1 files changed, 63 insertions, 0 deletions
diff --git a/src/SMAPI/Framework/Logging/InterceptingTextWriter.cs b/src/SMAPI/Framework/Logging/InterceptingTextWriter.cs
new file mode 100644
index 00000000..9ca61b59
--- /dev/null
+++ b/src/SMAPI/Framework/Logging/InterceptingTextWriter.cs
@@ -0,0 +1,63 @@
+using System;
+using System.IO;
+using System.Text;
+
+namespace StardewModdingAPI.Framework.Logging
+{
+    /// <summary>A text writer which allows intercepting output.</summary>
+    internal class InterceptingTextWriter : TextWriter
+    {
+        /*********
+        ** Accessors
+        *********/
+        /// <summary>The underlying console output.</summary>
+        public TextWriter Out { get; }
+
+        /// <summary>The character encoding in which the output is written.</summary>
+        public override Encoding Encoding => this.Out.Encoding;
+
+        /// <summary>Whether to intercept console output.</summary>
+        public bool ShouldIntercept { get; set; }
+
+        /// <summary>The event raised when a message is written to the console directly.</summary>
+        public event Action<string> OnMessageIntercepted;
+
+
+        /*********
+        ** Public methods
+        *********/
+        /// <summary>Construct an instance.</summary>
+        /// <param name="output">The underlying output writer.</param>
+        public InterceptingTextWriter(TextWriter output)
+        {
+            this.Out = output;
+        }
+
+        /// <summary>Writes a subarray of characters to the text string or stream.</summary>
+        /// <param name="buffer">The character array to write data from.</param>
+        /// <param name="index">The character position in the buffer at which to start retrieving data.</param>
+        /// <param name="count">The number of characters to write.</param>
+        public override void Write(char[] buffer, int index, int count)
+        {
+            if (this.ShouldIntercept)
+                this.OnMessageIntercepted?.Invoke(new string(buffer, index, count).TrimEnd('\r', '\n'));
+            else
+                this.Out.Write(buffer, index, count);
+        }
+
+        /// <summary>Writes a character to the text string or stream.</summary>
+        /// <param name="ch">The character to write to the text stream.</param>
+        /// <remarks>Console log messages from the game should be caught by <see cref="Write(char[],int,int)"/>. This method passes through anything that bypasses that method for some reason, since it's better to show it to users than hide it from everyone.</remarks>
+        public override void Write(char ch)
+        {
+            this.Out.Write(ch);
+        }
+
+        /// <summary>Releases the unmanaged resources used by the <see cref="T:System.IO.TextWriter" /> and optionally releases the managed resources.</summary>
+        /// <param name="disposing">true to release both managed and unmanaged resources; false to release only unmanaged resources.</param>
+        protected override void Dispose(bool disposing)
+        {
+            this.OnMessageIntercepted = null;
+        }
+    }
+}