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_view(parent),
  89     m_previewTimer(0),
  90     m_scrollAreaTimer(0),
  91     m_previewJobs(),
  92     m_dolphinModel(0),
  93     m_proxyModel(model),
  94     m_mimeTypeResolver(0),
  95     m_cutItemsCache(),
  96     m_previews(),
  97     m_pendingItems(),
  98     m_dispatchedItems()
  99 {
 100     Q_ASSERT(m_view->iconSize().isValid());  // each view must provide its current icon size
 101
 102     m_dolphinModel = static_cast<DolphinModel*>(m_proxyModel->sourceModel());
 103     connect(m_dolphinModel->dirLister(), SIGNAL(newItems(const KFileItemList&)),
 104             this, SLOT(generatePreviews(const KFileItemList&)));
 105
 106     QClipboard* clipboard = QApplication::clipboard();
 107     connect(clipboard, SIGNAL(dataChanged()),
 108             this, SLOT(updateCutItems()));
 109
 110     m_previewTimer = new QTimer(this);
 111     m_previewTimer->setSingleShot(true);
 112     connect(m_previewTimer, SIGNAL(timeout()), this, SLOT(dispatchPreviewQueue()));
 113
 114     // Whenever the scrollbar values have been changed, the pending previews should
 115     // be reordered in a way that the previews for the visible items are generated
 116     // first. The reordering is done with a small delay, so that during moving the
 117     // scrollbars the CPU load is kept low.
 118     m_scrollAreaTimer = new QTimer(this);
 119     m_scrollAreaTimer->setSingleShot(true);
 120     m_scrollAreaTimer->setInterval(200);
 121     connect(m_scrollAreaTimer, SIGNAL(timeout()),
 122             this, SLOT(resumePreviews()));
 123     connect(m_view->horizontalScrollBar(), SIGNAL(valueChanged(int)),
 124             this, SLOT(pausePreviews()));
 125     connect(m_view->verticalScrollBar(), SIGNAL(valueChanged(int)),
 126             this, SLOT(pausePreviews()));
 127 }
 128
 129 IconManager::~IconManager()
 130 {
 131     killPreviewJobs();
 132     m_pendingItems.clear();
 133     m_dispatchedItems.clear();
 134     if (m_mimeTypeResolver != 0) {
 135         m_mimeTypeResolver->deleteLater();
 136         m_mimeTypeResolver = 0;
 137     }
 138 }
 139
 140
 141 void IconManager::setShowPreview(bool show)
 142 {
 143     if (m_showPreview != show) {
 144         m_showPreview = show;
 145         m_cutItemsCache.clear();
 146         updateCutItems();
 147         if (show) {
 148             updatePreviews();
 149         }
 150     }
 151
 152     if (show && (m_mimeTypeResolver != 0)) {
 153         // don't resolve the MIME types if the preview is turned on
 154         m_mimeTypeResolver->deleteLater();
 155         m_mimeTypeResolver = 0;
 156     } else if (!show && (m_mimeTypeResolver == 0)) {
 157         // the preview is turned off: resolve the MIME-types so that
 158         // the icons gets updated
 159         m_mimeTypeResolver = new KMimeTypeResolver(m_view, m_dolphinModel);
 160     }
 161 }
 162
 163 void IconManager::updatePreviews()
 164 {
 165     if (!m_showPreview) {
 166         return;
 167     }
 168
 169     killPreviewJobs();
 170     m_cutItemsCache.clear();
 171     m_pendingItems.clear();
 172     m_dispatchedItems.clear();
 173
 174     KFileItemList itemList;
 175     const int rowCount = m_dolphinModel->rowCount();
 176     for (int row = 0; row < rowCount; ++row) {
 177         const QModelIndex index = m_dolphinModel->index(row, 0);
 178         KFileItem item = m_dolphinModel->itemForIndex(index);
 179         itemList.append(item);
 180     }
 181
 182     generatePreviews(itemList);
 183     updateCutItems();
 184 }
 185
 186 void IconManager::cancelPreviews()
 187 {
 188     killPreviewJobs();
 189     m_cutItemsCache.clear();
 190     m_pendingItems.clear();
 191     m_dispatchedItems.clear();
 192 }
 193
 194 void IconManager::generatePreviews(const KFileItemList& items)
 195 {
 196     applyCutItemEffect();
 197
 198     if (!m_showPreview) {
 199         return;
 200     }
 201
 202     KFileItemList orderedItems = items;
 203     orderItems(orderedItems);
 204
 205     foreach (const KFileItem& item, orderedItems) {
 206         m_pendingItems.append(item);
 207     }
 208
 209     startPreviewJob(orderedItems);
 210 }
 211
 212 void IconManager::addToPreviewQueue(const KFileItem& item, const QPixmap& pixmap)
 213 {
 214     ItemInfo preview;
 215     preview.url = item.url();
 216     preview.pixmap = pixmap;
 217     m_previews.append(preview);
 218
 219     m_dispatchedItems.append(item);
 220 }
 221
 222 void IconManager::slotPreviewJobFinished(KJob* job)
 223 {
 224     const int index = m_previewJobs.indexOf(job);
 225     m_previewJobs.removeAt(index);
 226
 227     if ((m_previewJobs.count() == 0) && m_clearItemQueues) {
 228         m_pendingItems.clear();
 229         m_dispatchedItems.clear();
 230     }
 231 }
 232
 233 void IconManager::updateCutItems()
 234 {
 235     // restore the icons of all previously selected items to the
 236     // original state...
 237     foreach (const ItemInfo& cutItem, m_cutItemsCache) {
 238         const QModelIndex index = m_dolphinModel->indexForUrl(cutItem.url);
 239         if (index.isValid()) {
 240             m_dolphinModel->setData(index, QIcon(cutItem.pixmap), Qt::DecorationRole);
 241         }
 242     }
 243     m_cutItemsCache.clear();
 244
 245     // ... and apply an item effect to all currently cut items
 246     applyCutItemEffect();
 247 }
 248
 249 void IconManager::dispatchPreviewQueue()
 250 {
 251     int previewsCount = m_previews.count();
 252     if (previewsCount > 0) {
 253         // Applying the previews to the model must be done step by step
 254         // in larger blocks: Applying a preview immediately when getting the signal
 255         // 'gotPreview()' from the PreviewJob is too expensive, as a relayout
 256         // of the view would be triggered for each single preview.
 257
 258         int dispatchCount = 30;
 259         if (dispatchCount > previewsCount) {
 260             dispatchCount = previewsCount;
 261         }
 262
 263         LayoutBlocker blocker(m_view);
 264         for (int i = 0; i < dispatchCount; ++i) {
 265             const ItemInfo& preview = m_previews.first();
 266             replaceIcon(preview.url, preview.pixmap);
 267             m_previews.pop_front();
 268         }
 269
 270         previewsCount = m_previews.count();
 271     }
 272
 273     const bool workingPreviewJobs = (m_previewJobs.count() > 0);
 274     if (workingPreviewJobs) {
 275         // poll for previews as long as not all preview jobs are finished
 276         m_previewTimer->start(200);
 277     } else if (previewsCount > 0) {
 278         // all preview jobs are finished but there are still pending previews
 279         // in the queue -> poll more aggressively
 280         m_previewTimer->start(10);
 281     }
 282 }
 283
 284 void IconManager::pausePreviews()
 285 {
 286     foreach (KJob* job, m_previewJobs) {
 287         Q_ASSERT(job != 0);
 288         job->suspend();
 289     }
 290     m_scrollAreaTimer->start();
 291 }
 292
 293 void IconManager::resumePreviews()
 294 {
 295     // Before creating new preview jobs the m_pendingItems queue must be
 296     // cleaned up by removing the already dispatched items. Implementation
 297     // note: The order of the m_dispatchedItems queue and the m_pendingItems
 298     // queue is usually equal. So even when having a lot of elements the
 299     // nested loop is no performance bottle neck, as the inner loop is only
 300     // entered once in most cases.
 301     foreach (const KFileItem& item, m_dispatchedItems) {
 302         KFileItemList::iterator begin = m_pendingItems.begin();
 303         KFileItemList::iterator end   = m_pendingItems.end();
 304         for (KFileItemList::iterator it = begin; it != end; ++it) {
 305             if ((*it).url() == item.url()) {
 306                 m_pendingItems.erase(it);
 307                 break;
 308             }
 309         }
 310     }
 311     m_dispatchedItems.clear();
 312
 313     KFileItemList orderedItems = m_pendingItems;
 314     orderItems(orderedItems);
 315
 316     // Kill all suspended preview jobs. Usually when a preview job
 317     // has been finished, slotPreviewJobFinished() clears all item queues.
 318     // This is not wanted in this case, as a new job is created afterwards
 319     // for m_pendingItems.
 320     m_clearItemQueues = false;
 321     killPreviewJobs();
 322     m_clearItemQueues = true;
 323
 324     startPreviewJob(orderedItems);
 325 }
 326
 327 void IconManager::replaceIcon(const KUrl& url, const QPixmap& pixmap)
 328 {
 329     Q_ASSERT(url.isValid());
 330     if (!m_showPreview) {
 331         // the preview has been canceled in the meantime
 332         return;
 333     }
 334
 335     // check whether the item is part of the directory lister (it is possible
 336     // that a preview from an old directory lister is received)
 337     KDirLister* dirLister = m_dolphinModel->dirLister();
 338     bool isOldPreview = true;
 339     const KUrl::List dirs = dirLister->directories();
 340     const QString itemDir = url.directory();
 341     foreach (const KUrl& url, dirs) {
 342         if (url.path() == itemDir) {
 343             isOldPreview = false;
 344             break;
 345         }
 346     }
 347     if (isOldPreview) {
 348         return;
 349     }
 350
 351     const QModelIndex idx = m_dolphinModel->indexForUrl(url);
 352     if (idx.isValid() && (idx.column() == 0)) {
 353         QPixmap icon = pixmap;
 354
 355         const KFileItem item = m_dolphinModel->itemForIndex(idx);
 356         const QString mimeType = item.mimetype();
 357         const QString mimeTypeGroup = mimeType.left(mimeType.indexOf('/'));
 358         if ((mimeTypeGroup != "image") || !applyImageFrame(icon)) {
 359             limitToSize(icon, m_view->iconSize());
 360         }
 361
 362         const QMimeData* mimeData = QApplication::clipboard()->mimeData();
 363         if (KonqMimeData::decodeIsCutSelection(mimeData) && isCutItem(item)) {
 364             // Remember the current icon in the cache for cut items before
 365             // the disabled effect is applied. This makes it possible restoring
 366             // the uncut version again when cutting other items.
 367             QList<ItemInfo>::iterator begin = m_cutItemsCache.begin();
 368             QList<ItemInfo>::iterator end   = m_cutItemsCache.end();
 369             for (QList<ItemInfo>::iterator it = begin; it != end; ++it) {
 370                 if ((*it).url == item.url()) {
 371                     (*it).pixmap = icon;
 372                     break;
 373                 }
 374             }
 375
 376             // apply the disabled effect to the icon for marking it as "cut item"
 377             // and apply the icon to the item
 378             KIconEffect iconEffect;
 379             icon = iconEffect.apply(icon, KIconLoader::Desktop, KIconLoader::DisabledState);
 380             m_dolphinModel->setData(idx, QIcon(icon), Qt::DecorationRole);
 381         } else {
 382             m_dolphinModel->setData(idx, QIcon(icon), Qt::DecorationRole);
 383         }
 384     }
 385 }
 386
 387 bool IconManager::isCutItem(const KFileItem& item) const
 388 {
 389     const QMimeData* mimeData = QApplication::clipboard()->mimeData();
 390     const KUrl::List cutUrls = KUrl::List::fromMimeData(mimeData);
 391
 392     const KUrl itemUrl = item.url();
 393     foreach (const KUrl& url, cutUrls) {
 394         if (url == itemUrl) {
 395             return true;
 396         }
 397     }
 398
 399     return false;
 400 }
 401
 402 void IconManager::applyCutItemEffect()
 403 {
 404     const QMimeData* mimeData = QApplication::clipboard()->mimeData();
 405     if (!KonqMimeData::decodeIsCutSelection(mimeData)) {
 406         return;
 407     }
 408
 409     KFileItemList items;
 410     KDirLister* dirLister = m_dolphinModel->dirLister();
 411     const KUrl::List dirs = dirLister->directories();
 412     foreach (const KUrl& url, dirs) {
 413         items << dirLister->itemsForDir(url);
 414     }
 415
 416     foreach (const KFileItem& item, items) {
 417         if (isCutItem(item)) {
 418             const QModelIndex index = m_dolphinModel->indexForItem(item);
 419             const QVariant value = m_dolphinModel->data(index, Qt::DecorationRole);
 420             if (value.type() == QVariant::Icon) {
 421                 const QIcon icon(qvariant_cast<QIcon>(value));
 422                 const QSize actualSize = icon.actualSize(m_view->iconSize());
 423                 QPixmap pixmap = icon.pixmap(actualSize);
 424
 425                 // remember current pixmap for the item to be able
 426                 // to restore it when other items get cut
 427                 ItemInfo cutItem;
 428                 cutItem.url = item.url();
 429                 cutItem.pixmap = pixmap;
 430                 m_cutItemsCache.append(cutItem);
 431
 432                 // apply icon effect to the cut item
 433                 KIconEffect iconEffect;
 434                 pixmap = iconEffect.apply(pixmap, KIconLoader::Desktop, KIconLoader::DisabledState);
 435                 m_dolphinModel->setData(index, QIcon(pixmap), Qt::DecorationRole);
 436             }
 437         }
 438     }
 439 }
 440
 441 bool IconManager::applyImageFrame(QPixmap& icon)
 442 {
 443     const QSize maxSize = m_view->iconSize();
 444     const bool applyFrame = (maxSize.width()  > KIconLoader::SizeSmallMedium) &&
 445                             (maxSize.height() > KIconLoader::SizeSmallMedium) &&
 446                             ((icon.width()  > KIconLoader::SizeLarge) ||
 447                              (icon.height() > KIconLoader::SizeLarge));
 448     if (!applyFrame) {
 449         // the maximum size or the image itself is too small for a frame
 450         return false;
 451     }
 452
 453     const int frame = 4;
 454     const int doubleFrame = frame * 2;
 455
 456     // resize the icon to the maximum size minus the space required for the frame
 457     limitToSize(icon, QSize(maxSize.width() - doubleFrame, maxSize.height() - doubleFrame));
 458
 459     QPainter painter;
 460     const QPalette palette = m_view->palette();
 461     QPixmap framedIcon(icon.size().width() + doubleFrame, icon.size().height() + doubleFrame);
 462     framedIcon.fill(palette.color(QPalette::Normal, QPalette::Base));
 463     const int width = framedIcon.width() - 1;
 464     const int height = framedIcon.height() - 1;
 465
 466     painter.begin(&framedIcon);
 467     painter.drawPixmap(frame, frame, icon);
 468
 469     // add a border
 470     painter.setPen(palette.color(QPalette::Text));
 471     painter.setBrush(Qt::NoBrush);
 472     painter.drawRect(0, 0, width, height);
 473     painter.drawRect(1, 1, width - 2, height - 2);
 474
 475     // dim image frame by 12.5 %
 476     painter.setPen(QColor(0, 0, 0, 32));
 477     painter.drawRect(frame, frame, width - doubleFrame, height - doubleFrame);
 478     painter.end();
 479
 480     icon = framedIcon;
 481
 482     // provide an alpha channel for the border
 483     QPixmap alphaChannel(icon.size());
 484     alphaChannel.fill();
 485
 486     QPainter alphaPainter(&alphaChannel);
 487     alphaPainter.setBrush(Qt::NoBrush);
 488     alphaPainter.setPen(QColor(32, 32, 32));
 489     alphaPainter.drawRect(0, 0, width, height);
 490     alphaPainter.setPen(QColor(64, 64, 64));
 491     alphaPainter.drawRect(1, 1, width - 2, height - 2);
 492
 493     icon.setAlphaChannel(alphaChannel);
 494     return true;
 495 }
 496
 497 void IconManager::limitToSize(QPixmap& icon, const QSize& maxSize)
 498 {
 499     if ((icon.width() > maxSize.width()) || (icon.height() > maxSize.height())) {
 500         icon = icon.scaled(maxSize, Qt::KeepAspectRatio, Qt::SmoothTransformation);
 501     }
 502 }
 503
 504 void IconManager::startPreviewJob(const KFileItemList& items)
 505 {
 506     if (items.count() == 0) {
 507         return;
 508     }
 509
 510     const QSize size = m_view->iconSize();
 511     KIO::PreviewJob* job = KIO::filePreview(items, 128, 128);
 512     connect(job, SIGNAL(gotPreview(const KFileItem&, const QPixmap&)),
 513             this, SLOT(addToPreviewQueue(const KFileItem&, const QPixmap&)));
 514     connect(job, SIGNAL(finished(KJob*)),
 515             this, SLOT(slotPreviewJobFinished(KJob*)));
 516
 517     m_previewJobs.append(job);
 518     m_previewTimer->start(200);
 519 }
 520
 521 void IconManager::killPreviewJobs()
 522 {
 523     foreach (KJob* job, m_previewJobs) {
 524         Q_ASSERT(job != 0);
 525         job->kill();
 526     }
 527     m_previewJobs.clear();
 528 }
 529
 530 void IconManager::orderItems(KFileItemList& items)
 531 {
 532     // Order the items in a way that the preview for the visible items
 533     // is generated first, as this improves the feeled performance a lot.
 534     //
 535     // Implementation note: 2 different algorithms are used for the sorting.
 536     // Algorithm 1 is faster when having a lot of items in comparison
 537     // to the number of rows in the model. Algorithm 2 is faster
 538     // when having quite less items in comparison to the number of rows in
 539     // the model. Choosing the right algorithm is important when having directories
 540     // with several hundreds or thousands of items.
 541
 542     const int itemCount = items.count();
 543     const int rowCount = m_proxyModel->rowCount();
 544     const QRect visibleArea = m_view->viewport()->rect();
 545
 546     if (itemCount * 10 > rowCount) {
 547         // Algorithm 1: The number of items is > 10 % of the row count. Parse all rows
 548         // and check whether the received row is part of the item list.
 549         for (int row = 0; row < rowCount; ++row) {
 550             const QModelIndex proxyIndex = m_proxyModel->index(row, 0);
 551             const QRect itemRect = m_view->visualRect(proxyIndex);
 552             const QModelIndex dirIndex = m_proxyModel->mapToSource(proxyIndex);
 553
 554             KFileItem item = m_dolphinModel->itemForIndex(dirIndex);  // O(1)
 555             const KUrl url = item.url();
 556
 557             // check whether the item is part of the item list 'items'
 558             int index = -1;
 559             for (int i = 0; i < itemCount; ++i) {
 560                 if (items[i].url() == url) {
 561                     index = i;
 562                     break;
 563                 }
 564             }
 565
 566             if ((index > 0) && itemRect.intersects(visibleArea)) {
 567                 // The current item is (at least partly) visible. Move it
 568                 // to the front of the list, so that the preview is
 569                 // generated earlier.
 570                 items.removeAt(index);
 571                 items.insert(0, item);
 572             }
 573         }
 574     } else {
 575         // Algorithm 2: The number of items is <= 10 % of the row count. In this case iterate
 576         // all items and receive the corresponding row from the item.
 577         for (int i = 0; i < itemCount; ++i) {
 578             const QModelIndex dirIndex = m_dolphinModel->indexForItem(items[i]); // O(n) (n = number of rows)
 579             const QModelIndex proxyIndex = m_proxyModel->mapFromSource(dirIndex);
 580             const QRect itemRect = m_view->visualRect(proxyIndex);
 581
 582             if (itemRect.intersects(visibleArea)) {
 583                 // The current item is (at least partly) visible. Move it
 584                 // to the front of the list, so that the preview is
 585                 // generated earlier.
 586                 items.insert(0, items[i]);
 587                 items.removeAt(i + 1);
 588             }
 589         }
 590     }
 591 }
 592
 593 #include "iconmanager.moc"