1 files changed, 27 insertions, 0 deletions

diff --git a/src/WixToolset.Core.Native/IWindowsInstallerValidatorCallback.cs b/src/WixToolset.Core.Native/IWindowsInstallerValidatorCallback.cs
new file mode 100644
index 00000000..f4aff134
--- /dev/null
+++ b/src/WixToolset.Core.Native/IWindowsInstallerValidatorCallback.cs
@@ -0,0 +1,27 @@
+// Copyright (c) .NET Foundation and contributors. All rights reserved. Licensed under the Microsoft Reciprocal License. See LICENSE.TXT file in the project root for full license information.
+
+namespace WixToolset.Core.Native
+{
+    /// <summary>
+    /// Callbacks during validation.
+    /// </summary>
+    public interface IWindowsInstallerValidatorCallback
+    {
+        /// <summary>
+        /// Indicates if the validator callback encountered an error.
+        /// </summary>
+        bool EncounteredError { get; }
+
+        /// <summary>
+        /// Validation blocked by another Windows Installer operation.
+        /// </summary>
+        void ValidationBlocked();
+
+        /// <summary>
+        /// Validation message from an ICE.
+        /// </summary>
+        /// <param name="message">The validation message.</param>
+        /// <returns>True if validation should continue; otherwise cancel the validation.</returns>
+        bool ValidationMessage(ValidationMessage message);
+    }
+}