Developer CD Series 1997 February: Tool Chest/Dev.CD Feb 97 TC.toast/Sample Code/Files/Folder Watching/Folder Watcher FBA ƒ/Sources/FBA.c

C/C++ Source or Header | 1996-02-16 | 5.3 KB | 241 lines | [TEXT/CWIE]

// FBA.c
//
// Folder Watcher FBA by Greg Sutton
// Base code for this FBA by Chris White
// ©Apple Computer Inc 1996, all rights reserved.


    // Includes
#include "FBA.h"
#include "FBAAppleEvents.h"
#include "FBATask.h"
#include "FBALists.h"

#include <GestaltEqu.h>
#include <LowMem.h>
#include <Events.h>
#include <Notification.h>
#include <Resources.h>

#ifdef DEVELOPMENT
    #include <TextEdit.h>
    #include <Dialogs.h>
#endif


    // Prototypes
static Boolean            HasFullExtFSDispatching( void );
static Boolean            HasProcessManager( void );
static void                InitCycleTime( void );
static unsigned long    GetResourceCycleTime( void );

static void                CheckEventQueue( void );

static void                Notify( StringPtr notice, Boolean fFatal );

static pascal void        MyResponse( NMRecPtr n );


    // Globals
#if !defined(THINK_C) && !defined(__MWERKS__)
        QDGlobals       qd;
#endif

short             gQuit = false;
unsigned long    gCycleTime;            // Time requested to check all folders

    // Constants
const unsigned long    DefaultCycleTime = 30;    // Default cycle time for all folders
                                            // to be checked in seconds.
const short            StackSize = 32;            // Default stack size for an FBA is 2K
                                            // Set StackSize to the K wanted.


void    main( void )
{
    long            numBytes,
                    newLimit;
    Boolean            fQuit;

                // set the stack size
     numBytes = StackSize * 1024;
                // calculate the absolute memory byte by
                // offsetting the stack base
     newLimit = (long)LMGetCurStackBase( ) - numBytes;
                // check that there is enough memory for stack increase
     if ((long)GetApplLimit( ) > newLimit)
          SetApplLimit( (Ptr)newLimit );

    InitGraf( &qd.thePort );

#ifdef DEVELOPMENT    // See 'FBA.h' for #define
    InitFonts( );
    InitWindows( );
    InitMenus( );
    TEInit( );
    InitDialogs( 0L );
    InitCursor( );
#endif

    if ( noErr != InitAppleEvents( ) )
        Notify( "\pFolder Watcher failed to initialize Apple events", kFatalErr );

    if ( ! HasFullExtFSDispatching( ) )
        Notify( "\pFolder Watcher failed due to limited CatSearch", kFatalErr );

    if ( ! HasProcessManager( ) )
        Notify( "\pFolder Watcher failed due to no Process Manager", kFatalErr );

    if ( ! InitTask( ) )
        Notify( "\pFolder Watcher failed due to bad task initialization", kFatalErr );

    InitWatchFolders( );
    InitCycleTime( );

    fQuit = gQuit;                        // Initialization may set gQuit to true

    while ( ! fQuit )
    {
        CheckEventQueue( );

        if ( gQuit )                    // We want to quit
            fQuit = CanQuitTask( );        // Check that our task can quit now
    }
}


static void    CheckEventQueue( void )
{
    long                    sleepTicks = 1;    // First time through return from
                                            //  WaitNextEvent() as quick as possible.
    EventRecord             anEvent;
    OSErr                    err;

    WaitNextEvent( highLevelEventMask, &anEvent, sleepTicks, NULL );

    switch ( anEvent.what )
    {
        case kHighLevelEvent :
            err = DoAppleEvent( &anEvent );
        break;
    }

        // Call background task no matter if event
        //  is a high level or null event.
    sleepTicks = DoBackgroundTask( );        // Do our background task or return
                                            //  an updated sleep time.
}


// See if File Manager will pass CatSearch requests to external file systems.

static Boolean    HasFullExtFSDispatching( void )
{
    long        response;
    Boolean        result = false;

    if ( noErr == Gestalt( gestaltFSAttr, &response ) )
        result = ((response & (1L << gestaltFullExtFSDispatching)) != 0);

    return result;
}


// Check that we have the process manager

static Boolean    HasProcessManager( void )
{
    long        response;
    Boolean        result = false;

    if ( noErr == Gestalt( gestaltOSAttr, &response ) )
        result = true;

    return result;
}


static void    InitCycleTime( void )
{
    gCycleTime = GetResourceCycleTime();
}


unsigned long    GetCycleTime( void )
{
    return gCycleTime;
}


// If there are 'Cycl' resources then use the first of these for the sleep time.
// Otherwise use the default cycle time. The time is supposed to be in seconds.

static unsigned long GetResourceCycleTime( void )
{
    short            count;
    Handle             aHandle;
    unsigned long    result = DefaultCycleTime;

    count = Count1Resources( kCycleTimeResource );
    if ( count )
    {
        aHandle = Get1IndResource( kCycleTimeResource, 1 );
        if ( aHandle )
        {
            result = *(unsigned long *) *aHandle;
            ReleaseResource( aHandle );
        }
    }

    return result;
}



static pascal void MyResponse ( NMRecPtr n )
{
    DisposePtr ( (Ptr) n->nmStr );
    NMRemove ( n );
    if ( ! n->nmRefCon )        // true if error was fatal
        DisposePtr ( (Ptr) n );
    else
        n->nmRefCon = 0L;

    return;
}


// Use the Notification manager to display a message.
// Pass true to fFatal if the applcation is to quit afterwards.

void    Notify( StringPtr notice, Boolean fFatal )
{
    // remember, no user interface to play with
    NMRecPtr    notePtr;
    OSErr        err;

    notePtr = (NMRecPtr) NewPtr ( sizeof ( NMRec ) );
    if ( MemError ( ) )
        return;

    notePtr->qType = nmType;            // standard queue type for NM
    notePtr->nmMark = 0;                // background only
    notePtr->nmIcon = 0L;
    notePtr->nmSound = (Handle) -1L;    // use system alert snd
    notePtr->nmStr = NULL;
    notePtr->nmStr = (StringPtr) NewPtr ( sizeof ( Str255 ) );
    BlockMoveData( notice, notePtr->nmStr, notice[0] + 1 );
    notePtr->nmResp = NewNMProc( MyResponse );
    notePtr->nmRefCon = fFatal;

    err = NMInstall ( notePtr );
    if ( err == noErr && fFatal )
    {
        while ( notePtr->nmRefCon )
            CheckEventQueue( );
        gQuit = true;
    }

    return;
}