Add precompiled header to inherited C++ code

Adds a "precompiled_header" property to UserClass, fills in the value
from Project properties, and then uses a"precompiled_header" template
to generate the precompiled header (if the user supplied one).

output/xml/default.cppcode

@@ -304,6 +304,12 @@
 		<template name="event_handler_comment">
 			// Handlers for $basename events.
 		</template>
+		<template name="precompiled_header">
+			#ifnotnull $precompiled_header
+			@{
+				$precompiled_header
+			@}
+		</template>
 		<template name="header_include">@#include &quot;$gen_file.h&quot;</template>
 		<template name="source_include">@#include &quot;$file.h&quot;</template>
 		<template name="class_decl">

output/xml/default.xml

@@ -227,6 +227,7 @@
     <property name="file" type="text"/>
     <property name="gen_file" type="text"/>
     <property name="type" type="text"/>
+    <property name="precompiled_header" type="text"/>
   </objectinfo>
 
   <objectinfo class="AUI" type="interface">

src/codegen/cppcg.cpp

@@ -457,6 +457,13 @@ void CppCodeGenerator::GenerateInheritedClass( PObjectBase userClasses, PObjectB
 	m_header->Indent();
 
 	// Start source file
+	code = GetCode(userClasses, wxT("precompiled_header"));
+    if (!code.empty())
+    {
+        m_source->WriteLn(code);
+        m_source->WriteLn(wxEmptyString);
+    }
+
 	code = GetCode( userClasses, wxT("source_include") );
 	m_source->WriteLn( code );
 	m_source->WriteLn( wxEmptyString );

src/rad/appdata.cpp

@@ -2367,6 +2367,7 @@ void ApplicationData::GenerateCode( bool panelOnly, bool noDelayed )
 	NotifyCodeGeneration( panelOnly, !noDelayed );
 }
 
+// Properties in ../output/xml/default.xml and code templates in ../output/xml/default.cppcode
 void ApplicationData::GenerateInheritedClass( PObjectBase form, wxString className, wxString path, wxString file )
 {
 	try
@@ -2391,8 +2392,9 @@ void ApplicationData::GenerateInheritedClass( PObjectBase form, wxString classNa
 		PProperty fileProp = obj->GetProperty( wxT( "file" ) );
 		PProperty genfileProp = obj->GetProperty( wxT( "gen_file" ) );
 		PProperty typeProp = obj->GetProperty( wxT( "type" ) );
+		PProperty typePCH = obj->GetProperty(wxT("precompiled_header"));
 
-		if ( !( baseNameProp && nameProp && fileProp && typeProp && genfileProp ) )
+		if (!(baseNameProp && nameProp && fileProp && typeProp && genfileProp && typePCH))
 		{
 			wxLogWarning( wxT("Missing Property") );
 			return;
@@ -2426,6 +2428,12 @@ void ApplicationData::GenerateInheritedClass( PObjectBase form, wxString classNa
 		genfileProp->SetValue( genFile.GetFullPath() );
 		typeProp->SetValue( form->GetClassName() );
 
+        PProperty pPCH = project->GetProperty(wxT("precompiled_header"));
+        if (pPCH)
+        {
+            typePCH->SetValue(pPCH->GetValue());
+        }
+
 		// Determine if Microsoft BOM should be used
 		bool useMicrosoftBOM = false;
 		PProperty pUseMicrosoftBOM = project->GetProperty( _("use_microsoft_bom") );