From f33ca7db8018e9a827cbce71a51cfd2616bfdda4 Mon Sep 17 00:00:00 2001
From: Joao Matos <joao@tritao.eu>
Date: Sat, 20 Feb 2021 20:41:33 +0000
Subject: [PATCH] Add new pass to convert C++ FastDelegate types into CppSharp
 delegates.

---
 src/Generator/Driver.cs                       |  1 +
 .../Passes/FastDelegateToDelegatesPass.cs     | 75 +++++++++++++++++++
 2 files changed, 76 insertions(+)
 create mode 100644 src/Generator/Passes/FastDelegateToDelegatesPass.cs

diff --git a/src/Generator/Driver.cs b/src/Generator/Driver.cs
index 85822f49..9940c4c9 100644
--- a/src/Generator/Driver.cs
+++ b/src/Generator/Driver.cs
@@ -254,6 +254,7 @@ namespace CppSharp
 
             TranslationUnitPasses.AddPass(new FlattenAnonymousTypesToFields());
             TranslationUnitPasses.AddPass(new CleanInvalidDeclNamesPass());
+            TranslationUnitPasses.AddPass(new FastDelegateToDelegatesPass());
             TranslationUnitPasses.AddPass(new FieldToPropertyPass());
             TranslationUnitPasses.AddPass(new CheckIgnoredDeclsPass());
             TranslationUnitPasses.AddPass(new CheckFlagEnumsPass());
diff --git a/src/Generator/Passes/FastDelegateToDelegatesPass.cs b/src/Generator/Passes/FastDelegateToDelegatesPass.cs
new file mode 100644
index 00000000..1ed83421
--- /dev/null
+++ b/src/Generator/Passes/FastDelegateToDelegatesPass.cs
@@ -0,0 +1,75 @@
+using System;
+using System.Linq;
+using CppSharp.AST;
+using CppSharp.AST.Extensions;
+using CppSharp.Passes;
+using Type = CppSharp.AST.Type;
+
+namespace CppSharp
+{
+    public class FastDelegateToDelegatesPass : TranslationUnitPass
+    {
+        static bool IsFastDelegate(Type type)
+        {
+            if (!type.TryGetClass(out var @class))
+                return false;
+
+            return @class.Name == "FastDelegate";
+        }
+
+        public override bool VisitTranslationUnit(TranslationUnit unit)
+        {
+            if (unit.FileNameWithoutExtension == "FastDelegates" &&
+                unit.Namespaces.Any(n => n.Name == "fastdelegate"))
+            {
+                unit.GenerationKind = GenerationKind.None;
+                return true;
+            }
+
+            return base.VisitTranslationUnit(unit);
+        }
+
+        public override bool VisitFieldDecl(Field field)
+        {
+            if (!IsFastDelegate(field.Type))
+                return false;
+
+            var templateSpecType = field.Type as TemplateSpecializationType;
+            if (templateSpecType == null)
+                throw new Exception("Expected a template specialization type as delegate type");
+
+            var functionType = templateSpecType.Arguments.First().Type.Type as FunctionType;
+            if (functionType == null)
+                throw new Exception("Expected a function type as inner delegate type");
+
+            var @class = field.Namespace as Class;
+            var @event = new Event
+            {
+                Name = field.Name,
+                Namespace = @class,
+                QualifiedType = new QualifiedType(functionType),
+                GenerationKind = GenerationKind.Generate
+            };
+
+            int paramIndex = 0;
+            foreach (var param in functionType.Parameters)
+            {
+                var newParam = new Parameter(param)
+                {
+                    GenerationKind = GenerationKind.Generate,
+                };
+
+                if (string.IsNullOrEmpty(newParam.Name))
+                    newParam.Name = $"arg{paramIndex}";
+
+                @event.Parameters.Add(newParam);
+                paramIndex++;
+            }
+
+            @class.Declarations.Add(@event);
+            field.GenerationKind = GenerationKind.None;
+
+            return base.VisitFieldDecl(field);
+        }
+    }
+}
\ No newline at end of file