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(0)
  65     {
  66         if (view->inherits("QListView")) {
  67             m_view = qobject_cast<QListView*>(view);
  68             m_uniformSizes = m_view->uniformItemSizes();
  69             m_view->setUniformItemSizes(true);
  70         }
  71     }
  72
  73     ~LayoutBlocker()
  74     {
  75         if (m_view != 0) {
  76             m_view->setUniformItemSizes(m_uniformSizes);
  77         }
  78     }
  79
  80 private:
  81     bool m_uniformSizes;
  82     QListView* m_view;
  83 };
  84
  85 IconManager::IconManager(QAbstractItemView* parent, DolphinSortFilterProxyModel* model) :
  86     QObject(parent),
  87     m_showPreview(false),
  88     m_clearItemQueues(true),
  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     }
 232 }
 233
 234 void IconManager::updateCutItems()
 235 {
 236     // restore the icons of all previously selected items to the
 237     // original state...
 238     foreach (const ItemInfo& cutItem, m_cutItemsCache) {
 239         const QModelIndex index = m_dolphinModel->indexForUrl(cutItem.url);
 240         if (index.isValid()) {
 241             m_dolphinModel->setData(index, QIcon(cutItem.pixmap), Qt::DecorationRole);
 242         }
 243     }
 244     m_cutItemsCache.clear();
 245
 246     // ... and apply an item effect to all currently cut items
 247     applyCutItemEffect();
 248 }
 249
 250 void IconManager::dispatchPreviewQueue()
 251 {
 252     int previewsCount = m_previews.count();
 253     if (previewsCount > 0) {
 254         // Applying the previews to the model must be done step by step
 255         // in larger blocks: Applying a preview immediately when getting the signal
 256         // 'gotPreview()' from the PreviewJob is too expensive, as a relayout
 257         // of the view would be triggered for each single preview.
 258
 259         int dispatchCount = 30;
 260         if (dispatchCount > previewsCount) {
 261             dispatchCount = previewsCount;
 262         }
 263
 264         LayoutBlocker blocker(m_view);
 265         for (int i = 0; i < dispatchCount; ++i) {
 266             const ItemInfo& preview = m_previews.first();
 267             replaceIcon(preview.url, preview.pixmap);
 268             m_previews.pop_front();
 269         }
 270
 271         previewsCount = m_previews.count();
 272     }
 273
 274     const bool workingPreviewJobs = (m_previewJobs.count() > 0);
 275     if (workingPreviewJobs) {
 276         // poll for previews as long as not all preview jobs are finished
 277         m_previewTimer->start(200);
 278     } else if (previewsCount > 0) {
 279         // all preview jobs are finished but there are still pending previews
 280         // in the queue -> poll more aggressively
 281         m_previewTimer->start(10);
 282     }
 283 }
 284
 285 void IconManager::pausePreviews()
 286 {
 287     foreach (KJob* job, m_previewJobs) {
 288         Q_ASSERT(job != 0);
 289         job->suspend();
 290     }
 291     m_scrollAreaTimer->start();
 292 }
 293
 294 void IconManager::resumePreviews()
 295 {
 296     // Before creating new preview jobs the m_pendingItems queue must be
 297     // cleaned up by removing the already dispatched items. Implementation
 298     // note: The order of the m_dispatchedItems queue and the m_pendingItems
 299     // queue is usually equal. So even when having a lot of elements the
 300     // nested loop is no performance bottle neck, as the inner loop is only
 301     // entered once in most cases.
 302     foreach (const KFileItem& item, m_dispatchedItems) {
 303         KFileItemList::iterator begin = m_pendingItems.begin();
 304         KFileItemList::iterator end   = m_pendingItems.end();
 305         for (KFileItemList::iterator it = begin; it != end; ++it) {
 306             if ((*it).url() == item.url()) {
 307                 m_pendingItems.erase(it);
 308                 break;
 309             }
 310         }
 311     }
 312     m_dispatchedItems.clear();
 313
 314     KFileItemList orderedItems = m_pendingItems;
 315     orderItems(orderedItems);
 316
 317     // Kill all suspended preview jobs. Usually when a preview job
 318     // has been finished, slotPreviewJobFinished() clears all item queues.
 319     // This is not wanted in this case, as a new job is created afterwards
 320     // for m_pendingItems.
 321     m_clearItemQueues = false;
 322     killPreviewJobs();
 323     m_clearItemQueues = true;
 324
 325     startPreviewJob(orderedItems);
 326 }
 327
 328 void IconManager::replaceIcon(const KUrl& url, const QPixmap& pixmap)
 329 {
 330     Q_ASSERT(url.isValid());
 331     if (!m_showPreview) {
 332         // the preview has been canceled in the meantime
 333         return;
 334     }
 335
 336     // check whether the item is part of the directory lister (it is possible
 337     // that a preview from an old directory lister is received)
 338     KDirLister* dirLister = m_dolphinModel->dirLister();
 339     bool isOldPreview = true;
 340     const KUrl::List dirs = dirLister->directories();
 341     const QString itemDir = url.directory();
 342     foreach (const KUrl& url, dirs) {
 343         if (url.path() == itemDir) {
 344             isOldPreview = false;
 345             break;
 346         }
 347     }
 348     if (isOldPreview) {
 349         return;
 350     }
 351
 352     const QModelIndex idx = m_dolphinModel->indexForUrl(url);
 353     if (idx.isValid() && (idx.column() == 0)) {
 354         QPixmap icon = pixmap;
 355
 356         const KFileItem item = m_dolphinModel->itemForIndex(idx);
 357         const QString mimeType = item.mimetype();
 358         const QString mimeTypeGroup = mimeType.left(mimeType.indexOf('/'));
 359         if ((mimeTypeGroup != "image") || !applyImageFrame(icon)) {
 360             limitToSize(icon, m_view->iconSize());
 361         }
 362
 363         const QMimeData* mimeData = QApplication::clipboard()->mimeData();
 364         if (KonqMimeData::decodeIsCutSelection(mimeData) && isCutItem(item)) {
 365             // Remember the current icon in the cache for cut items before
 366             // the disabled effect is applied. This makes it possible restoring
 367             // the uncut version again when cutting other items.
 368             QList<ItemInfo>::iterator begin = m_cutItemsCache.begin();
 369             QList<ItemInfo>::iterator end   = m_cutItemsCache.end();
 370             for (QList<ItemInfo>::iterator it = begin; it != end; ++it) {
 371                 if ((*it).url == item.url()) {
 372                     (*it).pixmap = icon;
 373                     break;
 374                 }
 375             }
 376
 377             // apply the disabled effect to the icon for marking it as "cut item"
 378             // and apply the icon to the item
 379             KIconEffect iconEffect;
 380             icon = iconEffect.apply(icon, KIconLoader::Desktop, KIconLoader::DisabledState);
 381             m_dolphinModel->setData(idx, QIcon(icon), Qt::DecorationRole);
 382         } else {
 383             m_dolphinModel->setData(idx, QIcon(icon), Qt::DecorationRole);
 384         }
 385     }
 386 }
 387
 388 bool IconManager::isCutItem(const KFileItem& item) const
 389 {
 390     const QMimeData* mimeData = QApplication::clipboard()->mimeData();
 391     const KUrl::List cutUrls = KUrl::List::fromMimeData(mimeData);
 392
 393     const KUrl itemUrl = item.url();
 394     foreach (const KUrl& url, cutUrls) {
 395         if (url == itemUrl) {
 396             return true;
 397         }
 398     }
 399
 400     return false;
 401 }
 402
 403 void IconManager::applyCutItemEffect()
 404 {
 405     const QMimeData* mimeData = QApplication::clipboard()->mimeData();
 406     if (!KonqMimeData::decodeIsCutSelection(mimeData)) {
 407         return;
 408     }
 409
 410     KFileItemList items;
 411     KDirLister* dirLister = m_dolphinModel->dirLister();
 412     const KUrl::List dirs = dirLister->directories();
 413     foreach (const KUrl& url, dirs) {
 414         items << dirLister->itemsForDir(url);
 415     }
 416
 417     foreach (const KFileItem& item, items) {
 418         if (isCutItem(item)) {
 419             const QModelIndex index = m_dolphinModel->indexForItem(item);
 420             const QVariant value = m_dolphinModel->data(index, Qt::DecorationRole);
 421             if (value.type() == QVariant::Icon) {
 422                 const QIcon icon(qvariant_cast<QIcon>(value));
 423                 const QSize actualSize = icon.actualSize(m_view->iconSize());
 424                 QPixmap pixmap = icon.pixmap(actualSize);
 425
 426                 // remember current pixmap for the item to be able
 427                 // to restore it when other items get cut
 428                 ItemInfo cutItem;
 429                 cutItem.url = item.url();
 430                 cutItem.pixmap = pixmap;
 431                 m_cutItemsCache.append(cutItem);
 432
 433                 // apply icon effect to the cut item
 434                 KIconEffect iconEffect;
 435                 pixmap = iconEffect.apply(pixmap, KIconLoader::Desktop, KIconLoader::DisabledState);
 436                 m_dolphinModel->setData(index, QIcon(pixmap), Qt::DecorationRole);
 437             }
 438         }
 439     }
 440 }
 441
 442 bool IconManager::applyImageFrame(QPixmap& icon)
 443 {
 444     const QSize maxSize = m_view->iconSize();
 445     const bool applyFrame = (maxSize.width()  > KIconLoader::SizeSmallMedium) &&
 446                             (maxSize.height() > KIconLoader::SizeSmallMedium) &&
 447                             ((icon.width()  > KIconLoader::SizeLarge) ||
 448                              (icon.height() > KIconLoader::SizeLarge));
 449     if (!applyFrame) {
 450         // the maximum size or the image itself is too small for a frame
 451         return false;
 452     }
 453
 454     const int frame = 4;
 455     const int doubleFrame = frame * 2;
 456
 457     // resize the icon to the maximum size minus the space required for the frame
 458     limitToSize(icon, QSize(maxSize.width() - doubleFrame, maxSize.height() - doubleFrame));
 459
 460     QPainter painter;
 461     const QPalette palette = m_view->palette();
 462     QPixmap framedIcon(icon.size().width() + doubleFrame, icon.size().height() + doubleFrame);
 463     framedIcon.fill(palette.color(QPalette::Normal, QPalette::Base));
 464     const int width = framedIcon.width() - 1;
 465     const int height = framedIcon.height() - 1;
 466
 467     painter.begin(&framedIcon);
 468     painter.drawPixmap(frame, frame, icon);
 469
 470     // add a border
 471     painter.setPen(palette.color(QPalette::Text));
 472     painter.setBrush(Qt::NoBrush);
 473     painter.drawRect(0, 0, width, height);
 474     painter.drawRect(1, 1, width - 2, height - 2);
 475
 476     // dim image frame by 12.5 %
 477     painter.setPen(QColor(0, 0, 0, 32));
 478     painter.drawRect(frame, frame, width - doubleFrame, height - doubleFrame);
 479     painter.end();
 480
 481     icon = framedIcon;
 482
 483     // provide an alpha channel for the border
 484     QPixmap alphaChannel(icon.size());
 485     alphaChannel.fill();
 486
 487     QPainter alphaPainter(&alphaChannel);
 488     alphaPainter.setBrush(Qt::NoBrush);
 489     alphaPainter.setPen(QColor(32, 32, 32));
 490     alphaPainter.drawRect(0, 0, width, height);
 491     alphaPainter.setPen(QColor(64, 64, 64));
 492     alphaPainter.drawRect(1, 1, width - 2, height - 2);
 493
 494     icon.setAlphaChannel(alphaChannel);
 495     return true;
 496 }
 497
 498 void IconManager::limitToSize(QPixmap& icon, const QSize& maxSize)
 499 {
 500     if ((icon.width() > maxSize.width()) || (icon.height() > maxSize.height())) {
 501         icon = icon.scaled(maxSize, Qt::KeepAspectRatio, Qt::SmoothTransformation);
 502     }
 503 }
 504
 505 void IconManager::startPreviewJob(const KFileItemList& items)
 506 {
 507     if (items.count() == 0) {
 508         return;
 509     }
 510
 511     const QSize size = m_view->iconSize();
 512     KIO::PreviewJob* job = KIO::filePreview(items, 128, 128);
 513     connect(job, SIGNAL(gotPreview(const KFileItem&, const QPixmap&)),
 514             this, SLOT(addToPreviewQueue(const KFileItem&, const QPixmap&)));
 515     connect(job, SIGNAL(finished(KJob*)),
 516             this, SLOT(slotPreviewJobFinished(KJob*)));
 517
 518     m_previewJobs.append(job);
 519     m_previewTimer->start(200);
 520 }
 521
 522 void IconManager::killPreviewJobs()
 523 {
 524     foreach (KJob* job, m_previewJobs) {
 525         Q_ASSERT(job != 0);
 526         job->kill();
 527     }
 528     m_previewJobs.clear();
 529 }
 530
 531 void IconManager::orderItems(KFileItemList& items)
 532 {
 533     // Order the items in a way that the preview for the visible items
 534     // is generated first, as this improves the feeled performance a lot.
 535     //
 536     // Implementation note: 2 different algorithms are used for the sorting.
 537     // Algorithm 1 is faster when having a lot of items in comparison
 538     // to the number of rows in the model. Algorithm 2 is faster
 539     // when having quite less items in comparison to the number of rows in
 540     // the model. Choosing the right algorithm is important when having directories
 541     // with several hundreds or thousands of items.
 542
 543     const int itemCount = items.count();
 544     const int rowCount = m_proxyModel->rowCount();
 545     const QRect visibleArea = m_view->viewport()->rect();
 546
 547     if (itemCount * 10 > rowCount) {
 548         // Algorithm 1: The number of items is > 10 % of the row count. Parse all rows
 549         // and check whether the received row is part of the item list.
 550         for (int row = 0; row < rowCount; ++row) {
 551             const QModelIndex proxyIndex = m_proxyModel->index(row, 0);
 552             const QRect itemRect = m_view->visualRect(proxyIndex);
 553             const QModelIndex dirIndex = m_proxyModel->mapToSource(proxyIndex);
 554
 555             KFileItem item = m_dolphinModel->itemForIndex(dirIndex);  // O(1)
 556             const KUrl url = item.url();
 557
 558             // check whether the item is part of the item list 'items'
 559             int index = -1;
 560             for (int i = 0; i < itemCount; ++i) {
 561                 if (items[i].url() == url) {
 562                     index = i;
 563                     break;
 564                 }
 565             }
 566
 567             if ((index > 0) && itemRect.intersects(visibleArea)) {
 568                 // The current item is (at least partly) visible. Move it
 569                 // to the front of the list, so that the preview is
 570                 // generated earlier.
 571                 items.removeAt(index);
 572                 items.insert(0, item);
 573             }
 574         }
 575     } else {
 576         // Algorithm 2: The number of items is <= 10 % of the row count. In this case iterate
 577         // all items and receive the corresponding row from the item.
 578         for (int i = 0; i < itemCount; ++i) {
 579             const QModelIndex dirIndex = m_dolphinModel->indexForItem(items[i]); // O(n) (n = number of rows)
 580             const QModelIndex proxyIndex = m_proxyModel->mapFromSource(dirIndex);
 581             const QRect itemRect = m_view->visualRect(proxyIndex);
 582
 583             if (itemRect.intersects(visibleArea)) {
 584                 // The current item is (at least partly) visible. Move it
 585                 // to the front of the list, so that the preview is
 586                 // generated earlier.
 587                 items.insert(0, items[i]);
 588                 items.removeAt(i + 1);
 589             }
 590         }
 591     }
 592 }
 593
 594 #include "iconmanager.moc"