/*

    File:       SVAEObjectsExist.c

    Contains:   

    Written by: Original version by Jon Lansdell and Nigel Humphreys.

                3.1 updates by Greg Sutton.

    Copyright:  Copyright © 1995-1999 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):

                7/20/1999   Karl Groethe    Updated for Metrowerks Codewarror Pro 2.1

*/

#include "SVAEObjectsExist.h"

#include "SVEditAEUtils.h"

#pragma segment AppleEvent

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

//  Name:       DoObjectsExist

//  Purpose:    Handles the kAEDoObjectsExist AppleEvent. Basically just

//              tries to resolve the object to see if it exists.

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

pascal OSErr DoObjectsExist(const AppleEvent    *theAppleEvent,

                                    AppleEvent  *reply, 

                                    long        handlerRefCon)

{

#pragma unused (handlerRefCon)

    AEDesc          directObject = {typeNull, NULL},

                    directDesc = {typeNull, NULL},

                    replyDesc = {typeNull, NULL};

    long            itemCount;

    Boolean         exists;

    OSErr           existsErr,

                    err;

    err = AEGetParamDesc(theAppleEvent, keyDirectObject, typeWildCard, &directObject);

    err = GotRequiredParams(theAppleEvent);

    if (noErr != err) goto done;

    if (typeNull == directObject.descriptorType)

        exists = true;      // Yes, our application does exist?????

    else

    {

        existsErr = AEResolve(&directObject, kAEIDoMinimum, &directDesc);

        if (noErr == existsErr)

        {

            if (typeAEList == directDesc.descriptorType)    // If it's a list then objects

            {                                               // exist only if the list

                err = AECountItems(&directDesc, &itemCount);// is not empty.

                if (noErr != err) goto done;

                if (itemCount)

                    exists = true;

                else

                    exists = false;

            }

            else

                exists = true;                              // Otherwise it resolved

        }                                                   // so it exists.

        else

            exists = false;

    }

    err = AECreateDesc(typeBoolean, (Ptr)&exists, sizeof(exists), &replyDesc);

    if (noErr != err) goto done;

    err = AddResultToReply(&replyDesc, reply, err);

done:

    if (directObject.dataHandle)

        AEDisposeDesc(&directObject);

    if (directDesc.dataHandle)

        AEDisposeDesc(&directDesc);

    if (replyDesc.dataHandle)

        AEDisposeDesc(&replyDesc);

    return(err);

} // DoObjectsExist