From 4d886d083ca6cb2d635da2d29efb804b2680b6de Mon Sep 17 00:00:00 2001 From: Peter Penz Date: Sun, 21 Sep 2008 19:57:37 +0000 Subject: renamed IconManager to KFilePreviewGenerator svn path=/trunk/KDE/kdebase/apps/; revision=863324 --- src/kfilepreviewgenerator.cpp | 596 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 596 insertions(+) create mode 100644 src/kfilepreviewgenerator.cpp (limited to 'src/kfilepreviewgenerator.cpp') diff --git a/src/kfilepreviewgenerator.cpp b/src/kfilepreviewgenerator.cpp new file mode 100644 index 000000000..e81f66980 --- /dev/null +++ b/src/kfilepreviewgenerator.cpp @@ -0,0 +1,596 @@ +/*************************************************************************** + * Copyright (C) 2008 by Peter Penz * + * * + * 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, Boston, MA 02110-1301 USA * + ***************************************************************************/ + +#include "kfilepreviewgenerator.h" + +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include +#include +#include +#include +#include +#include + +/** + * If the passed item view is an instance of QListView, expensive + * layout operations are blocked in the constructor and are unblocked + * again in the destructor. + * + * This helper class is a workaround for the following huge performance + * problem when having directories with several 1000 items: + * - each change of an icon emits a dataChanged() signal from the model + * - QListView iterates through all items on each dataChanged() signal + * and invokes QItemDelegate::sizeHint() + * - the sizeHint() implementation of KFileItemDelegate is quite complex, + * invoking it 1000 times for each icon change might block the UI + * + * QListView does not invoke QItemDelegate::sizeHint() when the + * uniformItemSize property has been set to true, so this property is + * set before exchanging a block of icons. It is important to reset + * it again before the event loop is entered, otherwise QListView + * would not get the correct size hints after dispatching the layoutChanged() + * signal. + */ +class LayoutBlocker { +public: + LayoutBlocker(QAbstractItemView* view) : + m_uniformSizes(false), + m_view(qobject_cast(view)) + { + if (m_view != 0) { + m_uniformSizes = m_view->uniformItemSizes(); + m_view->setUniformItemSizes(true); + } + } + + ~LayoutBlocker() + { + if (m_view != 0) { + m_view->setUniformItemSizes(m_uniformSizes); + } + } + +private: + bool m_uniformSizes; + QListView* m_view; +}; + +KFilePreviewGenerator::KFilePreviewGenerator(QAbstractItemView* parent, KDirSortFilterProxyModel* model) : + QObject(parent), + m_showPreview(false), + m_clearItemQueues(true), + m_hasCutSelection(false), + m_pendingVisiblePreviews(0), + m_view(parent), + m_previewTimer(0), + m_scrollAreaTimer(0), + m_previewJobs(), + m_dirModel(0), + m_proxyModel(model), + m_mimeTypeResolver(0), + m_cutItemsCache(), + m_previews(), + m_pendingItems(), + m_dispatchedItems() +{ + Q_ASSERT(m_view->iconSize().isValid()); // each view must provide its current icon size + + m_dirModel = static_cast(m_proxyModel->sourceModel()); + connect(m_dirModel->dirLister(), SIGNAL(newItems(const KFileItemList&)), + this, SLOT(generatePreviews(const KFileItemList&))); + + QClipboard* clipboard = QApplication::clipboard(); + connect(clipboard, SIGNAL(dataChanged()), + this, SLOT(updateCutItems())); + + m_previewTimer = new QTimer(this); + m_previewTimer->setSingleShot(true); + connect(m_previewTimer, SIGNAL(timeout()), this, SLOT(dispatchPreviewQueue())); + + // Whenever the scrollbar values have been changed, the pending previews should + // be reordered in a way that the previews for the visible items are generated + // first. The reordering is done with a small delay, so that during moving the + // scrollbars the CPU load is kept low. + m_scrollAreaTimer = new QTimer(this); + m_scrollAreaTimer->setSingleShot(true); + m_scrollAreaTimer->setInterval(200); + connect(m_scrollAreaTimer, SIGNAL(timeout()), + this, SLOT(resumePreviews())); + connect(m_view->horizontalScrollBar(), SIGNAL(valueChanged(int)), + this, SLOT(pausePreviews())); + connect(m_view->verticalScrollBar(), SIGNAL(valueChanged(int)), + this, SLOT(pausePreviews())); +} + +KFilePreviewGenerator::~KFilePreviewGenerator() +{ + killPreviewJobs(); + m_pendingItems.clear(); + m_dispatchedItems.clear(); + if (m_mimeTypeResolver != 0) { + m_mimeTypeResolver->deleteLater(); + m_mimeTypeResolver = 0; + } +} + +void KFilePreviewGenerator::setShowPreview(bool show) +{ + if (m_showPreview != show) { + m_showPreview = show; + m_cutItemsCache.clear(); + updateCutItems(); + if (show) { + updatePreviews(); + } + } + + if (show && (m_mimeTypeResolver != 0)) { + // don't resolve the MIME types if the preview is turned on + m_mimeTypeResolver->deleteLater(); + m_mimeTypeResolver = 0; + } else if (!show && (m_mimeTypeResolver == 0)) { + // the preview is turned off: resolve the MIME-types so that + // the icons gets updated + m_mimeTypeResolver = new KMimeTypeResolver(m_view, m_dirModel); + } +} + +void KFilePreviewGenerator::updatePreviews() +{ + if (!m_showPreview) { + return; + } + + killPreviewJobs(); + m_cutItemsCache.clear(); + m_pendingItems.clear(); + m_dispatchedItems.clear(); + + KFileItemList itemList; + const int rowCount = m_dirModel->rowCount(); + for (int row = 0; row < rowCount; ++row) { + const QModelIndex index = m_dirModel->index(row, 0); + KFileItem item = m_dirModel->itemForIndex(index); + itemList.append(item); + } + + generatePreviews(itemList); + updateCutItems(); +} + +void KFilePreviewGenerator::cancelPreviews() +{ + killPreviewJobs(); + m_cutItemsCache.clear(); + m_pendingItems.clear(); + m_dispatchedItems.clear(); +} + +void KFilePreviewGenerator::generatePreviews(const KFileItemList& items) +{ + applyCutItemEffect(); + + if (!m_showPreview) { + return; + } + + KFileItemList orderedItems = items; + orderItems(orderedItems); + + foreach (const KFileItem& item, orderedItems) { + m_pendingItems.append(item); + } + + startPreviewJob(orderedItems); +} + +void KFilePreviewGenerator::addToPreviewQueue(const KFileItem& item, const QPixmap& pixmap) +{ + if (!m_showPreview) { + // the preview has been canceled in the meantime + return; + } + const KUrl url = item.url(); + + // check whether the item is part of the directory lister (it is possible + // that a preview from an old directory lister is received) + KDirLister* dirLister = m_dirModel->dirLister(); + bool isOldPreview = true; + const KUrl::List dirs = dirLister->directories(); + const QString itemDir = url.directory(); + foreach (const KUrl& url, dirs) { + if (url.path() == itemDir) { + isOldPreview = false; + break; + } + } + if (isOldPreview) { + return; + } + + QPixmap icon = pixmap; + + const QString mimeType = item.mimetype(); + const QString mimeTypeGroup = mimeType.left(mimeType.indexOf('/')); + if ((mimeTypeGroup != "image") || !applyImageFrame(icon)) { + limitToSize(icon, m_view->iconSize()); + } + + if (m_hasCutSelection && isCutItem(item)) { + // Remember the current icon in the cache for cut items before + // the disabled effect is applied. This makes it possible restoring + // the uncut version again when cutting other items. + QList::iterator begin = m_cutItemsCache.begin(); + QList::iterator end = m_cutItemsCache.end(); + for (QList::iterator it = begin; it != end; ++it) { + if ((*it).url == item.url()) { + (*it).pixmap = icon; + break; + } + } + + // apply the disabled effect to the icon for marking it as "cut item" + // and apply the icon to the item + KIconEffect iconEffect; + icon = iconEffect.apply(icon, KIconLoader::Desktop, KIconLoader::DisabledState); + } + + // remember the preview and URL, so that it can be applied to the model + // in KFilePreviewGenerator::dispatchPreviewQueue() + ItemInfo preview; + preview.url = url; + preview.pixmap = icon; + m_previews.append(preview); + + m_dispatchedItems.append(item); +} + +void KFilePreviewGenerator::slotPreviewJobFinished(KJob* job) +{ + const int index = m_previewJobs.indexOf(job); + m_previewJobs.removeAt(index); + + if ((m_previewJobs.count() == 0) && m_clearItemQueues) { + m_pendingItems.clear(); + m_dispatchedItems.clear(); + m_pendingVisiblePreviews = 0; + QMetaObject::invokeMethod(this, "dispatchPreviewQueue", Qt::QueuedConnection); + } +} + +void KFilePreviewGenerator::updateCutItems() +{ + // restore the icons of all previously selected items to the + // original state... + foreach (const ItemInfo& cutItem, m_cutItemsCache) { + const QModelIndex index = m_dirModel->indexForUrl(cutItem.url); + if (index.isValid()) { + m_dirModel->setData(index, QIcon(cutItem.pixmap), Qt::DecorationRole); + } + } + m_cutItemsCache.clear(); + + // ... and apply an item effect to all currently cut items + applyCutItemEffect(); +} + +void KFilePreviewGenerator::dispatchPreviewQueue() +{ + const int previewsCount = m_previews.count(); + if (previewsCount > 0) { + // Applying the previews to the model must be done step by step + // in larger blocks: Applying a preview immediately when getting the signal + // 'gotPreview()' from the PreviewJob is too expensive, as a relayout + // of the view would be triggered for each single preview. + LayoutBlocker blocker(m_view); + for (int i = 0; i < previewsCount; ++i) { + const ItemInfo& preview = m_previews.first(); + + const QModelIndex idx = m_dirModel->indexForUrl(preview.url); + if (idx.isValid() && (idx.column() == 0)) { + m_dirModel->setData(idx, QIcon(preview.pixmap), Qt::DecorationRole); + } + + m_previews.pop_front(); + if (m_pendingVisiblePreviews > 0) { + --m_pendingVisiblePreviews; + } + } + } + + if (m_pendingVisiblePreviews > 0) { + // As long as there are pending previews for visible items, poll + // the preview queue each 200 ms. If there are no pending previews, + // the queue is dispatched in slotPreviewJobFinished(). + m_previewTimer->start(200); + } +} + +void KFilePreviewGenerator::pausePreviews() +{ + foreach (KJob* job, m_previewJobs) { + Q_ASSERT(job != 0); + job->suspend(); + } + m_scrollAreaTimer->start(); +} + +void KFilePreviewGenerator::resumePreviews() +{ + // Before creating new preview jobs the m_pendingItems queue must be + // cleaned up by removing the already dispatched items. Implementation + // note: The order of the m_dispatchedItems queue and the m_pendingItems + // queue is usually equal. So even when having a lot of elements the + // nested loop is no performance bottle neck, as the inner loop is only + // entered once in most cases. + foreach (const KFileItem& item, m_dispatchedItems) { + KFileItemList::iterator begin = m_pendingItems.begin(); + KFileItemList::iterator end = m_pendingItems.end(); + for (KFileItemList::iterator it = begin; it != end; ++it) { + if ((*it).url() == item.url()) { + m_pendingItems.erase(it); + break; + } + } + } + m_dispatchedItems.clear(); + + m_pendingVisiblePreviews = 0; + dispatchPreviewQueue(); + + KFileItemList orderedItems = m_pendingItems; + orderItems(orderedItems); + + // Kill all suspended preview jobs. Usually when a preview job + // has been finished, slotPreviewJobFinished() clears all item queues. + // This is not wanted in this case, as a new job is created afterwards + // for m_pendingItems. + m_clearItemQueues = false; + killPreviewJobs(); + m_clearItemQueues = true; + + startPreviewJob(orderedItems); +} + +bool KFilePreviewGenerator::isCutItem(const KFileItem& item) const +{ + const QMimeData* mimeData = QApplication::clipboard()->mimeData(); + const KUrl::List cutUrls = KUrl::List::fromMimeData(mimeData); + + const KUrl itemUrl = item.url(); + foreach (const KUrl& url, cutUrls) { + if (url == itemUrl) { + return true; + } + } + + return false; +} + +void KFilePreviewGenerator::applyCutItemEffect() +{ + const QMimeData* mimeData = QApplication::clipboard()->mimeData(); + m_hasCutSelection = KonqMimeData::decodeIsCutSelection(mimeData); + if (!m_hasCutSelection) { + return; + } + + KFileItemList items; + KDirLister* dirLister = m_dirModel->dirLister(); + const KUrl::List dirs = dirLister->directories(); + foreach (const KUrl& url, dirs) { + items << dirLister->itemsForDir(url); + } + + foreach (const KFileItem& item, items) { + if (isCutItem(item)) { + const QModelIndex index = m_dirModel->indexForItem(item); + const QVariant value = m_dirModel->data(index, Qt::DecorationRole); + if (value.type() == QVariant::Icon) { + const QIcon icon(qvariant_cast(value)); + const QSize actualSize = icon.actualSize(m_view->iconSize()); + QPixmap pixmap = icon.pixmap(actualSize); + + // remember current pixmap for the item to be able + // to restore it when other items get cut + ItemInfo cutItem; + cutItem.url = item.url(); + cutItem.pixmap = pixmap; + m_cutItemsCache.append(cutItem); + + // apply icon effect to the cut item + KIconEffect iconEffect; + pixmap = iconEffect.apply(pixmap, KIconLoader::Desktop, KIconLoader::DisabledState); + m_dirModel->setData(index, QIcon(pixmap), Qt::DecorationRole); + } + } + } +} + +bool KFilePreviewGenerator::applyImageFrame(QPixmap& icon) +{ + const QSize maxSize = m_view->iconSize(); + const bool applyFrame = (maxSize.width() > KIconLoader::SizeSmallMedium) && + (maxSize.height() > KIconLoader::SizeSmallMedium) && + ((icon.width() > KIconLoader::SizeLarge) || + (icon.height() > KIconLoader::SizeLarge)); + if (!applyFrame) { + // the maximum size or the image itself is too small for a frame + return false; + } + + const int frame = 4; + const int doubleFrame = frame * 2; + + // resize the icon to the maximum size minus the space required for the frame + limitToSize(icon, QSize(maxSize.width() - doubleFrame, maxSize.height() - doubleFrame)); + + QPainter painter; + const QPalette palette = m_view->palette(); + QPixmap framedIcon(icon.size().width() + doubleFrame, icon.size().height() + doubleFrame); + framedIcon.fill(palette.color(QPalette::Normal, QPalette::Base)); + const int width = framedIcon.width() - 1; + const int height = framedIcon.height() - 1; + + painter.begin(&framedIcon); + painter.drawPixmap(frame, frame, icon); + + // add a border + painter.setPen(palette.color(QPalette::Text)); + painter.drawRect(0, 0, width, height); + painter.drawRect(1, 1, width - 2, height - 2); + + painter.setCompositionMode(QPainter::CompositionMode_Plus); + QColor blendColor = palette.color(QPalette::Normal, QPalette::Base); + + blendColor.setAlpha(255 - 32); + painter.setPen(blendColor); + painter.drawRect(0, 0, width, height); + + blendColor.setAlpha(255 - 64); + painter.setPen(blendColor); + painter.drawRect(1, 1, width - 2, height - 2); + painter.end(); + + icon = framedIcon; + + return true; +} + +void KFilePreviewGenerator::limitToSize(QPixmap& icon, const QSize& maxSize) +{ + if ((icon.width() > maxSize.width()) || (icon.height() > maxSize.height())) { + icon = icon.scaled(maxSize, Qt::KeepAspectRatio, Qt::FastTransformation); + } +} + +void KFilePreviewGenerator::startPreviewJob(const KFileItemList& items) +{ + if (items.count() == 0) { + return; + } + + const QMimeData* mimeData = QApplication::clipboard()->mimeData(); + m_hasCutSelection = KonqMimeData::decodeIsCutSelection(mimeData); + + const QSize size = m_view->iconSize(); + + // PreviewJob internally caches items always with the size of + // 128 x 128 pixels or 256 x 256 pixels. A downscaling is done + // by PreviewJob if a smaller size is requested. As the KFilePreviewGenerator must + // do a downscaling anyhow because of the frame, only the provided + // cache sizes are requested. + const int cacheSize = (size.width() > 128) || (size.height() > 128) ? 256 : 128; + KIO::PreviewJob* job = KIO::filePreview(items, cacheSize, cacheSize); + connect(job, SIGNAL(gotPreview(const KFileItem&, const QPixmap&)), + this, SLOT(addToPreviewQueue(const KFileItem&, const QPixmap&))); + connect(job, SIGNAL(finished(KJob*)), + this, SLOT(slotPreviewJobFinished(KJob*))); + + m_previewJobs.append(job); + m_previewTimer->start(200); +} + +void KFilePreviewGenerator::killPreviewJobs() +{ + foreach (KJob* job, m_previewJobs) { + Q_ASSERT(job != 0); + job->kill(); + } + m_previewJobs.clear(); +} + +void KFilePreviewGenerator::orderItems(KFileItemList& items) +{ + // Order the items in a way that the preview for the visible items + // is generated first, as this improves the feeled performance a lot. + // + // Implementation note: 2 different algorithms are used for the sorting. + // Algorithm 1 is faster when having a lot of items in comparison + // to the number of rows in the model. Algorithm 2 is faster + // when having quite less items in comparison to the number of rows in + // the model. Choosing the right algorithm is important when having directories + // with several hundreds or thousands of items. + + const int itemCount = items.count(); + const int rowCount = m_proxyModel->rowCount(); + const QRect visibleArea = m_view->viewport()->rect(); + + int insertPos = 0; + if (itemCount * 10 > rowCount) { + // Algorithm 1: The number of items is > 10 % of the row count. Parse all rows + // and check whether the received row is part of the item list. + for (int row = 0; row < rowCount; ++row) { + const QModelIndex proxyIndex = m_proxyModel->index(row, 0); + const QRect itemRect = m_view->visualRect(proxyIndex); + const QModelIndex dirIndex = m_proxyModel->mapToSource(proxyIndex); + + KFileItem item = m_dirModel->itemForIndex(dirIndex); // O(1) + const KUrl url = item.url(); + + // check whether the item is part of the item list 'items' + int index = -1; + for (int i = 0; i < itemCount; ++i) { + if (items.at(i).url() == url) { + index = i; + break; + } + } + + if ((index > 0) && itemRect.intersects(visibleArea)) { + // The current item is (at least partly) visible. Move it + // to the front of the list, so that the preview is + // generated earlier. + items.removeAt(index); + items.insert(insertPos, item); + ++insertPos; + ++m_pendingVisiblePreviews; + } + } + } else { + // Algorithm 2: The number of items is <= 10 % of the row count. In this case iterate + // all items and receive the corresponding row from the item. + for (int i = 0; i < itemCount; ++i) { + const QModelIndex dirIndex = m_dirModel->indexForItem(items.at(i)); // O(n) (n = number of rows) + const QModelIndex proxyIndex = m_proxyModel->mapFromSource(dirIndex); + const QRect itemRect = m_view->visualRect(proxyIndex); + + if (itemRect.intersects(visibleArea)) { + // The current item is (at least partly) visible. Move it + // to the front of the list, so that the preview is + // generated earlier. + items.insert(insertPos, items.at(i)); + items.removeAt(i + 1); + ++insertPos; + ++m_pendingVisiblePreviews; + } + } + } +} + +#include "kfilepreviewgenerator.moc" -- cgit v1.3