rewrite content interception using latest proposed API (#255)

src/StardewModdingAPI/Events/ContentEvents.cs

@@ -1,6 +1,4 @@
 using System;
-using System.Collections.Generic;
-using System.Diagnostics.CodeAnalysis;
 using StardewModdingAPI.Framework;
 
 namespace StardewModdingAPI.Events
@@ -8,21 +6,6 @@ namespace StardewModdingAPI.Events
     /// <summary>Events raised when the game loads content.</summary>
     public static class ContentEvents
     {
-        /*********
-        ** Properties
-        *********/
-        /// <summary>Tracks the installed mods.</summary>
-        private static ModRegistry ModRegistry;
-
-        /// <summary>Encapsulates monitoring and logging.</summary>
-        private static IMonitor Monitor;
-
-        /// <summary>The mods using the experimental API for which a warning has been raised.</summary>
-        private static readonly HashSet<string> WarnedMods = new HashSet<string>();
-
-        /// <summary>The backing field for <see cref="AfterAssetLoaded"/>.</summary>
-        [SuppressMessage("ReSharper", "InconsistentNaming")]
-        private static event EventHandler<IContentEventHelper> _AfterAssetLoaded;
 
         /*********
         ** Events
@@ -30,35 +13,10 @@ namespace StardewModdingAPI.Events
         /// <summary>Raised after the content language changes.</summary>
         public static event EventHandler<EventArgsValueChanged<string>> AfterLocaleChanged;
 
-        /// <summary>Raised when an XNB file is being read into the cache. Mods can change the data here before it's cached.</summary>
-#if EXPERIMENTAL
-        public
-#else
-        internal
-#endif
-            static event EventHandler<IContentEventHelper> AfterAssetLoaded
-        {
-            add
-            {
-                ContentEvents.RaiseContentExperimentalWarning();
-                ContentEvents._AfterAssetLoaded += value;
-            }
-            remove => ContentEvents._AfterAssetLoaded -= value;
-        }
-
 
         /*********
         ** Internal methods
         *********/
-        /// <summary>Injects types required for backwards compatibility.</summary>
-        /// <param name="modRegistry">Tracks the installed mods.</param>
-        /// <param name="monitor">Encapsulates monitoring and logging.</param>
-        internal static void Shim(ModRegistry modRegistry, IMonitor monitor)
-        {
-            ContentEvents.ModRegistry = modRegistry;
-            ContentEvents.Monitor = monitor;
-        }
-
         /// <summary>Raise an <see cref="AfterLocaleChanged"/> event.</summary>
         /// <param name="monitor">Encapsulates monitoring and logging.</param>
         /// <param name="oldLocale">The previous locale.</param>
@@ -67,28 +25,5 @@ namespace StardewModdingAPI.Events
         {
             monitor.SafelyRaiseGenericEvent($"{nameof(ContentEvents)}.{nameof(ContentEvents.AfterLocaleChanged)}", ContentEvents.AfterLocaleChanged?.GetInvocationList(), null, new EventArgsValueChanged<string>(oldLocale, newLocale));
         }
-
-        /// <summary>Raise an <see cref="AfterAssetLoaded"/> event.</summary>
-        /// <param name="monitor">Encapsulates monitoring and logging.</param>
-        /// <param name="contentHelper">Encapsulates access and changes to content being read from a data file.</param>
-        internal static void InvokeAfterAssetLoaded(IMonitor monitor, IContentEventHelper contentHelper)
-        {
-            monitor.SafelyRaiseGenericEvent($"{nameof(ContentEvents)}.{nameof(ContentEvents.AfterAssetLoaded)}", ContentEvents._AfterAssetLoaded?.GetInvocationList(), null, contentHelper);
-        }
-
-
-        /*********
-        ** Private methods
-        *********/
-        /// <summary>Raise an 'experimental API' warning for a mod using the content API.</summary>
-        private static void RaiseContentExperimentalWarning()
-        {
-            string modName = ContentEvents.ModRegistry.GetModFromStack() ?? "An unknown mod";
-            if (!ContentEvents.WarnedMods.Contains(modName))
-            {
-                ContentEvents.WarnedMods.Add(modName);
-                ContentEvents.Monitor.Log($"{modName} used the undocumented and experimental content API, which may change or be removed without warning.", LogLevel.Warn);
-            }
-        }
     }
 }

src/StardewModdingAPI/Framework/Content/AssetData.cs

@@ -0,0 +1,44 @@
+using System;
+
+namespace StardewModdingAPI.Framework.Content
+{
+    /// <summary>Base implementation for a content helper which encapsulates access and changes to content being read from a data file.</summary>
+    /// <typeparam name="TValue">The interface value type.</typeparam>
+    internal class AssetData<TValue> : AssetInfo, IAssetData<TValue>
+    {
+        /*********
+        ** Accessors
+        *********/
+        /// <summary>The content data being read.</summary>
+        public TValue Data { get; protected set; }
+
+
+        /*********
+        ** Public methods
+        *********/
+        /// <summary>Construct an instance.</summary>
+        /// <param name="locale">The content's locale code, if the content is localised.</param>
+        /// <param name="assetName">The normalised asset name being read.</param>
+        /// <param name="data">The content data being read.</param>
+        /// <param name="getNormalisedPath">Normalises an asset key to match the cache key.</param>
+        public AssetData(string locale, string assetName, TValue data, Func<string, string> getNormalisedPath)
+            : base(locale, assetName, data.GetType(), getNormalisedPath)
+        {
+            this.Data = data;
+        }
+
+        /// <summary>Replace the entire content value with the given value. This is generally not recommended, since it may break compatibility with other mods or different versions of the game.</summary>
+        /// <param name="value">The new content value.</param>
+        /// <exception cref="ArgumentNullException">The <paramref name="value"/> is null.</exception>
+        /// <exception cref="InvalidCastException">The <paramref name="value"/>'s type is not compatible with the loaded asset's type.</exception>
+        public void ReplaceWith(TValue value)
+        {
+            if (value == null)
+                throw new ArgumentNullException(nameof(value), "Can't set a loaded asset to a null value.");
+            if (!this.DataType.IsInstanceOfType(value))
+                throw new InvalidCastException($"Can't replace loaded asset of type {this.GetFriendlyTypeName(this.DataType)} with value of type {this.GetFriendlyTypeName(value.GetType())}. The new type must be compatible to prevent game errors.");
+
+            this.Data = value;
+        }
+    }
+}

src/StardewModdingAPI/Framework/Content/AssetDataForDictionary.cs

@@ -5,7 +5,7 @@ using System.Linq;
 namespace StardewModdingAPI.Framework.Content
 {
     /// <summary>Encapsulates access and changes to dictionary content being read from a data file.</summary>
-    internal class ContentEventHelperForDictionary<TKey, TValue> : ContentEventData<IDictionary<TKey, TValue>>, IContentEventHelperForDictionary<TKey, TValue>
+    internal class AssetDataForDictionary<TKey, TValue> : AssetData<IDictionary<TKey, TValue>>, IAssetDataForDictionary<TKey, TValue>
     {
         /*********
         ** Public methods
@@ -15,7 +15,7 @@ namespace StardewModdingAPI.Framework.Content
         /// <param name="assetName">The normalised asset name being read.</param>
         /// <param name="data">The content data being read.</param>
         /// <param name="getNormalisedPath">Normalises an asset key to match the cache key.</param>
-        public ContentEventHelperForDictionary(string locale, string assetName, IDictionary<TKey, TValue> data, Func<string, string> getNormalisedPath)
+        public AssetDataForDictionary(string locale, string assetName, IDictionary<TKey, TValue> data, Func<string, string> getNormalisedPath)
             : base(locale, assetName, data, getNormalisedPath) { }
 
         /// <summary>Add or replace an entry in the dictionary.</summary>

src/StardewModdingAPI/Framework/Content/AssetDataForImage.cs

@@ -5,7 +5,7 @@ using Microsoft.Xna.Framework.Graphics;
 namespace StardewModdingAPI.Framework.Content
 {
     /// <summary>Encapsulates access and changes to dictionary content being read from a data file.</summary>
-    internal class ContentEventHelperForImage : ContentEventData<Texture2D>, IContentEventHelperForImage
+    internal class AssetDataForImage : AssetData<Texture2D>, IAssetDataForImage
     {
         /*********
         ** Public methods
@@ -15,7 +15,7 @@ namespace StardewModdingAPI.Framework.Content
         /// <param name="assetName">The normalised asset name being read.</param>
         /// <param name="data">The content data being read.</param>
         /// <param name="getNormalisedPath">Normalises an asset key to match the cache key.</param>
-        public ContentEventHelperForImage(string locale, string assetName, Texture2D data, Func<string, string> getNormalisedPath)
+        public AssetDataForImage(string locale, string assetName, Texture2D data, Func<string, string> getNormalisedPath)
             : base(locale, assetName, data, getNormalisedPath) { }
 
         /// <summary>Overwrite part of the image.</summary>

src/StardewModdingAPI/Framework/Content/AssetDataForObject.cs

@@ -5,7 +5,7 @@ using Microsoft.Xna.Framework.Graphics;
 namespace StardewModdingAPI.Framework.Content
 {
     /// <summary>Encapsulates access and changes to content being read from a data file.</summary>
-    internal class ContentEventHelper : ContentEventData<object>, IContentEventHelper
+    internal class AssetDataForObject : AssetData<object>, IAssetData
     {
         /*********
         ** Public methods
@@ -15,23 +15,23 @@ namespace StardewModdingAPI.Framework.Content
         /// <param name="assetName">The normalised asset name being read.</param>
         /// <param name="data">The content data being read.</param>
         /// <param name="getNormalisedPath">Normalises an asset key to match the cache key.</param>
-        public ContentEventHelper(string locale, string assetName, object data, Func<string, string> getNormalisedPath)
+        public AssetDataForObject(string locale, string assetName, object data, Func<string, string> getNormalisedPath)
             : base(locale, assetName, data, getNormalisedPath) { }
 
         /// <summary>Get a helper to manipulate the data as a dictionary.</summary>
         /// <typeparam name="TKey">The expected dictionary key.</typeparam>
         /// <typeparam name="TValue">The expected dictionary balue.</typeparam>
         /// <exception cref="InvalidOperationException">The content being read isn't a dictionary.</exception>
-        public IContentEventHelperForDictionary<TKey, TValue> AsDictionary<TKey, TValue>()
+        public IAssetDataForDictionary<TKey, TValue> AsDictionary<TKey, TValue>()
         {
-            return new ContentEventHelperForDictionary<TKey, TValue>(this.Locale, this.AssetName, this.GetData<IDictionary<TKey, TValue>>(), this.GetNormalisedPath);
+            return new AssetDataForDictionary<TKey, TValue>(this.Locale, this.AssetName, this.GetData<IDictionary<TKey, TValue>>(), this.GetNormalisedPath);
         }
 
         /// <summary>Get a helper to manipulate the data as an image.</summary>
         /// <exception cref="InvalidOperationException">The content being read isn't an image.</exception>
-        public IContentEventHelperForImage AsImage()
+        public IAssetDataForImage AsImage()
         {
-            return new ContentEventHelperForImage(this.Locale, this.AssetName, this.GetData<Texture2D>(), this.GetNormalisedPath);
+            return new AssetDataForImage(this.Locale, this.AssetName, this.GetData<Texture2D>(), this.GetNormalisedPath);
         }
 
         /// <summary>Get the data as a given type.</summary>

src/StardewModdingAPI/Framework/Content/AssetInfo.cs

@@ -4,9 +4,7 @@ using Microsoft.Xna.Framework.Graphics;
 
 namespace StardewModdingAPI.Framework.Content
 {
-    /// <summary>Base implementation for a content helper which encapsulates access and changes to content being read from a data file.</summary>
+    internal class AssetInfo : IAssetInfo
-    /// <typeparam name="TValue">The interface value type.</typeparam>
-    internal class ContentEventData<TValue> : EventArgs, IContentEventData<TValue>
     {
         /*********
         ** Properties
@@ -24,9 +22,6 @@ namespace StardewModdingAPI.Framework.Content
         /// <summary>The normalised asset name being read. The format may change between platforms; see <see cref="IsAssetName"/> to compare with a known path.</summary>
         public string AssetName { get; }
 
-        /// <summary>The content data being read.</summary>
-        public TValue Data { get; protected set; }
-
         /// <summary>The content data type.</summary>
         public Type DataType { get; }
 
@@ -37,23 +32,13 @@ namespace StardewModdingAPI.Framework.Content
         /// <summary>Construct an instance.</summary>
         /// <param name="locale">The content's locale code, if the content is localised.</param>
         /// <param name="assetName">The normalised asset name being read.</param>
-        /// <param name="data">The content data being read.</param>
+        /// <param name="type">The content type being read.</param>
         /// <param name="getNormalisedPath">Normalises an asset key to match the cache key.</param>
-        public ContentEventData(string locale, string assetName, TValue data, Func<string, string> getNormalisedPath)
+        public AssetInfo(string locale, string assetName, Type type, Func<string, string> getNormalisedPath)
-            : this(locale, assetName, data, data.GetType(), getNormalisedPath) { }
-
-        /// <summary>Construct an instance.</summary>
-        /// <param name="locale">The content's locale code, if the content is localised.</param>
-        /// <param name="assetName">The normalised asset name being read.</param>
-        /// <param name="data">The content data being read.</param>
-        /// <param name="dataType">The content data type being read.</param>
-        /// <param name="getNormalisedPath">Normalises an asset key to match the cache key.</param>
-        public ContentEventData(string locale, string assetName, TValue data, Type dataType, Func<string, string> getNormalisedPath)
         {
             this.Locale = locale;
             this.AssetName = assetName;
-            this.Data = data;
+            this.DataType = type;
-            this.DataType = dataType;
             this.GetNormalisedPath = getNormalisedPath;
         }
 
@@ -65,20 +50,6 @@ namespace StardewModdingAPI.Framework.Content
             return this.AssetName.Equals(path, StringComparison.InvariantCultureIgnoreCase);
         }
 
-        /// <summary>Replace the entire content value with the given value. This is generally not recommended, since it may break compatibility with other mods or different versions of the game.</summary>
-        /// <param name="value">The new content value.</param>
-        /// <exception cref="ArgumentNullException">The <paramref name="value"/> is null.</exception>
-        /// <exception cref="InvalidCastException">The <paramref name="value"/>'s type is not compatible with the loaded asset's type.</exception>
-        public void ReplaceWith(TValue value)
-        {
-            if (value == null)
-                throw new ArgumentNullException(nameof(value), "Can't set a loaded asset to a null value.");
-            if (!this.DataType.IsInstanceOfType(value))
-                throw new InvalidCastException($"Can't replace loaded asset of type {this.GetFriendlyTypeName(this.DataType)} with value of type {this.GetFriendlyTypeName(value.GetType())}. The new type must be compatible to prevent game errors.");
-
-            this.Data = value;
-        }
-
 
         /*********
         ** Protected methods

src/StardewModdingAPI/Framework/ContentHelper.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Collections.Generic;
 using System.Diagnostics.CodeAnalysis;
 using System.IO;
 using System.Linq;
@@ -32,6 +33,13 @@ namespace StardewModdingAPI.Framework
         private readonly string ModName;
 
 
+        /*********
+        ** Accessors
+        *********/
+        /// <summary>Editors which change content assets after they're loaded.</summary>
+        internal IList<IAssetEditor> AssetEditors { get; } = new List<IAssetEditor>();
+
+
         /*********
         ** Public methods
         *********/

src/StardewModdingAPI/Framework/SContentManager.cs

@@ -3,11 +3,9 @@ using System.Collections.Generic;
 using System.Globalization;
 using System.IO;
 using System.Linq;
-using System.Threading;
 using Microsoft.Xna.Framework;
 using Microsoft.Xna.Framework.Content;
 using StardewModdingAPI.AssemblyRewriters;
-using StardewModdingAPI.Events;
 using StardewModdingAPI.Framework.Content;
 using StardewModdingAPI.Framework.Reflection;
 using StardewValley;
@@ -42,6 +40,9 @@ namespace StardewModdingAPI.Framework
         /*********
         ** Accessors
         *********/
+        /// <summary>Implementations which change assets after they're loaded.</summary>
+        internal IDictionary<IModMetadata, IList<IAssetEditor>> Editors { get; } = new Dictionary<IModMetadata, IList<IAssetEditor>>();
+
         /// <summary>The absolute path to the <see cref="ContentManager.RootDirectory"/>.</summary>
         public string FullRootDirectory => Path.Combine(Constants.ExecutionPath, this.RootDirectory);
 
@@ -49,13 +50,6 @@ namespace StardewModdingAPI.Framework
         /*********
         ** Public methods
         *********/
-        /// <summary>Construct an instance.</summary>
-        /// <param name="serviceProvider">The service provider to use to locate services.</param>
-        /// <param name="rootDirectory">The root directory to search for content.</param>
-        /// <param name="monitor">Encapsulates monitoring and logging.</param>
-        public SContentManager(IServiceProvider serviceProvider, string rootDirectory, IMonitor monitor)
-            : this(serviceProvider, rootDirectory, Thread.CurrentThread.CurrentUICulture, null, monitor) { }
-
         /// <summary>Construct an instance.</summary>
         /// <param name="serviceProvider">The service provider to use to locate services.</param>
         /// <param name="rootDirectory">The root directory to search for content.</param>
@@ -66,8 +60,8 @@ namespace StardewModdingAPI.Framework
             : base(serviceProvider, rootDirectory, currentCulture, languageCodeOverride)
         {
             // initialise
-            this.Monitor = monitor;
             IReflectionHelper reflection = new ReflectionHelper();
+            this.Monitor = monitor;
 
             // get underlying fields for interception
             this.Cache = reflection.GetPrivateField<Dictionary<string, object>>(this, "loadedAssets").GetValue();
@@ -125,14 +119,20 @@ namespace StardewModdingAPI.Framework
             if (this.IsNormalisedKeyLoaded(assetName))
                 return base.Load<T>(assetName);
 
-            // load data
-            T data = base.Load<T>(assetName);
-
             // let mods intercept content
-            IContentEventHelper helper = new ContentEventHelper(cacheLocale, assetName, data, this.NormaliseAssetName);
+            IAssetInfo info = new AssetInfo(cacheLocale, assetName, typeof(T), this.NormaliseAssetName);
-            ContentEvents.InvokeAfterAssetLoaded(this.Monitor, helper);
+            Lazy<IAssetData> data = new Lazy<IAssetData>(() => new AssetDataForObject(info.Locale, info.AssetName, base.Load<T>(assetName), this.NormaliseAssetName));
-            this.Cache[assetName] = helper.Data;
+            if (this.TryOverrideAssetLoad(info, data, out T result))
-            return (T)helper.Data;
+            {
+                if (result == null)
+                    throw new InvalidCastException($"Can't override asset '{assetName}' with a null value.");
+
+                this.Cache[assetName] = result;
+                return result;
+            }
+
+            // fallback to default behavior
+            return base.Load<T>(assetName);
         }
 
         /// <summary>Inject an asset into the cache.</summary>
@@ -171,5 +171,35 @@ namespace StardewModdingAPI.Framework
                 ? locale
                 : null;
         }
+
+        /// <summary>Try to override an asset being loaded.</summary>
+        /// <typeparam name="T">The asset type.</typeparam>
+        /// <param name="info">The asset metadata.</param>
+        /// <param name="data">The loaded asset data.</param>
+        /// <param name="result">The asset to use instead.</param>
+        /// <returns>Returns whether the asset should be overridden by <paramref name="result"/>.</returns>
+        private bool TryOverrideAssetLoad<T>(IAssetInfo info, Lazy<IAssetData> data, out T result)
+        {
+            bool edited = false;
+
+            // apply editors
+            foreach (var modEditors in this.Editors)
+            {
+                IModMetadata mod = modEditors.Key;
+                foreach (IAssetEditor editor in modEditors.Value)
+                {
+                    if (!editor.CanEdit<T>(info))
+                        continue;
+
+                    this.Monitor.Log($"{mod.DisplayName} intercepted {info.AssetName}.", LogLevel.Trace);
+                    editor.Edit<T>(data.Value);
+                    edited = true;
+                }
+            }
+
+            // return result
+            result = edited ? (T)data.Value.Data : default(T);
+            return edited;
+        }
     }
 }

src/StardewModdingAPI/Framework/SGame.cs

@@ -4,6 +4,7 @@ using System.Collections.Generic;
 using System.Diagnostics;
 using System.Diagnostics.CodeAnalysis;
 using System.Linq;
+using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.Xna.Framework;
 using Microsoft.Xna.Framework.Graphics;
@@ -29,6 +30,9 @@ namespace StardewModdingAPI.Framework
         /****
         ** SMAPI state
         ****/
+        /// <summary>Encapsulates monitoring and logging.</summary>
+        private readonly IMonitor Monitor;
+
         /// <summary>The maximum number of consecutive attempts SMAPI should make to recover from a draw error.</summary>
         private readonly Countdown DrawCrashTimer = new Countdown(60); // 60 ticks = roughly one second
 
@@ -48,8 +52,6 @@ namespace StardewModdingAPI.Framework
         /// <summary>Whether the game's zoom level is at 100% (i.e. nothing should be scaled).</summary>
         public bool ZoomLevelIsOne => Game1.options.zoomLevel.Equals(1.0f);
 
-        /// <summary>Encapsulates monitoring and logging.</summary>
-        private readonly IMonitor Monitor;
 
         /****
         ** Game state
@@ -189,7 +191,7 @@ namespace StardewModdingAPI.Framework
             //   2. Since Game1.content isn't initialised yet, and we need one main instance to
             //      support custom map tilesheets, detect when Game1.content is being initialised
             //      and use the same instance.
-            this.Content = new SContentManager(this.Content.ServiceProvider, this.Content.RootDirectory, this.Monitor);
+            this.Content = new SContentManager(this.Content.ServiceProvider, this.Content.RootDirectory, Thread.CurrentThread.CurrentUICulture, null, this.Monitor);
         }
 
         /****
@@ -206,7 +208,7 @@ namespace StardewModdingAPI.Framework
                 return mainContentManager;
 
             // build new instance
-            return new SContentManager(this.Content.ServiceProvider, this.Content.RootDirectory, this.Monitor);
+            return new SContentManager(this.Content.ServiceProvider, this.Content.RootDirectory, Thread.CurrentThread.CurrentUICulture, null, this.Monitor);
         }
 
         /// <summary>The method called when the game is updating its state. This happens roughly 60 times per second.</summary>

src/StardewModdingAPI/IAssetData.cs

@@ -0,0 +1,47 @@
+using System;
+
+namespace StardewModdingAPI
+{
+    /// <summary>Generic metadata and methods for a content asset being loaded.</summary>
+    /// <typeparam name="TValue">The expected data type.</typeparam>
+    public interface IAssetData<TValue> : IAssetInfo
+    {
+        /*********
+        ** Accessors
+        *********/
+        /// <summary>The content data being read.</summary>
+        TValue Data { get; }
+
+
+        /*********
+        ** Public methods
+        *********/
+        /// <summary>Replace the entire content value with the given value. This is generally not recommended, since it may break compatibility with other mods or different versions of the game.</summary>
+        /// <param name="value">The new content value.</param>
+        /// <exception cref="ArgumentNullException">The <paramref name="value"/> is null.</exception>
+        /// <exception cref="InvalidCastException">The <paramref name="value"/>'s type is not compatible with the loaded asset's type.</exception>
+        void ReplaceWith(TValue value);
+    }
+
+    /// <summary>Generic metadata and methods for a content asset being loaded.</summary>
+    public interface IAssetData : IAssetData<object>
+    {
+        /*********
+        ** Public methods
+        *********/
+        /// <summary>Get a helper to manipulate the data as a dictionary.</summary>
+        /// <typeparam name="TKey">The expected dictionary key.</typeparam>
+        /// <typeparam name="TValue">The expected dictionary value.</typeparam>
+        /// <exception cref="InvalidOperationException">The content being read isn't a dictionary.</exception>
+        IAssetDataForDictionary<TKey, TValue> AsDictionary<TKey, TValue>();
+
+        /// <summary>Get a helper to manipulate the data as an image.</summary>
+        /// <exception cref="InvalidOperationException">The content being read isn't an image.</exception>
+        IAssetDataForImage AsImage();
+
+        /// <summary>Get the data as a given type.</summary>
+        /// <typeparam name="TData">The expected data type.</typeparam>
+        /// <exception cref="InvalidCastException">The data can't be converted to <typeparamref name="TData"/>.</exception>
+        TData GetData<TData>();
+    }
+}

src/StardewModdingAPI/IAssetDataForDictionary.cs

@@ -4,7 +4,7 @@ using System.Collections.Generic;
 namespace StardewModdingAPI
 {
     /// <summary>Encapsulates access and changes to dictionary content being read from a data file.</summary>
-    public interface IContentEventHelperForDictionary<TKey, TValue> : IContentEventData<IDictionary<TKey, TValue>>
+    public interface IAssetDataForDictionary<TKey, TValue> : IAssetData<IDictionary<TKey, TValue>>
     {
         /*********
         ** Public methods

src/StardewModdingAPI/IAssetDataForImage.cs

@@ -5,7 +5,7 @@ using Microsoft.Xna.Framework.Graphics;
 namespace StardewModdingAPI
 {
     /// <summary>Encapsulates access and changes to dictionary content being read from a data file.</summary>
-    public interface IContentEventHelperForImage : IContentEventData<Texture2D>
+    public interface IAssetDataForImage : IAssetData<Texture2D>
     {
         /*********
         ** Public methods

src/StardewModdingAPI/IAssetEditor.cs

@@ -0,0 +1,17 @@
+namespace StardewModdingAPI
+{
+    /// <summary>Edits a loaded content asset.</summary>
+    public interface IAssetEditor
+    {
+        /*********
+        ** Public methods
+        *********/
+        /// <summary>Get whether this instance can edit the given asset.</summary>
+        /// <param name="asset">Basic metadata about the asset being loaded.</param>
+        bool CanEdit<T>(IAssetInfo asset);
+
+        /// <summary>Edit a matched asset.</summary>
+        /// <param name="asset">A helper which encapsulates metadata about an asset and enables changes to it.</param>
+        void Edit<T>(IAssetData asset);
+    }
+}

src/StardewModdingAPI/IAssetInfo.cs

@@ -1,10 +1,9 @@
-using System;
+using System;
 
 namespace StardewModdingAPI
 {
-    /// <summary>Generic metadata and methods for a content asset being loaded.</summary>
+    /// <summary>Basic metadata for a content asset.</summary>
-    /// <typeparam name="TValue">The expected data type.</typeparam>
+    public interface IAssetInfo
-    public interface IContentEventData<TValue>
     {
         /*********
         ** Accessors
@@ -15,9 +14,6 @@ namespace StardewModdingAPI
         /// <summary>The normalised asset name being read. The format may change between platforms; see <see cref="IsAssetName"/> to compare with a known path.</summary>
         string AssetName { get; }
 
-        /// <summary>The content data being read.</summary>
-        TValue Data { get; }
-
         /// <summary>The content data type.</summary>
         Type DataType { get; }
 
@@ -28,11 +24,5 @@ namespace StardewModdingAPI
         /// <summary>Get whether the asset name being loaded matches a given name after normalisation.</summary>
         /// <param name="path">The expected asset path, relative to the game's content folder and without the .xnb extension or locale suffix (like 'Data\ObjectInformation').</param>
         bool IsAssetName(string path);
-
-        /// <summary>Replace the entire content value with the given value. This is generally not recommended, since it may break compatibility with other mods or different versions of the game.</summary>
-        /// <param name="value">The new content value.</param>
-        /// <exception cref="ArgumentNullException">The <paramref name="value"/> is null.</exception>
-        /// <exception cref="InvalidCastException">The <paramref name="value"/>'s type is not compatible with the loaded asset's type.</exception>
-        void ReplaceWith(TValue value);
     }
 }

src/StardewModdingAPI/IContentEventHelper.cs

@@ -1,26 +0,0 @@
-using System;
-
-namespace StardewModdingAPI
-{
-    /// <summary>Encapsulates access and changes to content being read from a data file.</summary>
-    public interface IContentEventHelper : IContentEventData<object>
-    {
-        /*********
-        ** Public methods
-        *********/
-        /// <summary>Get a helper to manipulate the data as a dictionary.</summary>
-        /// <typeparam name="TKey">The expected dictionary key.</typeparam>
-        /// <typeparam name="TValue">The expected dictionary balue.</typeparam>
-        /// <exception cref="InvalidOperationException">The content being read isn't a dictionary.</exception>
-        IContentEventHelperForDictionary<TKey, TValue> AsDictionary<TKey, TValue>();
-
-        /// <summary>Get a helper to manipulate the data as an image.</summary>
-        /// <exception cref="InvalidOperationException">The content being read isn't an image.</exception>
-        IContentEventHelperForImage AsImage();
-
-        /// <summary>Get the data as a given type.</summary>
-        /// <typeparam name="TData">The expected data type.</typeparam>
-        /// <exception cref="InvalidCastException">The data can't be converted to <typeparamref name="TData"/>.</exception>
-        TData GetData<TData>();
-    }
-}

src/StardewModdingAPI/Program.cs

@@ -330,7 +330,6 @@ namespace StardewModdingAPI
             Config.Shim(this.DeprecationManager);
             Log.Shim(this.DeprecationManager, this.GetSecondaryMonitor("legacy mod"), this.ModRegistry);
             Mod.Shim(this.DeprecationManager);
-            ContentEvents.Shim(this.ModRegistry, this.Monitor);
             GameEvents.Shim(this.DeprecationManager);
             PlayerEvents.Shim(this.DeprecationManager);
             TimeEvents.Shim(this.DeprecationManager);
@@ -489,7 +488,8 @@ namespace StardewModdingAPI
             this.Monitor.Log("Detecting common issues...", LogLevel.Trace);
             bool issuesFound = false;
 
-            // object format (commonly broken by outdated mods)
+
+            // object format (commonly broken by outdated files)
             {
                 // detect issues
                 bool hasObjectIssues = false;
@@ -689,11 +689,14 @@ namespace StardewModdingAPI
             // initialise loaded mods
             foreach (IModMetadata metadata in this.ModRegistry.GetMods())
             {
+                // add interceptors
+                if (metadata.Mod.Helper.Content is ContentHelper helper)
+                    this.ContentManager.Editors[metadata] = helper.AssetEditors;
+
+                // call entry method
                 try
                 {
                     IMod mod = metadata.Mod;
-
-                    // call entry methods
                     (mod as Mod)?.Entry(); // deprecated since 1.0
                     mod.Entry(mod.Helper);
 

src/StardewModdingAPI/StardewModdingAPI.csproj

@@ -97,6 +97,7 @@
     <Compile Include="ContentSource.cs" />
     <Compile Include="Events\ContentEvents.cs" />
     <Compile Include="Events\EventArgsValueChanged.cs" />
+    <Compile Include="Framework\Content\AssetInfo.cs" />
     <Compile Include="Framework\Exceptions\SContentLoadException.cs" />
     <Compile Include="Framework\Command.cs" />
     <Compile Include="Config.cs" />
@@ -136,10 +137,10 @@
     <Compile Include="Framework\ModLoading\AssemblyParseResult.cs" />
     <Compile Include="Framework\CommandManager.cs" />
     <Compile Include="Framework\ContentHelper.cs" />
-    <Compile Include="Framework\Content\ContentEventData.cs" />
+    <Compile Include="Framework\Content\AssetData.cs" />
-    <Compile Include="Framework\Content\ContentEventHelper.cs" />
+    <Compile Include="Framework\Content\AssetDataForObject.cs" />
-    <Compile Include="Framework\Content\ContentEventHelperForDictionary.cs" />
+    <Compile Include="Framework\Content\AssetDataForDictionary.cs" />
-    <Compile Include="Framework\Content\ContentEventHelperForImage.cs" />
+    <Compile Include="Framework\Content\AssetDataForImage.cs" />
     <Compile Include="Context.cs" />
     <Compile Include="Framework\Logging\ConsoleInterceptionManager.cs" />
     <Compile Include="Framework\Logging\InterceptingTextWriter.cs" />
@@ -156,11 +157,12 @@
     <Compile Include="Framework\Serialisation\SelectiveStringEnumConverter.cs" />
     <Compile Include="Framework\Serialisation\ManifestFieldConverter.cs" />
     <Compile Include="Framework\TranslationHelper.cs" />
+    <Compile Include="IAssetEditor.cs" />
+    <Compile Include="IAssetInfo.cs" />
     <Compile Include="ICommandHelper.cs" />
-    <Compile Include="IContentEventData.cs" />
+    <Compile Include="IAssetData.cs" />
-    <Compile Include="IContentEventHelper.cs" />
+    <Compile Include="IAssetDataForDictionary.cs" />
-    <Compile Include="IContentEventHelperForDictionary.cs" />
+    <Compile Include="IAssetDataForImage.cs" />
-    <Compile Include="IContentEventHelperForImage.cs" />
     <Compile Include="IContentHelper.cs" />
     <Compile Include="IManifestDependency.cs" />
     <Compile Include="IModRegistry.cs" />