1 files changed, 131 insertions, 0 deletions
diff --git a/src/SMAPI/Framework/InternalExtensions.cs b/src/SMAPI/Framework/InternalExtensions.cs
new file mode 100644
index 00000000..3709e05d
--- /dev/null
+++ b/src/SMAPI/Framework/InternalExtensions.cs
@@ -0,0 +1,131 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Reflection;
+using Microsoft.Xna.Framework.Graphics;
+using StardewModdingAPI.Framework.Reflection;
+using StardewValley;
+
+namespace StardewModdingAPI.Framework
+{
+    /// <summary>Provides extension methods for SMAPI's internal use.</summary>
+    internal static class InternalExtensions
+    {
+        /****
+        ** IMonitor
+        ****/
+        /// <summary>Safely raise an <see cref="EventHandler"/> event, and intercept any exceptions thrown by its handlers.</summary>
+        /// <param name="monitor">Encapsulates monitoring and logging.</param>
+        /// <param name="name">The event name for error messages.</param>
+        /// <param name="handlers">The event handlers.</param>
+        /// <param name="sender">The event sender.</param>
+        /// <param name="args">The event arguments (or <c>null</c> to pass <see cref="EventArgs.Empty"/>).</param>
+        public static void SafelyRaisePlainEvent(this IMonitor monitor, string name, IEnumerable<Delegate> handlers, object sender = null, EventArgs args = null)
+        {
+            if (handlers == null)
+                return;
+
+            foreach (EventHandler handler in handlers.Cast<EventHandler>())
+            {
+                // handle SMAPI exiting
+                if (monitor.IsExiting)
+                {
+                    monitor.Log($"SMAPI shutting down: aborting {name} event.", LogLevel.Warn);
+                    return;
+                }
+
+                // raise event
+                try
+                {
+                    handler.Invoke(sender, args ?? EventArgs.Empty);
+                }
+                catch (Exception ex)
+                {
+                    monitor.Log($"A mod failed handling the {name} event:\n{ex.GetLogSummary()}", LogLevel.Error);
+                }
+            }
+        }
+
+        /// <summary>Safely raise an <see cref="EventHandler{TEventArgs}"/> event, and intercept any exceptions thrown by its handlers.</summary>
+        /// <typeparam name="TEventArgs">The event argument object type.</typeparam>
+        /// <param name="monitor">Encapsulates monitoring and logging.</param>
+        /// <param name="name">The event name for error messages.</param>
+        /// <param name="handlers">The event handlers.</param>
+        /// <param name="sender">The event sender.</param>
+        /// <param name="args">The event arguments.</param>
+        public static void SafelyRaiseGenericEvent<TEventArgs>(this IMonitor monitor, string name, IEnumerable<Delegate> handlers, object sender, TEventArgs args)
+        {
+            if (handlers == null)
+                return;
+
+            foreach (EventHandler<TEventArgs> handler in handlers.Cast<EventHandler<TEventArgs>>())
+            {
+                try
+                {
+                    handler.Invoke(sender, args);
+                }
+                catch (Exception ex)
+                {
+                    monitor.Log($"A mod failed handling the {name} event:\n{ex.GetLogSummary()}", LogLevel.Error);
+                }
+            }
+        }
+
+        /// <summary>Log a message for the player or developer the first time it occurs.</summary>
+        /// <param name="monitor">The monitor through which to log the message.</param>
+        /// <param name="hash">The hash of logged messages.</param>
+        /// <param name="message">The message to log.</param>
+        /// <param name="level">The log severity level.</param>
+        public static void LogOnce(this IMonitor monitor, HashSet<string> hash, string message, LogLevel level = LogLevel.Trace)
+        {
+            if (!hash.Contains(message))
+            {
+                monitor.Log(message, level);
+                hash.Add(message);
+            }
+        }
+
+        /****
+        ** Exceptions
+        ****/
+        /// <summary>Get a string representation of an exception suitable for writing to the error log.</summary>
+        /// <param name="exception">The error to summarise.</param>
+        public static string GetLogSummary(this Exception exception)
+        {
+            switch (exception)
+            {
+                case TypeLoadException ex:
+                    return $"Failed loading type '{ex.TypeName}': {exception}";
+
+                case ReflectionTypeLoadException ex:
+                    string summary = exception.ToString();
+                    foreach (Exception childEx in ex.LoaderExceptions)
+                        summary += $"\n\n{childEx.GetLogSummary()}";
+                    return summary;
+
+                default:
+                    return exception.ToString();
+            }
+        }
+
+        /****
+        ** Sprite batch
+        ****/
+        /// <summary>Get whether the sprite batch is between a begin and end pair.</summary>
+        /// <param name="spriteBatch">The sprite batch to check.</param>
+        /// <param name="reflection">The reflection helper with which to access private fields.</param>
+        public static bool IsOpen(this SpriteBatch spriteBatch, Reflector reflection)
+        {
+            // get field name
+            const string fieldName =
+#if SMAPI_FOR_WINDOWS
+            "inBeginEndPair";
+#else
+            "_beginCalled";
+#endif
+
+            // get result
+            return reflection.GetPrivateField<bool>(Game1.spriteBatch, fieldName).GetValue();
+        }
+    }
+}