kolourpaint/layers/selections/kpSelectionDrag.cpp

/*
   Copyright (c) 2003-2007 Clarence Dang <dang@kde.org>
   Copyright (c) 2011 Martin Koller <kollix@aon.at>
   All rights reserved.

   Redistribution and use in source and binary forms, with or without
   modification, are permitted provided that the following conditions
   are met:

   1. Redistributions of source code must retain the above copyright
      notice, this list of conditions and the following disclaimer.
   2. Redistributions in binary form must reproduce the above copyright
      notice, this list of conditions and the following disclaimer in the
      documentation and/or other materials provided with the distribution.

   THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
   IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
   OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
   IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
   INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
   NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
   THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/


#define DEBUG_KP_SELECTION_DRAG 0


#include "kpSelectionDrag.h"

#include <QDataStream>
#include <QImage>
#include <QIODevice>
#include <QUrl>

#include "kpLogCategories.h"

#include "kpSelectionFactory.h"
#include "layers/selections/image/kpAbstractImageSelection.h"
#include "layers/selections/image/kpRectangularImageSelection.h"

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

// public static
const char * const kpSelectionDrag::SelectionMimeType =
    "application/x-kolourpaint-selection-400";

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

kpSelectionDrag::kpSelectionDrag (const kpAbstractImageSelection &sel)
{
#if DEBUG_KP_SELECTION_DRAG && 1
    qCDebug(kpLogLayers) << "kpSelectionDrag() w=" << sel.width ()
               << " h=" << sel.height ();
#endif

    Q_ASSERT (sel.hasContent ());

    // Store as selection.
    QByteArray ba;
    {
        QDataStream stream (&ba, QIODevice::WriteOnly);
        stream << sel;
    }
    setData (kpSelectionDrag::SelectionMimeType, ba);

    // Store as image (so that QMimeData::hasImage()) works).
    // OPT: an awful waste of memory storing image in both selection and QImage
    const QImage image = sel.baseImage ();
#if DEBUG_KP_SELECTION_DRAG && 1
    qCDebug(kpLogLayers) << "\timage: w=" << image.width ()
               << " h=" << image.height ();
#endif
    if (image.isNull ())
    {
        // TODO: proper error handling.
        qCCritical(kpLogLayers) << "kpSelectionDrag::setSelection() could not convert to image";
    }
    else {
        setImageData (image);
    }
}

//---------------------------------------------------------------------
// public static

bool kpSelectionDrag::canDecode(const QMimeData *mimeData)
{
    Q_ASSERT(mimeData);

#if DEBUG_KP_SELECTION_DRAG
    qCDebug(kpLogLayers) << "kpSelectionDrag::canDecode()"
             << "hasSel=" << mimeData->hasFormat(kpSelectionDrag::SelectionMimeType)
             << "hasImage=" << mimeData->hasImage();
#endif

    // mimeData->hasImage() would not check if the data is a valid image
    return mimeData->hasFormat(kpSelectionDrag::SelectionMimeType) ||
           !qvariant_cast<QImage>(mimeData->imageData()).isNull();
}

//---------------------------------------------------------------------
// public static

kpAbstractImageSelection *kpSelectionDrag::decode(const QMimeData *mimeData)
{
#if DEBUG_KP_SELECTION_DRAG
    qCDebug(kpLogLayers) << "kpSelectionDrag::decode(kpAbstractSelection)";
#endif
    Q_ASSERT (mimeData);

    if (mimeData->hasFormat (kpSelectionDrag::SelectionMimeType))
    {
    #if DEBUG_KP_SELECTION_DRAG
        qCDebug(kpLogLayers) << "\tmimeSource hasFormat selection - just return it in QByteArray";
    #endif
        QByteArray data = mimeData->data (kpSelectionDrag::SelectionMimeType);
        QDataStream stream (&data, QIODevice::ReadOnly);

        return kpSelectionFactory::FromStream (stream);
    }


#if DEBUG_KP_SELECTION_DRAG
    qCDebug(kpLogLayers) << "\tmimeSource doesn't provide selection - try image";
#endif

    QImage image = qvariant_cast <QImage> (mimeData->imageData ());
    if (!image.isNull ())
    {
#if DEBUG_KP_SELECTION_DRAG
        qCDebug(kpLogLayers) << "\tok w=" << image.width () << " h=" << image.height ();
#endif

        return new kpRectangularImageSelection (
                    QRect (0, 0, image.width (), image.height ()), image);
    }

    if ( mimeData->hasUrls() )  // no image, check for path to local image file
    {
        QList<QUrl> urls = mimeData->urls();

        if ( urls.count() && urls[0].isLocalFile() )
        {
            image.load(urls[0].toLocalFile());

            if ( !image.isNull() )
            {
                return new kpRectangularImageSelection(
                            QRect(0, 0, image.width(), image.height()), image);
            }
        }
    }

      #if DEBUG_KP_SELECTION_DRAG
        qCDebug(kpLogLayers) << "kpSelectionDrag::decode(kpAbstractSelection) mimeSource had no sel "
                      "and could not decode to image";
      #endif
      return nullptr;

}

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