/*

    File:       MoreResources.c

    Contains:   Resource Manager utilities

    Written by: Quinn

    Copyright:  Copyright © 2000 by Apple Computer, Inc., all rights reserved.

                You may incorporate this Apple sample source code into your program(s) without

                restriction. This Apple sample source code has been provided "AS IS" and the

                responsibility for its operation is yours. You are not permitted to redistribute

                this Apple sample source code as "Apple sample source code" after having made

                changes. If you're going to re-distribute the source, we require that you make

                it clear in the source that the code was descended from Apple sample source

                code, but that you've made changes.

    Change History (most recent first):

         <2>      3/9/00    gaw     API changes for MoreAppleEvents

         <1>      6/3/00    Quinn   First checked in.

*/

/////////////////////////////////////////////////////////////////

// MoreIsBetter Setup

#include "MoreSetup.h"

// Mac OS Interfaces

#include <Resources.h>

// MIB Prototypes

// Our Prototypes

#include "MoreResources.h"

/////////////////////////////////////////////////////////////////

/*

    Returns ResError() or, if itÕs noErr and p is nil,

    returns resNotFound.  The rationale for this routine

    is that, under some documented circumstances, GetResource

    can return nil but not set ResErr.

    pResHdl     input:  a resource handle

    RESULT CODES

    ____________

    Same as results for ResError

    ____________

*/

pascal OSErr MoreResError(const void *pResHdl)

    // See comment in interface part.

{

    OSErr err;

    err = ResError();

    if ((err == noErr) && (pResHdl == nil)) {

        err = resNotFound;

    }

    return err;

}// end MoreResError

/******************************************************************************

    Given an FSSpec to a file, open it with write permission.

    Check to make sure that the file reference returned actually has write

    permission and return an error if it doesn't.

    pFSSpec     input:  The file to be opened.

    pRefNum     output: File reference for the newly opened file.

    RESULT CODES

    ____________

        Same as results for FSpOpenResFile()

    ____________

*/

pascal OSErr MoreResOpenResFileForWrite(const FSSpec *pFSSpec, SInt16 *pRefNum)

{

    OSErr       anErr = noErr;

    *pRefNum = FSpOpenResFile( pFSSpec, fsRdWrPerm );

    if ( *pRefNum == -1 )

    {

        anErr = ResError();

    }

    else    //  Got it open, but can it be written to?

    {

        if ( ! MoreResIsResFileRefNumWritable( *pRefNum ) )

        {

            anErr = permErr;

            CloseResFile( *pRefNum );

            *pRefNum = -1;

        }

    }

    return anErr;

}//end MoreResOpenResFileForWrite

/******************************************************************************

    Utility routine to check that a file opened with read/write permission

    does in fact have read/write permission.

    It is possible to get a read-only file reference for a resource file that has

    been opened with read/write permission.  This routine verify that a file open

    with read/write permission does in fact have write permission.

    pRefNum     input:  File reference number for file to be checked.

    RESULT CODES

    ____________

        true        The resource file was really opened with write permission

        false       It wasn't

    ____________

*/

pascal Boolean MoreResIsResFileRefNumWritable(const SInt16 pRefNum)

{

    FCBPBRec    fcbPB;

    Boolean     result = false;

    fcbPB.ioNamePtr = nil;

    fcbPB.ioVRefNum = 0;

    fcbPB.ioRefNum = pRefNum;

    fcbPB.ioFCBIndx = 0;

    if ( PBGetFCBInfoSync( &fcbPB ) == noErr )

    {

        result = ( (fcbPB.ioFCBFlags & kioFCBWriteMask) != 0 );

    }

    return result;

}//end MoreResIsResFileRefNumWritable

//******************************************************************************