File indexing completed on 2024-05-05 04:19:18

 // 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.h"
 
 // Qt
 
 // KF
 
 // Local
 #include "gwenview_app_debug.h"
 #include <lib/document/documentfactory.h>
 
 namespace Gwenview
 {
 #undef ENABLE_LOG
 #undef LOG
 // #define ENABLE_LOG
 #ifdef ENABLE_LOG
 #define LOG(x) qCDebug(GWENVIEW_APP_LOG) << x
 #else
 #define LOG(x) ;
 #endif
 
 struct PreloaderPrivate {
     Preloader *q = nullptr;
     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(), nullptr, q, nullptr);
         mDocument = nullptr;
     }
 };
 
 Preloader::Preloader(QObject *parent)
     : QObject(parent)
     , d(new PreloaderPrivate)
 {
     d->q = this;
 }
 
 Preloader::~Preloader()
 {
     delete d;
 }
 
 void Preloader::preload(const QUrl &url, const QSize &size)
 {
     LOG("url=" << url);
     if (d->mDocument) {
         disconnect(d->mDocument.data(), nullptr, this, nullptr);
     }
 
     d->mDocument = DocumentFactory::instance()->load(url);
     d->mSize = size;
     connect(d->mDocument.data(), &Document::metaInfoUpdated, this, &Preloader::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
 
 #include "moc_preloader.cpp"