/*

    File:       Sample.c

    Contains:   This is just a hacked version of CSample.  Ignore any bits referring to the

                traffic lights, etc.

    Written by:     

    Copyright:  Copyright © 1999 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):

                8/9/1999    Karl Groethe    Updated for Metrowerks Codewarror Pro 2.1

                9/13/96     PG              brought code into 20th century.

*/

#include <Types.h>

#include <Resources.h>

#include <QuickDraw.h>

#include <Fonts.h>

#include <Events.h>

#include <Windows.h>

#include <Menus.h>

#include <TextEdit.h>

#include <Dialogs.h>

#include <Desk.h>

#include <ToolUtils.h>

#include <Memory.h>

#include <SegLoad.h>

#include <Files.h>

#include <OSUtils.h>

#include <OSEvents.h>

#include <DiskInit.h>

#include <Packages.h>

#include <Traps.h>

#include <Limits.h>

#include <Processes.h>

#include "Sample.h"     /* bring in all the #defines for Sample */

#include "Password.h"

/* The "g" prefix is used to emphasize that a variable is global. */

/* GMac is used to hold the result of a SysEnvirons call. This makes

   it convenient for any routine to check the environment. */

SysEnvRec   gMac;               /* set up by Initialize */

/* GHasWaitNextEvent is set at startup, and tells whether the WaitNextEvent

   trap is available. If it is false, we know that we must call GetNextEvent. */

Boolean     gHasWaitNextEvent;  /* set up by Initialize */

/* GInBackground is maintained by our osEvent handling routines. Any part of

   the program can check it to find out if it is currently in the background. */

Boolean     gInBackground;      /* maintained by Initialize and DoEvent */

/* The following globals are the state of the window. If we supported more than

   one window, they would be attatched to each document, rather than globals. */

/* Define HiWrd and LoWrd macros for efficiency. */

#define HiWrd(aLong)    (((aLong) >> 16) & 0xFFFF)

#define LoWrd(aLong)    ((aLong) & 0xFFFF)

/* Define TopLeft and BotRight macros for convenience. Notice the implicit

   dependency on the ordering of fields within a Rect */

#define TopLeft(aRect)  (* (Point *) &(aRect).top)

#define BotRight(aRect) (* (Point *) &(aRect).bottom)

#ifdef applec

    /* This routine is part of the MPW runtime library. This external

        reference to it is done so that we can unload its segment, %A5Init. */

    extern void _DataInit();

#endif

/*  Display an alert that tells the user an error occurred, then exit the program.

    This routine is used as an ultimate bail-out for serious errors that prohibit

    the continuation of the application. Errors that do not require the termination

    of the application should be handled in a different manner. Error checking and

    reporting has a place even in the simplest application. The error number is used

    to index an 'STR#' resource so that a relevant message can be displayed. */

#pragma segment Main

static void AlertUser(void)

{

    short       itemHit;

    SetCursor(&qd.arrow);

    itemHit = Alert(rUserAlert, nil);

    ExitToShell();

} /* AlertUser */

/*  Check to see if a given trap is implemented. This is only used by the

    Initialize routine in this program, so we put it in the Initialize segment.

    The recommended approach to see if a trap is implemented is to see if

    the address of the trap routine is the same as the address of the

    Unimplemented trap. */

/*  1.02 - Needs to be called after call to SysEnvirons so that it can check

    if a ToolTrap is out of range of a pre-MacII ROM. */

#pragma segment Initialize

// check to see if a given trap is implemented. We follow IM VI-3-8.

static Boolean TrapAvailable(short theTrap)

{

    TrapType theTrapType;

    short numToolboxTraps;

    if ((theTrap & 0x0800) > 0)

        theTrapType = ToolTrap;

    else

        theTrapType = OSTrap;

    if (theTrapType == ToolTrap)

    {

        theTrap = theTrap & 0x07ff;

        if (NGetTrapAddress(_InitGraf, ToolTrap) == NGetTrapAddress(0xaa6e, ToolTrap))

            numToolboxTraps = 0x0200;

        else

            numToolboxTraps = 0x0400;

        if (theTrap >= numToolboxTraps)

            theTrap = _Unimplemented;

    };

    return (NGetTrapAddress(theTrap, theTrapType) != NGetTrapAddress(_Unimplemented, ToolTrap));

}

/*  Set up the whole world, including global variables, Toolbox managers,

    and menus. We also create our one application window at this time.

    Since window storage is non-relocateable, how and when to allocate space

    for windows is very important so that heap fragmentation does not occur.

    Because Sample has only one window and it is only disposed when the application

    quits, we will allocate its space here, before anything that might be a locked

    relocatable object gets into the heap. This way, we can force the storage to be

    in the lowest memory available in the heap. Window storage can differ widely

    amongst applications depending on how many windows are created and disposed. */

/*  1.01 - The code that used to be part of ForceEnvirons has been moved into

    this module. If an error is detected, instead of merely doing an ExitToShell,

    which leaves the user without much to go on, we call AlertUser, which puts

    up a simple alert that just says an error occurred and then calls ExitToShell.

    Since there is no other cleanup needed at this point if an error is detected,

    this form of error- handling is acceptable. If more sophisticated error recovery

    is needed, an exception mechanism, such as is provided by Signals, can be used. */

#pragma segment Initialize

static void Initialize (void)

{   Handle      menuBar;

    long        total, contig;

    EventRecord event;

    short       count;

    gInBackground = false;

    InitGraf((Ptr) &qd.thePort);

    InitFonts();

    InitWindows();

    InitMenus();

    TEInit();

    InitDialogs(nil);

    InitCursor();

    /*  Call MPPOpen and ATPLoad at this point to initialize AppleTalk,

        if you are using it. */

    /*  NOTE -- It is no longer necessary, and actually unhealthy, to check

        PortBUse and SPConfig before opening AppleTalk. The drivers are capable

        of checking for port availability themselves. */

    /*  This next bit of code is necessary to allow the default button of our

        alert be outlined.

        1.02 - Changed to call EventAvail so that we don't lose some important

        events. */

    for (count = 1; count <= 3; count++)

        EventAvail(everyEvent, &event);

    /*  Ignore the error returned from SysEnvirons; even if an error occurred,

        the SysEnvirons glue will fill in the SysEnvRec. You can save a redundant

        call to SysEnvirons by calling it after initializing AppleTalk. */

    SysEnvirons(kSysEnvironsVersion, &gMac);

    /* Make sure that the machine has at least 128K ROMs. If it doesn't, exit. */

    if (gMac.machineType < 0) AlertUser();

    /*  1.02 - Move TrapAvailable call to after SysEnvirons so that we can tell

        in TrapAvailable if a tool trap value is out of range. */

    gHasWaitNextEvent = TrapAvailable(_WaitNextEvent);

    /*  1.01 - We used to make a check for memory at this point by examining ApplLimit,

        ApplicationZone, and StackSpace and comparing that to the minimum size we told

        MultiFinder we needed. This did not work well because it assumed too much about

        the relationship between what we asked MultiFinder for and what we would actually

        get back, as well as how to measure it. Instead, we will use an alternate

        method comprised of two steps. */

    /*  It is better to first check the size of the application heap against a value

        that you have determined is the smallest heap the application can reasonably

        work in. This number should be derived by examining the size of the heap that

        is actually provided by MultiFinder when the minimum size requested is used.

        The derivation of the minimum size requested from MultiFinder is described

        in Sample.h. The check should be made because the preferred size can end up

        being set smaller than the minimum size by the user. This extra check acts to

        insure that your application is starting from a solid memory foundation. */

    if ((long) GetApplLimit() - (long) ApplicationZone() < kMinHeap) AlertUser();

    /*  Next, make sure that enough memory is free for your application to run. It

        is possible for a situation to arise where the heap may have been of required

        size, but a large scrap was loaded which left too little memory. To check for

        this, call PurgeSpace and compare the result with a value that you have determined

        is the minimum amount of free memory your application needs at initialization.

        This number can be derived several different ways. One way that is fairly

        straightforward is to run the application in the minimum size configuration

        as described previously. Call PurgeSpace at initialization and examine the value

        returned. However, you should make sure that this result is not being modified

        by the scrap's presence. You can do that by calling ZeroScrap before calling

        PurgeSpace. Make sure to remove that call before shipping, though. */

    /* ZeroScrap(); */

    PurgeSpace(&total, &contig);

    if (total < kMinSpace) AlertUser();

    /*  The extra benefit to waiting until after the Toolbox Managers have been initialized

        to check memory is that we can now give the user an alert to tell him/her what

        happened. Although it is possible that the memory situation could be worsened by

        displaying an alert, MultiFinder would gracefully exit the application with

        an informative alert if memory became critical. Here we are acting more

        in a preventative manner to avoid future disaster from low-memory problems. */

    menuBar = GetNewMBar(rMenuBar);         /* read menus into menu bar */

    if ( menuBar == nil ) AlertUser();

    SetMenuBar(menuBar);                    /* install menus */

    DisposeHandle(menuBar);

    AppendResMenu(GetMenuHandle(mApple), 'DRVR');   /* add DA names to Apple menu */

    DrawMenuBar();

} /*Initialize*/

/*  Get the global coordinates of the mouse. When you call OSEventAvail

    it will return either a pending event or a null event. In either case,

    the where field of the event record will contain the current position

    of the mouse in global coordinates and the modifiers field will reflect

    the current state of the modifiers. Another way to get the global

    coordinates is to call GetMouse and LocalToGlobal, but that requires

    being sure that thePort is set to a valid port. */

#pragma segment Main

static void GetGlobalMouse (Point *mouse)

{

    EventRecord event;

    OSEventAvail(kNoEvents, &event);    /* we aren't interested in any events */

    *mouse = event.where;               /* just the mouse position */

} /*GetGlobalMouse*/

/* Check to see if a window belongs to a desk accessory. */

#pragma segment Main

static Boolean IsDAWindow (WindowPtr    window)

{

    if ( window == nil )

        return false;

    else    /* DA windows have negative windowKinds */

        return ( ((WindowPeek) window)->windowKind < 0 );

} /*IsDAWindow*/

/*  Check to see if a window belongs to the application. If the window pointer

    passed was NIL, then it could not be an application window. WindowKinds

    that are negative belong to the system and windowKinds less than userKind

    are reserved by Apple except for windowKinds equal to dialogKind, which

    mean it is a dialog.

    1.02 - In order to reduce the chance of accidentally treating some window

    as an AppWindow that shouldn't be, we'll only return true if the windowkind

    is userKind. If you add different kinds of windows to Sample you'll need

    to change how this all works. */

#pragma segment Main

static Boolean IsAppWindow (WindowPtr   window)

{

    short       windowKind;

    if ( window == nil )

        return false;

    else {  /* application windows have windowKinds = userKind (8) */

        windowKind = ((WindowPeek) window)->windowKind;

        return ( windowKind == userKind );

    }

} /*IsAppWindow*/

/*  Change the cursor's shape, depending on its position. This also calculates the region

    where the current cursor resides (for WaitNextEvent). If the mouse is ever outside of

    that region, an event would be generated, causing this routine to be called,

    allowing us to change the region to the region the mouse is currently in. If

    there is more to the event than just Òthe mouse movedÓ, we get called before the

    event is processed to make sure the cursor is the right one. In any (ahem) event,

    this is called again before we  fall back into WNE. */

#pragma segment Main

static void AdjustCursor(Point mouse, RgnHandle region)

{

    WindowPtr   window;

    RgnHandle   arrowRgn;

    RgnHandle   plusRgn;

    Rect        globalPortRect;

    window = FrontWindow(); /* we only adjust the cursor when we are in front */

    if ( (! gInBackground) && (! IsDAWindow(window)) ) {

        /* calculate regions for different cursor shapes */

        arrowRgn = NewRgn();

        plusRgn = NewRgn();

        /* start with a big, big rectangular region */

        SetRectRgn(arrowRgn, kExtremeNeg, kExtremeNeg, kExtremePos, kExtremePos);

        /* calculate plusRgn */

        if ( IsAppWindow(window) ) {

            SetPort(window);    /* make a global version of the viewRect */

            SetOrigin(-window->portBits.bounds.left, -window->portBits.bounds.top);

            globalPortRect = window->portRect;

            RectRgn(plusRgn, &globalPortRect);

            SectRgn(plusRgn, window->visRgn, plusRgn);

            SetOrigin(0, 0);

        }

        /* subtract other regions from arrowRgn */

        DiffRgn(arrowRgn, plusRgn, arrowRgn);

        /* change the cursor and the region parameter */

        if ( PtInRgn(mouse, plusRgn) ) {

            SetCursor(*GetCursor(plusCursor));

            CopyRgn(plusRgn, region);

        } else {

            SetCursor(&qd.arrow);

            CopyRgn(arrowRgn, region);

        }

        /* get rid of our local regions */

        DisposeRgn(arrowRgn);

        DisposeRgn(plusRgn);

    }

} /*AdjustCursor*/

/*  Enable and disable menus based on the current state.

    The user can only select enabled menu items. We set up all the menu items

    before calling MenuSelect or MenuKey, since these are the only times that

    a menu item can be selected. Note that MenuSelect is also the only time

    the user will see menu items. This approach to deciding what enable/

    disable state a menu item has the advantage of concentrating all

    the decision-making in one routine, as opposed to being spread throughout

    the application. Other application designs may take a different approach

    that is just as valid. */

#pragma segment Main

static void AdjustMenus (void)

{

    WindowPtr   window;

    MenuHandle  menu;

    window = FrontWindow();

    menu = GetMenuHandle(mFile);

    if ( IsDAWindow(window) )       /* we can allow desk accessories to be closed from the menu */

        EnableItem(menu, iClose);

    else

        DisableItem(menu, iClose);  /* but not our traffic light window */

    menu = GetMenuHandle(mEdit);

    if ( IsDAWindow(window) ) {     /* a desk accessory might need the edit menuÉ */

        EnableItem(menu, iUndo);

        EnableItem(menu, iCut);

        EnableItem(menu, iCopy);

        EnableItem(menu, iClear);

        EnableItem(menu, iPaste);

    } else {                        /* Ébut we donÕt use it */

        DisableItem(menu, iUndo);

        DisableItem(menu, iCut);

        DisableItem(menu, iCopy);

        DisableItem(menu, iClear);

        DisableItem(menu, iPaste);

    }

    menu = GetMenuHandle(mPassword);

        EnableItem(menu, iTwoItem);

        EnableItem(menu, iDifferentFont);

        EnableItem(menu, iInternalBuffer);

} /*AdjustMenus*/

/* Close a window. This handles desk accessory and application windows. */

/*  1.01 - At this point, if there was a document associated with a

    window, you could do any document saving processing if it is 'dirty'.

    DoCloseWindow would return true if the window actually closed, i.e.,

    the user didnÕt cancel from a save dialog. This result is handy when

    the user quits an application, but then cancels the save of a document

    associated with a window. */

#pragma segment Main

static Boolean DoCloseWindow (WindowPtr window)

{

    if ( IsDAWindow(window) )

        CloseDeskAcc(((WindowPeek) window)->windowKind);

    else if ( IsAppWindow(window) )

        CloseWindow(window);

    return true;

} /*DoCloseWindow*/

/* Clean up the application and exit. We close all of the windows so that

 they can update their documents, if any. */

/*  1.01 - If we find out that a cancel has occurred, we won't exit to the

    shell, but will return instead. */

#pragma segment Main

static void Terminate (void)

{

    WindowPtr   aWindow;

    Boolean     closed;

    closed = true;

    do {

        aWindow = FrontWindow();                /* get the current front window */

        if (aWindow != nil)

            closed = DoCloseWindow(aWindow);    /* close this window */ 

    }

    while (closed && (aWindow != nil));

    if (closed)

        ExitToShell();                          /* exit if no cancellation */

} /*Terminate*/

/*  This is called when an item is chosen from the menu bar (after calling

    MenuSelect or MenuKey). It performs the right operation for each command.

    It is good to have both the result of MenuSelect and MenuKey go to

    one routine like this to keep everything organized. */

#pragma segment Main

static void DoMenuCommand (long menuResult)

{

    short       menuID;             /* the resource ID of the selected menu */

    short       menuItem;           /* the item number of the selected menu */

    short       itemHit;

    Str255      daName;

    short       daRefNum;

    Boolean     handledByDA;

    Str255      password;

    menuID = HiWord(menuResult);    /* use macros for efficiency to... */

    menuItem = LoWord(menuResult);  /* get menu item number and menu number */

    switch ( menuID ) {

        case mApple:

            switch ( menuItem ) {

                case iAbout:        /* bring up alert for About */

                    itemHit = Alert(rAboutAlert, nil);

                    break;

                default:            /* all non-About items in this menu are DAs */

                    /* type Str255 is an array in MPW 3 */

                    GetMenuItemText(GetMenuHandle(mApple), menuItem, daName);

                    daRefNum = OpenDeskAcc(daName);

                    break;

            }

            break;

        case mFile:

            switch ( menuItem ) {

                case iClose:

                    DoCloseWindow(FrontWindow());

                    break;

                case iQuit:

                    Terminate();

                    break;

            }

            break;

        case mEdit:                 /* call SystemEdit for DA editing & MultiFinder */

            handledByDA = SystemEdit(menuItem-1);   /* since we donÕt do any Editing */

            break;

        case mPassword:

            switch ( menuItem ) {

                case iTwoItem:

                    TwoItemDialog(password);

                    break;

                case iDifferentFont:

                    DifferentFontDialog(password);

                    break;

                case iInternalBuffer:

                    InternalBufferDialog(password);

                    break;

            }

            DisplayPassword(password);

            break;

    }

    HiliteMenu(0);                  /* unhighlight what MenuSelect (or MenuKey) hilited */

} /*DoMenuCommand*/

/*  This is called when a mouse-down event occurs in the content of a window.

    Other applications might want to call FindControl, TEClick, etc., to

    further process the click. */

#pragma segment Main

static void DoContentClick(WindowPtr    window)

{

#pragma unused (window)

} /*DoContentClick*/

/*  This is called when a window is activated or deactivated.

    In Sample, the Window Manager's handling of activate and

    deactivate events is sufficient. Other applications may have

    TextEdit records, controls, lists, etc., to activate/deactivate. */

#pragma segment Main

static void DoActivate(WindowPtr window, Boolean becomingActive)

{

    if ( IsAppWindow(window) ) {

        if ( becomingActive )

            /* do whatever you need to at activation */ ;

        else

            /* do whatever you need to at deactivation */ ;

    }

} /*DoActivate*/

/* Draw the contents of the application window. We do some drawing in color, using

   Classic QuickDraw's color capabilities. This will be black and white on old

   machines, but color on color machines. At this point, the windowÕs visRgn

   is set to allow drawing only where it needs to be done. */

#pragma segment Main

static void DrawWindow(WindowPtr    window)

{

    SetPort(window);

    EraseRect(&window->portRect);   /* clear out any garbage that may linger */

} /*DrawWindow*/

/*  This is called when an update event is received for a window.

    It calls DrawWindow to draw the contents of an application window.

    As an efficiency measure that does not have to be followed, it

    calls the drawing routine only if the visRgn is non-empty. This

    will handle situations where calculations for drawing or drawing

    itself is very time-consuming. */

#pragma segment Main

static void DoUpdate(WindowPtr  window)

{

    if ( IsAppWindow(window) ) {

        BeginUpdate(window);                /* this sets up the visRgn */

        if ( ! EmptyRgn(window->visRgn) )   /* draw if updating needs to be done */

            DrawWindow(window);

        EndUpdate(window);

    }

} /*DoUpdate*/

/* Do the right thing for an event. Determine what kind of event it is, and call

 the appropriate routines. */

#pragma segment Main

static void DoEvent (EventRecord    *event)

{

    short       part, err;

    WindowPtr   window;

    Boolean     hit;

    char        key;

    Point       aPoint;

    switch ( event->what ) {

        case mouseDown:

            part = FindWindow(event->where, &window);

            switch ( part ) {

                case inMenuBar:             /* process a mouse menu command (if any) */

                    AdjustMenus();

                    DoMenuCommand(MenuSelect(event->where));

                    break;

                case inSysWindow:           /* let the system handle the mouseDown */

                    SystemClick(event, window);

                    break;

                case inContent:

                    if ( window != FrontWindow() ) {

                        SelectWindow(window);

                        /*DoEvent(event);*/ /* use this line for "do first click" */

                    } else

                        DoContentClick(window);

                    break;

                case inDrag:                /* pass screenBits.bounds to get all gDevices */

                    DragWindow(window, event->where, &qd.screenBits.bounds);

                    break;

                case inGrow:

                    break;

                case inZoomIn:

                case inZoomOut:

                    hit = TrackBox(window, event->where, part);

                    if ( hit ) {

                        SetPort(window);                /* the window must be the current port... */

                        EraseRect(&window->portRect);   /* because of a bug in ZoomWindow */

                        ZoomWindow(window, part, true); /* note that we invalidate and erase... */

                        InvalRect(&window->portRect);   /* to make things look better on-screen */

                    }

                    break;

            }

            break;

        case keyDown:

        case autoKey:                       /* check for menukey equivalents */

            key = event->message & charCodeMask;

            if ( event->modifiers & cmdKey )            /* Command key down */

                if ( event->what == keyDown ) {

                    AdjustMenus();                      /* enable/disable/check menu items properly */

                    DoMenuCommand(MenuKey(key));

                }

            break;

        case activateEvt:

            DoActivate((WindowPtr) event->message, (event->modifiers & activeFlag) != 0);

            break;

        case updateEvt:

            DoUpdate((WindowPtr) event->message);

            break;

        /*  1.01 - It is not a bad idea to at least call DIBadMount in response

            to a diskEvt, so that the user can format a floppy. */

        case diskEvt:

            if ( HiWord(event->message) != noErr ) {

                SetPt(&aPoint, kDILeft, kDITop);

                err = DIBadMount(aPoint, event->message);

            }

            break;

        case kOSEvent:

        {

        /*  1.02 - must BitAND with 0x0FF to get only low byte */

            switch ((event->message >> 24) & 0x0FF) {       /* high byte of message */

                case kSuspendResumeMessage:     /* suspend/resume is also an activate/deactivate */

                    gInBackground = (event->message & kResumeMask) == 0;

                    DoActivate(FrontWindow(), !gInBackground);

                    break;

            }

            break;

        }   

    }

} /*DoEvent*/

/*  Get events forever, and handle them by calling DoEvent.

    Get the events by calling WaitNextEvent, if it's available, otherwise

    by calling GetNextEvent. Also call AdjustCursor each time through the loop. */

#pragma segment Main

static void EventLoop(void)

{

    RgnHandle   cursorRgn;

    Boolean     gotEvent;

    EventRecord event;

    Point       mouse;

    cursorRgn = NewRgn();           /* weÕll pass WNE an empty region the 1st time thru */

    do {

        /* use WNE if it is available */

        if ( gHasWaitNextEvent ) {

            GetGlobalMouse(&mouse);

            AdjustCursor(mouse, cursorRgn);

            gotEvent = WaitNextEvent(everyEvent, &event, LONG_MAX, cursorRgn);

        }

        else {

            SystemTask();

            gotEvent = GetNextEvent(everyEvent, &event);

        }

        if ( gotEvent ) {

            /* make sure we have the right cursor before handling the event */

            AdjustCursor(event.where, cursorRgn);

            DoEvent(&event);

        }

        /*  If you are using modeless dialogs that have editText items,

            you will want to call IsDialogEvent to give the caret a chance

            to blink, even if WNE/GNE returned FALSE. However, check FrontWindow

            for a non-NIL value before calling IsDialogEvent. */

    } while ( true );   /* loop forever; we quit via ExitToShell */

} /*EventLoop*/

#pragma segment Main

void main(void)

{

    #ifdef applec

        UnloadSeg((Ptr) _DataInit);     /* note that _DataInit must not be in Main! */

    #endif

    /* 1.01 - call to ForceEnvirons removed */

    /*  If you have stack requirements that differ from the default,

        then you could use SetApplLimit to increase StackSpace at 

        this point, before calling MaxApplZone. */

    MaxApplZone();                  /* expand the heap so code segments load at the top */

    Initialize();                   /* initialize the program */

    UnloadSeg((Ptr) Initialize);    /* note that Initialize must not be in Main! */

    EventLoop();                    /* call the main event loop */

}

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

*** 1.01 DoCloseBehind(window) was removed ***

    1.01 - DoCloseBehind was a good idea for closing windows when quitting

    and not having to worry about updating the windows, but it suffered

    from a fatal flaw. If a desk accessory owned two windows, it would

    close both those windows when CloseDeskAcc was called. When DoCloseBehind

    got around to calling DoCloseWindow for that other window that was already

    closed, things would go very poorly. Another option would be to have a

    procedure, GetRearWindow, that would go through the window list and return

    the last window. Instead, we decided to present the standard approach

    of getting and closing FrontWindow until FrontWindow returns NIL. This

    has a potential benefit in that the window whose document needs to be saved

    may be visible since it is the front window, therefore decreasing the

    chance of user confusion. For aesthetic reasons, the windows in the

    application should be checked for updates periodically and have the

    updates serviced.

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