Developer CD Series 1994…tember: Reference Library/Dev.CD Sep 94.toast/Periodicals/develop/develop Issue 18/develop 18 code/OSA Sample/Sources/ListOfLongs.cp

Text File | 1994-01-28 | 8.0 KB | 478 lines | [TEXT/MPS ]

/*
    File:        ListOfLongs.cp

    Contains:    TListOfLongs implementation.

    Developed by:

        Paul G Smith (commstalk hq & Full Moon Software, Inc)

        you can leave messages at (UK): 0727 844232; (US): 408 253 7199
        BUT I prefer to be contacted by e-mail
        AppleLink:     SMITH.PG
        Internet:     [e-mail]

        "SimpliFace" Sample code to accompany develop article
        on techniques for embedding scripts in applications.


    Ordered and un-ordered lists of long integers

*/

#include "ListOfLongs.h"

#ifndef __LIMITS__
#include <Limits.h>
#endif

#ifndef __ERRORS__
#include <Errors.h>
#endif

#ifndef __RESOURCES__
#include <Resources.h>
#endif

#ifndef __PACKAGES__
#include <Packages.h>
#endif




const short kLListChunkUnit = 16;
const short kLListChunkSize = kLListChunkUnit*sizeof(long);    // allocation chunk size

/*******************************************************************************
** TListOfLongs: Constructor/Destructor
********************************************************************************/

TListOfLongs::TListOfLongs()
{
    fNumItems = 0;
    fDataHandle = NewHandle(kLListChunkSize);
}


TListOfLongs::TListOfLongs(const TListOfLongs& oldObj)
{
    Handle h = oldObj.fDataHandle;
    HandToHand(&h);
    if (h)
        fDataHandle = h;
    fNumItems = oldObj.fNumItems;
}


TListOfLongs::~TListOfLongs(void)
{
    if (fDataHandle)
        DisposHandle(fDataHandle);
}


TListOfLongs& TListOfLongs::operator=(const TListOfLongs& oldObj)
{
    if (this != &oldObj)
    {
        Handle h = oldObj.fDataHandle;
        HandToHand(&h);
        if (h)
        {
            if (fDataHandle)
                DisposHandle(fDataHandle);
            fDataHandle = h;
        }
        fNumItems = oldObj.fNumItems;
    }
    return *this;
}


// the business

Handle TListOfLongs::GetData(void)
{
    Handle     h = NULL;
    long     numElems = fNumItems;
    OSErr    err = 0;

    if ((numElems > 0) && fDataHandle)
    {
        HLock(fDataHandle);
        err = PtrToHand(*fDataHandle, &h, numElems*sizeof(long));
        HUnlock(fDataHandle);
    }
    else
        h = NewHandle(0);

    return h;
}


void TListOfLongs::SetData(Handle h)
{
    fNumItems = 0;

    if (h)
    {
        long     hs = GetHandleSize(h);
        long    numItems = hs / sizeof(long);
        if (numItems < 0)
            numItems = 0;
        if (numItems)
        {
            Handle nh = h;
            OSErr err = HandToHand(&nh);
            if (!err)
            {
                fNumItems = numItems;
                DisposHandle(fDataHandle);
                fDataHandle = nh;
            }
        }
    }
}



OSErr TListOfLongs::ExpandDataHandle(long numLongs)
{
    OSErr err = 0;

    if (fDataHandle)
    {
        long     numElems = fNumItems;
        Handle    h = fDataHandle;
        long    oldSize = GetHandleSize(h);

        if (((numElems+numLongs) * sizeof(long)) > oldSize)
        {
            long    addSize = (numLongs / kLListChunkUnit) + 1;

            SetHandleSize(h, oldSize + addSize * kLListChunkSize);
            err = MemError();
        }
    }
    else
        err = nilHandleErr;

    return err;
}



OSErr TListOfLongs::ShrinkDataHandle(long numLongs)
{
    return noErr;        // do nothing, for time being
}



OSErr TListOfLongs::InsertElement(long val)
{
    OSErr err = noErr;

    if (!FindElement(val))    // if it's already there, do nothing
    {
        long     lastItem = fNumItems;
        long**     dh = (long**) fDataHandle;

        err = ExpandDataHandle(1);    // grows dh, if more room is needed

        HLock(fDataHandle);        // locks dh

        while (lastItem > 0)
        {
            long     lastVal = (*dh)[lastItem-1];    // because array is indexed from 0
            if (lastVal > val)
            {
                (*dh)[lastItem] = lastVal;
                lastItem--;
            }
            else
                break;    // insert here!
        }
        (*dh)[lastItem] = val;
        fNumItems = fNumItems + 1;

        HUnlock(fDataHandle);
    }

    return err;
}


void TListOfLongs::DeleteElement(long val)
{
    long    foundIndex = FindElement(val);

    if (foundIndex)
    {
        long     numElems = fNumItems;

        if ((numElems > 0) && fDataHandle)
        {
            long**     dh = (long**) fDataHandle;
            long    currentIndex = foundIndex-1;

            HLock(fDataHandle);        // locks dh

            while (currentIndex < numElems-1)
            {
                (*dh)[currentIndex] = (*dh)[currentIndex+1];
                currentIndex++;
            }
            fNumItems = fNumItems - 1;

            HUnlock(fDataHandle);

            ShrinkDataHandle(1);
        }
    }
}




long TListOfLongs::GetElement(long index)
{
    long     numElems = fNumItems;

    if ((numElems > 0) && fDataHandle)
    {
        long**     dh = (long**) fDataHandle;
        long    val = 0;

        HLock(fDataHandle);    // locks dh
        val = (*dh)[index-1];
        HUnlock(fDataHandle);

        return val;
    }
    else
        return 0;
}


long TListOfLongs::FindElement(long val)
{
    long     numElems = fNumItems;

    if ((numElems > 0) && fDataHandle)
    {
        long**     dh = (long**) fDataHandle;
        long     currentIndex = 0;
        long     currentVal = 0;
        long     lowBound = 1;
        long     highBound = numElems;
        Boolean    found = false;

        HLock(fDataHandle);    // locks dh

        do
        {
            currentIndex = (lowBound + highBound) >> 1;      // == divide by 2
            currentVal = (*dh)[currentIndex-1];
            if (val < currentVal)
                highBound = currentIndex-1;
            else
                lowBound = currentIndex+1;
            found = (val == currentVal);
        } while (!(found || (lowBound > highBound)));

        if (!found)
            currentIndex = 0;

        HUnlock(fDataHandle);

        return currentIndex;
    }
    else
        return 0;
}



/*******************************************************************************
** TOrderedListOfLongs: Constructor/Destructor
********************************************************************************/

TOrderedListOfLongs::TOrderedListOfLongs()
{
}


TOrderedListOfLongs::TOrderedListOfLongs(const TOrderedListOfLongs& oldObj)
{
    (TListOfLongs&)(*this) = (TListOfLongs&)oldObj;
}


TOrderedListOfLongs::~TOrderedListOfLongs(void)
{
}


TOrderedListOfLongs& TOrderedListOfLongs::operator=(const TOrderedListOfLongs& oldObj)
{
    (TListOfLongs&)(*this) = (TListOfLongs&)oldObj;
    return *this;
}


// the business


OSErr TOrderedListOfLongs::InsertElement(long val)
{
    return -1;
}


OSErr TOrderedListOfLongs::InsertElementAt(long val, long index)
{
    OSErr err = noErr;

    if (!FindElement(val))    // if it's already there, do nothing
    {
        long     lastItem = fNumItems;
        long**     dh = (long**) fDataHandle;

        err = ExpandDataHandle(1);    // grows dh, if more room is needed

        HLock(fDataHandle);        // locks dh

        if (index <= 1)
            index = 1;
        while (lastItem >= index)
        {
            (*dh)[lastItem] = (*dh)[lastItem-1]; // because array is indexed from 0
            lastItem--;
        }
        (*dh)[lastItem] = val;
        fNumItems = fNumItems + 1;

        HUnlock(fDataHandle);
    }

    return err;
}


long TOrderedListOfLongs::FindElement(long val)
{
    long     numElems = fNumItems;

    if ((numElems > 0) && fDataHandle)
    {
        long**     dh = (long**) fDataHandle;
        long     currentIndex = numElems;
        long     currentVal;
        Boolean    found = false;

        HLock(fDataHandle);    // locks dh

        do
        {
            currentVal = (*dh)[currentIndex-1];
            found = (val == currentVal);
            if (!found)
                currentIndex--;
        } while (!found && currentIndex > 0);

        if (!found)
            currentIndex = 0;

        HUnlock(fDataHandle);

        return currentIndex;
    }
    else
        return 0;
}



/*******************************************************************************
** TStackOfLongs: Constructor/Destructor
********************************************************************************/

TStackOfLongs::TStackOfLongs()
{
}


TStackOfLongs::TStackOfLongs(const TStackOfLongs& oldObj)
{
    (TListOfLongs&)(*this) = (TListOfLongs&)oldObj;
}


TStackOfLongs::~TStackOfLongs(void)
{
}


TStackOfLongs& TStackOfLongs::operator=(const TStackOfLongs& oldObj)
{
    (TListOfLongs&)(*this) = (TListOfLongs&)oldObj;
    return *this;
}


// the business


OSErr TStackOfLongs::InsertElement(long val)
{
    return -1;
}


long TStackOfLongs::FindElement(long val)
{
    return -1;
}



OSErr TStackOfLongs::PushElement(long val)
{
    OSErr     err = noErr;
    long     lastItem = fNumItems;
    long**     dh = (long**) fDataHandle;

    err = ExpandDataHandle(1);    // grows dh, if more room is needed

    HLock(fDataHandle);        // locks dh
    (*dh)[lastItem] = val;
    fNumItems = fNumItems + 1;
    HUnlock(fDataHandle);

    return err;
}


OSErr TStackOfLongs::PopElement(long *val)
{
    OSErr     err = noErr;
    long    lastItem = fNumItems;
    long**     dh = (long**) fDataHandle;

    HLock(fDataHandle);        // locks dh
    if (lastItem > 0)
        *val = (*dh)[lastItem-1];
    else
        err = -1;
    fNumItems = fNumItems - 1;
    HUnlock(fDataHandle);

    if (!err)
        err = ShrinkDataHandle(1);

    return err;
}