Garbo/Garbo.cdr/mac/progrmng/transklc.sit/TransSkel.c.bin/TransSkel.c

C/C++ Source or Header | 1989-02-09 | 36.2 KB | 1,500 lines | [TEXT/KAHL]

/*
    TransSkel version 2.01 - Transportable application skeleton

    TransSkel is public domain and was originally written by:

                Paul DuBois
                Wisconsin Regional Primate Research Center
                1220 Capital Court
                Madison WI  53715-1299  USA

    UUCP:        {allegra,uunet}!uwvax!rhesus!dubois
    Internet:    [e-mail]

    Additional changes were made by

                Owen Hartnett
                OHM Software Company
                163 Richard Drive
                Tiverton, RI 02878  USA

    UUCP:        {allegra,uunet}!brunix!omh
    Internet:    [e-mail]
    CSNET:        [e-mail]

    Owen is also responsible for the port to Lightspeed Pascal.

    This version of TransSkel written for LightspeedC.  LightspeedC is a
    trademark of:
            THINK Technologies, Inc
            420 Bedford Street  Suite 350
            Lexington, MA  02173  USA

    Change history is in TSHistory.c
*/


/*
    The following symbol controls support for dialogs.
    "#define    supportDialogs" enables support.
    "#undef        supportDialogs" disables support.
*/

# define    supportDialogs


# ifdef        supportDialogs
#    include    <DialogMgr.h>
# else
#    include    <WindowMgr.h>
# endif

# include    <EventMgr.h>
# include    <MenuMgr.h>


/*
    Integer and Longint should be typedef'd to the 2-byte and 4-byte
    integer types for the compiler being used.  These are int and long
    for LightspeedC.
*/

typedef int        Integer;
typedef long    Longint;


# define    nil            0L
# define    mBarHeight    20    /* menu bar height.  All window sizing
                               code takes this into account */


/*
    New(TypeName) returns handle to new object, for any TypeName.
    If there is insufficient memory, the result is nil.
*/

# define    New(x)    (x **) NewHandle ((Size) sizeof (x))



/*
    Window and Menu handler types, constants, variables.

    whList and mhList are the lists of window and menu handlers.
    whClobOnRmve and mhClobOnRmve are true if the handler disposal proc
    is to be called when a handler is removed.  They are temporarily set
    false when handlers are installed for windows or menus that already
    have handlers - the old handler is removed WITHOUT calling the
    disposal proc.

    Default lower limits on window sizing of 80 pixels both directions is
    sufficient to allow text windows room to draw a grow box and scroll
    bars without having the thumb and arrows overlap.  These values may
    be changed if such a constraint is undesirable with SkelGrowBounds.
    Default upper limits are for the Macintosh, not the Lisa, but are set
    per machine in SkelInit.
*/

typedef struct WHandler    WHandler;

struct WHandler
{
    WindowPtr    whWind;            /* window/dialog to be handled  */
    ProcPtr        whClobber;        /* data structure disposal proc */
    ProcPtr        whMouse;        /* mouse-click handler proc     */
    ProcPtr        whKey;            /* key-click handler proc       */
    ProcPtr        whUpdate;        /* update handler proc          */
    ProcPtr        whActivate;        /* activate event handler proc  */
    ProcPtr        whClose;        /* close "event" handler proc   */
    ProcPtr        whIdle;            /* main loop proc               */
# ifdef    supportDialogs
    ProcPtr        whEvent;        /* event proc                   */
# endif
    Rect        whGrow;            /* limits on window sizing      */
    Boolean        whSized;        /* true = window was resized    */
    Boolean        whFrontOnly;    /* true = idle only when active */
    WHandler    **whNext;        /* next window handler          */
};

static WHandler    **whList = nil;
static Boolean    whClobOnRmve = true;
static Rect        growRect = { 80, 80, 512, 342 - mBarHeight };

typedef struct MHandler    MHandler;

struct MHandler
{
    Integer        mhID;            /* menu id                     */
    ProcPtr        mhSelect;        /* item selection handler proc */
    ProcPtr        mhClobber;        /* menu disposal handler proc  */
    MHandler    **mhNext;        /* next menu handler           */
};


static MHandler    **mhList = nil;            /* list of menu handlers */
static Boolean    mhClobOnRmve = true;


/*
    Variables for default Apple menu handler.  appleID is set to 1 if
    SkelApple is called and is the id of the Apple menu, appleAboutProc
    is the procedure to execute if there is an About... item and it's
    chosen from the Apple menu.  If doAbout is true, then the menu
    contains the About... item, otherwise it's just desk accessories.
*/

static MenuHandle    appleMenu;
static Integer        appleID = 0;
static ProcPtr        appleAboutProc = nil;
static Boolean        doAbout = false;


/*
    Miscellaneous

    screenPort points to the window manager port.

    doneFlag determines when SkelMain returns.  It is set by calling
    SkelWhoa(), which is how the host requests a halt.

    pBkgnd points to a background procedure, to be run during event
    processing.  Set it with SkelBackground.  If nil, there's no
    procedure.

    pEvent points to an event-inspecting hook, to be run whenever an
    event occurs.  Set it with SkelEventHook.  If nil, there's no
    procedure.

    eventMask controls the event types requested in the GetNextEvent
    call in SkelMain.

    diskInitPt is the location at which the disk initialization dialog
    appears, if an uninitialized disk is inserted.
*/

static GrafPtr    screenPort;
static Integer    doneFlag = false;
static ProcPtr    pBkgnd = nil;
static Boolean    (*pEvent)() = nil;
static Integer    eventMask = everyEvent;
static Point    diskInitPt = { /* v = */ 120, /* h = */ 100 };

static WindowPtr    oldWindow = nil;
static WHandler        **oldWDHandler = nil;


# ifdef    supportDialogs

/*
    dlogEventMask specifies events that are passed to dialogs.
    Others are ignored.  Standard mask passes, mousedown, keydown,
    autokey, update, activate and null events.  Null events are
    controlled by bit 0 (always forced on).
*/

static Integer    dlogEventMask = 0x16b;

# endif


/* -------------------------------------------------------------------- */
/*                        Internal (private) Routines                        */
/* -------------------------------------------------------------------- */


/*
    Get handler associated with user or dialog window.
    Return nil if window doesn't belong to any known handler.
    This routine is absolutely fundamental to TransSkel.
*/


static WHandler **GetWDHandler (theWind)
WindowPtr    theWind;
{
register WHandler    **h;

    if (theWind == oldWindow)
        return(oldWDHandler);        /* return handler of cached window */

    for (h = whList; h != nil; h = (**h).whNext)
    {
        if ((**h).whWind == theWind)
        {
            oldWindow = theWind;    /* set cached window and handler */
            oldWDHandler = h;
            return (h);
        }
    }
    return (nil);
}


/*
    Get handler associated with user window.
    Return nil if window doesn't belong to any known handler.
    The order of the two tests is critical:  theWind might be nil.
*/

static WHandler **GetWHandler (theWind)
WindowPtr    theWind;
{
register WHandler    **h;

    if ((h = GetWDHandler (theWind)) != nil
        && ((WindowPeek) theWind)->windowKind != dialogKind)
    {
            return (h);
    }
    return (nil);
}


# ifdef    supportDialogs

/*
    Get handler associated with dialog window.
    Return nil if window doesn't belong to any known handler.
    The order of the two tests is critical:  theDialog might be nil.
*/

static WHandler **GetDHandler (theDialog)
DialogPtr    theDialog;
{
register WHandler    **h;

    if ((h = GetWDHandler (theDialog)) != nil
        && ((WindowPeek) theDialog)->windowKind == dialogKind)
    {
            return (h);
    }
    return (nil);
}

# endif


/*
    General menu-handler.  Just passes selection to the handler's
    select routine.  If the select routine is nil, selecting items from
    the menu is a nop.
*/

static DoMenuCommand (command)
Longint        command;
{
register Integer    menu;
register Integer    item;
register MHandler    **mh;
register ProcPtr    p;

    menu = HiWord (command);
    item = LoWord (command);
    for (mh = mhList; mh != nil; mh = (**mh).mhNext)
    {
        if ((menu == (**mh).mhID) && ((p = (**mh).mhSelect) != nil))
        {
            (*p) (item);
            break;
        }
    }
    HiliteMenu (0);        /* command done, turn off menu hiliting */
}


/*
    Apple menu handler

    DoAppleItem:  If the first item was chosen, and there's an "About..."
    item, call the procedure associated with it (if not nil).  If there
    is no "About..." item or the item was not the first one, then open
    the associated desk accessory.  The port is saved and restored
    because OpenDeskAcc does not always preserve it correctly.

    DoAppleClobber disposes of the Apple menu.
*/


static DoAppleItem (item)
Integer    item;
{
GrafPtr    curPort;
Str255    str;
Handle    h;

    if (doAbout && item == 1)
    {
        if (appleAboutProc != nil)
            (*appleAboutProc) ();
    }
    else
    {
        GetPort (&curPort);
        GetItem (appleMenu, item, str);        /* get DA name */
        SetResLoad (false);
        h = GetNamedResource ('DRVR', str);
        SetResLoad (true);
        if (h != nil)
        {
            ResrvMem (SizeResource (h) + 0x1000);
            (void) OpenDeskAcc (str);            /* open it */
        }
        SetPort (curPort);
    }
}

static DoAppleClobber () { DisposeMenu (appleMenu); }


/* -------------------------------------------------------------------- */
/*                        Window-handler routing routines                    */
/*                                                                        */
/*    See manual for discussion of port-setting behavior.  In general,    */
/*    the current port is made to associate with the active window.        */
/*    This is done in DoActivate for non-dialog windows, in DoDialog        */
/*    for dialog windows.                                                    */
/* -------------------------------------------------------------------- */


/*
    Pass local mouse coordinates, click time, and the modifiers flag
    word to the handler.  Should not be necessary to set the port, as
    the click is passed to the active window's handler.
*/

static DoMouse (h, theEvent)
WHandler    **h;
EventRecord    *theEvent;
{
register ProcPtr    p;
Point                thePt;

    if (h != nil)
    {
        if ((p = (**h).whMouse) != nil)
        {
            thePt = theEvent->where;    /* make local copy */
            GlobalToLocal (&thePt);
            (*p) (thePt, theEvent->when, theEvent->modifiers);
        }
    }
}


/*
    Pass the character and the modifiers flag word to the handler.
    Should not be necessary to set the port, as the click is passed
    to the active window's handler.
*/

static DoKey (h, ch, mods)
WHandler    **h;
char        ch;
Integer        mods;
{
register ProcPtr    p;

    if (h != nil)
    {
        if ((p = (**h).whKey) != nil)
            (*p) (ch, mods);
    }
}


/*
    Call the window updating procedure, passing to it an indicator whether
    the window has been resized or not.  Then clear the flag, assuming
    the update proc took whatever action was necessary to respond to
    resizing.

    If the handler doesn't have any update proc, the Begin/EndUpdate
    stuff is still done, to clear the update region.  Otherwise the
    Window Manager will keep generating update events for the window,
    stalling updates of other windows.

    Make sure to save and restore the port, as it's not always the
    active window that is updated.
*/

static DoUpdate (h)
WHandler    **h;
{
register WHandler    **rh;
register ProcPtr    p;
register GrafPtr    updPort;
GrafPtr                tmpPort;

    if ((rh = h) != nil)
    {
        GetPort (&tmpPort);
        SetPort (updPort = (**rh).whWind);
        BeginUpdate (updPort);
        if ((p = (**rh).whUpdate) != nil)
        {
            (*p) ((**rh).whSized);
            (**rh).whSized = false;
        }
        EndUpdate (updPort);
        SetPort (tmpPort);
    }
}


/*
    Pass activate/deactivate notification to handler.  On activate,
    set the port to the window coming active.  Normally this is done by
    the user clicking in a window.

    *** BUT ***
    Under certain conditions, a deactivate may be generated for a window
    that has not had the port set to it by a preceding activate.  If an
    application puts up window A, then window B in front of A, then
    starts processing events, the first events will be a deactivate for A
    and an activate for B.  Since it therefore can't be assumed the port
    was set to A by an activate, the port needs to be set for deactivates
    as well.

    This matters not a whit for the more usual cases that occur.  If a
    deactivate for one window is followed by an activate for another, the
    port will still be switched properly to the newly active window.  If
    no activate follows the deactivate, the deactivated window is the last
    one, and it doesn't matter what the port ends up set to, anyway.
*/

static DoActivate (h, active)
WHandler    **h;
Boolean        active;
{
register ProcPtr    p;

    if (h != nil)
    {
        SetPort ((**h).whWind);
        if ((p = (**h).whActivate) != nil)
            (*p) (active);
    }
}


/*
    Execute a window handler's close box proc.  The close proc for
    handlers for temp windows that want to remove themselves when the
    window is closed can call SkelRmveWind to dispose of the window
    and remove the handler from the window handler list.  Thus, windows
    may be dynamically created and destroyed without filling up the
    handler list with a bunch of invalid handlers.

    If the handler doesn't have a close proc, just hide the window.
    The host should provide some way of reopening the window (perhaps
    a menu selection).  Otherwise the window will be lost from user
    control if it is hidden, since it won't receive user-initiated
    events.

    This is called both for regular and dialog windows.

    Since the close box of only the active window may be clicked, it
    is not necessary to set the port.
*/

static DoClose (h)
WHandler    **h;
{
register WHandler    **rh;
register ProcPtr    p;

    if ((rh = h) != nil)
    {
        if ((p = (**rh).whClose) != nil)
            (*p) ();
        else
            HideWindow ((**rh).whWind);
    }
}


/*
    Execute a window handler's clobber proc.  This is called both
    for regular and dialog windows.

    Must save, set and restore port, since any window (not just active
    one) may be clobbered at any time.

    Don't need to check whether handler is nil, as in other handler
    procedures, since this is only called by SkelRmveWind with a
    known-valid handler.
*/

static DoClobber (h)
WHandler    **h;
{
register ProcPtr    p;
GrafPtr                tmpPort;

    GetPort (&tmpPort);
    SetPort ((**h).whWind);
    if ((p = (**h).whClobber) != nil)
        (*p) ();
    SetPort (tmpPort);
}


# ifdef    supportDialogs

/* -------------------------------------------------------------------- */
/*                            Dialog-handling routines                    */
/* -------------------------------------------------------------------- */


/*
    Handle event if it's for a (modeless) dialog.  The event must be one
    of those that is passed to dialogs according to dlogEventMask.
    This mask can be set so that disk-inserts, for instance, don't
    get eaten up.

    Examine event and set port if dialog window is coming active (for
    normal windows, DoActivate sets the port; there's no such thing
    for dialogs, so it's done here.)  When this is done, the trio
    of GetPort/SetPort/SetPort calls commented out below doesn't appear
    to be necessary any longer.  If you want to be cautious, it doesn't
    hurt to uncomment them...
*/

static DoDialog (theEvent)
register EventRecord    *theEvent;
{
register WHandler    **dh;
DialogPtr            theDialog;
register Integer    what;
Integer                item;
GrafPtr                tmpPort;
WindowPeek            w;

/*
    handle command keys before they get to IsDialogEvent
*/

    what = theEvent->what;
    if((what == keyDown || what == autoKey) && (theEvent->modifiers & cmdKey))
    {
           DoMenuCommand (MenuKey (theEvent->message & charCodeMask));
           return (true);
    }

    if (((1 << what) & dlogEventMask) && IsDialogEvent (theEvent))
    {
        /* ugly programming award semi-finalist follows */
        if (theEvent->what == activateEvt            /* if activate */
            && (theEvent->modifiers & activeFlag)    /* and coming active */
            && (w=(WindowPeek) theEvent->message)->windowKind
                    == dialogKind)
        {
            SetPort ((GrafPtr) w);
        }
        if (DialogSelect (theEvent, &theDialog, &item)
           && (dh = GetDHandler (theDialog)) != nil
           && (**dh).whEvent != nil)
        {
            /*GetPort (&tmpPort);*/
            /*SetPort (theDialog);*/
            (*(**dh).whEvent) (item, theEvent);
            /*SetPort (tmpPort);*/
        }
        return (true);
    }
    return (false);
}

# endif


/* -------------------------------------------------------------------- */
/*                            Event-handling routines                        */
/* -------------------------------------------------------------------- */


/*
    Have either zoomed a window or sized it manually.  Invalidate
    it to force an update and set the 'resized' flag in the window
    handler true.  The port is assumed to be set to the port that changed
    size.
*/

static TriggerUpdate (h, grownPort)
WHandler    **h;
GrafPtr        grownPort;
{
    InvalRect (&grownPort->portRect);
    if (h != nil)
        (**h).whSized = true;
}


/*
    Size a window.  If the window has a handler, use the grow limits
    in the handler record, otherwise use the defaults.

    The portRect is invalidated to force an update event.  The handler's
    update procedure should check the parameter passed to it to check
    whether the window has changed size, if it needs to adjust itself to
    the new size.  THIS IS A CONVENTION.  Update procs must notice grow
    "events", there is no procedure specifically for such events.

    The clipping rectangle is not reset.  If the host application
    keeps the clipping set equal to the portRect or something similar,
    then it will have to arrange to treat window growing with more
    care.

    Since the grow region of only the active window may be clicked,
    it should not be necessary to set the port.
*/

static DoGrow (h, growPort, startPt)
WHandler    **h;
GrafPtr        growPort;
Point        startPt;
{
Rect                r;
register Longint    growRes;

    if (h != nil)
        r = (**h).whGrow;
    else
        r = growRect;    /* use default */

    /* grow result non-zero if size change    */

    if (growRes = GrowWindow (growPort, startPt, &r))
    {
        SizeWindow (growPort, LoWord (growRes), HiWord (growRes), false);
        TriggerUpdate (h, growPort);
    }
}


/*
    Zoom the current window.  Very similar to DoGrow

    Since the zoombox of only the active window may be clicked,
    it should not be necessary to set the port.
*/

static DoZoom (h, zoomPort, partCode)
register WHandler    **h;
GrafPtr                zoomPort;
short                partCode;
{
    ZoomWindow (zoomPort, partCode, 0);
    TriggerUpdate (h, zoomPort);
}


/*
    General event handler
*/

static DoEvent (theEvent)
register EventRecord    *theEvent;

{
Point                evtPt;
GrafPtr                evtPort;
register Integer    evtPart;
register char        evtChar;
register Integer    evtMods;
register Longint    evtMsge;
register WHandler    **h;
Rect                r;

# ifdef    supportDialogs

    if(DoDialog (theEvent))
        return;

# endif

    evtPt = theEvent->where;
    evtMods = theEvent->modifiers;
    evtMsge = theEvent->message;

    switch (theEvent->what)
    {

        /*case nullEvent:
            break;*/
/*
    Mouse click.  Get the window that the click occurred in, and the
    part of the window.  GetWDHandler is called here, not GetWHandler, since
    we need the handler for a window which might turn out to be a dialog
    window, e.g., if the click is in a close box.
*/
        case mouseDown:
        {
            evtPart = FindWindow (evtPt, &evtPort);
            h = GetWDHandler (evtPort);

            switch (evtPart)
            {
/*
    Click in a desk accessory window.  Pass back to the system.
*/
                case inSysWindow:
                {
                    SystemClick (theEvent, evtPort);
                    break;
                }
/*
    Click in menu bar.  Track the mouse and execute selected command,
    if any.
*/
                case inMenuBar:
                {
                    DoMenuCommand (MenuSelect (evtPt));
                    break;
                }
/*
    Click in grow box.  Resize window.
*/
                case inGrow:
                {
                    DoGrow (h, evtPort, evtPt);
                    break;
                }
/*
    Click in title bar.  Drag the window around.  Leave at least
    4 pixels visible in both directions.
    Bug fix:  The window is selected first to make sure it's at least
    activated (unless the command key is down-see Inside Macintosh).
    DragWindow seems to call StillDown first, so that clicks in drag
    regions while machine is busy don't otherwise bring window to front if
    the mouse is already up by the time DragWindow is called.
*/
                case inDrag:
                {
                    if (evtPort != FrontWindow () && (evtMods & cmdKey) == 0)
                        SelectWindow (evtPort);
                    r = screenPort->portRect;
                    r.top += mBarHeight;            /* skip down past menu bar */
                    InsetRect (&r, 4, 4);
                    DragWindow (evtPort, evtPt, &r);
                    break;
                }
/*
    Click in close box.  Call the close proc if the window has one.
*/
                case inGoAway:
                {
                    if (TrackGoAway (evtPort, evtPt))
                        DoClose (h);
                    break;
                }

/*
    Click in zoom box.  Track the click and then zoom the window if
    necessary
*/
                case inZoomIn:
                case inZoomOut:
                {
                    if (TrackBox (evtPort, evtPt, evtPart))
                        DoZoom (h, evtPort, evtPart);
                    break;
                }
/*
    Click in content region.  If the window wasn't frontmost (active),
    just select it, otherwise pass the click to the window's mouse
    click handler.
*/
                case inContent:
                {
                    if (evtPort != FrontWindow ())
                        SelectWindow (evtPort);
                    else
                        DoMouse (h, theEvent);
                    break;
                }

            }
            break;    /* mouseDown */
        }
/*
    Key event.  If the command key was down, process as menu item
    selection, otherwise pass the character and the modifiers flags
    to the active window's key handler.

    If dialogs are supported, there's no check for command-key
    equivalents, since that would have been checked in DoDialog.
*/
        case keyDown:
        case autoKey:
        {
            evtChar = evtMsge & charCodeMask;

# ifndef    supportDialogs

            if (evtMods & cmdKey)        /* try menu equivalent */
            {
                DoMenuCommand (MenuKey (evtChar));
                break;
            }

# endif

            DoKey (GetWHandler (FrontWindow ()), evtChar, evtMods);
            break;
        }
/*
    Update a window.
*/
        case updateEvt:
        {
            DoUpdate (GetWHandler ((WindowPtr) evtMsge));
            break;
        }
/*
    Activate or deactivate a window.
*/
        case activateEvt:
        {
            DoActivate (GetWHandler ((WindowPtr) evtMsge),
                        ((evtMods & activeFlag) != 0));
            break;
        }
/*
    handle inserts of uninitialized disks
*/
        case diskEvt:
        {
            if (HiWord (evtMsge) != noErr)
            {
                DILoad ();
                (void) DIBadMount (diskInitPt, evtMsge);
                DIUnload ();
            }
            break;
        }
    }
}


/* -------------------------------------------------------------------- */
/*                        Interface (public) Routines                        */
/* -------------------------------------------------------------------- */


/*
    Initialize the various Macintosh Managers.
    Set default upper limits on window sizing.
    FlushEvents does NOT toss disk insert events, so that disks
    inserted while the application is starting up don't result
    in dead drives.

    noMasters is the number of times to call MoreMasters.  gzProc is
    the address of a grow zone procedure to call if memory allocation
    problems occur.  Pass nil if none to be used.
*/

SkelInit (noMasters, gzProc)
int        noMasters;
ProcPtr    gzProc;
{
    while (noMasters-- > 0)
        MoreMasters ();

    if (gzProc != nil)
        SetGrowZone (gzProc);

    MaxApplZone ();
    FlushEvents (everyEvent - diskMask, 0 );
    InitGraf (&thePort);
    InitFonts ();
    InitWindows ();
    InitMenus ();
    TEInit ();
    InitDialogs (nil);        /* no restart proc */
    InitCursor ();
/*
    Set upper limits of window sizing to machine screen size.  Allow
    for the menu bar.
*/
    GetWMgrPort (&screenPort);
    growRect.right = screenPort->portRect.right;
    growRect.bottom = screenPort->portRect.bottom - mBarHeight;
}


/*
    Main loop.

    Task care of DA's with SystemTask.
    Run background task if there is one.
    If there is an event, check for an event hook.  If there isn't
    one defined, or if there is but it returns false, call the
    general event handler.  (Hook returns true if TransSkel should
    ignore the event.)
    If no event, call the "no-event" handler for the front window and for
    any other windows with idle procedures that are always supposed
    to run.  This is done in such a way that it is safe for idle procs
    to remove the handler for their own window if they want (unlikely,
    but...)  This loop doesn't check whether the window is really
    a dialog window or not, but it doesn't have to, because such
    things always have a nil idle proc.

    doneFlag is reset upon exit.  This allows SkelMain to be called
    repeatedly, or recursively.

    Null events are examined (in SkelMain) and passed to the event
    handler.  This is necessary to make sure, if dialogs are supported,
    that DialogSelect gets called repeatedly, or the caret won't blink
    if a dialog has any editText items.

    Null events are not passed to any event-inspecting hook that may
    be installed.
*/

SkelMain ()
{
EventRecord            theEvent;
register WHandler    **wh, **wh2;
register WindowPtr    w;
Boolean                haveEvent;
GrafPtr                tmpPort;
register ProcPtr    p;

    while (!doneFlag)
    {
        SystemTask ();
        if (pBkgnd != nil)
            (*pBkgnd) ();

/*
    Now watch carefully.  GetNextEvent calls SystemEvent to handle some
    DA events, and returns false if the event was handled.  However, in
    such cases the event record will still have the event that occurred,
    *not* a null event, as you might reasonably expect.  So it's not
    enough to look at haveEvent.

    Previous versions figured (wrongly) that haveEvent==false meant a null
    event had occurred, and passed it through to DoEvent and DoDialog, so
    that caret-blinking in dialog TextEdit items would occur.  But cmd-key
    equivalents while DA windows were in front, in particular, allowed
    already-processed DA events to get into DoEvent (because haveEvent
    was false), and they got handled twice because when the event record
    was examined, lo and behold, it had a cmd-key event!  So now this
    logic is used:

    If have a real event, and there's no event hook or there is but it
    doesn't handle the event, OR if the "non-event" is a true nullEvent,
    then process it.
*/

        haveEvent = GetNextEvent (eventMask, &theEvent);

        if ((haveEvent && (pEvent == nil || (*pEvent)(&theEvent) == false))
                || theEvent.what == nullEvent)
            DoEvent(&theEvent);

/*
    Run applicable idle procs.  Make sure to save and restore the port,
    since idle procs for the non-active window may be run.
*/

        if (!haveEvent)
        {
            GetPort (&tmpPort);
            for (wh = whList; wh != nil; wh = wh2)
            {
                wh2 = (**wh).whNext;
                w = (**wh).whWind;
                if ( (w == FrontWindow () || !(**wh).whFrontOnly ) )
                {
                    SystemTask ();
                    if ((p = (**wh).whIdle) != nil)
                    {
                        SetPort (w);
                        (*p) ();
                    }
                }
            }
            SetPort (tmpPort);
        }
    }
    doneFlag = false;
}


/*
    Tell SkelMain to stop
*/

SkelWhoa () { doneFlag = true; }


/*
    Clobber all the menu, window and dialog handlers
*/

SkelClobber ()
{
    while (whList != nil)
        SkelRmveWind ((**whList).whWind);

    while (mhList != nil)
        SkelRmveMenu (GetMHandle((**mhList).mhID));
}


/* -------------------------------------------------------------------- */
/*                        Menu-handler interface routines                    */
/* -------------------------------------------------------------------- */


/*
    Install handler for a menu.  Remove any previous handler for it.
    Pass the following parameters:

    theMenu    Handle to the menu to be handled.  Must be created by host.
    pSelect    Proc that handles selection of items from menu.  If this is
            nil, the menu is installed, but nothing happens when items
            are selected from it.
    pClobber Proc for disposal of handler's data structures.  Usually
            nil for menus that remain in menu bar until program
            termination.

    The menu is installed, and also drawn in the menu bar if drawBar true.

    Return 0 if no handler could be allocated, non-zero if successful.
*/

SkelMenu (theMenu, pSelect, pClobber, drawBar)
MenuHandle    theMenu;
ProcPtr        pSelect;
ProcPtr        pClobber;
Boolean        drawBar;
{
register MHandler    **mh;

    mhClobOnRmve = false;
    SkelRmveMenu (theMenu);
    mhClobOnRmve = true;

    if ((mh = New (MHandler)) != nil)
    {
        (**mh).mhNext = mhList;
        mhList = mh;
        (**mh).mhID = (**theMenu).menuID;    /* get menu id number */
        (**mh).mhSelect = pSelect;            /* install selection handler */
        (**mh).mhClobber = pClobber;        /* install disposal handler */
        InsertMenu (theMenu, 0);            /* put menu at end of menu bar */
    }
    if (drawBar)
        DrawMenuBar ();
    return (mh != nil);
}


/*
    Remove a menu handler.  This calls the handler's disposal routine
    and then takes the handler out of the handler list and disposes
    of it.

    Note that the menu MUST be deleted from the menu bar before calling
    the clobber proc, because the menu bar will end up filled with
    garbage if the menu was allocated with NewMenu (see discussion of
    DisposeMenu in Menu Manager section of Inside Macintosh).
*/

SkelRmveMenu (theMenu)
MenuHandle    theMenu;
{
register Integer    mID;
register MHandler    **h, **h2;
register ProcPtr    p;

    mID = (**theMenu).menuID;
    if (mhList != nil)                /* if list empty, ignore */
    {
        if ((**mhList).mhID == mID)    /* is it the first element? */
        {
            h2 = mhList;
            mhList = (**mhList).mhNext;
        }
        else
        {
            for (h = mhList; h != nil; h = h2)
            {
                h2 = (**h).mhNext;
                if (h2 == nil)
                    return;                        /* menu not in list! */
                if ((**h2).mhID == mID)            /* found it */
                {
                    (**h).mhNext = (**h2).mhNext;
                    break;
                }
            }
        }
        DeleteMenu (mID);
        DrawMenuBar ();
        if (mhClobOnRmve && (p = (**h2).mhClobber) != nil)
            (*p) (theMenu);                /* call disposal routine */
        DisposHandle (h2);                /* get rid of handler record */
    }
}


/*
    Install a handler for the Apple menu.

    SkelApple is called if TransSkel is supposed to handle the apple
    menu itself.  aboutTitle is the title of the first item.  If nil,
    then only desk accessories are put into the menu.  If not nil, then
    the title is entered as the first item, followed by a gray line,
    then the desk accessories.

    SkelApple does not cause the menubar to be drawn, so if the Apple
    menu is the only menu, DrawMenuBar must be called afterward.

    No value is returned, unlike SkelMenu.  It is assumed that SkelApple
    will be called so early in the application that the call the SkelMenu
    is virtually certain to succeed.  If it doesn't, there's probably
    little hope for the application anyway.
*/

SkelApple (aboutTitle, aboutProc)
StringPtr    aboutTitle;
ProcPtr        aboutProc;
{
    appleID = 1;
    appleMenu = NewMenu (appleID, "\p\024");    /* 024 = apple character */
    if (aboutTitle != nil)
    {
        doAbout = true;
        AppendMenu (appleMenu, aboutTitle);    /* add About... item title */
        AppendMenu (appleMenu, "\p(-");        /* add gray line */
        appleAboutProc = aboutProc;
    }
    AddResMenu (appleMenu, 'DRVR');        /* add desk accessories */
    (void) SkelMenu (appleMenu, DoAppleItem, DoAppleClobber, false);
}


/* -------------------------------------------------------------------- */
/*                    Window-handler interface routines                    */
/* -------------------------------------------------------------------- */


/*
    Install handler for a window and set current port to it.  Remove
    any previous handler for it.  Pass the following parameters:

    theWind    Pointer to the window to be handled.  Must be created by host.
    pMouse    Proc to handle mouse clicks in window.  The proc will be
            passed the point (in local coordinates), the time of the
            click, and the modifier flags word.
    pKey    Proc to handle key clicks in window.  The proc will be passed
            the character and the modifier flags word.
    pUpdate    Proc for updating window.  TransSkel brackets calls to update
            procs with calls to BeginUpdate and EndUpdate, so the visRgn
            is set up correctly.  A flag is passed indicating whether the
            window was resized or not.  BY CONVENTION, the entire portRect
            is invalidated when the window is resized.  That way, the
            handler's update proc can redraw the entire content region
            without interference from BeginUpdate/EndUpdate.  The flag
            is set to false after the update proc is called; the
            assumption is made that it will notice the resizing and
            respond appropriately.
    pActivate Proc to execute when window is activated or deactivated.
            A boolean is passed to it which is true if the window is
            coming active, false if it's going inactive.
    pClose    Proc to execute when mouse clicked in close box.  Useful
            mainly to temp window handlers that want to know when to
            self-destruct (with SkelRmveWind).
    pClobber Proc for disposal of handler's data structures
    pIdle    Proc to execute when no events are pending.
    frontOnly True if pIdle should execute on no events only when
            theWind is frontmost, false if executes all the time.  Note
            that if it always goes, everything else may be slowed down!

    If a particular procedure is not needed (e.g., key events are
    not processed by a handler), pass nil in place of the appropriate
    procedure address.

    Return zero if no handler could be allocated, non-zero if successful.
    If zero is returned, the port will not have changed.
*/

SkelWindow (theWind, pMouse, pKey, pUpdate, pActivate, pClose,
                pClobber, pIdle, frontOnly)

WindowPtr    theWind;
ProcPtr        pMouse, pKey, pUpdate, pActivate, pClose, pClobber, pIdle;
Boolean        frontOnly;
{
register WHandler    **hHand, *hPtr;

    whClobOnRmve = false;
    SkelRmveWind (theWind);
    whClobOnRmve = true;

/*
    Get new handler, attach to list of handlers.  It is attached to the
    beginning of the list, which is simpler; the order is presumably
    irrelevant to the host, anyway.
*/

    if ((hHand = New (WHandler)) != nil)
    {
        (**hHand).whNext = whList;
        whList = hHand;

/*
    Fill in handler fields
*/

        hPtr = *hHand;
        hPtr->whWind = theWind;
        hPtr->whMouse = pMouse;
        hPtr->whKey = pKey;
        hPtr->whUpdate = pUpdate;
        hPtr->whActivate = pActivate;
        hPtr->whClose = pClose;
        hPtr->whClobber = pClobber;
        hPtr->whIdle = pIdle;
        hPtr->whFrontOnly = frontOnly;
        hPtr->whSized = false;
        hPtr->whGrow = growRect;
        SetPort (theWind);
    }
    return (hHand != nil);
}


/*
    Remove a window handler.  This calls the handler's disposal routine
    and then takes the handler out of the handler list and disposes
    of it.

    SkelRmveWind is also called by SkelRmveDlog.

    Note that if the window cache variable is set to the window whose
    handler is being clobbered, the variable must be zeroed.
*/

SkelRmveWind (theWind)
WindowPtr    theWind;
{
register WHandler    **h, **h2;

    if (theWind == oldWindow)
        oldWindow = nil;

    if (whList != nil)        /* if list empty, ignore */
    {
        if ((**whList).whWind == theWind)    /* is it the first element? */
        {
            h2 = whList;
            whList = (**whList).whNext;
        }
        else
        {
            for (h = whList; h != nil; h = h2)
            {
                h2 = (**h).whNext;
                if (h2 == nil)
                    return;                        /* theWind not in list! */
                if ((**h2).whWind == theWind)    /* found it */
                {
                    (**h).whNext = (**h2).whNext;
                    break;
                }
            }
        }
        if (whClobOnRmve)
            DoClobber (h2);        /* call disposal routine */
        DisposHandle (h2);        /* get rid of handler record */
    }
}


# ifdef    supportDialogs

/* -------------------------------------------------------------------- */
/*                    Dialog-handler interface routines                    */
/* -------------------------------------------------------------------- */


/*
    Install a handler for a modeless dialog window and set the port
    to it.  Remove any previous handler for it. SkelDialog calls
    SkelWindow as a subsidiary to install a window handler, then sets
    the event procedure on return.

    Pass the following parameters:

    theDialog    Pointer to the dialog to be handled.  Must be created
            by host.
    pEvent    Event-handling proc for dialog events.
    pClose    Proc to execute when mouse clicked in close box.  Useful
            mainly to dialog handlers that want to know when to
            self-destruct (with SkelRmveDlog).
    pClobber Proc for disposal of handler's data structures

    If a particular procedure is not needed, pass nil in place of
    the appropriate procedure address.

    Return zero if no handler could be allocated, non-zero if successful.
    If zero is returned, the port will not have changed.
*/

SkelDialog (theDialog, pEvent, pClose, pClobber)
DialogPtr    theDialog;
ProcPtr        pEvent;
ProcPtr        pClose;
ProcPtr        pClobber;
{
int        swOk;

    if (SkelWindow (theDialog, nil, nil, nil, nil, pClose, pClobber, nil, false))
    {
        (**GetWDHandler (theDialog)).whEvent = pEvent;
        return (1);
    }
    return (0);
}


/*
    Remove a dialog and its handler
*/

SkelRmveDlog (theDialog)
DialogPtr    theDialog;
{
    SkelRmveWind (theDialog);
}

# endif


/* -------------------------------------------------------------------- */
/*                    Miscellaneous interface routines                    */
/* -------------------------------------------------------------------- */


/*
    Override the default sizing limits for a window, or, if theWind
    is nil, reset the default limits used by SkelWindow.
*/

SkelGrowBounds (theWind, hLo, vLo, hHi, vHi)
WindowPtr    theWind;
Integer            hLo, vLo, hHi, vHi;
{
register WHandler    **h;
Rect                r;

    if (theWind == nil)
        SetRect (&growRect, hLo, vLo, hHi, vHi);
    else if ((h = GetWHandler (theWind)) != nil)
    {
        SetRect (&r, hLo, vLo, hHi, vHi);
        (**h).whGrow = r;
    }
}


/*
    Set the event mask.
*/

SkelEventMask (mask)
Integer        mask;
{
    eventMask = mask;
}


/*
    Return the event mask.
*/

SkelGetEventMask (mask)
Integer        *mask;
{
    *mask = eventMask;
}


/*
    Install a background task.  If p is nil, the current task is
    disabled.
*/

SkelBackground (p)
ProcPtr    p;
{
    pBkgnd = p;
}


/*
    Return the current background task.  Return nil if none.
*/

SkelGetBackground (p)
ProcPtr    *p;
{
    *p = pBkgnd;
}


/*
    Install an event-inspecting hook.  If p is nil, the hook is
    disabled.
*/

SkelEventHook (p)
Boolean    (*p)();
{
    pEvent = p;
}


/*
    Return the current event-inspecting hook.  Return nil if none.
*/

SkelGetEventHook (p)
Boolean    (**p)();
{
    *p = pEvent;
}


# ifdef    supportDialogs

/*
    Set the mask for event types that will be passed to dialogs.
    Bit 1 is always set, so that null events will be examined.
    (If this is not done, the caret does not blink in editText items.)
*/

SkelDlogMask (mask)
Integer        mask;
{
    dlogEventMask = mask | 1;
}


/*
    Return the current dialog event mask.
*/

SkelGetDlogMask (mask)
Integer        *mask;
{
    *mask = dlogEventMask;
}

# endif