#include "cPreferencesFile.h"


// ===========================================================================
//	cPreferencesFile.cpp	   Version 1.0	©1998 Joakim Braun All rights reserved.
// ===========================================================================
//
//	CONTENTS:		cPreferencesFile is a subclass of the Metrowerks PowerPlant LFile class
//				with functions to read and write resources in preferences files.

//	REQUIRES:		PowerPlant LFile.

//	HOW TO USE:		Instantiate a cPreferencesFile and use it for getting and setting resources:
//					
//					cPreferencesFile	myPrefs("\pMy preferences", kPrefsFileCreator, kPrefsFileType, true);

//					Handle aHandle = myPrefs.GetPrefsResource(kMyResType, kMyResNum);

//	cPreferencesFile is free for any and all use. 
//	Do not distribute modified source code under my name.

//	No support promised, no liability accepted. Provided "as is". 
//	That said, I can be reached at braun@swipnet.se.
//	Latest version at http://home4.swipnet.se/~w-41308/

//	Change history:
//	1.0	September 11, 1998		First release


// -----------------------------------------------------------------
//	Ä	Constructor 
// -----------------------------------------------------------------
//	Try to locate preferences file. If it doesn't exist and inCreateMissingFile is true, create it.

cPreferencesFile:: cPreferencesFile(Str255 inPrefsFileName, OSType inPrefsFileCreator, OSType inPrefsFileType, Boolean inCreateMissingFile){
 	
 	if(MakeSelfFileSpec(inPrefsFileName) == fnfErr && inCreateMissingFile){
 	 		
 		try{
 			CreateNewFile(inPrefsFileCreator, inPrefsFileType);
 		}
 		catch(...){
 			
 			// Don't throw exceptions from constructors
 		}
 	}
 }


// -----------------------------------------------------------------
//	Ä	MakeSelfFileSpec() 
// -----------------------------------------------------------------
//	Try to create FSSpec for preferences file, store it in mMacFileSpec

OSErr cPreferencesFile::MakeSelfFileSpec(Str255 inPrefsFileName){
	
	long	prefsDirID 	= 0;
	short 	prefsVRefNum 	= 0;
	OSErr 	result 		= ::FindFolder(kOnSystemDisk, kPreferencesFolderType, true, &prefsVRefNum, &prefsDirID);
	
	if (result != noErr)
		return result;
		
	return ::FSMakeFSSpec(prefsVRefNum, prefsDirID, inPrefsFileName, &mMacFileSpec);	
}

// -----------------------------------------------------------------
//	Ä	GetPrefsResource() 
// -----------------------------------------------------------------
//	Try to get handle of a given resource. Throw exception on error or NULL handle if inThrowIfError is true.
//	Otherwise, return handle, whether it's NULL or not.

Handle 	cPreferencesFile:: GetPrefsResource(OSType inResType, ResIDT inResNum, Boolean inThrowIfError){
	
	Int16	currResFile 	= ::CurResFile();
	Int16	resForkID 	= -1;
	Handle 	result 		= NULL;
	
	try{
	
		resForkID = OpenResourceFork(fsRdPerm);
		
		result = ::Get1Resource(inResType, inResNum);
		
		ThrowIfResError_();
		ThrowIfNil_(result);
		
		::DetachResource(result);
		
		CloseResourceFork();
		::UseResFile(currResFile);
	}
	catch(...){
		
		CloseResourceFork();
		::UseResFile(currResFile);
		
		if(inThrowIfError)
			throw;
	}
	
	return result;
}

// -----------------------------------------------------------------
//	Ä	SetPrefsResource() 
// -----------------------------------------------------------------
//	Set resource data of a given resource to data provided.
//	Throw exception on error if inThrowIfError is true,
//	otherwise return error code.
//	inResDataH will be turned into a resource handle by this operation.
//	If inAdoptHandle is true, deletes inResDataH.

OSErr 	cPreferencesFile:: SetPrefsResource(Handle inResDataH, OSType inResType, ResIDT inResNum, Str255 inResName, Boolean inAdoptHandle, Boolean inThrowIfError){
	
	OSErr	result			= noErr;
	Handle 	resHandle 		= NULL;
	Int16	currResFile 		= ::CurResFile();
	Int16	resForkID 		= -1;
		
	try{
	
		resForkID = OpenResourceFork(fsRdWrPerm);
					
		// Delete existing resource
		resHandle = ::Get1Resource(inResType, inResNum);
		
		if(resHandle){
			
			::RemoveResource(resHandle);
			::DisposeHandle(resHandle);
		}
		
		resHandle = inResDataH;
		
		// Add new resource
		::AddResource(resHandle, inResType, inResNum, inResName);
		result = ::ResError();
		ThrowIfOSErr_(result);
		
		::UpdateResFile(resForkID);
		result = ::ResError();
		ThrowIfOSErr_(result);
		
		if(inAdoptHandle)
			::ReleaseResource(resHandle);
		
		CloseResourceFork();
		::UseResFile(currResFile);
	}
	catch(...){
		
		CloseResourceFork();
		::UseResFile(currResFile);
		
		if(inThrowIfError)
			throw;
	}
	
	return result;
}

// -----------------------------------------------------------------
//	Ä	SetPrefsResource() 
// -----------------------------------------------------------------
//	Same as above, except takes pointer and Int32 instead of handle

OSErr 	cPreferencesFile:: SetPrefsResource(void* inData, Int32 inDataLength, OSType inResType, ResIDT inResNum, Str255 inResName, Boolean inAdoptHandle, Boolean inThrowIfError){
	
	Handle 	resHandle = ::NewHandle(inDataLength);
	OSErr	result = noErr;
	
	if(resHandle){
		
		::BlockMove(inData, &**resHandle, inDataLength);
		result = SetPrefsResource(resHandle, inResType, inResNum, inResName, true, inThrowIfError);
	}
	else
		result = memFullErr;
		
	if(inThrowIfError)
		ThrowIfOSErr_(result);
	
	return result;
}