digikam/digikam/libs/threadimageio/loadingdescription.cpp

/* ============================================================
 *
 * This file is a part of digiKam project
 * http://www.digikam.org
 *
 * Date        : 2007-02-03
 * Description : Loading parameters for multithreaded loading
 *
 * Copyright (C) 2006-2007 by Marcel Wiesweg <marcel.wiesweg@gmx.de>
 *
 * This program is free software; you can redistribute it
 * and/or modify it under the terms of the GNU General
 * Public License as published by the Free Software Foundation;
 * either version 2, or (at your option)
 * any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * ============================================================ */

// Local includes.

#include "loadingdescription.h"

namespace Digikam
{

bool LoadingDescription::PreviewParameters::operator==(const PreviewParameters &other) const
{
    return isPreview  == other.isPreview
            && size       == other.size
            && exifRotate == other.exifRotate;
}

LoadingDescription::LoadingDescription(const TQString &filePath)
    : filePath(filePath)
{
    rawDecodingSettings = DRawDecoding();
}

LoadingDescription::LoadingDescription(const TQString &filePath, DRawDecoding settings)
    : filePath(filePath), rawDecodingSettings(settings)
{
}

LoadingDescription::LoadingDescription(const TQString &filePath, int size, bool exifRotate)
    : filePath(filePath)
{
    rawDecodingSettings = DRawDecoding();
    previewParameters.isPreview  = false;
    previewParameters.size       = size;
    previewParameters.exifRotate = exifRotate;
}

TQString LoadingDescription::cacheKey() const
{
    // Here we have the knowledge which LoadingDescriptions / RawFileDecodingSettings
    // must be cached separately.
    // Current assumption:
    // Eight-bit images are needed for LightTable, and if 16-bit is enabled,
    // 16-bit half size images for the histogram sidebar,
    // and 16-bit full size images for the image editor.
    // Use previewParameters.size, not isPreview - if it is 0, full loading is used.

    TQString suffix = rawDecodingSettings.sixteenBitsImage ? "-16" : "-8";

    if (rawDecodingSettings.halfSizeColorImage)
        return filePath + suffix + "-halfSizeColorImage";
    else if (previewParameters.size)
        return filePath + suffix + "-previewImage";
    else
        return filePath + suffix;
}

TQStringList LoadingDescription::lookupCacheKeys() const
{
    // Build a hierarchy which cache entries may be used for this LoadingDescription.
    // Typically, the first is the best, but an actual loading operation may use a
    // lower-quality loading and will effectively only add the last entry of the
    // list to the cache, although it can accept the first if already available.
    // Sixteen-bit images cannot be used used instead of eight-bit ones because
    // color management is needed to display them.

    TQString suffix = rawDecodingSettings.sixteenBitsImage ? "-16" : "-8";

    TQStringList keys;
    keys.append(filePath + suffix);
    if (rawDecodingSettings.halfSizeColorImage)
        keys.append(filePath + suffix + "-halfSizeColorImage");
    if (previewParameters.size)
        keys.append(filePath + suffix + "-previewImage");
    return keys;
}

bool LoadingDescription::isReducedVersion() const
{
    // return true if this loads anything but the full version
    return rawDecodingSettings.halfSizeColorImage
        || previewParameters.isPreview;
}

bool LoadingDescription::operator==(const LoadingDescription &other) const
{
    return filePath == other.filePath &&
            rawDecodingSettings == other.rawDecodingSettings &&
            previewParameters == other.previewParameters;
}

bool LoadingDescription::equalsIgnoreReducedVersion(const LoadingDescription &other) const
{
    return filePath == other.filePath;
}

bool LoadingDescription::equalsOrBetterThan(const LoadingDescription &other) const
{
    // This method is similar to operator==. But it returns true as well if other
    // Loads a "better" version than this.
    // Preview parameters must have the same size, or other has no size restriction.
    // All raw decoding settings must be equal, only the half size parameter is allowed to vary.

    DRawDecoding fullSize = other.rawDecodingSettings;
    fullSize.halfSizeColorImage = false;

    return filePath == other.filePath &&
            (
             rawDecodingSettings == other.rawDecodingSettings ||
             rawDecodingSettings == fullSize
            ) &&
            (
             (previewParameters.size == other.previewParameters.size) ||
              other.previewParameters.size
            );
}

TQStringList LoadingDescription::possibleCacheKeys(const TQString &filePath)
{
    TQStringList keys;
    keys.append(filePath + "-16");
    keys.append(filePath + "-16-halfSizeColorImage");
    keys.append(filePath + "-16-previewImage");
    keys.append(filePath + "-8");
    keys.append(filePath + "-8-halfSizeColorImage");
    keys.append(filePath + "-8-previewImage");
    return keys;
}


} // namespace Digikam