add prototype content event + helper to manipulate XNB data (#173)

1 files changed, 69 insertions, 0 deletions

diff --git a/src/StardewModdingAPI/Events/ContentEvents.cs b/src/StardewModdingAPI/Events/ContentEvents.cs
new file mode 100644
index 00000000..cc07f242
--- /dev/null
+++ b/src/StardewModdingAPI/Events/ContentEvents.cs
@@ -0,0 +1,69 @@
+using System;
+using System.Collections.Generic;
+using StardewModdingAPI.Framework;
+
+namespace StardewModdingAPI.Events
+{
+    /// <summary>Events raised when the game loads content.</summary>
+    [Obsolete("This is an undocumented experimental API and may change without warning.")]
+    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>();
+
+
+        /*********
+        ** Events
+        *********/
+        /// <summary>Raised when an XNB file is being read into the cache. Mods can change the data here before it's cached.</summary>
+        public static event EventHandler<IContentEventHelper> AssetLoading;
+
+
+        /*********
+        ** 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="AssetLoading"/> 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 InvokeAssetLoading(IMonitor monitor, IContentEventHelper contentHelper)
+        {
+            // raise warning about experimental API
+            foreach (Delegate handler in ContentEvents.AssetLoading.GetInvocationList())
+            {
+                string modName = ContentEvents.ModRegistry.GetModFrom(handler) ?? "An unknown mod";
+                if (!ContentEvents.WarnedMods.Contains(modName))
+                {
+                    ContentEvents.WarnedMods.Add(modName);
+                    ContentEvents.Monitor.Log($"{modName} used the undocumented and experimental content API, which may change or be removed without warning.", LogLevel.Warn);
+                }
+            }
+
+            // raise event
+            monitor.SafelyRaiseGenericEvent($"{nameof(ContentEvents)}.{nameof(ContentEvents.AssetLoading)}", ContentEvents.AssetLoading?.GetInvocationList(), null, contentHelper);
+        }
+
+        /// <summary>Get whether there are any <see cref="AssetLoading"/> listeners.</summary>
+        internal static bool HasAssetLoadingListeners()
+        {
+            return ContentEvents.AssetLoading != null;
+        }
+    }
+}