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// vim: set tabstop=4 shiftwidth=4 expandtab:
/*
Gwenview: an image viewer
Copyright 2008 Aurélien Gâteau <agateau@kde.org>
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
of the License, 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.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Cambridge, MA 02110-1301, USA.
*/
// Self
#include "preloader.moc"
// Qt
// KDE
#include <KDebug>
// Local
#include <lib/document/documentfactory.h>
namespace Gwenview
{
#undef ENABLE_LOG
#undef LOG
//#define ENABLE_LOG
#ifdef ENABLE_LOG
#define LOG(x) kDebug() << x
#else
#define LOG(x) ;
#endif
struct PreloaderPrivate
{
Preloader* q;
Document::Ptr mDocument;
QSize mSize;
void forgetDocument()
{
// Forget about the document. Keeping a reference to it would prevent it
// from being garbage collected.
QObject::disconnect(mDocument.data(), 0, q, 0);
mDocument = 0;
}
};
Preloader::Preloader(QObject* parent)
: QObject(parent)
, d(new PreloaderPrivate)
{
d->q = this;
}
Preloader::~Preloader()
{
delete d;
}
void Preloader::preload(const KUrl& url, const QSize& size)
{
LOG("url=" << url);
if (d->mDocument) {
disconnect(d->mDocument.data(), 0, this, 0);
}
d->mDocument = DocumentFactory::instance()->load(url);
d->mSize = size;
connect(d->mDocument.data(), SIGNAL(metaInfoUpdated()),
SLOT(doPreload()));
if (d->mDocument->size().isValid()) {
LOG("size is already available");
doPreload();
}
}
void Preloader::doPreload()
{
if (!d->mDocument) {
return;
}
if (d->mDocument->loadingState() == Document::LoadingFailed) {
LOG("loading failed");
d->forgetDocument();
return;
}
if (!d->mDocument->size().isValid()) {
LOG("size not available yet");
return;
}
qreal zoom = qMin(
d->mSize.width() / qreal(d->mDocument->width()),
d->mSize.height() / qreal(d->mDocument->height())
);
if (zoom < Document::maxDownSampledZoom()) {
LOG("preloading down sampled, zoom=" << zoom);
d->mDocument->prepareDownSampledImageForZoom(zoom);
} else {
LOG("preloading full image");
d->mDocument->startLoadingFullImage();
}
d->forgetDocument();
}
} // namespace
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