File indexing completed on 2024-12-01 12:36:08

 /*
     This file is part of the KDE project
     SPDX-FileCopyrightText: 2001 Martin R. Jones <mjones@kde.org>
     SPDX-FileCopyrightText: 2001 Carsten Pfeiffer <pfeiffer@kde.org>
     SPDX-FileCopyrightText: 2008 Rafael Fernández López <ereslibre@kde.org>
 
     SPDX-License-Identifier: LGPL-2.0-only
 */
 
 #include "kimagefilepreview.h"
 
 #include <QCheckBox>
 #include <QLabel>
 #include <QPainter>
 #include <QResizeEvent>
 #include <QStyle>
 #include <QTimeLine>
 #include <QVBoxLayout>
 
 #include <KConfig>
 #include <KConfigGroup>
 #include <KIconLoader>
 #include <KLocalizedString>
 #include <kfileitem.h>
 #include <kio/previewjob.h>
 
 /**** KImageFilePreview ****/
 
 class KImageFilePreviewPrivate
 {
 public:
     KImageFilePreviewPrivate(KImageFilePreview *qq)
         : q(qq)
     {
         if (q->style()->styleHint(QStyle::SH_Widget_Animate, nullptr, q)) {
             m_timeLine = new QTimeLine(150, q);
             m_timeLine->setEasingCurve(QEasingCurve::InCurve);
             m_timeLine->setDirection(QTimeLine::Forward);
             m_timeLine->setFrameRange(0, 100);
         }
     }
 
     void slotResult(KJob *);
     void slotFailed(const KFileItem &);
     void slotStepAnimation();
     void slotFinished();
     void slotActuallyClear();
 
     KImageFilePreview *q = nullptr;
     QUrl currentURL;
     QUrl lastShownURL;
     QLabel *imageLabel;
     KIO::PreviewJob *m_job = nullptr;
     QTimeLine *m_timeLine = nullptr;
     QPixmap m_pmCurrent;
     QPixmap m_pmTransition;
     float m_pmCurrentOpacity = 1;
     float m_pmTransitionOpacity = 0;
     bool clear = true;
 };
 
 KImageFilePreview::KImageFilePreview(QWidget *parent)
     : KPreviewWidgetBase(parent)
     , d(new KImageFilePreviewPrivate(this))
 {
     QVBoxLayout *vb = new QVBoxLayout(this);
     vb->setContentsMargins(0, 0, 0, 0);
 
     d->imageLabel = new QLabel(this);
     d->imageLabel->setAlignment(Qt::AlignHCenter | Qt::AlignVCenter);
     d->imageLabel->setSizePolicy(QSizePolicy(QSizePolicy::Expanding, QSizePolicy::Expanding));
     vb->addWidget(d->imageLabel);
 
     setSupportedMimeTypes(KIO::PreviewJob::supportedMimeTypes());
     setMinimumWidth(50);
 
     if (d->m_timeLine) {
         connect(d->m_timeLine, &QTimeLine::frameChanged, this, [this]() {
             d->slotStepAnimation();
         });
         connect(d->m_timeLine, &QTimeLine::finished, this, [this]() {
             d->slotFinished();
         });
     }
 }
 
 KImageFilePreview::~KImageFilePreview()
 {
     if (d->m_job) {
         d->m_job->kill();
     }
 }
 
 void KImageFilePreview::showPreview()
 {
     // Pass a copy since clearPreview() will clear currentURL
     QUrl url = d->currentURL;
     showPreview(url, true);
 }
 
 // called via KPreviewWidgetBase interface
 void KImageFilePreview::showPreview(const QUrl &url)
 {
     showPreview(url, false);
 }
 
 void KImageFilePreview::showPreview(const QUrl &url, bool force)
 {
     /* clang-format off */
     if (!url.isValid()
         || (d->lastShownURL.isValid()
             && url.matches(d->lastShownURL, QUrl::StripTrailingSlash)
             && d->currentURL.isValid())) {
         return;
     }
     /* clang-format on*/
 
     d->clear = false;
     d->currentURL = url;
     d->lastShownURL = url;
 
     int w = d->imageLabel->contentsRect().width() - 4;
     int h = d->imageLabel->contentsRect().height() - 4;
 
     if (d->m_job) {
         disconnect(d->m_job, nullptr, this, nullptr);
 
         d->m_job->kill();
     }
 
     d->m_job = createJob(url, w, h);
     if (force) { // explicitly requested previews shall always be generated!
         d->m_job->setIgnoreMaximumSize(true);
     }
 
     connect(d->m_job, &KJob::result, this, [this](KJob *job) {
         d->slotResult(job);
     });
     connect(d->m_job, &KIO::PreviewJob::gotPreview, this, &KImageFilePreview::gotPreview);
     connect(d->m_job, &KIO::PreviewJob::failed, this, [this](const KFileItem &item) {
         d->slotFailed(item);
     });
 }
 
 void KImageFilePreview::resizeEvent(QResizeEvent *)
 {
     // Nothing to do, if no current preview
     if (d->imageLabel->pixmap().isNull()) {
         return;
     }
 
     clearPreview();
     d->currentURL = QUrl(); // force this to actually happen
     showPreview(d->lastShownURL);
 }
 
 QSize KImageFilePreview::sizeHint() const
 {
     return QSize(100, 200);
 }
 
 KIO::PreviewJob *KImageFilePreview::createJob(const QUrl &url, int w, int h)
 {
     if (!url.isValid()) {
         return nullptr;
     }
 
     KFileItemList items;
     items.append(KFileItem(url));
     QStringList plugins = KIO::PreviewJob::availablePlugins();
 
     KIO::PreviewJob *previewJob = KIO::filePreview(items, QSize(w, h), &plugins);
 #if KIOWIDGETS_BUILD_DEPRECATED_SINCE(5, 102)
     previewJob->setOverlayIconAlpha(0);
 #endif
     previewJob->setScaleType(KIO::PreviewJob::Scaled);
     return previewJob;
 }
 
 void KImageFilePreview::gotPreview(const KFileItem &item, const QPixmap &pm)
 {
     if (item.url() != d->currentURL) { // Shouldn't happen
         return;
     }
 
     if (d->m_timeLine) {
         if (d->m_timeLine->state() == QTimeLine::Running) {
             d->m_timeLine->setCurrentTime(0);
         }
 
         d->m_pmTransition = pm;
         d->m_pmTransitionOpacity = 0;
         d->m_pmCurrentOpacity = 1;
         d->m_timeLine->setDirection(QTimeLine::Forward);
         d->m_timeLine->start();
     } else {
         d->imageLabel->setPixmap(pm);
     }
 }
 
 void KImageFilePreviewPrivate::slotFailed(const KFileItem &item)
 {
     if (item.isDir()) {
         imageLabel->clear();
     } else if (item.url() == currentURL) { // should always be the case
         imageLabel->setPixmap(QIcon::fromTheme(QStringLiteral("image-missing")).pixmap(KIconLoader::SizeLarge, QIcon::Disabled));
     }
 }
 
 void KImageFilePreviewPrivate::slotResult(KJob *job)
 {
     if (job == m_job) {
         m_job = nullptr;
     }
 }
 
 void KImageFilePreviewPrivate::slotStepAnimation()
 {
     const QSize currSize = m_pmCurrent.size();
     const QSize transitionSize = m_pmTransition.size();
     const int width = std::max(currSize.width(), transitionSize.width());
     const int height = std::max(currSize.height(), transitionSize.height());
     QPixmap pm(QSize(width, height));
     pm.fill(Qt::transparent);
 
     QPainter p(&pm);
     p.setOpacity(m_pmCurrentOpacity);
 
     // If we have a current pixmap
     if (!m_pmCurrent.isNull()) {
         p.drawPixmap(QPoint(((float)pm.size().width() - m_pmCurrent.size().width()) / 2.0, ((float)pm.size().height() - m_pmCurrent.size().height()) / 2.0),
                      m_pmCurrent);
     }
     if (!m_pmTransition.isNull()) {
         p.setOpacity(m_pmTransitionOpacity);
         p.drawPixmap(
             QPoint(((float)pm.size().width() - m_pmTransition.size().width()) / 2.0, ((float)pm.size().height() - m_pmTransition.size().height()) / 2.0),
             m_pmTransition);
     }
     p.end();
 
     imageLabel->setPixmap(pm);
 
     m_pmCurrentOpacity = qMax(m_pmCurrentOpacity - 0.4, 0.0); // krazy:exclude=qminmax
     m_pmTransitionOpacity = qMin(m_pmTransitionOpacity + 0.4, 1.0); // krazy:exclude=qminmax
 }
 
 void KImageFilePreviewPrivate::slotFinished()
 {
     m_pmCurrent = m_pmTransition;
     m_pmTransitionOpacity = 0;
     m_pmCurrentOpacity = 1;
     m_pmTransition = QPixmap();
     // The animation might have lost some frames. Be sure that if the last one
     // was dropped, the last image shown is the opaque one.
     imageLabel->setPixmap(m_pmCurrent);
     clear = false;
 }
 
 void KImageFilePreview::clearPreview()
 {
     if (d->m_job) {
         d->m_job->kill();
         d->m_job = nullptr;
     }
 
     if (d->clear || (d->m_timeLine && d->m_timeLine->state() == QTimeLine::Running)) {
         return;
     }
 
     if (d->m_timeLine) {
         d->m_pmTransition = QPixmap();
         // If we add a previous preview then we run the animation
         if (!d->m_pmCurrent.isNull()) {
             d->m_timeLine->setCurrentTime(0);
             d->m_timeLine->setDirection(QTimeLine::Backward);
             d->m_timeLine->start();
         }
         d->currentURL.clear();
         d->clear = true;
     } else {
         d->imageLabel->clear();
     }
 }
 
 #include "moc_kimagefilepreview.cpp"