src/iconmanager.cpp

   1 /***************************************************************************
   2  *   Copyright (C) 2008 by Peter Penz <peter.penz@gmx.at>                  *
   3  *                                                                         *
   4  *   This program is free software; you can redistribute it and/or modify  *
   5  *   it under the terms of the GNU General Public License as published by  *
   6  *   the Free Software Foundation; either version 2 of the License, or     *
   7  *   (at your option) any later version.                                   *
   8  *                                                                         *
   9  *   This program is distributed in the hope that it will be useful,       *
  10  *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
  11  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
  12  *   GNU General Public License for more details.                          *
  13  *                                                                         *
  14  *   You should have received a copy of the GNU General Public License     *
  15  *   along with this program; if not, write to the                         *
  16  *   Free Software Foundation, Inc.,                                       *
  17  *   51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA            *
  18  ***************************************************************************/
  19
  20 #include "iconmanager.h"
  21
  22 #include "dolphinmodel.h"
  23 #include "dolphinsortfilterproxymodel.h"
  24
  25 #include <kiconeffect.h>
  26 #include <kio/previewjob.h>
  27 #include <kdirlister.h>
  28 #include <kmimetyperesolver.h>
  29 #include <konqmimedata.h>
  30
  31 #include <QApplication>
  32 #include <QAbstractItemView>
  33 #include <QClipboard>
  34 #include <QColor>
  35 #include <QListView>
  36 #include <QPainter>
  37 #include <QScrollBar>
  38 #include <QIcon>
  39
  40 /**
  41  * If the passed item view is an instance of QListView, expensive
  42  * layout operations are blocked in the constructor and are unblocked
  43  * again in the destructor.
  44  *
  45  * This helper class is a workaround for the following huge performance
  46  * problem when having directories with several 1000 items:
  47  * - each change of an icon emits a dataChanged() signal from the model
  48  * - QListView iterates through all items on each dataChanged() signal
  49  *   and invokes QItemDelegate::sizeHint()
  50  * - the sizeHint() implementation of KFileItemDelegate is quite complex,
  51  *   invoking it 1000 times for each icon change might block the UI
  52  *
  53  * QListView does not invoke QItemDelegate::sizeHint() when the
  54  * uniformItemSize property has been set to true, so this property is
  55  * set before exchanging a block of icons. It is important to reset
  56  * it again before the event loop is entered, otherwise QListView
  57  * would not get the correct size hints after dispatching the layoutChanged()
  58  * signal.
  59  */
  60 class LayoutBlocker {
  61 public:
  62     LayoutBlocker(QAbstractItemView* view) :
  63         m_uniformSizes(false),
  64         m_view(qobject_cast<QListView*>(view))
  65     {
  66         if (m_view != 0) {
  67             m_uniformSizes = m_view->uniformItemSizes();
  68             m_view->setUniformItemSizes(true);
  69         }
  70     }
  71
  72     ~LayoutBlocker()
  73     {
  74         if (m_view != 0) {
  75             m_view->setUniformItemSizes(m_uniformSizes);
  76         }
  77     }
  78
  79 private:
  80     bool m_uniformSizes;
  81     QListView* m_view;
  82 };
  83
  84 IconManager::IconManager(QAbstractItemView* parent, DolphinSortFilterProxyModel* model) :
  85     QObject(parent),
  86     m_showPreview(false),
  87     m_clearItemQueues(true),
  88     m_pendingVisiblePreviews(0),
  89     m_view(parent),
  90     m_previewTimer(0),
  91     m_scrollAreaTimer(0),
  92     m_previewJobs(),
  93     m_dolphinModel(0),
  94     m_proxyModel(model),
  95     m_mimeTypeResolver(0),
  96     m_cutItemsCache(),
  97     m_previews(),
  98     m_pendingItems(),
  99     m_dispatchedItems()
 100 {
 101     Q_ASSERT(m_view->iconSize().isValid());  // each view must provide its current icon size
 102
 103     m_dolphinModel = static_cast<DolphinModel*>(m_proxyModel->sourceModel());
 104     connect(m_dolphinModel->dirLister(), SIGNAL(newItems(const KFileItemList&)),
 105             this, SLOT(generatePreviews(const KFileItemList&)));
 106
 107     QClipboard* clipboard = QApplication::clipboard();
 108     connect(clipboard, SIGNAL(dataChanged()),
 109             this, SLOT(updateCutItems()));
 110
 111     m_previewTimer = new QTimer(this);
 112     m_previewTimer->setSingleShot(true);
 113     connect(m_previewTimer, SIGNAL(timeout()), this, SLOT(dispatchPreviewQueue()));
 114
 115     // Whenever the scrollbar values have been changed, the pending previews should
 116     // be reordered in a way that the previews for the visible items are generated
 117     // first. The reordering is done with a small delay, so that during moving the
 118     // scrollbars the CPU load is kept low.
 119     m_scrollAreaTimer = new QTimer(this);
 120     m_scrollAreaTimer->setSingleShot(true);
 121     m_scrollAreaTimer->setInterval(200);
 122     connect(m_scrollAreaTimer, SIGNAL(timeout()),
 123             this, SLOT(resumePreviews()));
 124     connect(m_view->horizontalScrollBar(), SIGNAL(valueChanged(int)),
 125             this, SLOT(pausePreviews()));
 126     connect(m_view->verticalScrollBar(), SIGNAL(valueChanged(int)),
 127             this, SLOT(pausePreviews()));
 128 }
 129
 130 IconManager::~IconManager()
 131 {
 132     killPreviewJobs();
 133     m_pendingItems.clear();
 134     m_dispatchedItems.clear();
 135     if (m_mimeTypeResolver != 0) {
 136         m_mimeTypeResolver->deleteLater();
 137         m_mimeTypeResolver = 0;
 138     }
 139 }
 140
 141
 142 void IconManager::setShowPreview(bool show)
 143 {
 144     if (m_showPreview != show) {
 145         m_showPreview = show;
 146         m_cutItemsCache.clear();
 147         updateCutItems();
 148         if (show) {
 149             updatePreviews();
 150         }
 151     }
 152
 153     if (show && (m_mimeTypeResolver != 0)) {
 154         // don't resolve the MIME types if the preview is turned on
 155         m_mimeTypeResolver->deleteLater();
 156         m_mimeTypeResolver = 0;
 157     } else if (!show && (m_mimeTypeResolver == 0)) {
 158         // the preview is turned off: resolve the MIME-types so that
 159         // the icons gets updated
 160         m_mimeTypeResolver = new KMimeTypeResolver(m_view, m_dolphinModel);
 161     }
 162 }
 163
 164 void IconManager::updatePreviews()
 165 {
 166     if (!m_showPreview) {
 167         return;
 168     }
 169
 170     killPreviewJobs();
 171     m_cutItemsCache.clear();
 172     m_pendingItems.clear();
 173     m_dispatchedItems.clear();
 174
 175     KFileItemList itemList;
 176     const int rowCount = m_dolphinModel->rowCount();
 177     for (int row = 0; row < rowCount; ++row) {
 178         const QModelIndex index = m_dolphinModel->index(row, 0);
 179         KFileItem item = m_dolphinModel->itemForIndex(index);
 180         itemList.append(item);
 181     }
 182
 183     generatePreviews(itemList);
 184     updateCutItems();
 185 }
 186
 187 void IconManager::cancelPreviews()
 188 {
 189     killPreviewJobs();
 190     m_cutItemsCache.clear();
 191     m_pendingItems.clear();
 192     m_dispatchedItems.clear();
 193 }
 194
 195 void IconManager::generatePreviews(const KFileItemList& items)
 196 {
 197     applyCutItemEffect();
 198
 199     if (!m_showPreview) {
 200         return;
 201     }
 202
 203     KFileItemList orderedItems = items;
 204     orderItems(orderedItems);
 205
 206     foreach (const KFileItem& item, orderedItems) {
 207         m_pendingItems.append(item);
 208     }
 209
 210     startPreviewJob(orderedItems);
 211 }
 212
 213 void IconManager::addToPreviewQueue(const KFileItem& item, const QPixmap& pixmap)
 214 {
 215     ItemInfo preview;
 216     preview.url = item.url();
 217     preview.pixmap = pixmap;
 218     m_previews.append(preview);
 219
 220     m_dispatchedItems.append(item);
 221 }
 222
 223 void IconManager::slotPreviewJobFinished(KJob* job)
 224 {
 225     const int index = m_previewJobs.indexOf(job);
 226     m_previewJobs.removeAt(index);
 227
 228     if ((m_previewJobs.count() == 0) && m_clearItemQueues) {
 229         m_pendingItems.clear();
 230         m_dispatchedItems.clear();
 231         m_pendingVisiblePreviews = 0;
 232         QMetaObject::invokeMethod(this, "dispatchPreviewQueue", Qt::QueuedConnection);
 233     }
 234 }
 235
 236 void IconManager::updateCutItems()
 237 {
 238     // restore the icons of all previously selected items to the
 239     // original state...
 240     foreach (const ItemInfo& cutItem, m_cutItemsCache) {
 241         const QModelIndex index = m_dolphinModel->indexForUrl(cutItem.url);
 242         if (index.isValid()) {
 243             m_dolphinModel->setData(index, QIcon(cutItem.pixmap), Qt::DecorationRole);
 244         }
 245     }
 246     m_cutItemsCache.clear();
 247
 248     // ... and apply an item effect to all currently cut items
 249     applyCutItemEffect();
 250 }
 251
 252 void IconManager::dispatchPreviewQueue()
 253 {
 254     const int previewsCount = m_previews.count();
 255     if (previewsCount > 0) {
 256         // Applying the previews to the model must be done step by step
 257         // in larger blocks: Applying a preview immediately when getting the signal
 258         // 'gotPreview()' from the PreviewJob is too expensive, as a relayout
 259         // of the view would be triggered for each single preview.
 260         LayoutBlocker blocker(m_view);
 261         for (int i = 0; i < previewsCount; ++i) {
 262             const ItemInfo& preview = m_previews.first();
 263             replaceIcon(preview.url, preview.pixmap);
 264             m_previews.pop_front();
 265             if (m_pendingVisiblePreviews > 0) {
 266                 --m_pendingVisiblePreviews;
 267             }
 268         }
 269     }
 270
 271     if (m_pendingVisiblePreviews > 0) {
 272         // As long as there are pending previews for visible items, poll
 273         // the preview queue each 200 ms. If there are no pending previews,
 274         // the queue is dispatched in slotPreviewJobFinished().
 275         m_previewTimer->start(200);
 276     }
 277 }
 278
 279 void IconManager::pausePreviews()
 280 {
 281     foreach (KJob* job, m_previewJobs) {
 282         Q_ASSERT(job != 0);
 283         job->suspend();
 284     }
 285     m_scrollAreaTimer->start();
 286 }
 287
 288 void IconManager::resumePreviews()
 289 {
 290     // Before creating new preview jobs the m_pendingItems queue must be
 291     // cleaned up by removing the already dispatched items. Implementation
 292     // note: The order of the m_dispatchedItems queue and the m_pendingItems
 293     // queue is usually equal. So even when having a lot of elements the
 294     // nested loop is no performance bottle neck, as the inner loop is only
 295     // entered once in most cases.
 296     foreach (const KFileItem& item, m_dispatchedItems) {
 297         KFileItemList::iterator begin = m_pendingItems.begin();
 298         KFileItemList::iterator end   = m_pendingItems.end();
 299         for (KFileItemList::iterator it = begin; it != end; ++it) {
 300             if ((*it).url() == item.url()) {
 301                 m_pendingItems.erase(it);
 302                 break;
 303             }
 304         }
 305     }
 306     m_dispatchedItems.clear();
 307
 308     KFileItemList orderedItems = m_pendingItems;
 309     orderItems(orderedItems);
 310
 311     // Kill all suspended preview jobs. Usually when a preview job
 312     // has been finished, slotPreviewJobFinished() clears all item queues.
 313     // This is not wanted in this case, as a new job is created afterwards
 314     // for m_pendingItems.
 315     m_clearItemQueues = false;
 316     killPreviewJobs();
 317     m_clearItemQueues = true;
 318
 319     startPreviewJob(orderedItems);
 320 }
 321
 322 void IconManager::replaceIcon(const KUrl& url, const QPixmap& pixmap)
 323 {
 324     Q_ASSERT(url.isValid());
 325     if (!m_showPreview) {
 326         // the preview has been canceled in the meantime
 327         return;
 328     }
 329
 330     // check whether the item is part of the directory lister (it is possible
 331     // that a preview from an old directory lister is received)
 332     KDirLister* dirLister = m_dolphinModel->dirLister();
 333     bool isOldPreview = true;
 334     const KUrl::List dirs = dirLister->directories();
 335     const QString itemDir = url.directory();
 336     foreach (const KUrl& url, dirs) {
 337         if (url.path() == itemDir) {
 338             isOldPreview = false;
 339             break;
 340         }
 341     }
 342     if (isOldPreview) {
 343         return;
 344     }
 345
 346     const QModelIndex idx = m_dolphinModel->indexForUrl(url);
 347     if (idx.isValid() && (idx.column() == 0)) {
 348         QPixmap icon = pixmap;
 349
 350         const KFileItem item = m_dolphinModel->itemForIndex(idx);
 351         const QString mimeType = item.mimetype();
 352         const QString mimeTypeGroup = mimeType.left(mimeType.indexOf('/'));
 353         if ((mimeTypeGroup != "image") || !applyImageFrame(icon)) {
 354             limitToSize(icon, m_view->iconSize());
 355         }
 356
 357         const QMimeData* mimeData = QApplication::clipboard()->mimeData();
 358         if (KonqMimeData::decodeIsCutSelection(mimeData) && isCutItem(item)) {
 359             // Remember the current icon in the cache for cut items before
 360             // the disabled effect is applied. This makes it possible restoring
 361             // the uncut version again when cutting other items.
 362             QList<ItemInfo>::iterator begin = m_cutItemsCache.begin();
 363             QList<ItemInfo>::iterator end   = m_cutItemsCache.end();
 364             for (QList<ItemInfo>::iterator it = begin; it != end; ++it) {
 365                 if ((*it).url == item.url()) {
 366                     (*it).pixmap = icon;
 367                     break;
 368                 }
 369             }
 370
 371             // apply the disabled effect to the icon for marking it as "cut item"
 372             // and apply the icon to the item
 373             KIconEffect iconEffect;
 374             icon = iconEffect.apply(icon, KIconLoader::Desktop, KIconLoader::DisabledState);
 375             m_dolphinModel->setData(idx, QIcon(icon), Qt::DecorationRole);
 376         } else {
 377             m_dolphinModel->setData(idx, QIcon(icon), Qt::DecorationRole);
 378         }
 379     }
 380 }
 381
 382 bool IconManager::isCutItem(const KFileItem& item) const
 383 {
 384     const QMimeData* mimeData = QApplication::clipboard()->mimeData();
 385     const KUrl::List cutUrls = KUrl::List::fromMimeData(mimeData);
 386
 387     const KUrl itemUrl = item.url();
 388     foreach (const KUrl& url, cutUrls) {
 389         if (url == itemUrl) {
 390             return true;
 391         }
 392     }
 393
 394     return false;
 395 }
 396
 397 void IconManager::applyCutItemEffect()
 398 {
 399     const QMimeData* mimeData = QApplication::clipboard()->mimeData();
 400     if (!KonqMimeData::decodeIsCutSelection(mimeData)) {
 401         return;
 402     }
 403
 404     KFileItemList items;
 405     KDirLister* dirLister = m_dolphinModel->dirLister();
 406     const KUrl::List dirs = dirLister->directories();
 407     foreach (const KUrl& url, dirs) {
 408         items << dirLister->itemsForDir(url);
 409     }
 410
 411     foreach (const KFileItem& item, items) {
 412         if (isCutItem(item)) {
 413             const QModelIndex index = m_dolphinModel->indexForItem(item);
 414             const QVariant value = m_dolphinModel->data(index, Qt::DecorationRole);
 415             if (value.type() == QVariant::Icon) {
 416                 const QIcon icon(qvariant_cast<QIcon>(value));
 417                 const QSize actualSize = icon.actualSize(m_view->iconSize());
 418                 QPixmap pixmap = icon.pixmap(actualSize);
 419
 420                 // remember current pixmap for the item to be able
 421                 // to restore it when other items get cut
 422                 ItemInfo cutItem;
 423                 cutItem.url = item.url();
 424                 cutItem.pixmap = pixmap;
 425                 m_cutItemsCache.append(cutItem);
 426
 427                 // apply icon effect to the cut item
 428                 KIconEffect iconEffect;
 429                 pixmap = iconEffect.apply(pixmap, KIconLoader::Desktop, KIconLoader::DisabledState);
 430                 m_dolphinModel->setData(index, QIcon(pixmap), Qt::DecorationRole);
 431             }
 432         }
 433     }
 434 }
 435
 436 bool IconManager::applyImageFrame(QPixmap& icon)
 437 {
 438     const QSize maxSize = m_view->iconSize();
 439     const bool applyFrame = (maxSize.width()  > KIconLoader::SizeSmallMedium) &&
 440                             (maxSize.height() > KIconLoader::SizeSmallMedium) &&
 441                             ((icon.width()  > KIconLoader::SizeLarge) ||
 442                              (icon.height() > KIconLoader::SizeLarge));
 443     if (!applyFrame) {
 444         // the maximum size or the image itself is too small for a frame
 445         return false;
 446     }
 447
 448     const int frame = 4;
 449     const int doubleFrame = frame * 2;
 450
 451     // resize the icon to the maximum size minus the space required for the frame
 452     limitToSize(icon, QSize(maxSize.width() - doubleFrame, maxSize.height() - doubleFrame));
 453
 454     QPainter painter;
 455     const QPalette palette = m_view->palette();
 456     QPixmap framedIcon(icon.size().width() + doubleFrame, icon.size().height() + doubleFrame);
 457     framedIcon.fill(palette.color(QPalette::Normal, QPalette::Base));
 458     const int width = framedIcon.width() - 1;
 459     const int height = framedIcon.height() - 1;
 460
 461     painter.begin(&framedIcon);
 462     painter.drawPixmap(frame, frame, icon);
 463
 464     // add a border
 465     painter.setPen(palette.color(QPalette::Text));
 466     painter.setBrush(Qt::NoBrush);
 467     painter.drawRect(0, 0, width, height);
 468     painter.drawRect(1, 1, width - 2, height - 2);
 469
 470     // dim image frame by 12.5 %
 471     painter.setPen(QColor(0, 0, 0, 32));
 472     painter.drawRect(frame, frame, width - doubleFrame, height - doubleFrame);
 473     painter.end();
 474
 475     icon = framedIcon;
 476
 477     // provide an alpha channel for the border
 478     QPixmap alphaChannel(icon.size());
 479     alphaChannel.fill();
 480
 481     QPainter alphaPainter(&alphaChannel);
 482     alphaPainter.setBrush(Qt::NoBrush);
 483     alphaPainter.setPen(QColor(32, 32, 32));
 484     alphaPainter.drawRect(0, 0, width, height);
 485     alphaPainter.setPen(QColor(64, 64, 64));
 486     alphaPainter.drawRect(1, 1, width - 2, height - 2);
 487
 488     icon.setAlphaChannel(alphaChannel);
 489     return true;
 490 }
 491
 492 void IconManager::limitToSize(QPixmap& icon, const QSize& maxSize)
 493 {
 494     if ((icon.width() > maxSize.width()) || (icon.height() > maxSize.height())) {
 495         icon = icon.scaled(maxSize, Qt::KeepAspectRatio, Qt::SmoothTransformation);
 496     }
 497 }
 498
 499 void IconManager::startPreviewJob(const KFileItemList& items)
 500 {
 501     if (items.count() == 0) {
 502         return;
 503     }
 504
 505     const QSize size = m_view->iconSize();
 506     KIO::PreviewJob* job = KIO::filePreview(items, 128, 128);
 507     connect(job, SIGNAL(gotPreview(const KFileItem&, const QPixmap&)),
 508             this, SLOT(addToPreviewQueue(const KFileItem&, const QPixmap&)));
 509     connect(job, SIGNAL(finished(KJob*)),
 510             this, SLOT(slotPreviewJobFinished(KJob*)));
 511
 512     m_previewJobs.append(job);
 513     m_previewTimer->start(200);
 514 }
 515
 516 void IconManager::killPreviewJobs()
 517 {
 518     foreach (KJob* job, m_previewJobs) {
 519         Q_ASSERT(job != 0);
 520         job->kill();
 521     }
 522     m_previewJobs.clear();
 523 }
 524
 525 void IconManager::orderItems(KFileItemList& items)
 526 {
 527     // Order the items in a way that the preview for the visible items
 528     // is generated first, as this improves the feeled performance a lot.
 529     //
 530     // Implementation note: 2 different algorithms are used for the sorting.
 531     // Algorithm 1 is faster when having a lot of items in comparison
 532     // to the number of rows in the model. Algorithm 2 is faster
 533     // when having quite less items in comparison to the number of rows in
 534     // the model. Choosing the right algorithm is important when having directories
 535     // with several hundreds or thousands of items.
 536
 537     const int itemCount = items.count();
 538     const int rowCount = m_proxyModel->rowCount();
 539     const QRect visibleArea = m_view->viewport()->rect();
 540
 541     if (itemCount * 10 > rowCount) {
 542         // Algorithm 1: The number of items is > 10 % of the row count. Parse all rows
 543         // and check whether the received row is part of the item list.
 544         for (int row = 0; row < rowCount; ++row) {
 545             const QModelIndex proxyIndex = m_proxyModel->index(row, 0);
 546             const QRect itemRect = m_view->visualRect(proxyIndex);
 547             const QModelIndex dirIndex = m_proxyModel->mapToSource(proxyIndex);
 548
 549             KFileItem item = m_dolphinModel->itemForIndex(dirIndex);  // O(1)
 550             const KUrl url = item.url();
 551
 552             // check whether the item is part of the item list 'items'
 553             int index = -1;
 554             for (int i = 0; i < itemCount; ++i) {
 555                 if (items[i].url() == url) {
 556                     index = i;
 557                     break;
 558                 }
 559             }
 560
 561             if ((index > 0) && itemRect.intersects(visibleArea)) {
 562                 // The current item is (at least partly) visible. Move it
 563                 // to the front of the list, so that the preview is
 564                 // generated earlier.
 565                 items.removeAt(index);
 566                 items.insert(0, item);
 567                 ++m_pendingVisiblePreviews;
 568             }
 569         }
 570     } else {
 571         // Algorithm 2: The number of items is <= 10 % of the row count. In this case iterate
 572         // all items and receive the corresponding row from the item.
 573         for (int i = 0; i < itemCount; ++i) {
 574             const QModelIndex dirIndex = m_dolphinModel->indexForItem(items[i]); // O(n) (n = number of rows)
 575             const QModelIndex proxyIndex = m_proxyModel->mapFromSource(dirIndex);
 576             const QRect itemRect = m_view->visualRect(proxyIndex);
 577
 578             if (itemRect.intersects(visibleArea)) {
 579                 // The current item is (at least partly) visible. Move it
 580                 // to the front of the list, so that the preview is
 581                 // generated earlier.
 582                 items.insert(0, items[i]);
 583                 items.removeAt(i + 1);
 584                 ++m_pendingVisiblePreviews;
 585             }
 586         }
 587     }
 588 }
 589
 590 #include "iconmanager.moc"