plasma-workspace/applets/notifications/plugin/thumbnailer.cpp

/*
    Copyright (C) 2016 Kai Uwe Broulik <kde@privat.broulik.de>

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
    License as published by the Free Software Foundation; either
    version 2.1 of the License, or (at your option) any later version.

    This library 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
    Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public
    License along with this library; if not, write to the Free Software
    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
*/

#include "thumbnailer.h"

#include <KIO/PreviewJob>

#include <QApplication>
#include <QClipboard>
#include <QIcon>
#include <QMimeData>
#include <QMenu>
#include <QQuickItem>
#include <QTimer>
#include <QQuickWindow>

#include <KFileItemActions>
#include <KFileItemListProperties>
#include <KLocalizedString>
#include <KProtocolManager>
#include <KPropertiesDialog>
#include <KUrlMimeData>

#include <KIO/OpenFileManagerWindowJob>

Thumbnailer::Thumbnailer(QObject *parent) : QObject(parent)
{

}

Thumbnailer::~Thumbnailer() = default;

void Thumbnailer::classBegin()
{

}

void Thumbnailer::componentComplete()
{
    m_inited = true;
    generatePreview();
}

QUrl Thumbnailer::url() const
{
    return m_url;
}

void Thumbnailer::setUrl(const QUrl &url)
{
    if (m_url != url) {
        m_url = url;
        emit urlChanged();

        generatePreview();
    }
}

QSize Thumbnailer::size() const
{
    return m_size;
}

void Thumbnailer::setSize(const QSize &size)
{
    if (m_size != size) {
        m_size = size;
        emit sizeChanged();

        generatePreview();
    }
}

bool Thumbnailer::hasPreview() const
{
    return !m_pixmap.isNull();
}

QPixmap Thumbnailer::pixmap() const
{
    return m_pixmap;
}

QSize Thumbnailer::pixmapSize() const
{
    return m_pixmap.size();
}

QString Thumbnailer::iconName() const
{
    return m_iconName;
}

bool Thumbnailer::menuVisible() const
{
    return m_menuVisible;
}

void Thumbnailer::showContextMenu(int x, int y, const QString &path, QQuickItem *ctx)
{
    if (!ctx || !ctx->window()) {
        return;
    }

    const QUrl url(path);
    if (!url.isValid()) {
        return;
    }

    KFileItem fileItem(url);

    QMenu *menu = new QMenu();
    menu->setAttribute(Qt::WA_DeleteOnClose, true);

    connect(menu, &QMenu::aboutToHide, this, [this] {
        m_menuVisible = false;
        emit menuVisibleChanged();
    });

    if (KProtocolManager::supportsListing(url)) {
        QAction *openContainingFolderAction = menu->addAction(QIcon::fromTheme(QStringLiteral("folder-open")), i18n("Open Containing Folder"));
        connect(openContainingFolderAction, &QAction::triggered, [url] {
            KIO::highlightInFileManager({url});
        });
    }

    menu->addSeparator();

    // KStandardAction? But then the Ctrl+C shortcut makes no sense in this context
    QAction *copyAction = menu->addAction(QIcon::fromTheme(QStringLiteral("edit-copy")), i18n("&Copy"));
    connect(copyAction, &QAction::triggered, [fileItem] {
        // inspired by KDirModel::mimeData()
        QMimeData *data = new QMimeData(); // who cleans it up?
        KUrlMimeData::setUrls({fileItem.url()}, {fileItem.mostLocalUrl()}, data);
        QApplication::clipboard()->setMimeData(data);
    });

    KFileItemActions *actions = new KFileItemActions(menu);
    KFileItemListProperties itemProperties(KFileItemList({fileItem}));
    actions->setItemListProperties(itemProperties);

    actions->addOpenWithActionsTo(menu);
    actions->addServiceActionsTo(menu);
    actions->addPluginActionsTo(menu);

    QAction *propertiesAction = menu->addAction(QIcon::fromTheme(QStringLiteral("document-properties")), i18n("Properties"));
    connect(propertiesAction, &QAction::triggered, [fileItem] {
        KPropertiesDialog *dialog = new KPropertiesDialog(fileItem.url());
        dialog->setAttribute(Qt::WA_DeleteOnClose);
        dialog->show();
    });

    //this is a workaround where Qt will fail to realise a mouse has been released
    // this happens if a window which does not accept focus spawns a new window that takes focus and X grab
    // whilst the mouse is depressed
    // https://bugreports.qt.io/browse/QTBUG-59044
    // this causes the next click to go missing

    //by releasing manually we avoid that situation
    auto ungrabMouseHack = [ctx]() {
        if (ctx->window()->mouseGrabberItem()) {
            ctx->window()->mouseGrabberItem()->ungrabMouse();
        }
    };

    QTimer::singleShot(0, ctx, ungrabMouseHack);
    //end workaround

    QPoint pos;
    if (x == -1 && y == -1) { // align "bottom left of ctx"
        menu->adjustSize();

        pos = ctx->mapToGlobal(QPointF(0, ctx->height())).toPoint();

        if (!qApp->isRightToLeft()) {
            pos.rx() += ctx->width();
            pos.rx() -= menu->width();
        }
    } else {
        pos = ctx->mapToGlobal(QPointF(x, y)).toPoint();
    }

    menu->popup(pos);

    m_menuVisible = true;
    emit menuVisibleChanged();
}

void Thumbnailer::generatePreview()
{
    if (!m_inited) {
        return;
    }

    if (!m_url.isValid() || !m_url.isLocalFile() || !m_size.isValid()) {
        return;
    }

    auto maxSize = qMax(m_size.width(), m_size.height());
    KIO::PreviewJob *job = KIO::filePreview(KFileItemList({KFileItem(m_url)}), QSize(maxSize,maxSize));
    job->setScaleType(KIO::PreviewJob::Scaled);
    job->setIgnoreMaximumSize(true);

    connect(job, &KIO::PreviewJob::gotPreview, this, [this](const KFileItem &item, const QPixmap &preview) {
        Q_UNUSED(item);
        m_pixmap = preview;
        emit pixmapChanged();

        if (!m_iconName.isEmpty()) {
            m_iconName.clear();
            emit iconNameChanged();
        }
    });

    connect(job, &KIO::PreviewJob::failed, this, [this](const KFileItem &item) {
        m_pixmap = QPixmap();
        emit pixmapChanged();

        const QString &iconName = item.determineMimeType().iconName();
        if (m_iconName != iconName) {
            m_iconName = iconName;
            emit iconNameChanged();
        }
    });

    job->start();
}