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     if (!m_showPreview) {
 216         // the preview has been canceled in the meantime
 217         return;
 218     }
 219     const KUrl url = item.url();
 220
 221     // check whether the item is part of the directory lister (it is possible
 222     // that a preview from an old directory lister is received)
 223     KDirLister* dirLister = m_dolphinModel->dirLister();
 224     bool isOldPreview = true;
 225     const KUrl::List dirs = dirLister->directories();
 226     const QString itemDir = url.directory();
 227     foreach (const KUrl& url, dirs) {
 228         if (url.path() == itemDir) {
 229             isOldPreview = false;
 230             break;
 231         }
 232     }
 233     if (isOldPreview) {
 234         return;
 235     }
 236
 237     QPixmap icon = pixmap;
 238
 239     const QString mimeType = item.mimetype();
 240     const QString mimeTypeGroup = mimeType.left(mimeType.indexOf('/'));
 241     if ((mimeTypeGroup != "image") || !applyImageFrame(icon)) {
 242         limitToSize(icon, m_view->iconSize());
 243     }
 244
 245     const QMimeData* mimeData = QApplication::clipboard()->mimeData();
 246     if (KonqMimeData::decodeIsCutSelection(mimeData) && isCutItem(item)) {
 247         // Remember the current icon in the cache for cut items before
 248         // the disabled effect is applied. This makes it possible restoring
 249         // the uncut version again when cutting other items.
 250         QList<ItemInfo>::iterator begin = m_cutItemsCache.begin();
 251         QList<ItemInfo>::iterator end   = m_cutItemsCache.end();
 252         for (QList<ItemInfo>::iterator it = begin; it != end; ++it) {
 253             if ((*it).url == item.url()) {
 254                 (*it).pixmap = icon;
 255                 break;
 256             }
 257         }
 258
 259         // apply the disabled effect to the icon for marking it as "cut item"
 260         // and apply the icon to the item
 261         KIconEffect iconEffect;
 262         icon = iconEffect.apply(icon, KIconLoader::Desktop, KIconLoader::DisabledState);
 263     }
 264
 265     // remember the preview and URL, so that it can be applied to the model
 266     // in IconManager::dispatchPreviewQueue()
 267     ItemInfo preview;
 268     preview.url = url;
 269     preview.pixmap = icon;
 270     m_previews.append(preview);
 271
 272     m_dispatchedItems.append(item);
 273 }
 274
 275 void IconManager::slotPreviewJobFinished(KJob* job)
 276 {
 277     const int index = m_previewJobs.indexOf(job);
 278     m_previewJobs.removeAt(index);
 279
 280     if ((m_previewJobs.count() == 0) && m_clearItemQueues) {
 281         m_pendingItems.clear();
 282         m_dispatchedItems.clear();
 283         m_pendingVisiblePreviews = 0;
 284         QMetaObject::invokeMethod(this, "dispatchPreviewQueue", Qt::QueuedConnection);
 285     }
 286 }
 287
 288 void IconManager::updateCutItems()
 289 {
 290     // restore the icons of all previously selected items to the
 291     // original state...
 292     foreach (const ItemInfo& cutItem, m_cutItemsCache) {
 293         const QModelIndex index = m_dolphinModel->indexForUrl(cutItem.url);
 294         if (index.isValid()) {
 295             m_dolphinModel->setData(index, QIcon(cutItem.pixmap), Qt::DecorationRole);
 296         }
 297     }
 298     m_cutItemsCache.clear();
 299
 300     // ... and apply an item effect to all currently cut items
 301     applyCutItemEffect();
 302 }
 303
 304 void IconManager::dispatchPreviewQueue()
 305 {
 306     const int previewsCount = m_previews.count();
 307     if (previewsCount > 0) {
 308         // Applying the previews to the model must be done step by step
 309         // in larger blocks: Applying a preview immediately when getting the signal
 310         // 'gotPreview()' from the PreviewJob is too expensive, as a relayout
 311         // of the view would be triggered for each single preview.
 312         LayoutBlocker blocker(m_view);
 313         for (int i = 0; i < previewsCount; ++i) {
 314             const ItemInfo& preview = m_previews.first();
 315
 316             const QModelIndex idx = m_dolphinModel->indexForUrl(preview.url);
 317             if (idx.isValid() && (idx.column() == 0)) {
 318                 m_dolphinModel->setData(idx, QIcon(preview.pixmap), Qt::DecorationRole);
 319             }
 320
 321             m_previews.pop_front();
 322             if (m_pendingVisiblePreviews > 0) {
 323                 --m_pendingVisiblePreviews;
 324             }
 325         }
 326     }
 327
 328     if (m_pendingVisiblePreviews > 0) {
 329         // As long as there are pending previews for visible items, poll
 330         // the preview queue each 200 ms. If there are no pending previews,
 331         // the queue is dispatched in slotPreviewJobFinished().
 332         m_previewTimer->start(200);
 333     }
 334 }
 335
 336 void IconManager::pausePreviews()
 337 {
 338     foreach (KJob* job, m_previewJobs) {
 339         Q_ASSERT(job != 0);
 340         job->suspend();
 341     }
 342     m_scrollAreaTimer->start();
 343 }
 344
 345 void IconManager::resumePreviews()
 346 {
 347     // Before creating new preview jobs the m_pendingItems queue must be
 348     // cleaned up by removing the already dispatched items. Implementation
 349     // note: The order of the m_dispatchedItems queue and the m_pendingItems
 350     // queue is usually equal. So even when having a lot of elements the
 351     // nested loop is no performance bottle neck, as the inner loop is only
 352     // entered once in most cases.
 353     foreach (const KFileItem& item, m_dispatchedItems) {
 354         KFileItemList::iterator begin = m_pendingItems.begin();
 355         KFileItemList::iterator end   = m_pendingItems.end();
 356         for (KFileItemList::iterator it = begin; it != end; ++it) {
 357             if ((*it).url() == item.url()) {
 358                 m_pendingItems.erase(it);
 359                 break;
 360             }
 361         }
 362     }
 363     m_dispatchedItems.clear();
 364
 365     KFileItemList orderedItems = m_pendingItems;
 366     orderItems(orderedItems);
 367
 368     // Kill all suspended preview jobs. Usually when a preview job
 369     // has been finished, slotPreviewJobFinished() clears all item queues.
 370     // This is not wanted in this case, as a new job is created afterwards
 371     // for m_pendingItems.
 372     m_clearItemQueues = false;
 373     killPreviewJobs();
 374     m_clearItemQueues = true;
 375
 376     startPreviewJob(orderedItems);
 377 }
 378
 379 bool IconManager::isCutItem(const KFileItem& item) const
 380 {
 381     const QMimeData* mimeData = QApplication::clipboard()->mimeData();
 382     const KUrl::List cutUrls = KUrl::List::fromMimeData(mimeData);
 383
 384     const KUrl itemUrl = item.url();
 385     foreach (const KUrl& url, cutUrls) {
 386         if (url == itemUrl) {
 387             return true;
 388         }
 389     }
 390
 391     return false;
 392 }
 393
 394 void IconManager::applyCutItemEffect()
 395 {
 396     const QMimeData* mimeData = QApplication::clipboard()->mimeData();
 397     if (!KonqMimeData::decodeIsCutSelection(mimeData)) {
 398         return;
 399     }
 400
 401     KFileItemList items;
 402     KDirLister* dirLister = m_dolphinModel->dirLister();
 403     const KUrl::List dirs = dirLister->directories();
 404     foreach (const KUrl& url, dirs) {
 405         items << dirLister->itemsForDir(url);
 406     }
 407
 408     foreach (const KFileItem& item, items) {
 409         if (isCutItem(item)) {
 410             const QModelIndex index = m_dolphinModel->indexForItem(item);
 411             const QVariant value = m_dolphinModel->data(index, Qt::DecorationRole);
 412             if (value.type() == QVariant::Icon) {
 413                 const QIcon icon(qvariant_cast<QIcon>(value));
 414                 const QSize actualSize = icon.actualSize(m_view->iconSize());
 415                 QPixmap pixmap = icon.pixmap(actualSize);
 416
 417                 // remember current pixmap for the item to be able
 418                 // to restore it when other items get cut
 419                 ItemInfo cutItem;
 420                 cutItem.url = item.url();
 421                 cutItem.pixmap = pixmap;
 422                 m_cutItemsCache.append(cutItem);
 423
 424                 // apply icon effect to the cut item
 425                 KIconEffect iconEffect;
 426                 pixmap = iconEffect.apply(pixmap, KIconLoader::Desktop, KIconLoader::DisabledState);
 427                 m_dolphinModel->setData(index, QIcon(pixmap), Qt::DecorationRole);
 428             }
 429         }
 430     }
 431 }
 432
 433 bool IconManager::applyImageFrame(QPixmap& icon)
 434 {
 435     const QSize maxSize = m_view->iconSize();
 436     const bool applyFrame = (maxSize.width()  > KIconLoader::SizeSmallMedium) &&
 437                             (maxSize.height() > KIconLoader::SizeSmallMedium) &&
 438                             ((icon.width()  > KIconLoader::SizeLarge) ||
 439                              (icon.height() > KIconLoader::SizeLarge));
 440     if (!applyFrame) {
 441         // the maximum size or the image itself is too small for a frame
 442         return false;
 443     }
 444
 445     const int frame = 4;
 446     const int doubleFrame = frame * 2;
 447
 448     // resize the icon to the maximum size minus the space required for the frame
 449     limitToSize(icon, QSize(maxSize.width() - doubleFrame, maxSize.height() - doubleFrame));
 450
 451     QPainter painter;
 452     const QPalette palette = m_view->palette();
 453     QPixmap framedIcon(icon.size().width() + doubleFrame, icon.size().height() + doubleFrame);
 454     framedIcon.fill(palette.color(QPalette::Normal, QPalette::Base));
 455     const int width = framedIcon.width() - 1;
 456     const int height = framedIcon.height() - 1;
 457
 458     painter.begin(&framedIcon);
 459     painter.drawPixmap(frame, frame, icon);
 460
 461     // add a border
 462     painter.setPen(palette.color(QPalette::Text));
 463     painter.setBrush(Qt::NoBrush);
 464     painter.drawRect(0, 0, width, height);
 465     painter.drawRect(1, 1, width - 2, height - 2);
 466
 467     // dim image frame by 12.5 %
 468     painter.setPen(QColor(0, 0, 0, 32));
 469     painter.drawRect(frame, frame, width - doubleFrame, height - doubleFrame);
 470     painter.end();
 471
 472     icon = framedIcon;
 473
 474     // provide an alpha channel for the border
 475     QPixmap alphaChannel(icon.size());
 476     alphaChannel.fill();
 477
 478     QPainter alphaPainter(&alphaChannel);
 479     alphaPainter.setBrush(Qt::NoBrush);
 480     alphaPainter.setPen(QColor(32, 32, 32));
 481     alphaPainter.drawRect(0, 0, width, height);
 482     alphaPainter.setPen(QColor(64, 64, 64));
 483     alphaPainter.drawRect(1, 1, width - 2, height - 2);
 484
 485     icon.setAlphaChannel(alphaChannel);
 486     return true;
 487 }
 488
 489 void IconManager::limitToSize(QPixmap& icon, const QSize& maxSize)
 490 {
 491     if ((icon.width() > maxSize.width()) || (icon.height() > maxSize.height())) {
 492         icon = icon.scaled(maxSize, Qt::KeepAspectRatio, Qt::SmoothTransformation);
 493     }
 494 }
 495
 496 void IconManager::startPreviewJob(const KFileItemList& items)
 497 {
 498     if (items.count() == 0) {
 499         return;
 500     }
 501
 502     const QSize size = m_view->iconSize();
 503     KIO::PreviewJob* job = KIO::filePreview(items, 128, 128);
 504     connect(job, SIGNAL(gotPreview(const KFileItem&, const QPixmap&)),
 505             this, SLOT(addToPreviewQueue(const KFileItem&, const QPixmap&)));
 506     connect(job, SIGNAL(finished(KJob*)),
 507             this, SLOT(slotPreviewJobFinished(KJob*)));
 508
 509     m_previewJobs.append(job);
 510     m_previewTimer->start(200);
 511 }
 512
 513 void IconManager::killPreviewJobs()
 514 {
 515     foreach (KJob* job, m_previewJobs) {
 516         Q_ASSERT(job != 0);
 517         job->kill();
 518     }
 519     m_previewJobs.clear();
 520 }
 521
 522 void IconManager::orderItems(KFileItemList& items)
 523 {
 524     // Order the items in a way that the preview for the visible items
 525     // is generated first, as this improves the feeled performance a lot.
 526     //
 527     // Implementation note: 2 different algorithms are used for the sorting.
 528     // Algorithm 1 is faster when having a lot of items in comparison
 529     // to the number of rows in the model. Algorithm 2 is faster
 530     // when having quite less items in comparison to the number of rows in
 531     // the model. Choosing the right algorithm is important when having directories
 532     // with several hundreds or thousands of items.
 533
 534     const int itemCount = items.count();
 535     const int rowCount = m_proxyModel->rowCount();
 536     const QRect visibleArea = m_view->viewport()->rect();
 537
 538     if (itemCount * 10 > rowCount) {
 539         // Algorithm 1: The number of items is > 10 % of the row count. Parse all rows
 540         // and check whether the received row is part of the item list.
 541         for (int row = 0; row < rowCount; ++row) {
 542             const QModelIndex proxyIndex = m_proxyModel->index(row, 0);
 543             const QRect itemRect = m_view->visualRect(proxyIndex);
 544             const QModelIndex dirIndex = m_proxyModel->mapToSource(proxyIndex);
 545
 546             KFileItem item = m_dolphinModel->itemForIndex(dirIndex);  // O(1)
 547             const KUrl url = item.url();
 548
 549             // check whether the item is part of the item list 'items'
 550             int index = -1;
 551             for (int i = 0; i < itemCount; ++i) {
 552                 if (items[i].url() == url) {
 553                     index = i;
 554                     break;
 555                 }
 556             }
 557
 558             if ((index > 0) && itemRect.intersects(visibleArea)) {
 559                 // The current item is (at least partly) visible. Move it
 560                 // to the front of the list, so that the preview is
 561                 // generated earlier.
 562                 items.removeAt(index);
 563                 items.insert(0, item);
 564                 ++m_pendingVisiblePreviews;
 565             }
 566         }
 567     } else {
 568         // Algorithm 2: The number of items is <= 10 % of the row count. In this case iterate
 569         // all items and receive the corresponding row from the item.
 570         for (int i = 0; i < itemCount; ++i) {
 571             const QModelIndex dirIndex = m_dolphinModel->indexForItem(items[i]); // O(n) (n = number of rows)
 572             const QModelIndex proxyIndex = m_proxyModel->mapFromSource(dirIndex);
 573             const QRect itemRect = m_view->visualRect(proxyIndex);
 574
 575             if (itemRect.intersects(visibleArea)) {
 576                 // The current item is (at least partly) visible. Move it
 577                 // to the front of the list, so that the preview is
 578                 // generated earlier.
 579                 items.insert(0, items[i]);
 580                 items.removeAt(i + 1);
 581                 ++m_pendingVisiblePreviews;
 582             }
 583         }
 584     }
 585 }
 586
 587 #include "iconmanager.moc"