Add UniTaskAsyncEnumerable.EveryValueChanged

src/UniTask/Assets/Plugins/UniTask/Runtime/Linq/UnityExtensions/EveryUpdate.cs

@@ -1,7 +1,4 @@
-using Cysharp.Threading.Tasks.Internal;
-using System;
-using System.Collections.Generic;
-using System.Threading;
+using System.Threading;
 
 namespace Cysharp.Threading.Tasks.Linq
 {

src/UniTask/Assets/Plugins/UniTask/Runtime/Linq/UnityExtensions/EveryValueChanged.cs

@@ -0,0 +1,241 @@
+using Cysharp.Threading.Tasks.Internal;
+using System;
+using System.Collections.Generic;
+using System.Threading;
+
+namespace Cysharp.Threading.Tasks.Linq
+{
+    public static partial class UniTaskAsyncEnumerable
+    {
+        public static IUniTaskAsyncEnumerable<TProperty> EveryValueChanged<TTarget, TProperty>(TTarget target, Func<TTarget, TProperty> propertySelector, PlayerLoopTiming monitorTiming = PlayerLoopTiming.Update, IEqualityComparer<TProperty> equalityComparer = null)
+            where TTarget : class
+        {
+            var unityObject = target as UnityEngine.Object;
+            var isUnityObject = target is UnityEngine.Object; // don't use (unityObject == null)
+
+            if (isUnityObject)
+            {
+                return new EveryValueChangedUnityObject<TTarget, TProperty>(target, propertySelector, equalityComparer ?? UnityEqualityComparer.GetDefault<TProperty>(), monitorTiming);
+            }
+            else
+            {
+                return new EveryValueChangedStandardObject<TTarget, TProperty>(target, propertySelector, equalityComparer ?? UnityEqualityComparer.GetDefault<TProperty>(), monitorTiming);
+            }
+        }
+    }
+
+    internal sealed class EveryValueChangedUnityObject<TTarget, TProperty> : IUniTaskAsyncEnumerable<TProperty>
+    {
+        readonly TTarget target;
+        readonly Func<TTarget, TProperty> propertySelector;
+        readonly IEqualityComparer<TProperty> equalityComparer;
+        readonly PlayerLoopTiming monitorTiming;
+
+        public EveryValueChangedUnityObject(TTarget target, Func<TTarget, TProperty> propertySelector, IEqualityComparer<TProperty> equalityComparer, PlayerLoopTiming monitorTiming)
+        {
+            this.target = target;
+            this.propertySelector = propertySelector;
+            this.equalityComparer = equalityComparer;
+            this.monitorTiming = monitorTiming;
+        }
+
+        public IUniTaskAsyncEnumerator<TProperty> GetAsyncEnumerator(CancellationToken cancellationToken = default)
+        {
+            return new _EveryValueChanged(target, propertySelector, equalityComparer, monitorTiming, cancellationToken);
+        }
+
+        sealed class _EveryValueChanged : MoveNextSource, IUniTaskAsyncEnumerator<TProperty>, IPlayerLoopItem
+        {
+            readonly TTarget target;
+            readonly UnityEngine.Object targetAsUnityObject;
+            readonly IEqualityComparer<TProperty> equalityComparer;
+            readonly Func<TTarget, TProperty> propertySelector;
+            CancellationToken cancellationToken;
+
+            bool first;
+            TProperty currentValue;
+            bool disposed;
+
+            public _EveryValueChanged(TTarget target, Func<TTarget, TProperty> propertySelector, IEqualityComparer<TProperty> equalityComparer, PlayerLoopTiming monitorTiming, CancellationToken cancellationToken)
+            {
+                this.target = target;
+                this.targetAsUnityObject = target as UnityEngine.Object;
+                this.propertySelector = propertySelector;
+                this.equalityComparer = equalityComparer;
+                this.cancellationToken = cancellationToken;
+                this.first = true;
+                TaskTracker.TrackActiveTask(this, 2);
+                PlayerLoopHelper.AddAction(monitorTiming, this);
+            }
+
+            public TProperty Current => currentValue;
+
+            public UniTask<bool> MoveNextAsync()
+            {
+                // return false instead of throw
+                if (disposed || cancellationToken.IsCancellationRequested) return CompletedTasks.False;
+
+                if (first)
+                {
+                    first = false;
+                    if (targetAsUnityObject == null)
+                    {
+                        return CompletedTasks.False;
+                    }
+                    this.currentValue = propertySelector(target);
+                    return CompletedTasks.True;
+                }
+
+                completionSource.Reset();
+                return new UniTask<bool>(this, completionSource.Version);
+            }
+
+            public UniTask DisposeAsync()
+            {
+                if (!disposed)
+                {
+                    disposed = true;
+                    TaskTracker.RemoveTracking(this);
+                }
+                return default;
+            }
+
+            public bool MoveNext()
+            {
+                if (disposed || cancellationToken.IsCancellationRequested || targetAsUnityObject == null) // destroyed = cancel.
+                {
+                    completionSource.TrySetResult(false);
+                    DisposeAsync().Forget();
+                    return false;
+                }
+
+                TProperty nextValue = default(TProperty);
+                try
+                {
+                    nextValue = propertySelector(target);
+                    if (equalityComparer.Equals(currentValue, nextValue))
+                    {
+                        return true;
+                    }
+                }
+                catch (Exception ex)
+                {
+                    completionSource.TrySetException(ex);
+                    DisposeAsync().Forget();
+                    return false;
+                }
+
+                currentValue = nextValue;
+                completionSource.TrySetResult(true);
+                return true;
+            }
+        }
+    }
+
+    internal sealed class EveryValueChangedStandardObject<TTarget, TProperty> : IUniTaskAsyncEnumerable<TProperty>
+        where TTarget : class
+    {
+        readonly WeakReference<TTarget> target;
+        readonly Func<TTarget, TProperty> propertySelector;
+        readonly IEqualityComparer<TProperty> equalityComparer;
+        readonly PlayerLoopTiming monitorTiming;
+
+        public EveryValueChangedStandardObject(TTarget target, Func<TTarget, TProperty> propertySelector, IEqualityComparer<TProperty> equalityComparer, PlayerLoopTiming monitorTiming)
+        {
+            this.target = new WeakReference<TTarget>(target, false);
+            this.propertySelector = propertySelector;
+            this.equalityComparer = equalityComparer;
+            this.monitorTiming = monitorTiming;
+        }
+
+        public IUniTaskAsyncEnumerator<TProperty> GetAsyncEnumerator(CancellationToken cancellationToken = default)
+        {
+            return new _EveryValueChanged(target, propertySelector, equalityComparer, monitorTiming, cancellationToken);
+        }
+
+        sealed class _EveryValueChanged : MoveNextSource, IUniTaskAsyncEnumerator<TProperty>, IPlayerLoopItem
+        {
+            readonly WeakReference<TTarget> target;
+            readonly IEqualityComparer<TProperty> equalityComparer;
+            readonly Func<TTarget, TProperty> propertySelector;
+            CancellationToken cancellationToken;
+
+            bool first;
+            TProperty currentValue;
+            bool disposed;
+
+            public _EveryValueChanged(WeakReference<TTarget> target, Func<TTarget, TProperty> propertySelector, IEqualityComparer<TProperty> equalityComparer, PlayerLoopTiming monitorTiming, CancellationToken cancellationToken)
+            {
+                this.target = target;
+                this.propertySelector = propertySelector;
+                this.equalityComparer = equalityComparer;
+                this.cancellationToken = cancellationToken;
+                this.first = true;
+                TaskTracker.TrackActiveTask(this, 2);
+                PlayerLoopHelper.AddAction(monitorTiming, this);
+            }
+
+            public TProperty Current => currentValue;
+
+            public UniTask<bool> MoveNextAsync()
+            {
+                if (disposed || cancellationToken.IsCancellationRequested) return CompletedTasks.False;
+
+                if (first)
+                {
+                    first = false;
+                    if (!target.TryGetTarget(out var t))
+                    {
+                        return CompletedTasks.False;
+                    }
+                    this.currentValue = propertySelector(t);
+                    return CompletedTasks.True;
+                }
+
+                completionSource.Reset();
+                return new UniTask<bool>(this, completionSource.Version);
+            }
+
+            public UniTask DisposeAsync()
+            {
+                if (!disposed)
+                {
+                    disposed = true;
+                    TaskTracker.RemoveTracking(this);
+                }
+                return default;
+            }
+
+            public bool MoveNext()
+            {
+                UnityEngine.Debug.Log("TRY_RESULT:" + target.TryGetTarget(out var _));
+                if (disposed || cancellationToken.IsCancellationRequested || !target.TryGetTarget(out var t))
+                {
+                    completionSource.TrySetResult(false);
+                    DisposeAsync().Forget();
+                    return false;
+                }
+
+                TProperty nextValue = default(TProperty);
+                try
+                {
+                    nextValue = propertySelector(t);
+                    if (equalityComparer.Equals(currentValue, nextValue))
+                    {
+                        return true;
+                    }
+                }
+                catch (Exception ex)
+                {
+                    completionSource.TrySetException(ex);
+                    DisposeAsync().Forget();
+                    return false;
+                }
+
+                currentValue = nextValue;
+                completionSource.TrySetResult(true);
+                return true;
+            }
+        }
+    }
+}

src/UniTask/Assets/Plugins/UniTask/Runtime/Linq/UnityExtensions/EveryValueChanged.cs.meta

@@ -0,0 +1,11 @@
+fileFormatVersion: 2
+guid: 1ec39f1c41c305344854782c935ad354
+MonoImporter:
+  externalObjects: {}
+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: 0
+  icon: {instanceID: 0}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: