 // this is a script for testing
 
+using RhythmHeavenMania.Editor;
+
 namespace RhythmHeavenMania.Tests
 {
     public class WTF : MonoBehaviour
     {
+        public GameObject test;
+
         private void Update()
         {
+            if (Input.GetKeyDown(KeyCode.Z))
+            {
+                GetComponent<CommandManager>().Execute(new TestCommand(test, new Vector3(Random.Range(-8f, 8f), Random.Range(-6f, 6f))));
+            }
         }
     }
 }