Add C code generator GenerateClassEvents for common event handling.

src/Generator/Generators/C/CCodeGenerator.cs

@@ -312,6 +312,18 @@ namespace CppSharp.Generators.C
             return true;
         }
 
+        public virtual void GenerateClassEvents(Class @class)
+        {
+            Indent();
+
+            foreach (var @event in @class.Events)
+            {
+                if (!@event.IsGenerated) continue;
+                @event.Visit(this);
+            }
+
+            Unindent();
+        }
         public virtual string GetMethodIdentifier(Function function,
             TypePrinterContextKind context = TypePrinterContextKind.Managed)
         {

src/Generator/Generators/C/CppHeaders.cs

@@ -490,7 +490,7 @@ namespace CppSharp.Generators.Cpp
             return true;
         }
 
-        public void GenerateClassEvents(Class @class)
+        public override void GenerateClassEvents(Class @class)
         {
             Indent();
 

src/Generator/Generators/CLI/CLIHeaders.cs

@@ -462,7 +462,7 @@ namespace CppSharp.Generators.CLI
             PopBlock();
         }
 
-        public void GenerateClassEvents(Class @class)
+        public override void GenerateClassEvents(Class @class)
         {
             foreach (var @event in @class.Events)
             {

src/Generator/Generators/CodeGenerator.cs

@@ -398,7 +398,7 @@ namespace CppSharp.Generators
 
         public virtual bool VisitEvent(Event @event)
         {
-            throw new NotImplementedException();
+            return true;
         }
 
         public virtual bool VisitProperty(Property property)

src/Generator/Generators/QuickJS/QuickJSHeaders.cs

@@ -47,5 +47,10 @@ namespace CppSharp.Generators.Cpp
 
             return true;
         }
+
+        public override bool VisitEvent(Event @event)
+        {
+            return true;
+        }
     }
 }