reinit.pas translated to C++ - delphi

Question

I have semi-successfully translated reinit.pas to C++ to use it in my project. The part where int __fastcall LoadNewResourceModule(LCID locale); is called works fine, in fact I can even call it prior to Application->Initialize() and it will load the proper language at startup. However, the part that calls void __fastcall ReinitializeForms(void); does not work, and gives a runtime error:
Resource TControl not found
Here is the dirty version of .cpp, and .h, I've yet to clean it up and comment it properly, at this point the thing just has to work fully. Please help me sort this out.
//---------------------------------------------------------------------------
#include <System.Classes.hpp>
#include <SysInit.hpp>
#include <Vcl.Forms.hpp>
#pragma hdrstop
#include "reinit.h"
//---------------------------------------------------------------------------
#pragma package(smart_init)
class TAsInheritedReader : public TReader
{
public:
void __fastcall ReadPrefix(TFilerFlags &_flags, int &_aChildPos);
inline __fastcall TAsInheritedReader(TStream* Stream, int BufSize) : TReader(Stream, BufSize) {}
};
//---------------------------------------------------------------------------
void __fastcall TAsInheritedReader::ReadPrefix(TFilerFlags &_flags, int &_aChildPos)
{
TReader::ReadPrefix(_flags, _aChildPos);
_flags = _flags << ffInherited;
}
//---------------------------------------------------------------------------
int __fastcall SetResourceHInstance(int _newInstance)
{
PLibModule CurModule = LibModuleList;
while(CurModule != NULL) {
if (reinterpret_cast<void*>(CurModule->Instance) == HInstance) {
if (CurModule->ResInstance != CurModule->Instance) {
FreeLibrary(reinterpret_cast<HMODULE>(CurModule->ResInstance));
CurModule->ResInstance = _newInstance;
return _newInstance;
}
CurModule = CurModule->Next;
}
}
return 0;
}
//---------------------------------------------------------------------------
int __fastcall LoadNewResourceModule(LCID locale)
{
wchar_t FileName[260];
PChar P;
wchar_t LocaleName[4];
int NewInst = 0;
GetModuleFileName(HInstance, FileName, sizeof(FileName));
GetLocaleInfo(locale, LOCALE_SABBREVLANGNAME, LocaleName, sizeof(LocaleName));
P = PChar(&FileName) + lstrlen(FileName);
while((*P != L'.') && (P != reinterpret_cast<PChar>(&FileName))) {
--P;
}
if (P != reinterpret_cast<PChar>(&FileName)) {
++P;
if (LocaleName[0] != L'\0') {
NewInst = reinterpret_cast<int>(LoadLibraryEx(FileName, 0, LOAD_LIBRARY_AS_DATAFILE));
if (NewInst == 0) {
LocaleName[2] = L'\0';
lstrcpy(P, LocaleName);
NewInst = reinterpret_cast<int>(LoadLibraryEx(FileName, 0, LOAD_LIBRARY_AS_DATAFILE));
}
}
}
if (NewInst != 0) {
return SetResourceHInstance(NewInst);
}
return 0;
}
//---------------------------------------------------------------------------
bool __fastcall InternalReloadComponentRes(const String ResName, THandle HInst, TComponent* Instance)
{
//TResourceStream* ResStream = new TResourceStream;
//TAsInheritedReader* AsInheritedReader = new TAsInheritedReader;
if (HInst == 0) {
HInst = reinterpret_cast<THandle>(HInstance);
}
THandle HRsrc = reinterpret_cast<THandle>(FindResource((HMODULE)HInst, (LPCWSTR)ResName.w_str(), (LPCWSTR)RT_RCDATA));
if(HRsrc != 0) {
return false;
}
/* THIS IS THE OFFENDING LINE OF CODE THAT THROWS EXCEPTION
I checked HInst, it is not 0...
ResName = "TControl"
and it throws exception here for some reason
saying resource tcontrol not found
*/
TResourceStream* ResStream = new TResourceStream(HInst, ResName, RT_RCDATA);
try {
TAsInheritedReader* AsInheritedReader = new TAsInheritedReader(ResStream, 4096);
try {
Instance = AsInheritedReader->ReadRootComponent(Instance);
} __finally {
delete AsInheritedReader;
}
}
__finally {
delete ResStream;
}
return true;
}
//---------------------------------------------------------------------------
bool __fastcall InitComponent(TClass ClassType)
{
if ((ClassType->ClassName() == "TComponent") || (ClassType->ClassName() == "RootAncestor")) {
return false;
}
InitComponent(ClassType->ClassParent());
return InternalReloadComponentRes(ClassType->ClassName(), FindResourceHInstance(FindClassHInstance(ClassType)), (TComponent*)&ClassType);
}
//---------------------------------------------------------------------------
bool __fastcall ReloadInheritedComponent(TComponent* Instance)
{
return InitComponent(Instance->ClassType());
}
//---------------------------------------------------------------------------
void __fastcall ReinitializeForms(void)
{
for(int i=0; i<Screen->FormCount-1; i++) {
ReloadInheritedComponent(Screen->Forms[i]);
}
}
#ifndef _reinit_h
#define _reinit_h
#include <windows.h>
extern int __fastcall LoadNewResourceModule(LCID locale);
extern void __fastcall ReinitializeForms(void);
#endif

Answer 1

You don't really need to translate the code at all. You can use Delphi .pas units as-is in C++Builder projects. Simply add the .pas file to your project and compile it, the IDE will generate a .hpp file that you can then #include in your C++ code.
In any case, your translation is not correct in many places.
For instance, the original code wasn't written with Unicode in mind, but you are using Unicode strings in your code. Expressions like sizeof(FileName) and sizeof(LocaleName) are the wrong buffer sizes to pass to the Win32 APIs being used, which can potentially allow buffer overflows. The code was clearly expecting BYTE-sized narrow characters, not WORD-sized wide characters.
It also looks like the original code was not written with 64-bit in mind, either. It is using 32-bit integers in places where 64-bit integers would be needed (for resource handles, etc).
So, the original code needs some updating to support modern systems properly.
But also, your translation of InitComponent() is wrong. It is using strings where the original code is using metaclass references instead, and it is passing the wrong value in the last parameter of InternalReloadComponentRes(), which you have not even declared correctly.
And also, your loop in ReinitializeForms() is skipping the last TForm in the Screen->Forms[] array.
Now, that all being said, try something more like this:
ReInit.h
#ifndef REINIT_H
#define REINIT_H
void __fastcall ReinitializeForms();
NativeUInt __fastcall LoadNewResourceModule(unsigned long Locale);
#endif
ReInit.cpp
#include "ReInit.h"
#include <Windows.hpp>
#include <SysInit.hpp>
#include <SysUtils.hpp>
#include <Classes.hpp>
#include <Forms.hpp>
#include <memory>
class TAsInheritedReader : public TReader
{
public:
void __fastcall ReadPrefix(TFilerFlags &Flags, int &AChildPos) override;
};
void __fastcall TAsInheritedReader::ReadPrefix(TFilerFlags &Flags, int &AChildPos)
{
TReader::ReadPrefix(Flags, AChildPos);
Flags << ffInherited;
}
NativeUInt __fastcall SetResourceHInstance(NativeUInt NewInstance)
{
PLibModule CurModule = LibModuleList;
while (CurModule)
{
if (CurModule->Instance == HInstance)
{
if (CurModule->ResInstance != CurModule->Instance)
::FreeLibrary(reinterpret_cast<HMODULE>(CurModule->ResInstance));
CurModule->ResInstance = NewInstance;
return NewInstance;
}
CurModule = CurModule->Next;
}
return 0;
}
NativeUInt __fastcall LoadNewResourceModule(unsigned long Locale)
{
WCHAR FileName[MAX_PATH+1] = {};
::GetModuleFileNameW(reinterpret_cast<HMODULE>(HInstance), FileName, MAX_PATH+1);
WCHAR LocaleName[5] = {};
::GetLocaleInfoW(Locale, LOCALE_SABBREVLANGNAME, LocaleName, 5);
LPWSTR P = &FileName[lstrlenW(FileName)];
while ((*P != L'.') && (P != FileName)) --P;
HMODULE NewInst = nullptr;
if (P != FileName)
{
++P;
if (LocaleName[0] != L'\0')
{
// Then look for a potential language/country translation
lstrcpyW(P, LocaleName);
NewInst = LoadLibraryEx(FileName, 0, LOAD_LIBRARY_AS_DATAFILE);
if (!NewInst)
{
// Finally look for a language only translation
LocaleName[2] = L'\0';
lstrcpyW(P, LocaleName);
NewInst = LoadLibraryEx(FileName, 0, LOAD_LIBRARY_AS_DATAFILE);
}
}
}
if (NewInst)
return SetResourceHInstance(reinterpret_cast<NativeUInt>(NewInst));
return 0;
}
bool __fastcall InternalReloadComponentRes(const UnicodeString &ResName, NativeUInt HInst, TComponent* &Instance)
{
// avoid possible EResNotFound exception
if (HInst == 0) HInst = HInstance;
HRSRC HRsrc = FindResourceW(reinterpret_cast<HMODULE>(HInst), ResName.c_str(), MAKEINTRESOURCEW(10)/*RT_RCDATA*/);
if (!HRsrc) return false;
auto ResStream = std::make_unique<TResourceStream>(HInst, ResName, MAKEINTRESOURCEW(10)/*RT_RCDATA*/);
auto AsInheritedReader = std::make_unique<TAsInheritedReader>(ResStream.get(), 4096);
Instance = AsInheritedReader->ReadRootComponent(Instance);
return true;
}
bool __fastcall ReloadInheritedComponent(TComponent *Instance, TClass RootAncestor)
{
const auto InitComponent = [&Instance,RootAncestor](TClass ClassType) -> bool
{
auto InitComponent_impl = [&Instance,RootAncestor](TClass ClassType, auto& InitComponent_ref) -> bool
{
if ((ClassType == __classid(TComponent)) || (ClassType == RootAncestor)) return false;
bool Result = InitComponent_ref(ClassType->ClassParent(), InitComponent_ref);
return InternalReloadComponentRes(ClassType->ClassName(), FindResourceHInstance(FindClassHInstance(ClassType)), Instance) || Result;
}
return InitComponent_impl(ClassType, InitComponent_impl);
}
return InitComponent(Instance->ClassType());
}
void __fastcall ReinitializeForms()
{
int Count = Screen->FormCount;
for(int i = 0; i < Count; ++i)
{
ReloadInheritedComponent(Screen->Forms[I], __classid(TForm));
}
}