exiv2/msvc/exivsimple/exivsimple.cpp

// exivsimple.cpp : Defines the entry point for the DLL application.
//

#include "stdafx.h"
#include "exivsimple.h"
#include "exif.hpp"
#include "iptc.hpp"
#include <cassert>

struct ExivImage
{
    Exiv2::IptcData iptcData;
    Exiv2::ExifData exifData;
    std::string fileName;
};

// Returns 0 if failed.
EXIVSIMPLE_API HIMAGE OpenImage(const char *file)
{
    assert(file);

    ExivImage *image = new ExivImage;
    image->fileName = file;

    // rc of 3 just means no iptc or exif data (not a real error)
    int rc = image->iptcData.read( file );
    if (rc==0 || rc==3)
        rc = image->exifData.read( file );

    if (rc!=0 && rc!=3)  {
        delete image;
        image = 0;
    }

    return (HIMAGE)image;
}

EXIVSIMPLE_API void FreeImage(HIMAGE img)
{
    if (img) {
        ExivImage *image = (ExivImage*)img;
        delete image;
    }
}

EXIVSIMPLE_API int SaveImage(HIMAGE img)
{
    assert(img);
    ExivImage *image = (ExivImage*)img;

    int rc = image->iptcData.write(image->fileName);
    if (rc==0)
        rc = image->exifData.write(image->fileName);

    return rc;
}

// This is weird because iptc and exif have not been "unified". Once
// the API is turned inside out, this DLL should not have to know
// about either... just generic images, keys, values, etc.
// buffsize should be the total size of *buff (including space full null)
// Note that if there is more than one entry (for some IPTC datasets) this
// returns the first one found. Currently no way to get the others.
EXIVSIMPLE_API int ReadMeta(HIMAGE img, const char *key, char *buff, int buffsize)
{
    assert(img && key && buff);
    if (img==0 || key==0 || buff==0 || buffsize==0) return -1;
    ExivImage *image = (ExivImage*)img;
    int rc = 2;

    try {
        Exiv2::IptcKey iptcKey(key);
        rc = 1;
        Exiv2::IptcData::const_iterator iter = image->iptcData.findKey(iptcKey);
        if (iter != image->iptcData.end()) {
            strncpy(buff, iter->value().toString().c_str(), buffsize);
            buff[buffsize-1] = 0;
            rc = 0;
        }
    } 
    catch(const Exiv2::Error&) {
    }

    if (rc) {
        // No iptc value, so try exif
        try {
            Exiv2::ExifKey exifKey(key);
            rc = 1;
            Exiv2::ExifData::const_iterator iter = image->exifData.findKey(exifKey);
            if (iter != image->exifData.end()) {
                strncpy(buff, iter->value().toString().c_str(), buffsize);
                buff[buffsize-1] = 0;
                rc = 0;
            }
        }
        catch(const Exiv2::Error&) {
        }
    }

    return rc;
}

// Overwrites existing value if found, otherwise creates a new one
// Passing invalidTypeId causes the type to be guessed.
// Guessing types is accurate for IPTC but not for EXIF.
EXIVSIMPLE_API int ModifyMeta(HIMAGE img, const char *key, const char *val, DllTypeId type)
{
    assert(img && key && val);
    if (img==0 || key==0 || val==0) return -1;
    ExivImage *image = (ExivImage*)img;
    int rc = 2;

    std::string data(val);
    // if data starts and ends with quotes, remove them
    if (data.at(0) == '\"' && data.at(data.size()-1) == '\"') {
        data = data.substr(1, data.size()-2);
    }

    try {
        Exiv2::IptcKey iptcKey(key);
        rc = 1;

        if (type == invalidTypeId)
            type = (DllTypeId)Exiv2::IptcDataSets::dataSetType(iptcKey.tag(), iptcKey.record());
        Exiv2::Value::AutoPtr value = Exiv2::Value::create((Exiv2::TypeId)type);
        value->read(data);

        Exiv2::IptcData::iterator iter = image->iptcData.findKey(iptcKey);
        if (iter != image->iptcData.end()) {
            iter->setValue(value.get());
            rc = 0;
        }
        else {
            rc = image->iptcData.add(iptcKey, value.get());
        }
    } 
    catch(const Exiv2::Error&) {
    }

    if (rc) {
        // Failed with iptc, so try exif
        try {
            Exiv2::ExifKey exifKey(key);
            rc = 1;

            // No way to get value type for exif... alwayst string??
            if (type == invalidTypeId)
                type = asciiString;
            Exiv2::Value::AutoPtr value = Exiv2::Value::create((Exiv2::TypeId)type);
            value->read(data);

            Exiv2::ExifData::iterator iter = image->exifData.findKey(exifKey);
            if (iter != image->exifData.end()) {
                iter->setValue(value.get());
                rc = 0;
            }
            else {
                image->exifData.add(exifKey, value.get());
                rc = 0;
            }
        }
        catch(const Exiv2::Error&) {
        }
    }

    return rc;
}

// Always creates a new metadata entry.
// Passing invalidTypeId causes the type to be guessed.
// Guessing types is accurate for IPTC but not for EXIF.
EXIVSIMPLE_API int AddMeta(HIMAGE img, const char *key, const char *val, DllTypeId type)
{
    assert(img && key && val);
    if (img==0 || key==0 || val==0) return -1;
    ExivImage *image = (ExivImage*)img;
    int rc = 2;

    std::string data(val);
    // if data starts and ends with quotes, remove them
    if (data.at(0) == '\"' && data.at(data.size()-1) == '\"') {
        data = data.substr(1, data.size()-2);
    }

    try {
        Exiv2::IptcKey iptcKey(key);
        rc = 1;

        if (type == invalidTypeId)
            type = (DllTypeId)Exiv2::IptcDataSets::dataSetType(iptcKey.tag(), iptcKey.record());
        Exiv2::Value::AutoPtr value = Exiv2::Value::create((Exiv2::TypeId)type);
        value->read(data);

        rc = image->iptcData.add(iptcKey, value.get());
    } 
    catch(const Exiv2::Error&) {
    }

    if (rc) {
        // Failed with iptc, so try exif
        try {
            Exiv2::ExifKey exifKey(key);
            rc = 1;

            // No way to get value type for exif... alwayst string??
            if (type == invalidTypeId)
                type = asciiString;
            Exiv2::Value::AutoPtr value = Exiv2::Value::create((Exiv2::TypeId)type);
            value->read(data);

            image->exifData.add(exifKey, value.get());
            rc = 0;
        }
        catch(const Exiv2::Error&) {
        }
    }

    return rc;
}

// If multiple entires exist, this only remove the first one
// found. Call multiple times to remove many.
EXIVSIMPLE_API int RemoveMeta(HIMAGE img, const char *key)
{
    assert(img && key);
    if (img==0 || key==0) return -1;
    ExivImage *image = (ExivImage*)img;
    int rc = 2;

    try {
        Exiv2::IptcKey iptcKey(key);
        rc = 1;
        Exiv2::IptcData::iterator iter = image->iptcData.findKey(iptcKey);
        if (iter != image->iptcData.end()) {
            image->iptcData.erase(iter);
            rc = 0;
        }
    } 
    catch(const Exiv2::Error&) {
    }

    if (rc) {
        // No iptc value, so try exif
        try {
            Exiv2::ExifKey exifKey(key);
            rc = 1;
            Exiv2::ExifData::iterator iter = image->exifData.findKey(exifKey);
            if (iter != image->exifData.end()) {
                image->exifData.erase(iter);
                rc = 0;
            }
        }
        catch(const Exiv2::Error&) {
        }
    }

    return rc;
}

EXIVSIMPLE_API int EnumMeta(HIMAGE img, METAENUMPROC proc, void *user)
{
    assert(img && proc);
    if (img==0 || proc==0) return -1;
    ExivImage *image = (ExivImage*)img;
    bool more = true;

    Exiv2::IptcData::const_iterator iend = image->iptcData.end();
    for (Exiv2::IptcData::const_iterator i = image->iptcData.begin(); 
            i != iend && more; ++i) {
        more = proc(i->key().c_str(), i->value().toString().c_str(), user);
    }

    Exiv2::ExifData::const_iterator eend = image->exifData.end();
    for (Exiv2::ExifData::const_iterator e = image->exifData.begin();
            e != eend && more; ++e) {
        more = proc(e->key().c_str(), e->value().toString().c_str(), user);
    }

    return 0;
}


BOOL APIENTRY DllMain( HANDLE hModule, 
                       DWORD  ul_reason_for_call, 
                       LPVOID lpReserved
					 )
{
	switch (ul_reason_for_call)
	{
	case DLL_PROCESS_ATTACH:
	case DLL_THREAD_ATTACH:
	case DLL_THREAD_DETACH:
	case DLL_PROCESS_DETACH:
		break;
	}
    return TRUE;
}