Glypha3/Source/Prefs.c

//============================================================================
//----------------------------------------------------------------------------
//									Prefs.c
//----------------------------------------------------------------------------
//============================================================================

// This is a slick little file that I re-use and re-use.  I wrote it to<74>
// seemlessly handle System 6 or System 7 with but a single call.  You need<65>
// to define your own "prefs" struct, but these routines will read and write<74>
// it to the System folder.

#include "Externs.h"
#include <Folders.h>							// Needed for creating a folder.
#include <GestaltEqu.h>							// Needed for the Gestalt() call.
#include <Script.h>								// I can't remember why I needed this.


#define	kPrefCreatorType	'zade'				// Change this to reflect your apps creator.
#define	kPrefFileType		'zadP'				// Change this to reflect your prefs type.
#define	kPrefFileName		"\pGlypha Prefs"	// Change this to reflect the name for your prefs.
#define	kDefaultPrefFName	"\pPreferences"		// Name of prefs folder (System 6 only).
#define kPrefsStringsID		160					// For easy localization.
#define	kPrefsFNameIndex	1					// This one works with the previous constant.


Boolean CanUseFindFolder (void);
Boolean GetPrefsFPath (long *, short *);
Boolean CreatePrefsFolder (short *);
Boolean GetPrefsFPath6 (short *);
Boolean WritePrefs (long *, short *, prefsInfo *);
Boolean WritePrefs6 (short *, prefsInfo *);
OSErr ReadPrefs (long *, short *, prefsInfo *);
OSErr ReadPrefs6 (short *, prefsInfo *);
Boolean DeletePrefs (long *, short *);
Boolean DeletePrefs6 (short *);


//==============================================================  Functions
//--------------------------------------------------------------  CanUseFindFolder

// Returns TRUE if we can use the FindFolder() call (a System 7 nicety).

Boolean CanUseFindFolder (void)
{
	OSErr		theErr;
	long		theFeature;
	
	if (!DoWeHaveGestalt())		// Darn, have to check for Gestalt() first.
		return(FALSE);			// If no Gestalt(), probably don't have FindFolder().
	
	theErr = Gestalt(gestaltFindFolderAttr, &theFeature);
	if (theErr != noErr)		// Use selector for FindFolder() attribute.
		return(FALSE);
								// Now do a bit test specifically for FindFolder().
	if (!BitTst(&theFeature, 31 - gestaltFindFolderPresent))
		return(FALSE);
	else
		return(TRUE);
}

//--------------------------------------------------------------  GetPrefsFPath

// This function gets the file path to the Preferences folder (for System 7).
// It is called only if we can use FindFolder() (see previous function).

Boolean GetPrefsFPath (long *prefDirID, short *systemVolRef)
{
	OSErr		theErr;
									// Here's the wiley FindFolder() call.
	theErr = FindFolder(kOnSystemDisk, kPreferencesFolderType, kCreateFolder, 
		systemVolRef, prefDirID);	// It returns to us the directory and volume ref.<2E>
	if (theErr != noErr)			// Assuming it worked at all!
		return(FALSE);
	
	return(TRUE);
}

//--------------------------------------------------------------  CreatePrefsFolder

// This function won't be necessary for System 7, for System 6 though, it creates<65>
// a folder ("Preferences") in the System folder and returns whether or not it worked.

Boolean CreatePrefsFolder (short *systemVolRef)
{
	HFileParam	fileParamBlock;
	Str255		folderName;
	OSErr		theErr;
										// Here's our localization.  Rather than<61>
										// hard-code the name "Preferences" in the code<64>
										// we pull up the text from a string resource.
	GetIndString(folderName, kPrefsStringsID, kPrefsFNameIndex);
										// Set up a file parameter block.
	fileParamBlock.ioVRefNum = *systemVolRef;
	fileParamBlock.ioDirID = 0;
	fileParamBlock.ioNamePtr = folderName;
	fileParamBlock.ioCompletion = 0L;
										// And create a directory (folder).
	theErr = PBDirCreate((HParmBlkPtr)&fileParamBlock, FALSE);
	if (theErr != noErr)				// See that it worked.
	{
		RedAlert("\pPrefs Creation Error");
		return(FALSE);
	}
	return(TRUE);
}

//-----------------------------------