src/kitemviews/kitemlistview.cpp

   1 /*
   2  * SPDX-FileCopyrightText: 2011 Peter Penz <peter.penz19@gmail.com>
   3  *
   4  * Based on the Itemviews NG project from Trolltech Labs
   5  *
   6  * SPDX-License-Identifier: GPL-2.0-or-later
   7  */
   8
   9 #include "kitemlistview.h"
  10
  11 #include "dolphindebug.h"
  12 #include "kitemlistcontainer.h"
  13 #include "kitemlistcontroller.h"
  14 #include "kitemlistheader.h"
  15 #include "kitemlistselectionmanager.h"
  16 #include "kitemlistviewaccessible.h"
  17 #include "kstandarditemlistwidget.h"
  18
  19 #include "private/kitemlistheaderwidget.h"
  20 #include "private/kitemlistrubberband.h"
  21 #include "private/kitemlistsizehintresolver.h"
  22 #include "private/kitemlistviewlayouter.h"
  23
  24 #include <QElapsedTimer>
  25 #include <QGraphicsSceneMouseEvent>
  26 #include <QGraphicsView>
  27 #include <QPropertyAnimation>
  28 #include <QStyleOptionRubberBand>
  29 #include <QTimer>
  30 #include <QVariantAnimation>
  31
  32 namespace
  33 {
  34 // Time in ms until reaching the autoscroll margin triggers
  35 // an initial autoscrolling
  36 const int InitialAutoScrollDelay = 700;
  37
  38 // Delay in ms for triggering the next autoscroll
  39 const int RepeatingAutoScrollDelay = 1000 / 60;
  40
  41 // Copied from the Kirigami.Units.shortDuration
  42 const int RubberFadeSpeed = 150;
  43
  44 const char *RubberPropertyName = "_kitemviews_rubberBandPosition";
  45 }
  46
  47 #ifndef QT_NO_ACCESSIBILITY
  48 QAccessibleInterface *accessibleInterfaceFactory(const QString &key, QObject *object)
  49 {
  50     Q_UNUSED(key)
  51
  52     if (KItemListContainer *container = qobject_cast<KItemListContainer *>(object)) {
  53         if (auto controller = container->controller(); controller) {
  54             if (KItemListView *view = controller->view(); view && view->accessibleParent()) {
  55                 return view->accessibleParent();
  56             }
  57         }
  58         return new KItemListContainerAccessible(container);
  59     } else if (KItemListView *view = qobject_cast<KItemListView *>(object)) {
  60         return new KItemListViewAccessible(view, view->accessibleParent());
  61     }
  62
  63     return nullptr;
  64 }
  65 #endif
  66
  67 KItemListView::KItemListView(QGraphicsWidget *parent)
  68     : QGraphicsWidget(parent)
  69     , m_enabledSelectionToggles(false)
  70     , m_grouped(false)
  71     , m_highlightEntireRow(false)
  72     , m_alternateBackgrounds(false)
  73     , m_supportsItemExpanding(false)
  74     , m_editingRole(false)
  75     , m_activeTransactions(0)
  76     , m_endTransactionAnimationHint(Animation)
  77     , m_itemSize()
  78     , m_controller(nullptr)
  79     , m_model(nullptr)
  80     , m_visibleRoles()
  81     , m_widgetCreator(nullptr)
  82     , m_groupHeaderCreator(nullptr)
  83     , m_styleOption()
  84     , m_visibleItems()
  85     , m_visibleGroups()
  86     , m_visibleCells()
  87     , m_scrollBarExtent(0)
  88     , m_layouter(nullptr)
  89     , m_animation(nullptr)
  90     , m_oldScrollOffset(0)
  91     , m_oldMaximumScrollOffset(0)
  92     , m_oldItemOffset(0)
  93     , m_oldMaximumItemOffset(0)
  94     , m_skipAutoScrollForRubberBand(false)
  95     , m_rubberBand(nullptr)
  96     , m_tapAndHoldIndicator(nullptr)
  97     , m_mousePos()
  98     , m_autoScrollIncrement(0)
  99     , m_autoScrollTimer(nullptr)
 100     , m_header(nullptr)
 101     , m_headerWidget(nullptr)
 102     , m_indicatorAnimation(nullptr)
 103     , m_dropIndicator()
 104     , m_sizeHintResolver(nullptr)
 105 {
 106     setAcceptHoverEvents(true);
 107     setAcceptTouchEvents(true);
 108
 109     m_sizeHintResolver = new KItemListSizeHintResolver(this);
 110
 111     m_layouter = new KItemListViewLayouter(m_sizeHintResolver, this);
 112
 113     m_animation = new KItemListViewAnimation(this);
 114     connect(m_animation, &KItemListViewAnimation::finished, this, &KItemListView::slotAnimationFinished);
 115
 116     m_rubberBand = new KItemListRubberBand(this);
 117     connect(m_rubberBand, &KItemListRubberBand::activationChanged, this, &KItemListView::slotRubberBandActivationChanged);
 118
 119     m_tapAndHoldIndicator = new KItemListRubberBand(this);
 120     m_indicatorAnimation = new QPropertyAnimation(m_tapAndHoldIndicator, "endPosition", this);
 121     connect(m_tapAndHoldIndicator, &KItemListRubberBand::activationChanged, this, [this](bool active) {
 122         if (active) {
 123             m_indicatorAnimation->setDuration(150);
 124             m_indicatorAnimation->setStartValue(QPointF(1, 1));
 125             m_indicatorAnimation->setEndValue(QPointF(40, 40));
 126             m_indicatorAnimation->start();
 127         }
 128         update();
 129     });
 130     connect(m_tapAndHoldIndicator, &KItemListRubberBand::endPositionChanged, this, [this]() {
 131         if (m_tapAndHoldIndicator->isActive()) {
 132             update();
 133         }
 134     });
 135
 136     m_headerWidget = new KItemListHeaderWidget(this);
 137     m_headerWidget->setVisible(false);
 138
 139     m_header = new KItemListHeader(this);
 140
 141 #ifndef QT_NO_ACCESSIBILITY
 142     QAccessible::installFactory(accessibleInterfaceFactory);
 143 #endif
 144 }
 145
 146 KItemListView::~KItemListView()
 147 {
 148     // The group headers are children of the widgets created by
 149     // widgetCreator(). So it is mandatory to delete the group headers
 150     // first.
 151     delete m_groupHeaderCreator;
 152     m_groupHeaderCreator = nullptr;
 153
 154     delete m_widgetCreator;
 155     m_widgetCreator = nullptr;
 156
 157     delete m_sizeHintResolver;
 158     m_sizeHintResolver = nullptr;
 159 }
 160
 161 void KItemListView::setScrollOffset(qreal offset)
 162 {
 163     if (offset < 0) {
 164         offset = 0;
 165     }
 166
 167     const qreal previousOffset = m_layouter->scrollOffset();
 168     if (offset == previousOffset) {
 169         return;
 170     }
 171
 172     m_layouter->setScrollOffset(offset);
 173     m_animation->setScrollOffset(offset);
 174
 175     // Don't check whether the m_layoutTimer is active: Changing the
 176     // scroll offset must always trigger a synchronous layout, otherwise
 177     // the smooth-scrolling might get jerky.
 178     doLayout(NoAnimation);
 179     onScrollOffsetChanged(offset, previousOffset);
 180 }
 181
 182 qreal KItemListView::scrollOffset() const
 183 {
 184     return m_layouter->scrollOffset();
 185 }
 186
 187 qreal KItemListView::maximumScrollOffset() const
 188 {
 189     return m_layouter->maximumScrollOffset();
 190 }
 191
 192 void KItemListView::setItemOffset(qreal offset)
 193 {
 194     if (m_layouter->itemOffset() == offset) {
 195         return;
 196     }
 197
 198     m_layouter->setItemOffset(offset);
 199     if (m_headerWidget->isVisible()) {
 200         m_headerWidget->setOffset(offset);
 201     }
 202
 203     // Don't check whether the m_layoutTimer is active: Changing the
 204     // item offset must always trigger a synchronous layout, otherwise
 205     // the smooth-scrolling might get jerky.
 206     doLayout(NoAnimation);
 207 }
 208
 209 qreal KItemListView::itemOffset() const
 210 {
 211     return m_layouter->itemOffset();
 212 }
 213
 214 qreal KItemListView::maximumItemOffset() const
 215 {
 216     return m_layouter->maximumItemOffset();
 217 }
 218
 219 int KItemListView::maximumVisibleItems() const
 220 {
 221     return m_layouter->maximumVisibleItems();
 222 }
 223
 224 void KItemListView::setVisibleRoles(const QList<QByteArray> &roles)
 225 {
 226     const QList<QByteArray> previousRoles = m_visibleRoles;
 227     m_visibleRoles = roles;
 228     onVisibleRolesChanged(roles, previousRoles);
 229
 230     m_sizeHintResolver->clearCache();
 231     m_layouter->markAsDirty();
 232
 233     if (m_itemSize.isEmpty()) {
 234         m_headerWidget->setColumns(roles);
 235         updatePreferredColumnWidths();
 236         if (!m_headerWidget->automaticColumnResizing()) {
 237             // The column-width of new roles are still 0. Apply the preferred
 238             // column-width as default with.
 239             for (const QByteArray &role : std::as_const(m_visibleRoles)) {
 240                 if (m_headerWidget->columnWidth(role) == 0) {
 241                     const qreal width = m_headerWidget->preferredColumnWidth(role);
 242                     m_headerWidget->setColumnWidth(role, width);
 243                 }
 244             }
 245
 246             applyColumnWidthsFromHeader();
 247         }
 248     }
 249
 250     const bool alternateBackgroundsChanged =
 251         m_itemSize.isEmpty() && ((roles.count() > 1 && previousRoles.count() <= 1) || (roles.count() <= 1 && previousRoles.count() > 1));
 252
 253     QHashIterator<int, KItemListWidget *> it(m_visibleItems);
 254     while (it.hasNext()) {
 255         it.next();
 256         KItemListWidget *widget = it.value();
 257         widget->setVisibleRoles(roles);
 258         if (alternateBackgroundsChanged) {
 259             updateAlternateBackgroundForWidget(widget);
 260         }
 261     }
 262
 263     doLayout(NoAnimation);
 264 }
 265
 266 QList<QByteArray> KItemListView::visibleRoles() const
 267 {
 268     return m_visibleRoles;
 269 }
 270
 271 void KItemListView::setAutoScroll(bool enabled)
 272 {
 273     if (enabled && !m_autoScrollTimer) {
 274         m_autoScrollTimer = new QTimer(this);
 275         m_autoScrollTimer->setSingleShot(true);
 276         connect(m_autoScrollTimer, &QTimer::timeout, this, &KItemListView::triggerAutoScrolling);
 277         m_autoScrollTimer->start(InitialAutoScrollDelay);
 278     } else if (!enabled && m_autoScrollTimer) {
 279         delete m_autoScrollTimer;
 280         m_autoScrollTimer = nullptr;
 281     }
 282 }
 283
 284 bool KItemListView::autoScroll() const
 285 {
 286     return m_autoScrollTimer != nullptr;
 287 }
 288
 289 void KItemListView::setEnabledSelectionToggles(bool enabled)
 290 {
 291     if (m_enabledSelectionToggles != enabled) {
 292         m_enabledSelectionToggles = enabled;
 293
 294         QHashIterator<int, KItemListWidget *> it(m_visibleItems);
 295         while (it.hasNext()) {
 296             it.next();
 297             it.value()->setEnabledSelectionToggle(enabled);
 298         }
 299     }
 300 }
 301
 302 bool KItemListView::enabledSelectionToggles() const
 303 {
 304     return m_enabledSelectionToggles;
 305 }
 306
 307 KItemListController *KItemListView::controller() const
 308 {
 309     return m_controller;
 310 }
 311
 312 KItemModelBase *KItemListView::model() const
 313 {
 314     return m_model;
 315 }
 316
 317 void KItemListView::setWidgetCreator(KItemListWidgetCreatorBase *widgetCreator)
 318 {
 319     delete m_widgetCreator;
 320     m_widgetCreator = widgetCreator;
 321 }
 322
 323 KItemListWidgetCreatorBase *KItemListView::widgetCreator() const
 324 {
 325     if (!m_widgetCreator) {
 326         m_widgetCreator = defaultWidgetCreator();
 327     }
 328     return m_widgetCreator;
 329 }
 330
 331 void KItemListView::setGroupHeaderCreator(KItemListGroupHeaderCreatorBase *groupHeaderCreator)
 332 {
 333     delete m_groupHeaderCreator;
 334     m_groupHeaderCreator = groupHeaderCreator;
 335 }
 336
 337 KItemListGroupHeaderCreatorBase *KItemListView::groupHeaderCreator() const
 338 {
 339     if (!m_groupHeaderCreator) {
 340         m_groupHeaderCreator = defaultGroupHeaderCreator();
 341     }
 342     return m_groupHeaderCreator;
 343 }
 344
 345 #ifndef QT_NO_ACCESSIBILITY
 346 void KItemListView::setAccessibleParentsObject(KItemListContainer *accessibleParentsObject)
 347 {
 348     Q_ASSERT(!m_accessibleParent);
 349     m_accessibleParent = new KItemListContainerAccessible(accessibleParentsObject);
 350 }
 351 KItemListContainerAccessible *KItemListView::accessibleParent()
 352 {
 353     Q_CHECK_PTR(m_accessibleParent); // We always want the accessibility tree/hierarchy to be complete.
 354     return m_accessibleParent;
 355 }
 356 #endif
 357
 358 QSizeF KItemListView::itemSize() const
 359 {
 360     return m_itemSize;
 361 }
 362
 363 const KItemListStyleOption &KItemListView::styleOption() const
 364 {
 365     return m_styleOption;
 366 }
 367
 368 void KItemListView::setGeometry(const QRectF &rect)
 369 {
 370     QGraphicsWidget::setGeometry(rect);
 371
 372     if (!m_model) {
 373         return;
 374     }
 375
 376     const QSizeF newSize = rect.size();
 377     if (m_itemSize.isEmpty()) {
 378         m_headerWidget->resize(rect.width(), m_headerWidget->size().height());
 379         if (m_headerWidget->automaticColumnResizing()) {
 380             applyAutomaticColumnWidths();
 381         } else {
 382             const qreal requiredWidth = columnWidthsSum() + 2 * m_headerWidget->sidePadding();
 383             const QSizeF dynamicItemSize(qMax(newSize.width(), requiredWidth), m_itemSize.height());
 384             m_layouter->setItemSize(dynamicItemSize);
 385         }
 386     }
 387
 388     m_layouter->setSize(newSize);
 389     // We don't animate the moving of the items here because
 390     // it would look like the items are slow to find their position.
 391     doLayout(NoAnimation);
 392 }
 393
 394 qreal KItemListView::verticalPageStep() const
 395 {
 396     qreal headerHeight = 0;
 397     if (m_headerWidget->isVisible()) {
 398         headerHeight = m_headerWidget->size().height();
 399     }
 400     return size().height() - headerHeight;
 401 }
 402
 403 std::optional<int> KItemListView::itemAt(const QPointF &pos) const
 404 {
 405     if (headerBoundaries().contains(pos)) {
 406         return std::nullopt;
 407     }
 408
 409     QHashIterator<int, KItemListWidget *> it(m_visibleItems);
 410     while (it.hasNext()) {
 411         it.next();
 412
 413         const KItemListWidget *widget = it.value();
 414         const QPointF mappedPos = widget->mapFromItem(this, pos);
 415         if (widget->contains(mappedPos) || widget->selectionRect().contains(mappedPos)) {
 416             return it.key();
 417         }
 418     }
 419
 420     return std::nullopt;
 421 }
 422
 423 bool KItemListView::isAboveSelectionToggle(int index, const QPointF &pos) const
 424 {
 425     if (!m_enabledSelectionToggles) {
 426         return false;
 427     }
 428
 429     const KItemListWidget *widget = m_visibleItems.value(index);
 430     if (widget) {
 431         const QRectF selectionToggleRect = widget->selectionToggleRect();
 432         if (!selectionToggleRect.isEmpty()) {
 433             const QPointF mappedPos = widget->mapFromItem(this, pos);
 434             return selectionToggleRect.contains(mappedPos);
 435         }
 436     }
 437     return false;
 438 }
 439
 440 bool KItemListView::isAboveExpansionToggle(int index, const QPointF &pos) const
 441 {
 442     const KItemListWidget *widget = m_visibleItems.value(index);
 443     if (widget) {
 444         const QRectF expansionToggleRect = widget->expansionToggleRect();
 445         if (!expansionToggleRect.isEmpty()) {
 446             const QPointF mappedPos = widget->mapFromItem(this, pos);
 447             return expansionToggleRect.contains(mappedPos);
 448         }
 449     }
 450     return false;
 451 }
 452
 453 bool KItemListView::isAboveText(int index, const QPointF &pos) const
 454 {
 455     const KItemListWidget *widget = m_visibleItems.value(index);
 456     if (widget) {
 457         const QRectF &textRect = widget->textRect();
 458         if (!textRect.isEmpty()) {
 459             const QPointF mappedPos = widget->mapFromItem(this, pos);
 460             return textRect.contains(mappedPos);
 461         }
 462     }
 463     return false;
 464 }
 465
 466 int KItemListView::firstVisibleIndex() const
 467 {
 468     return m_layouter->firstVisibleIndex();
 469 }
 470
 471 int KItemListView::lastVisibleIndex() const
 472 {
 473     return m_layouter->lastVisibleIndex();
 474 }
 475
 476 void KItemListView::calculateItemSizeHints(QVector<std::pair<qreal, bool>> &logicalHeightHints, qreal &logicalWidthHint) const
 477 {
 478     widgetCreator()->calculateItemSizeHints(logicalHeightHints, logicalWidthHint, this);
 479 }
 480
 481 void KItemListView::setSupportsItemExpanding(bool supportsExpanding)
 482 {
 483     if (m_supportsItemExpanding != supportsExpanding) {
 484         m_supportsItemExpanding = supportsExpanding;
 485         updateSiblingsInformation();
 486         onSupportsItemExpandingChanged(supportsExpanding);
 487     }
 488 }
 489
 490 bool KItemListView::supportsItemExpanding() const
 491 {
 492     return m_supportsItemExpanding;
 493 }
 494
 495 void KItemListView::setHighlightEntireRow(bool highlightEntireRow)
 496 {
 497     if (m_highlightEntireRow != highlightEntireRow) {
 498         m_highlightEntireRow = highlightEntireRow;
 499         onHighlightEntireRowChanged(highlightEntireRow);
 500     }
 501 }
 502
 503 bool KItemListView::highlightEntireRow() const
 504 {
 505     return m_highlightEntireRow;
 506 }
 507
 508 void KItemListView::setAlternateBackgrounds(bool alternate)
 509 {
 510     if (m_alternateBackgrounds != alternate) {
 511         m_alternateBackgrounds = alternate;
 512         updateAlternateBackgrounds();
 513     }
 514 }
 515
 516 bool KItemListView::alternateBackgrounds() const
 517 {
 518     return m_alternateBackgrounds;
 519 }
 520
 521 QRectF KItemListView::itemRect(int index) const
 522 {
 523     return m_layouter->itemRect(index);
 524 }
 525
 526 QRectF KItemListView::itemContextRect(int index) const
 527 {
 528     QRectF contextRect;
 529
 530     const KItemListWidget *widget = m_visibleItems.value(index);
 531     if (widget) {
 532         contextRect = widget->iconRect() | widget->textRect();
 533         contextRect.translate(itemRect(index).topLeft());
 534     }
 535
 536     return contextRect;
 537 }
 538
 539 bool KItemListView::isElided(int index) const
 540 {
 541     return m_sizeHintResolver->isElided(index);
 542 }
 543
 544 void KItemListView::scrollToItem(int index, ViewItemPosition viewItemPosition)
 545 {
 546     QRectF viewGeometry = geometry();
 547     if (m_headerWidget->isVisible()) {
 548         const qreal headerHeight = m_headerWidget->size().height();
 549         viewGeometry.adjust(0, headerHeight, 0, 0);
 550     }
 551     QRectF currentRect = itemRect(index);
 552
 553     if (layoutDirection() == Qt::RightToLeft && scrollOrientation() == Qt::Horizontal) {
 554         currentRect.moveTo(m_layouter->size().width() - currentRect.right(), 0);
 555     }
 556
 557     // Fix for Bug 311099 - View the underscore when using Ctrl + PageDown
 558     currentRect.adjust(-m_styleOption.horizontalMargin, -m_styleOption.verticalMargin, m_styleOption.horizontalMargin, m_styleOption.verticalMargin);
 559
 560     qreal offset = 0;
 561     switch (scrollOrientation()) {
 562     case Qt::Vertical:
 563         if (currentRect.top() < viewGeometry.top() || currentRect.bottom() > viewGeometry.bottom()) {
 564             switch (viewItemPosition) {
 565             case Beginning:
 566                 offset = currentRect.top() - viewGeometry.top();
 567                 break;
 568             case Middle:
 569                 offset = 0.5 * (currentRect.top() + currentRect.bottom() - (viewGeometry.top() + viewGeometry.bottom()));
 570                 break;
 571             case End:
 572                 offset = currentRect.bottom() - viewGeometry.bottom();
 573                 break;
 574             case Nearest:
 575                 if (currentRect.top() < viewGeometry.top()) {
 576                     offset = currentRect.top() - viewGeometry.top();
 577                 }
 578                 if (currentRect.bottom() > viewGeometry.bottom() + offset) {
 579                     offset += currentRect.bottom() - viewGeometry.bottom() - offset;
 580                 }
 581                 break;
 582             default:
 583                 Q_UNREACHABLE();
 584             }
 585         }
 586         break;
 587     case Qt::Horizontal:
 588         if (currentRect.left() < viewGeometry.left() || currentRect.right() > viewGeometry.right()) {
 589             switch (viewItemPosition) {
 590             case Beginning:
 591                 if (layoutDirection() == Qt::RightToLeft) {
 592                     offset = currentRect.right() - viewGeometry.right();
 593                 } else {
 594                     offset = currentRect.left() - viewGeometry.left();
 595                 }
 596                 break;
 597             case Middle:
 598                 offset = 0.5 * (currentRect.left() + currentRect.right() - (viewGeometry.left() + viewGeometry.right()));
 599                 break;
 600             case End:
 601                 if (layoutDirection() == Qt::RightToLeft) {
 602                     offset = currentRect.left() - viewGeometry.left();
 603                 } else {
 604                     offset = currentRect.right() - viewGeometry.right();
 605                 }
 606                 break;
 607             case Nearest:
 608                 if (layoutDirection() == Qt::RightToLeft) {
 609                     if (currentRect.left() < viewGeometry.left()) {
 610                         offset = currentRect.left() - viewGeometry.left();
 611                     }
 612                     if (currentRect.right() > viewGeometry.right() + offset) {
 613                         offset += currentRect.right() - viewGeometry.right() - offset;
 614                     }
 615                 } else {
 616                     if (currentRect.right() > viewGeometry.right()) {
 617                         offset = currentRect.right() - viewGeometry.right();
 618                     }
 619                     if (currentRect.left() < viewGeometry.left() + offset) {
 620                         offset += currentRect.left() - viewGeometry.left() - offset;
 621                     }
 622                 }
 623                 break;
 624             default:
 625                 Q_UNREACHABLE();
 626             }
 627         }
 628         break;
 629     default:
 630         Q_UNREACHABLE();
 631     }
 632
 633     if (!qFuzzyIsNull(offset)) {
 634         Q_EMIT scrollTo(scrollOffset() + offset);
 635         return;
 636     }
 637
 638     Q_EMIT scrollingStopped();
 639 }
 640
 641 void KItemListView::beginTransaction()
 642 {
 643     ++m_activeTransactions;
 644     if (m_activeTransactions == 1) {
 645         onTransactionBegin();
 646     }
 647 }
 648
 649 void KItemListView::endTransaction()
 650 {
 651     --m_activeTransactions;
 652     if (m_activeTransactions < 0) {
 653         m_activeTransactions = 0;
 654         qCWarning(DolphinDebug) << "Mismatch between beginTransaction()/endTransaction()";
 655     }
 656
 657     if (m_activeTransactions == 0) {
 658         onTransactionEnd();
 659         doLayout(m_endTransactionAnimationHint);
 660         m_endTransactionAnimationHint = Animation;
 661     }
 662 }
 663
 664 bool KItemListView::isTransactionActive() const
 665 {
 666     return m_activeTransactions > 0;
 667 }
 668
 669 void KItemListView::setHeaderVisible(bool visible)
 670 {
 671     if (visible && !m_headerWidget->isVisible()) {
 672         QStyleOptionHeader option;
 673         const QSize headerSize = style()->sizeFromContents(QStyle::CT_HeaderSection, &option, QSize());
 674
 675         m_headerWidget->setPos(0, 0);
 676         m_headerWidget->resize(size().width(), headerSize.height());
 677         m_headerWidget->setModel(m_model);
 678         m_headerWidget->setColumns(m_visibleRoles);
 679         m_headerWidget->setZValue(1);
 680
 681         connect(m_headerWidget, &KItemListHeaderWidget::columnWidthChanged, this, &KItemListView::slotHeaderColumnWidthChanged);
 682         connect(m_headerWidget, &KItemListHeaderWidget::sidePaddingChanged, this, &KItemListView::slotSidePaddingChanged);
 683         connect(m_headerWidget, &KItemListHeaderWidget::columnMoved, this, &KItemListView::slotHeaderColumnMoved);
 684         connect(m_headerWidget, &KItemListHeaderWidget::sortOrderChanged, this, &KItemListView::sortOrderChanged);
 685         connect(m_headerWidget, &KItemListHeaderWidget::sortRoleChanged, this, &KItemListView::sortRoleChanged);
 686         connect(m_headerWidget, &KItemListHeaderWidget::columnHovered, this, &KItemListView::columnHovered);
 687         connect(m_headerWidget, &KItemListHeaderWidget::columnUnHovered, this, &KItemListView::columnUnHovered);
 688
 689         m_layouter->setHeaderHeight(headerSize.height());
 690         m_headerWidget->setVisible(true);
 691     } else if (!visible && m_headerWidget->isVisible()) {
 692         disconnect(m_headerWidget, &KItemListHeaderWidget::columnWidthChanged, this, &KItemListView::slotHeaderColumnWidthChanged);
 693         disconnect(m_headerWidget, &KItemListHeaderWidget::sidePaddingChanged, this, &KItemListView::slotSidePaddingChanged);
 694         disconnect(m_headerWidget, &KItemListHeaderWidget::columnMoved, this, &KItemListView::slotHeaderColumnMoved);
 695         disconnect(m_headerWidget, &KItemListHeaderWidget::sortOrderChanged, this, &KItemListView::sortOrderChanged);
 696         disconnect(m_headerWidget, &KItemListHeaderWidget::sortRoleChanged, this, &KItemListView::sortRoleChanged);
 697         disconnect(m_headerWidget, &KItemListHeaderWidget::columnHovered, this, &KItemListView::columnHovered);
 698         disconnect(m_headerWidget, &KItemListHeaderWidget::columnUnHovered, this, &KItemListView::columnUnHovered);
 699
 700         m_layouter->setHeaderHeight(0);
 701         m_headerWidget->setVisible(false);
 702     }
 703 }
 704
 705 bool KItemListView::isHeaderVisible() const
 706 {
 707     return m_headerWidget->isVisible();
 708 }
 709
 710 KItemListHeader *KItemListView::header() const
 711 {
 712     return m_header;
 713 }
 714
 715 QPixmap KItemListView::createDragPixmap(const KItemSet &indexes) const
 716 {
 717     QPixmap pixmap;
 718
 719     if (indexes.count() == 1) {
 720         KItemListWidget *item = m_visibleItems.value(indexes.first());
 721         QGraphicsView *graphicsView = scene()->views()[0];
 722         if (item && graphicsView) {
 723             pixmap = item->createDragPixmap(nullptr, graphicsView);
 724         }
 725     } else {
 726         // TODO: Not implemented yet. Probably extend the interface
 727         // from KItemListWidget::createDragPixmap() to return a pixmap
 728         // that can be used for multiple indexes.
 729     }
 730
 731     return pixmap;
 732 }
 733
 734 void KItemListView::editRole(int index, const QByteArray &role)
 735 {
 736     KStandardItemListWidget *widget = qobject_cast<KStandardItemListWidget *>(m_visibleItems.value(index));
 737     if (!widget || m_editingRole) {
 738         return;
 739     }
 740
 741     m_editingRole = true;
 742     widget->setEditedRole(role);
 743
 744     connect(widget, &KItemListWidget::roleEditingCanceled, this, &KItemListView::slotRoleEditingCanceled);
 745     connect(widget, &KItemListWidget::roleEditingFinished, this, &KItemListView::slotRoleEditingFinished);
 746
 747     connect(this, &KItemListView::scrollOffsetChanged, widget, &KStandardItemListWidget::finishRoleEditing);
 748 }
 749
 750 void KItemListView::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget)
 751 {
 752     QGraphicsWidget::paint(painter, option, widget);
 753
 754     for (auto animation : std::as_const(m_rubberBandAnimations)) {
 755         QRectF rubberBandRect = animation->property(RubberPropertyName).toRectF();
 756
 757         const QPointF topLeft = rubberBandRect.topLeft();
 758         if (scrollOrientation() == Qt::Vertical) {
 759             rubberBandRect.moveTo(topLeft.x(), topLeft.y() - scrollOffset());
 760         } else {
 761             rubberBandRect.moveTo(topLeft.x() - scrollOffset(), topLeft.y());
 762         }
 763
 764         QStyleOptionRubberBand opt;
 765         initStyleOption(&opt);
 766         opt.shape = QRubberBand::Rectangle;
 767         opt.opaque = false;
 768         opt.rect = rubberBandRect.toRect();
 769
 770         painter->save();
 771
 772         painter->setOpacity(animation->currentValue().toReal());
 773         style()->drawControl(QStyle::CE_RubberBand, &opt, painter);
 774
 775         painter->restore();
 776     }
 777
 778     if (m_rubberBand->isActive()) {
 779         QRectF rubberBandRect = QRectF(m_rubberBand->startPosition(), m_rubberBand->endPosition()).normalized();
 780
 781         const QPointF topLeft = rubberBandRect.topLeft();
 782         if (scrollOrientation() == Qt::Vertical) {
 783             rubberBandRect.moveTo(topLeft.x(), topLeft.y() - scrollOffset());
 784         } else {
 785             rubberBandRect.moveTo(topLeft.x() - scrollOffset(), topLeft.y());
 786         }
 787
 788         QStyleOptionRubberBand opt;
 789         initStyleOption(&opt);
 790         opt.shape = QRubberBand::Rectangle;
 791         opt.opaque = false;
 792         opt.rect = rubberBandRect.toRect();
 793         style()->drawControl(QStyle::CE_RubberBand, &opt, painter);
 794     }
 795
 796     if (m_tapAndHoldIndicator->isActive()) {
 797         const QPointF indicatorSize = m_tapAndHoldIndicator->endPosition();
 798         const QRectF rubberBandRect =
 799             QRectF(m_tapAndHoldIndicator->startPosition() - indicatorSize, (m_tapAndHoldIndicator->startPosition()) + indicatorSize).normalized();
 800         QStyleOptionRubberBand opt;
 801         initStyleOption(&opt);
 802         opt.shape = QRubberBand::Rectangle;
 803         opt.opaque = false;
 804         opt.rect = rubberBandRect.toRect();
 805         style()->drawControl(QStyle::CE_RubberBand, &opt, painter);
 806     }
 807
 808     if (!m_dropIndicator.isEmpty()) {
 809         const QRectF r = m_dropIndicator.toRect();
 810
 811         QColor color = palette().brush(QPalette::Normal, QPalette::Text).color();
 812         painter->setPen(color);
 813
 814         // TODO: The following implementation works only for a vertical scroll-orientation
 815         // and assumes a height of the m_draggingInsertIndicator of 1.
 816         Q_ASSERT(r.height() == 1);
 817         painter->drawLine(r.left() + 1, r.top(), r.right() - 1, r.top());
 818
 819         color.setAlpha(128);
 820         painter->setPen(color);
 821         painter->drawRect(r.left(), r.top() - 1, r.width() - 1, 2);
 822     }
 823 }
 824
 825 QVariant KItemListView::itemChange(GraphicsItemChange change, const QVariant &value)
 826 {
 827     if (change == QGraphicsItem::ItemSceneHasChanged && scene()) {
 828         if (!scene()->views().isEmpty()) {
 829             m_styleOption.palette = scene()->views().at(0)->palette();
 830         }
 831     }
 832     return QGraphicsItem::itemChange(change, value);
 833 }
 834
 835 void KItemListView::setItemSize(const QSizeF &size)
 836 {
 837     const QSizeF previousSize = m_itemSize;
 838     if (size == previousSize) {
 839         return;
 840     }
 841
 842     // Skip animations when the number of rows or columns
 843     // are changed in the grid layout. Although the animation
 844     // engine can handle this usecase, it looks obtrusive.
 845     const bool animate = !changesItemGridLayout(m_layouter->size(), size, m_layouter->itemMargin());
 846
 847     const bool alternateBackgroundsChanged = m_alternateBackgrounds && ((m_itemSize.isEmpty() && !size.isEmpty()) || (!m_itemSize.isEmpty() && size.isEmpty()));
 848
 849     m_itemSize = size;
 850
 851     if (alternateBackgroundsChanged) {
 852         // For an empty item size alternate backgrounds are drawn if more than
 853         // one role is shown. Assure that the backgrounds for visible items are
 854         // updated when changing the size in this context.
 855         updateAlternateBackgrounds();
 856     }
 857
 858     if (size.isEmpty()) {
 859         if (m_headerWidget->automaticColumnResizing()) {
 860             updatePreferredColumnWidths();
 861         } else {
 862             // Only apply the changed height and respect the header widths
 863             // set by the user
 864             const qreal currentWidth = m_layouter->itemSize().width();
 865             const QSizeF newSize(currentWidth, size.height());
 866             m_layouter->setItemSize(newSize);
 867         }
 868     } else {
 869         m_layouter->setItemSize(size);
 870     }
 871
 872     m_sizeHintResolver->clearCache();
 873     doLayout(animate ? Animation : NoAnimation);
 874     onItemSizeChanged(size, previousSize);
 875 }
 876
 877 void KItemListView::setStyleOption(const KItemListStyleOption &option)
 878 {
 879     if (m_styleOption == option) {
 880         return;
 881     }
 882
 883     const KItemListStyleOption previousOption = m_styleOption;
 884     m_styleOption = option;
 885
 886     bool animate = true;
 887     const QSizeF margin(option.horizontalMargin, option.verticalMargin);
 888     if (margin != m_layouter->itemMargin()) {
 889         // Skip animations when the number of rows or columns
 890         // are changed in the grid layout. Although the animation
 891         // engine can handle this usecase, it looks obtrusive.
 892         animate = !changesItemGridLayout(m_layouter->size(), m_layouter->itemSize(), margin);
 893         m_layouter->setItemMargin(margin);
 894     }
 895
 896     if (m_grouped) {
 897         updateGroupHeaderHeight();
 898     }
 899
 900     if (animate && (previousOption.maxTextLines != option.maxTextLines || previousOption.maxTextWidth != option.maxTextWidth)) {
 901         // Animating a change of the maximum text size just results in expensive
 902         // temporary eliding and clipping operations and does not look good visually.
 903         animate = false;
 904     }
 905
 906     QHashIterator<int, KItemListWidget *> it(m_visibleItems);
 907     while (it.hasNext()) {
 908         it.next();
 909         it.value()->setStyleOption(option);
 910     }
 911
 912     m_sizeHintResolver->clearCache();
 913     m_layouter->markAsDirty();
 914     doLayout(animate ? Animation : NoAnimation);
 915
 916     if (m_itemSize.isEmpty()) {
 917         updatePreferredColumnWidths();
 918     }
 919
 920     onStyleOptionChanged(option, previousOption);
 921 }
 922
 923 void KItemListView::setScrollOrientation(Qt::Orientation orientation)
 924 {
 925     const Qt::Orientation previousOrientation = m_layouter->scrollOrientation();
 926     if (orientation == previousOrientation) {
 927         return;
 928     }
 929
 930     m_layouter->setScrollOrientation(orientation);
 931     m_animation->setScrollOrientation(orientation);
 932     m_sizeHintResolver->clearCache();
 933
 934     if (m_grouped) {
 935         QMutableHashIterator<KItemListWidget *, KItemListGroupHeader *> it(m_visibleGroups);
 936         while (it.hasNext()) {
 937             it.next();
 938             it.value()->setScrollOrientation(orientation);
 939         }
 940         updateGroupHeaderHeight();
 941     }
 942
 943     doLayout(NoAnimation);
 944
 945     onScrollOrientationChanged(orientation, previousOrientation);
 946     Q_EMIT scrollOrientationChanged(orientation, previousOrientation);
 947 }
 948
 949 Qt::Orientation KItemListView::scrollOrientation() const
 950 {
 951     return m_layouter->scrollOrientation();
 952 }
 953
 954 KItemListWidgetCreatorBase *KItemListView::defaultWidgetCreator() const
 955 {
 956     return nullptr;
 957 }
 958
 959 KItemListGroupHeaderCreatorBase *KItemListView::defaultGroupHeaderCreator() const
 960 {
 961     return nullptr;
 962 }
 963
 964 void KItemListView::initializeItemListWidget(KItemListWidget *item)
 965 {
 966     Q_UNUSED(item)
 967 }
 968
 969 bool KItemListView::itemSizeHintUpdateRequired(const QSet<QByteArray> &changedRoles) const
 970 {
 971     Q_UNUSED(changedRoles)
 972     return true;
 973 }
 974
 975 void KItemListView::onControllerChanged(KItemListController *current, KItemListController *previous)
 976 {
 977     Q_UNUSED(current)
 978     Q_UNUSED(previous)
 979 }
 980
 981 void KItemListView::onModelChanged(KItemModelBase *current, KItemModelBase *previous)
 982 {
 983     Q_UNUSED(current)
 984     Q_UNUSED(previous)
 985 }
 986
 987 void KItemListView::onScrollOrientationChanged(Qt::Orientation current, Qt::Orientation previous)
 988 {
 989     Q_UNUSED(current)
 990     Q_UNUSED(previous)
 991 }
 992
 993 void KItemListView::onItemSizeChanged(const QSizeF &current, const QSizeF &previous)
 994 {
 995     Q_UNUSED(current)
 996     Q_UNUSED(previous)
 997 }
 998
 999 void KItemListView::onScrollOffsetChanged(qreal current, qreal previous)
1000 {
1001     Q_UNUSED(current)
1002     Q_UNUSED(previous)
1003 }
1004
1005 void KItemListView::onVisibleRolesChanged(const QList<QByteArray> &current, const QList<QByteArray> &previous)
1006 {
1007     Q_UNUSED(current)
1008     Q_UNUSED(previous)
1009 }
1010
1011 void KItemListView::onStyleOptionChanged(const KItemListStyleOption &current, const KItemListStyleOption &previous)
1012 {
1013     Q_UNUSED(current)
1014     Q_UNUSED(previous)
1015 }
1016
1017 void KItemListView::onHighlightEntireRowChanged(bool highlightEntireRow)
1018 {
1019     Q_UNUSED(highlightEntireRow)
1020 }
1021
1022 void KItemListView::onSupportsItemExpandingChanged(bool supportsExpanding)
1023 {
1024     Q_UNUSED(supportsExpanding)
1025 }
1026
1027 void KItemListView::onTransactionBegin()
1028 {
1029 }
1030
1031 void KItemListView::onTransactionEnd()
1032 {
1033 }
1034
1035 bool KItemListView::event(QEvent *event)
1036 {
1037     switch (event->type()) {
1038     case QEvent::PaletteChange:
1039         updatePalette();
1040         break;
1041
1042     case QEvent::FontChange:
1043         updateFont();
1044         break;
1045
1046     case QEvent::FocusIn:
1047         focusInEvent(static_cast<QFocusEvent *>(event));
1048         event->accept();
1049         return true;
1050         break;
1051
1052     case QEvent::FocusOut:
1053         focusOutEvent(static_cast<QFocusEvent *>(event));
1054         event->accept();
1055         return true;
1056         break;
1057
1058     default:
1059         // Forward all other events to the controller and handle them there
1060         if (!m_editingRole && m_controller && m_controller->processEvent(event, transform())) {
1061             event->accept();
1062             return true;
1063         }
1064     }
1065
1066     return QGraphicsWidget::event(event);
1067 }
1068
1069 void KItemListView::mousePressEvent(QGraphicsSceneMouseEvent *event)
1070 {
1071     m_mousePos = transform().map(event->pos());
1072     event->accept();
1073 }
1074
1075 void KItemListView::mouseMoveEvent(QGraphicsSceneMouseEvent *event)
1076 {
1077     QGraphicsWidget::mouseMoveEvent(event);
1078
1079     m_mousePos = transform().map(event->pos());
1080     if (m_autoScrollTimer && !m_autoScrollTimer->isActive()) {
1081         m_autoScrollTimer->start(InitialAutoScrollDelay);
1082     }
1083 }
1084
1085 void KItemListView::dragEnterEvent(QGraphicsSceneDragDropEvent *event)
1086 {
1087     event->setAccepted(true);
1088     setAutoScroll(true);
1089 }
1090
1091 void KItemListView::dragMoveEvent(QGraphicsSceneDragDropEvent *event)
1092 {
1093     QGraphicsWidget::dragMoveEvent(event);
1094
1095     m_mousePos = transform().map(event->pos());
1096     if (m_autoScrollTimer && !m_autoScrollTimer->isActive()) {
1097         m_autoScrollTimer->start(InitialAutoScrollDelay);
1098     }
1099 }
1100
1101 void KItemListView::dragLeaveEvent(QGraphicsSceneDragDropEvent *event)
1102 {
1103     QGraphicsWidget::dragLeaveEvent(event);
1104     setAutoScroll(false);
1105 }
1106
1107 void KItemListView::dropEvent(QGraphicsSceneDragDropEvent *event)
1108 {
1109     QGraphicsWidget::dropEvent(event);
1110     setAutoScroll(false);
1111 }
1112
1113 QList<KItemListWidget *> KItemListView::visibleItemListWidgets() const
1114 {
1115     return m_visibleItems.values();
1116 }
1117
1118 void KItemListView::updateFont()
1119 {
1120     if (scene() && !scene()->views().isEmpty()) {
1121         KItemListStyleOption option = styleOption();
1122         option.font = scene()->views().first()->font();
1123         option.fontMetrics = QFontMetrics(option.font);
1124
1125         setStyleOption(option);
1126     }
1127 }
1128
1129 void KItemListView::updatePalette()
1130 {
1131     KItemListStyleOption option = styleOption();
1132     option.palette = palette();
1133     setStyleOption(option);
1134 }
1135
1136 void KItemListView::slotItemsInserted(const KItemRangeList &itemRanges)
1137 {
1138     if (m_itemSize.isEmpty()) {
1139         updatePreferredColumnWidths(itemRanges);
1140     }
1141
1142     const bool hasMultipleRanges = (itemRanges.count() > 1);
1143     if (hasMultipleRanges) {
1144         beginTransaction();
1145     }
1146
1147     m_layouter->markAsDirty();
1148
1149     m_sizeHintResolver->itemsInserted(itemRanges);
1150
1151     int previouslyInsertedCount = 0;
1152     for (const KItemRange &range : itemRanges) {
1153         // range.index is related to the model before anything has been inserted.
1154         // As in each loop the current item-range gets inserted the index must
1155         // be increased by the already previously inserted items.
1156         const int index = range.index + previouslyInsertedCount;
1157         const int count = range.count;
1158         if (index < 0 || count <= 0) {
1159             qCWarning(DolphinDebug) << "Invalid item range (index:" << index << ", count:" << count << ")";
1160             continue;
1161         }
1162         previouslyInsertedCount += count;
1163
1164         // Determine which visible items must be moved
1165         QList<int> itemsToMove;
1166         QHashIterator<int, KItemListWidget *> it(m_visibleItems);
1167         while (it.hasNext()) {
1168             it.next();
1169             const int visibleItemIndex = it.key();
1170             if (visibleItemIndex >= index) {
1171                 itemsToMove.append(visibleItemIndex);
1172             }
1173         }
1174
1175         // Update the indexes of all KItemListWidget instances that are located
1176         // after the inserted items. It is important to adjust the indexes in the order
1177         // from the highest index to the lowest index to prevent overlaps when setting the new index.
1178         std::sort(itemsToMove.begin(), itemsToMove.end());
1179         for (int i = itemsToMove.count() - 1; i >= 0; --i) {
1180             KItemListWidget *widget = m_visibleItems.value(itemsToMove[i]);
1181             Q_ASSERT(widget);
1182             const int newIndex = widget->index() + count;
1183             if (hasMultipleRanges) {
1184                 setWidgetIndex(widget, newIndex);
1185             } else {
1186                 // Try to animate the moving of the item
1187                 moveWidgetToIndex(widget, newIndex);
1188             }
1189         }
1190
1191         if (m_model->count() == count && m_activeTransactions == 0) {
1192             // Check whether a scrollbar is required to show the inserted items. In this case
1193             // the size of the layouter will be decreased before calling doLayout(): This prevents
1194             // an unnecessary temporary animation due to the geometry change of the inserted scrollbar.
1195             const bool verticalScrollOrientation = (scrollOrientation() == Qt::Vertical);
1196             const bool decreaseLayouterSize = (verticalScrollOrientation && maximumScrollOffset() > size().height())
1197                 || (!verticalScrollOrientation && maximumScrollOffset() > size().width());
1198             if (decreaseLayouterSize) {
1199                 const int scrollBarExtent = style()->pixelMetric(QStyle::PM_ScrollBarExtent);
1200
1201                 int scrollbarSpacing = 0;
1202                 if (style()->styleHint(QStyle::SH_ScrollView_FrameOnlyAroundContents)) {
1203                     scrollbarSpacing = style()->pixelMetric(QStyle::PM_ScrollView_ScrollBarSpacing);
1204                 }
1205
1206                 QSizeF layouterSize = m_layouter->size();
1207                 if (verticalScrollOrientation) {
1208                     layouterSize.rwidth() -= scrollBarExtent + scrollbarSpacing;
1209                 } else {
1210                     layouterSize.rheight() -= scrollBarExtent + scrollbarSpacing;
1211                 }
1212                 m_layouter->setSize(layouterSize);
1213             }
1214         }
1215
1216         if (!hasMultipleRanges) {
1217             doLayout(animateChangedItemCount(count) ? Animation : NoAnimation, index, count);
1218             updateSiblingsInformation();
1219         }
1220     }
1221
1222     if (m_controller) {
1223         m_controller->selectionManager()->itemsInserted(itemRanges);
1224     }
1225
1226     if (hasMultipleRanges) {
1227         m_endTransactionAnimationHint = NoAnimation;
1228         endTransaction();
1229
1230         updateSiblingsInformation();
1231     }
1232
1233     if (m_grouped && (hasMultipleRanges || itemRanges.first().count < m_model->count())) {
1234         // In case if items of the same group have been inserted before an item that
1235         // currently represents the first item of the group, the group header of
1236         // this item must be removed.
1237         updateVisibleGroupHeaders();
1238     }
1239
1240     if (useAlternateBackgrounds()) {
1241         updateAlternateBackgrounds();
1242     }
1243 }
1244
1245 void KItemListView::slotItemsRemoved(const KItemRangeList &itemRanges)
1246 {
1247     if (m_itemSize.isEmpty()) {
1248         // Don't pass the item-range: The preferred column-widths of
1249         // all items must be adjusted when removing items.
1250         updatePreferredColumnWidths();
1251     }
1252
1253     const bool hasMultipleRanges = (itemRanges.count() > 1);
1254     if (hasMultipleRanges) {
1255         beginTransaction();
1256     }
1257
1258     m_layouter->markAsDirty();
1259
1260     m_sizeHintResolver->itemsRemoved(itemRanges);
1261
1262     for (int i = itemRanges.count() - 1; i >= 0; --i) {
1263         const KItemRange &range = itemRanges[i];
1264         const int index = range.index;
1265         const int count = range.count;
1266         if (index < 0 || count <= 0) {
1267             qCWarning(DolphinDebug) << "Invalid item range (index:" << index << ", count:" << count << ")";
1268             continue;
1269         }
1270
1271         const int firstRemovedIndex = index;
1272         const int lastRemovedIndex = index + count - 1;
1273
1274         // Remember which items have to be moved because they are behind the removed range.
1275         QVector<int> itemsToMove;
1276
1277         // Remove all KItemListWidget instances that got deleted
1278         // Iterate over a const copy because the container is mutated within the loop
1279         // directly and in `recycleWidget()` (https://bugs.kde.org/show_bug.cgi?id=428374)
1280         const auto visibleItems = m_visibleItems;
1281         for (KItemListWidget *widget : visibleItems) {
1282             const int i = widget->index();
1283             if (i < firstRemovedIndex) {
1284                 continue;
1285             } else if (i > lastRemovedIndex) {
1286                 itemsToMove.append(i);
1287                 continue;
1288             }
1289
1290             m_animation->stop(widget);
1291             // Stopping the animation might lead to recycling the widget if
1292             // it is invisible (see slotAnimationFinished()).
1293             // Check again whether it is still visible:
1294             if (!m_visibleItems.contains(i)) {
1295                 continue;
1296             }
1297
1298             if (m_model->count() == 0 || hasMultipleRanges || !animateChangedItemCount(count)) {
1299                 // Remove the widget without animation
1300                 recycleWidget(widget);
1301             } else {
1302                 // Animate the removing of the items. Special case: When removing an item there
1303                 // is no valid model index available anymore. For the
1304                 // remove-animation the item gets removed from m_visibleItems but the widget
1305                 // will stay alive until the animation has been finished and will
1306                 // be recycled (deleted) in KItemListView::slotAnimationFinished().
1307                 m_visibleItems.remove(i);
1308                 widget->setIndex(-1);
1309                 m_animation->start(widget, KItemListViewAnimation::DeleteAnimation);
1310             }
1311         }
1312
1313         // Update the indexes of all KItemListWidget instances that are located
1314         // after the deleted items. It is important to update them in ascending
1315         // order to prevent overlaps when setting the new index.
1316         std::sort(itemsToMove.begin(), itemsToMove.end());
1317         for (int i : std::as_const(itemsToMove)) {
1318             KItemListWidget *widget = m_visibleItems.value(i);
1319             Q_ASSERT(widget);
1320             const int newIndex = i - count;
1321             if (hasMultipleRanges) {
1322                 setWidgetIndex(widget, newIndex);
1323             } else {
1324                 // Try to animate the moving of the item
1325                 moveWidgetToIndex(widget, newIndex);
1326             }
1327         }
1328
1329         if (!hasMultipleRanges) {
1330             // The decrease-layout-size optimization in KItemListView::slotItemsInserted()
1331             // assumes an updated geometry. If items are removed during an active transaction,
1332             // the transaction will be temporary deactivated so that doLayout() triggers a
1333             // geometry update if necessary.
1334             const int activeTransactions = m_activeTransactions;
1335             m_activeTransactions = 0;
1336             doLayout(animateChangedItemCount(count) ? Animation : NoAnimation, index, -count);
1337             m_activeTransactions = activeTransactions;
1338             updateSiblingsInformation();
1339         }
1340     }
1341
1342     if (m_controller) {
1343         m_controller->selectionManager()->itemsRemoved(itemRanges);
1344     }
1345
1346     if (hasMultipleRanges) {
1347         m_endTransactionAnimationHint = NoAnimation;
1348         endTransaction();
1349         updateSiblingsInformation();
1350     }
1351
1352     if (m_grouped && (hasMultipleRanges || m_model->count() > 0)) {
1353         // In case if the first item of a group has been removed, the group header
1354         // must be applied to the next visible item.
1355         updateVisibleGroupHeaders();
1356     }
1357
1358     if (useAlternateBackgrounds()) {
1359         updateAlternateBackgrounds();
1360     }
1361 }
1362
1363 void KItemListView::slotItemsMoved(const KItemRange &itemRange, const QList<int> &movedToIndexes)
1364 {
1365     m_sizeHintResolver->itemsMoved(itemRange, movedToIndexes);
1366     m_layouter->markAsDirty();
1367
1368     if (m_controller) {
1369         m_controller->selectionManager()->itemsMoved(itemRange, movedToIndexes);
1370     }
1371
1372     const int firstVisibleMovedIndex = qMax(firstVisibleIndex(), itemRange.index);
1373     const int lastVisibleMovedIndex = qMin(lastVisibleIndex(), itemRange.index + itemRange.count - 1);
1374
1375     for (int index = firstVisibleMovedIndex; index <= lastVisibleMovedIndex; ++index) {
1376         KItemListWidget *widget = m_visibleItems.value(index);
1377         if (widget) {
1378             updateWidgetProperties(widget, index);
1379             initializeItemListWidget(widget);
1380         }
1381     }
1382
1383     doLayout(NoAnimation);
1384     updateSiblingsInformation();
1385 }
1386
1387 void KItemListView::slotItemsChanged(const KItemRangeList &itemRanges, const QSet<QByteArray> &roles)
1388 {
1389     const bool updateSizeHints = itemSizeHintUpdateRequired(roles);
1390     if (updateSizeHints && m_itemSize.isEmpty()) {
1391         updatePreferredColumnWidths(itemRanges);
1392     }
1393
1394     for (const KItemRange &itemRange : itemRanges) {
1395         const int index = itemRange.index;
1396         const int count = itemRange.count;
1397
1398         if (updateSizeHints) {
1399             m_sizeHintResolver->itemsChanged(index, count, roles);
1400             m_layouter->markAsDirty();
1401         }
1402
1403         // Apply the changed roles to the visible item-widgets
1404         const int lastIndex = index + count - 1;
1405         for (int i = index; i <= lastIndex; ++i) {
1406             KItemListWidget *widget = m_visibleItems.value(i);
1407             if (widget) {
1408                 widget->setData(m_model->data(i), roles);
1409             }
1410         }
1411
1412         if (m_grouped && roles.contains(m_model->sortRole())) {
1413             // The sort-role has been changed which might result
1414             // in modified group headers
1415             updateVisibleGroupHeaders();
1416             doLayout(NoAnimation);
1417         }
1418
1419         QAccessibleTableModelChangeEvent ev(this, QAccessibleTableModelChangeEvent::DataChanged);
1420         ev.setFirstRow(itemRange.index);
1421         ev.setLastRow(itemRange.index + itemRange.count);
1422         QAccessible::updateAccessibility(&ev);
1423     }
1424
1425     doLayout(NoAnimation);
1426 }
1427
1428 void KItemListView::slotGroupsChanged()
1429 {
1430     updateVisibleGroupHeaders();
1431     doLayout(NoAnimation);
1432     updateSiblingsInformation();
1433 }
1434
1435 void KItemListView::slotGroupedSortingChanged(bool current)
1436 {
1437     m_grouped = current;
1438     m_layouter->markAsDirty();
1439
1440     if (m_grouped) {
1441         updateGroupHeaderHeight();
1442     } else {
1443         // Clear all visible headers. Note that the QHashIterator takes a copy of
1444         // m_visibleGroups. Therefore, it remains valid even if items are removed
1445         // from m_visibleGroups in recycleGroupHeaderForWidget().
1446         QHashIterator<KItemListWidget *, KItemListGroupHeader *> it(m_visibleGroups);
1447         while (it.hasNext()) {
1448             it.next();
1449             recycleGroupHeaderForWidget(it.key());
1450         }
1451         Q_ASSERT(m_visibleGroups.isEmpty());
1452     }
1453
1454     if (useAlternateBackgrounds()) {
1455         // Changing the group mode requires to update the alternate backgrounds
1456         // as with the enabled group mode the altering is done on base of the first
1457         // group item.
1458         updateAlternateBackgrounds();
1459     }
1460     updateSiblingsInformation();
1461     doLayout(NoAnimation);
1462 }
1463
1464 void KItemListView::slotSortOrderChanged(Qt::SortOrder current, Qt::SortOrder previous)
1465 {
1466     Q_UNUSED(current)
1467     Q_UNUSED(previous)
1468     if (m_grouped) {
1469         updateVisibleGroupHeaders();
1470         doLayout(NoAnimation);
1471     }
1472 }
1473
1474 void KItemListView::slotSortRoleChanged(const QByteArray &current, const QByteArray &previous)
1475 {
1476     Q_UNUSED(current)
1477     Q_UNUSED(previous)
1478     if (m_grouped) {
1479         updateVisibleGroupHeaders();
1480         doLayout(NoAnimation);
1481     }
1482 }
1483
1484 void KItemListView::slotCurrentChanged(int current, int previous)
1485 {
1486     Q_UNUSED(previous)
1487
1488     // In SingleSelection mode (e.g., in the Places Panel), the current item is
1489     // always the selected item. It is not necessary to highlight the current item then.
1490     if (m_controller->selectionBehavior() != KItemListController::SingleSelection) {
1491         KItemListWidget *previousWidget = m_visibleItems.value(previous, nullptr);
1492         if (previousWidget) {
1493             previousWidget->setCurrent(false);
1494         }
1495
1496         KItemListWidget *currentWidget = m_visibleItems.value(current, nullptr);
1497         if (currentWidget) {
1498             currentWidget->setCurrent(true);
1499         }
1500     }
1501
1502     QAccessibleEvent ev(this, QAccessible::Focus);
1503     ev.setChild(current);
1504     QAccessible::updateAccessibility(&ev);
1505 }
1506
1507 void KItemListView::slotSelectionChanged(const KItemSet &current, const KItemSet &previous)
1508 {
1509     Q_UNUSED(previous)
1510
1511     QHashIterator<int, KItemListWidget *> it(m_visibleItems);
1512     while (it.hasNext()) {
1513         it.next();
1514         const int index = it.key();
1515         KItemListWidget *widget = it.value();
1516         widget->setSelected(current.contains(index));
1517     }
1518 }
1519
1520 void KItemListView::slotAnimationFinished(QGraphicsWidget *widget, KItemListViewAnimation::AnimationType type)
1521 {
1522     KItemListWidget *itemListWidget = qobject_cast<KItemListWidget *>(widget);
1523     Q_ASSERT(itemListWidget);
1524
1525     if (type == KItemListViewAnimation::DeleteAnimation) {
1526         // As we recycle the widget in this case it is important to assure that no
1527         // other animation has been started. This is a convention in KItemListView and
1528         // not a requirement defined by KItemListViewAnimation.
1529         Q_ASSERT(!m_animation->isStarted(itemListWidget));
1530
1531         // All KItemListWidgets that are animated by the DeleteAnimation are not maintained
1532         // by m_visibleWidgets and must be deleted manually after the animation has
1533         // been finished.
1534         recycleGroupHeaderForWidget(itemListWidget);
1535         widgetCreator()->recycle(itemListWidget);
1536     } else {
1537         const int index = itemListWidget->index();
1538         const bool invisible = (index < m_layouter->firstVisibleIndex()) || (index > m_layouter->lastVisibleIndex());
1539         if (invisible && !m_animation->isStarted(itemListWidget)) {
1540             recycleWidget(itemListWidget);
1541         }
1542     }
1543 }
1544
1545 void KItemListView::slotRubberBandPosChanged()
1546 {
1547     update();
1548 }
1549
1550 void KItemListView::slotRubberBandActivationChanged(bool active)
1551 {
1552     if (active) {
1553         connect(m_rubberBand, &KItemListRubberBand::startPositionChanged, this, &KItemListView::slotRubberBandPosChanged);
1554         connect(m_rubberBand, &KItemListRubberBand::endPositionChanged, this, &KItemListView::slotRubberBandPosChanged);
1555         m_skipAutoScrollForRubberBand = true;
1556     } else {
1557         QRectF rubberBandRect = QRectF(m_rubberBand->startPosition(), m_rubberBand->endPosition()).normalized();
1558
1559         auto animation = new QVariantAnimation(this);
1560         animation->setStartValue(1.0);
1561         animation->setEndValue(0.0);
1562         animation->setDuration(RubberFadeSpeed);
1563         animation->setProperty(RubberPropertyName, rubberBandRect);
1564
1565         QEasingCurve curve;
1566         curve.setType(QEasingCurve::BezierSpline);
1567         curve.addCubicBezierSegment(QPointF(0.4, 0.0), QPointF(1.0, 1.0), QPointF(1.0, 1.0));
1568         animation->setEasingCurve(curve);
1569
1570         connect(animation, &QVariantAnimation::valueChanged, this, [=](const QVariant &) {
1571             update();
1572         });
1573         connect(animation, &QVariantAnimation::finished, this, [=]() {
1574             m_rubberBandAnimations.removeAll(animation);
1575             delete animation;
1576         });
1577         animation->start();
1578         m_rubberBandAnimations << animation;
1579
1580         disconnect(m_rubberBand, &KItemListRubberBand::startPositionChanged, this, &KItemListView::slotRubberBandPosChanged);
1581         disconnect(m_rubberBand, &KItemListRubberBand::endPositionChanged, this, &KItemListView::slotRubberBandPosChanged);
1582         m_skipAutoScrollForRubberBand = false;
1583     }
1584
1585     update();
1586 }
1587
1588 void KItemListView::slotHeaderColumnWidthChanged(const QByteArray &role, qreal currentWidth, qreal previousWidth)
1589 {
1590     Q_UNUSED(role)
1591     Q_UNUSED(currentWidth)
1592     Q_UNUSED(previousWidth)
1593
1594     m_headerWidget->setAutomaticColumnResizing(false);
1595     applyColumnWidthsFromHeader();
1596     doLayout(NoAnimation);
1597 }
1598
1599 void KItemListView::slotSidePaddingChanged(qreal width)
1600 {
1601     Q_UNUSED(width)
1602     if (m_headerWidget->automaticColumnResizing()) {
1603         applyAutomaticColumnWidths();
1604     }
1605     applyColumnWidthsFromHeader();
1606     doLayout(NoAnimation);
1607 }
1608
1609 void KItemListView::slotHeaderColumnMoved(const QByteArray &role, int currentIndex, int previousIndex)
1610 {
1611     Q_ASSERT(m_visibleRoles[previousIndex] == role);
1612
1613     const QList<QByteArray> previous = m_visibleRoles;
1614
1615     QList<QByteArray> current = m_visibleRoles;
1616     current.removeAt(previousIndex);
1617     current.insert(currentIndex, role);
1618
1619     setVisibleRoles(current);
1620
1621     Q_EMIT visibleRolesChanged(current, previous);
1622 }
1623
1624 void KItemListView::triggerAutoScrolling()
1625 {
1626     if (!m_autoScrollTimer) {
1627         return;
1628     }
1629
1630     int pos = 0;
1631     int visibleSize = 0;
1632     if (scrollOrientation() == Qt::Vertical) {
1633         pos = m_mousePos.y();
1634         visibleSize = size().height();
1635     } else {
1636         pos = m_mousePos.x();
1637         visibleSize = size().width();
1638     }
1639
1640     if (m_autoScrollTimer->interval() == InitialAutoScrollDelay) {
1641         m_autoScrollIncrement = 0;
1642     }
1643
1644     m_autoScrollIncrement = calculateAutoScrollingIncrement(pos, visibleSize, m_autoScrollIncrement);
1645     if (m_autoScrollIncrement == 0) {
1646         // The mouse position is not above an autoscroll margin (the autoscroll timer
1647         // will be restarted in mouseMoveEvent())
1648         m_autoScrollTimer->stop();
1649         return;
1650     }
1651
1652     if (m_rubberBand->isActive() && m_skipAutoScrollForRubberBand) {
1653         // If a rubberband selection is ongoing the autoscrolling may only get triggered
1654         // if the direction of the rubberband is similar to the autoscroll direction. This
1655         // prevents that starting to create a rubberband within the autoscroll margins starts
1656         // an autoscrolling.
1657
1658         const qreal minDiff = 4; // Ignore any autoscrolling if the rubberband is very small
1659         const qreal diff = (scrollOrientation() == Qt::Vertical) ? m_rubberBand->endPosition().y() - m_rubberBand->startPosition().y()
1660                                                                  : m_rubberBand->endPosition().x() - m_rubberBand->startPosition().x();
1661         if (qAbs(diff) < minDiff || (m_autoScrollIncrement < 0 && diff > 0) || (m_autoScrollIncrement > 0 && diff < 0)) {
1662             // The rubberband direction is different from the scroll direction (e.g. the rubberband has
1663             // been moved up although the autoscroll direction might be down)
1664             m_autoScrollTimer->stop();
1665             return;
1666         }
1667     }
1668
1669     // As soon as the autoscrolling has been triggered at least once despite having an active rubberband,
1670     // the autoscrolling may not get skipped anymore until a new rubberband is created
1671     m_skipAutoScrollForRubberBand = false;
1672
1673     const qreal maxVisibleOffset = qMax(qreal(0), maximumScrollOffset() - visibleSize);
1674     const qreal newScrollOffset = qMin(scrollOffset() + m_autoScrollIncrement, maxVisibleOffset);
1675     setScrollOffset(newScrollOffset);
1676
1677     // Trigger the autoscroll timer which will periodically call
1678     // triggerAutoScrolling()
1679     m_autoScrollTimer->start(RepeatingAutoScrollDelay);
1680 }
1681
1682 void KItemListView::slotGeometryOfGroupHeaderParentChanged()
1683 {
1684     KItemListWidget *widget = qobject_cast<KItemListWidget *>(sender());
1685     Q_ASSERT(widget);
1686     KItemListGroupHeader *groupHeader = m_visibleGroups.value(widget);
1687     Q_ASSERT(groupHeader);
1688     updateGroupHeaderLayout(widget);
1689 }
1690
1691 void KItemListView::slotRoleEditingCanceled(int index, const QByteArray &role, const QVariant &value)
1692 {
1693     disconnectRoleEditingSignals(index);
1694
1695     m_editingRole = false;
1696     Q_EMIT roleEditingCanceled(index, role, value);
1697 }
1698
1699 void KItemListView::slotRoleEditingFinished(int index, const QByteArray &role, const QVariant &value)
1700 {
1701     disconnectRoleEditingSignals(index);
1702
1703     m_editingRole = false;
1704     Q_EMIT roleEditingFinished(index, role, value);
1705 }
1706
1707 void KItemListView::setController(KItemListController *controller)
1708 {
1709     if (m_controller != controller) {
1710         KItemListController *previous = m_controller;
1711         if (previous) {
1712             KItemListSelectionManager *selectionManager = previous->selectionManager();
1713             disconnect(selectionManager, &KItemListSelectionManager::currentChanged, this, &KItemListView::slotCurrentChanged);
1714             disconnect(selectionManager, &KItemListSelectionManager::selectionChanged, this, &KItemListView::slotSelectionChanged);
1715         }
1716
1717         m_controller = controller;
1718
1719         if (controller) {
1720             KItemListSelectionManager *selectionManager = controller->selectionManager();
1721             connect(selectionManager, &KItemListSelectionManager::currentChanged, this, &KItemListView::slotCurrentChanged);
1722             connect(selectionManager, &KItemListSelectionManager::selectionChanged, this, &KItemListView::slotSelectionChanged);
1723         }
1724
1725         onControllerChanged(controller, previous);
1726     }
1727 }
1728
1729 void KItemListView::setModel(KItemModelBase *model)
1730 {
1731     if (m_model == model) {
1732         return;
1733     }
1734
1735     KItemModelBase *previous = m_model;
1736
1737     if (m_model) {
1738         disconnect(m_model, &KItemModelBase::itemsChanged, this, &KItemListView::slotItemsChanged);
1739         disconnect(m_model, &KItemModelBase::itemsInserted, this, &KItemListView::slotItemsInserted);
1740         disconnect(m_model, &KItemModelBase::itemsRemoved, this, &KItemListView::slotItemsRemoved);
1741         disconnect(m_model, &KItemModelBase::itemsMoved, this, &KItemListView::slotItemsMoved);
1742         disconnect(m_model, &KItemModelBase::groupsChanged, this, &KItemListView::slotGroupsChanged);
1743         disconnect(m_model, &KItemModelBase::groupedSortingChanged, this, &KItemListView::slotGroupedSortingChanged);
1744         disconnect(m_model, &KItemModelBase::sortOrderChanged, this, &KItemListView::slotSortOrderChanged);
1745         disconnect(m_model, &KItemModelBase::sortRoleChanged, this, &KItemListView::slotSortRoleChanged);
1746
1747         m_sizeHintResolver->itemsRemoved(KItemRangeList() << KItemRange(0, m_model->count()));
1748     }
1749
1750     m_model = model;
1751     m_layouter->setModel(model);
1752     m_grouped = model->groupedSorting();
1753
1754     if (m_model) {
1755         connect(m_model, &KItemModelBase::itemsChanged, this, &KItemListView::slotItemsChanged);
1756         connect(m_model, &KItemModelBase::itemsInserted, this, &KItemListView::slotItemsInserted);
1757         connect(m_model, &KItemModelBase::itemsRemoved, this, &KItemListView::slotItemsRemoved);
1758         connect(m_model, &KItemModelBase::itemsMoved, this, &KItemListView::slotItemsMoved);
1759         connect(m_model, &KItemModelBase::groupsChanged, this, &KItemListView::slotGroupsChanged);
1760         connect(m_model, &KItemModelBase::groupedSortingChanged, this, &KItemListView::slotGroupedSortingChanged);
1761         connect(m_model, &KItemModelBase::sortOrderChanged, this, &KItemListView::slotSortOrderChanged);
1762         connect(m_model, &KItemModelBase::sortRoleChanged, this, &KItemListView::slotSortRoleChanged);
1763
1764         const int itemCount = m_model->count();
1765         if (itemCount > 0) {
1766             slotItemsInserted(KItemRangeList() << KItemRange(0, itemCount));
1767         }
1768     }
1769
1770     onModelChanged(model, previous);
1771 }
1772
1773 KItemListRubberBand *KItemListView::rubberBand() const
1774 {
1775     return m_rubberBand;
1776 }
1777
1778 void KItemListView::doLayout(LayoutAnimationHint hint, int changedIndex, int changedCount)
1779 {
1780     if (m_activeTransactions > 0) {
1781         if (hint == NoAnimation) {
1782             // As soon as at least one property change should be done without animation,
1783             // the whole transaction will be marked as not animated.
1784             m_endTransactionAnimationHint = NoAnimation;
1785         }
1786         return;
1787     }
1788
1789     if (!m_model || m_model->count() < 0) {
1790         return;
1791     }
1792
1793     int firstVisibleIndex = m_layouter->firstVisibleIndex();
1794     if (firstVisibleIndex < 0) {
1795         emitOffsetChanges();
1796         return;
1797     }
1798
1799     // Do a sanity check of the scroll-offset property: When properties of the itemlist-view have been changed
1800     // it might be possible that the maximum offset got changed too. Assure that the full visible range
1801     // is still shown if the maximum offset got decreased.
1802     const qreal visibleOffsetRange = (scrollOrientation() == Qt::Horizontal) ? size().width() : size().height();
1803     const qreal maxOffsetToShowFullRange = maximumScrollOffset() - visibleOffsetRange;
1804     if (scrollOffset() > maxOffsetToShowFullRange) {
1805         m_layouter->setScrollOffset(qMax(qreal(0), maxOffsetToShowFullRange));
1806         firstVisibleIndex = m_layouter->firstVisibleIndex();
1807     }
1808
1809     const int lastVisibleIndex = m_layouter->lastVisibleIndex();
1810
1811     int firstSibblingIndex = -1;
1812     int lastSibblingIndex = -1;
1813     const bool supportsExpanding = supportsItemExpanding();
1814
1815     QList<int> reusableItems = recycleInvisibleItems(firstVisibleIndex, lastVisibleIndex, hint);
1816
1817     // Assure that for each visible item a KItemListWidget is available. KItemListWidget
1818     // instances from invisible items are reused. If no reusable items are
1819     // found then new KItemListWidget instances get created.
1820     const bool animate = (hint == Animation);
1821     for (int i = firstVisibleIndex; i <= lastVisibleIndex; ++i) {
1822         bool applyNewPos = true;
1823
1824         const QRectF itemBounds = m_layouter->itemRect(i);
1825         const QPointF newPos = itemBounds.topLeft();
1826         KItemListWidget *widget = m_visibleItems.value(i);
1827         if (!widget) {
1828             if (!reusableItems.isEmpty()) {
1829                 // Reuse a KItemListWidget instance from an invisible item
1830                 const int oldIndex = reusableItems.takeLast();
1831                 widget = m_visibleItems.value(oldIndex);
1832                 setWidgetIndex(widget, i);
1833                 updateWidgetProperties(widget, i);
1834                 initializeItemListWidget(widget);
1835             } else {
1836                 // No reusable KItemListWidget instance is available, create a new one
1837                 widget = createWidget(i);
1838             }
1839             widget->resize(itemBounds.size());
1840
1841             if (animate && changedCount < 0) {
1842                 // Items have been deleted.
1843                 if (i >= changedIndex) {
1844                     // The item is located behind the removed range. Move the
1845                     // created item to the imaginary old position outside the
1846                     // view. It will get animated to the new position later.
1847                     const int previousIndex = i - changedCount;
1848                     const QRectF itemRect = m_layouter->itemRect(previousIndex);
1849                     if (itemRect.isEmpty()) {
1850                         const QPointF invisibleOldPos = (scrollOrientation() == Qt::Vertical) ? QPointF(0, size().height()) : QPointF(size().width(), 0);
1851                         widget->setPos(invisibleOldPos);
1852                     } else {
1853                         widget->setPos(itemRect.topLeft());
1854                     }
1855                     applyNewPos = false;
1856                 }
1857             }
1858
1859             if (supportsExpanding && changedCount == 0) {
1860                 if (firstSibblingIndex < 0) {
1861                     firstSibblingIndex = i;
1862                 }
1863                 lastSibblingIndex = i;
1864             }
1865         }
1866
1867         if (animate) {
1868             if (m_animation->isStarted(widget, KItemListViewAnimation::MovingAnimation)) {
1869                 m_animation->start(widget, KItemListViewAnimation::MovingAnimation, newPos);
1870                 applyNewPos = false;
1871             }
1872
1873             const bool itemsRemoved = (changedCount < 0);
1874             const bool itemsInserted = (changedCount > 0);
1875             if (itemsRemoved && (i >= changedIndex)) {
1876                 // The item is located after the removed items. Animate the moving of the position.
1877                 applyNewPos = !moveWidget(widget, newPos);
1878             } else if (itemsInserted && i >= changedIndex) {
1879                 // The item is located after the first inserted item
1880                 if (i <= changedIndex + changedCount - 1) {
1881                     // The item is an inserted item. Animate the appearing of the item.
1882                     // For performance reasons no animation is done when changedCount is equal
1883                     // to all available items.
1884                     if (changedCount < m_model->count()) {
1885                         m_animation->start(widget, KItemListViewAnimation::CreateAnimation);
1886                     }
1887                 } else if (!m_animation->isStarted(widget, KItemListViewAnimation::CreateAnimation)) {
1888                     // The item was already there before, so animate the moving of the position.
1889                     // No moving animation is done if the item is animated by a create animation: This
1890                     // prevents a "move animation mess" when inserting several ranges in parallel.
1891                     applyNewPos = !moveWidget(widget, newPos);
1892                 }
1893             }
1894         } else {
1895             m_animation->stop(widget);
1896         }
1897
1898         if (applyNewPos) {
1899             widget->setPos(newPos);
1900         }
1901
1902         Q_ASSERT(widget->index() == i);
1903         widget->setVisible(true);
1904
1905         bool animateIconResizing = animate;
1906
1907         if (widget->size() != itemBounds.size()) {
1908             // Resize the widget for the item to the changed size.
1909             if (animate) {
1910                 // If a dynamic item size is used then no animation is done in the direction
1911                 // of the dynamic size.
1912                 if (m_itemSize.width() <= 0) {
1913                     // The width is dynamic, apply the new width without animation.
1914                     widget->resize(itemBounds.width(), widget->size().height());
1915                 } else if (m_itemSize.height() <= 0) {
1916                     // The height is dynamic, apply the new height without animation.
1917                     widget->resize(widget->size().width(), itemBounds.height());
1918                 }
1919                 m_animation->start(widget, KItemListViewAnimation::ResizeAnimation, itemBounds.size());
1920             } else {
1921                 widget->resize(itemBounds.size());
1922             }
1923         } else {
1924             animateIconResizing = false;
1925         }
1926
1927         const int newIconSize = widget->styleOption().iconSize;
1928         if (widget->iconSize() != newIconSize) {
1929             if (animateIconResizing) {
1930                 m_animation->start(widget, KItemListViewAnimation::IconResizeAnimation, newIconSize);
1931             } else {
1932                 widget->setIconSize(newIconSize);
1933             }
1934         }
1935
1936         // Updating the cell-information must be done as last step: The decision whether the
1937         // moving-animation should be started at all is based on the previous cell-information.
1938         const Cell cell(m_layouter->itemColumn(i), m_layouter->itemRow(i));
1939         m_visibleCells.insert(i, cell);
1940     }
1941
1942     // Delete invisible KItemListWidget instances that have not been reused
1943     for (int index : std::as_const(reusableItems)) {
1944         recycleWidget(m_visibleItems.value(index));
1945     }
1946
1947     if (supportsExpanding && firstSibblingIndex >= 0) {
1948         Q_ASSERT(lastSibblingIndex >= 0);
1949         updateSiblingsInformation(firstSibblingIndex, lastSibblingIndex);
1950     }
1951
1952     if (m_grouped) {
1953         // Update the layout of all visible group headers
1954         QHashIterator<KItemListWidget *, KItemListGroupHeader *> it(m_visibleGroups);
1955         while (it.hasNext()) {
1956             it.next();
1957             updateGroupHeaderLayout(it.key());
1958         }
1959     }
1960
1961     emitOffsetChanges();
1962 }
1963
1964 QList<int> KItemListView::recycleInvisibleItems(int firstVisibleIndex, int lastVisibleIndex, LayoutAnimationHint hint)
1965 {
1966     // Determine all items that are completely invisible and might be
1967     // reused for items that just got (at least partly) visible. If the
1968     // animation hint is set to 'Animation' items that do e.g. an animated
1969     // moving of their position are not marked as invisible: This assures
1970     // that a scrolling inside the view can be done without breaking an animation.
1971
1972     QList<int> items;
1973
1974     QHashIterator<int, KItemListWidget *> it(m_visibleItems);
1975     while (it.hasNext()) {
1976         it.next();
1977
1978         KItemListWidget *widget = it.value();
1979         const int index = widget->index();
1980         const bool invisible = (index < firstVisibleIndex) || (index > lastVisibleIndex);
1981
1982         if (invisible) {
1983             if (m_animation->isStarted(widget)) {
1984                 if (hint == NoAnimation) {
1985                     // Stopping the animation will call KItemListView::slotAnimationFinished()
1986                     // and the widget will be recycled if necessary there.
1987                     m_animation->stop(widget);
1988                 }
1989             } else {
1990                 widget->setVisible(false);
1991                 items.append(index);
1992
1993                 if (m_grouped) {
1994                     recycleGroupHeaderForWidget(widget);
1995                 }
1996             }
1997         }
1998     }
1999
2000     return items;
2001 }
2002
2003 bool KItemListView::moveWidget(KItemListWidget *widget, const QPointF &newPos)
2004 {
2005     if (widget->pos() == newPos) {
2006         return false;
2007     }
2008
2009     bool startMovingAnim = false;
2010
2011     if (m_itemSize.isEmpty()) {
2012         // The items are not aligned in a grid but either as columns or rows.
2013         startMovingAnim = true;
2014     } else {
2015         // When having a grid the moving-animation should only be started, if it is done within
2016         // one row in the vertical scroll-orientation or one column in the horizontal scroll-orientation.
2017         // Otherwise instead of a moving-animation a create-animation on the new position will be used
2018         // instead. This is done to prevent overlapping (and confusing) moving-animations.
2019         const int index = widget->index();
2020         const Cell cell = m_visibleCells.value(index);
2021         if (cell.column >= 0 && cell.row >= 0) {
2022             if (scrollOrientation() == Qt::Vertical) {
2023                 startMovingAnim = (cell.row == m_layouter->itemRow(index));
2024             } else {
2025                 startMovingAnim = (cell.column == m_layouter->itemColumn(index));
2026             }
2027         }
2028     }
2029
2030     if (startMovingAnim) {
2031         m_animation->start(widget, KItemListViewAnimation::MovingAnimation, newPos);
2032         return true;
2033     }
2034
2035     m_animation->stop(widget);
2036     m_animation->start(widget, KItemListViewAnimation::CreateAnimation);
2037     return false;
2038 }
2039
2040 void KItemListView::emitOffsetChanges()
2041 {
2042     const qreal newScrollOffset = m_layouter->scrollOffset();
2043     if (m_oldScrollOffset != newScrollOffset) {
2044         Q_EMIT scrollOffsetChanged(newScrollOffset, m_oldScrollOffset);
2045         m_oldScrollOffset = newScrollOffset;
2046     }
2047
2048     const qreal newMaximumScrollOffset = m_layouter->maximumScrollOffset();
2049     if (m_oldMaximumScrollOffset != newMaximumScrollOffset) {
2050         Q_EMIT maximumScrollOffsetChanged(newMaximumScrollOffset, m_oldMaximumScrollOffset);
2051         m_oldMaximumScrollOffset = newMaximumScrollOffset;
2052     }
2053
2054     const qreal newItemOffset = m_layouter->itemOffset();
2055     if (m_oldItemOffset != newItemOffset) {
2056         Q_EMIT itemOffsetChanged(newItemOffset, m_oldItemOffset);
2057         m_oldItemOffset = newItemOffset;
2058     }
2059
2060     const qreal newMaximumItemOffset = m_layouter->maximumItemOffset();
2061     if (m_oldMaximumItemOffset != newMaximumItemOffset) {
2062         Q_EMIT maximumItemOffsetChanged(newMaximumItemOffset, m_oldMaximumItemOffset);
2063         m_oldMaximumItemOffset = newMaximumItemOffset;
2064     }
2065 }
2066
2067 KItemListWidget *KItemListView::createWidget(int index)
2068 {
2069     KItemListWidget *widget = widgetCreator()->create(this);
2070     widget->setFlag(QGraphicsItem::ItemStacksBehindParent);
2071
2072     m_visibleItems.insert(index, widget);
2073     m_visibleCells.insert(index, Cell());
2074     updateWidgetProperties(widget, index);
2075     initializeItemListWidget(widget);
2076     return widget;
2077 }
2078
2079 void KItemListView::recycleWidget(KItemListWidget *widget)
2080 {
2081     if (m_grouped) {
2082         recycleGroupHeaderForWidget(widget);
2083     }
2084
2085     const int index = widget->index();
2086     m_visibleItems.remove(index);
2087     m_visibleCells.remove(index);
2088
2089     widgetCreator()->recycle(widget);
2090 }
2091
2092 void KItemListView::setWidgetIndex(KItemListWidget *widget, int index)
2093 {
2094     const int oldIndex = widget->index();
2095     m_visibleItems.remove(oldIndex);
2096     m_visibleCells.remove(oldIndex);
2097
2098     m_visibleItems.insert(index, widget);
2099     m_visibleCells.insert(index, Cell());
2100
2101     widget->setIndex(index);
2102 }
2103
2104 void KItemListView::moveWidgetToIndex(KItemListWidget *widget, int index)
2105 {
2106     const int oldIndex = widget->index();
2107     const Cell oldCell = m_visibleCells.value(oldIndex);
2108
2109     setWidgetIndex(widget, index);
2110
2111     const Cell newCell(m_layouter->itemColumn(index), m_layouter->itemRow(index));
2112     const bool vertical = (scrollOrientation() == Qt::Vertical);
2113     const bool updateCell = (vertical && oldCell.row == newCell.row) || (!vertical && oldCell.column == newCell.column);
2114     if (updateCell) {
2115         m_visibleCells.insert(index, newCell);
2116     }
2117 }
2118
2119 void KItemListView::setLayouterSize(const QSizeF &size, SizeType sizeType)
2120 {
2121     switch (sizeType) {
2122     case LayouterSize:
2123         m_layouter->setSize(size);
2124         break;
2125     case ItemSize:
2126         m_layouter->setItemSize(size);
2127         break;
2128     default:
2129         break;
2130     }
2131 }
2132
2133 void KItemListView::updateWidgetProperties(KItemListWidget *widget, int index)
2134 {
2135     widget->setVisibleRoles(m_visibleRoles);
2136     updateWidgetColumnWidths(widget);
2137     widget->setStyleOption(m_styleOption);
2138
2139     const KItemListSelectionManager *selectionManager = m_controller->selectionManager();
2140
2141     // In SingleSelection mode (e.g., in the Places Panel), the current item is
2142     // always the selected item. It is not necessary to highlight the current item then.
2143     if (m_controller->selectionBehavior() != KItemListController::SingleSelection) {
2144         widget->setCurrent(index == selectionManager->currentItem());
2145     }
2146     widget->setSelected(selectionManager->isSelected(index));
2147     widget->setHovered(false);
2148     widget->setEnabledSelectionToggle(enabledSelectionToggles());
2149     widget->setIndex(index);
2150     widget->setData(m_model->data(index));
2151     widget->setSiblingsInformation(QBitArray());
2152     updateAlternateBackgroundForWidget(widget);
2153
2154     if (m_grouped) {
2155         updateGroupHeaderForWidget(widget);
2156     }
2157 }
2158
2159 void KItemListView::updateGroupHeaderForWidget(KItemListWidget *widget)
2160 {
2161     Q_ASSERT(m_grouped);
2162
2163     const int index = widget->index();
2164     if (!m_layouter->isFirstGroupItem(index)) {
2165         // The widget does not represent the first item of a group
2166         // and hence requires no header
2167         recycleGroupHeaderForWidget(widget);
2168         return;
2169     }
2170
2171     const QList<QPair<int, QVariant>> groups = model()->groups();
2172     if (groups.isEmpty() || !groupHeaderCreator()) {
2173         return;
2174     }
2175
2176     KItemListGroupHeader *groupHeader = m_visibleGroups.value(widget);
2177     if (!groupHeader) {
2178         groupHeader = groupHeaderCreator()->create(this);
2179         groupHeader->setParentItem(widget);
2180         m_visibleGroups.insert(widget, groupHeader);
2181         connect(widget, &KItemListWidget::geometryChanged, this, &KItemListView::slotGeometryOfGroupHeaderParentChanged);
2182     }
2183     Q_ASSERT(groupHeader->parentItem() == widget);
2184
2185     const int groupIndex = groupIndexForItem(index);
2186     Q_ASSERT(groupIndex >= 0);
2187     groupHeader->setData(groups.at(groupIndex).second);
2188     groupHeader->setRole(model()->sortRole());
2189     groupHeader->setStyleOption(m_styleOption);
2190     groupHeader->setScrollOrientation(scrollOrientation());
2191     groupHeader->setItemIndex(index);
2192
2193     groupHeader->show();
2194 }
2195
2196 void KItemListView::updateGroupHeaderLayout(KItemListWidget *widget)
2197 {
2198     KItemListGroupHeader *groupHeader = m_visibleGroups.value(widget);
2199     Q_ASSERT(groupHeader);
2200
2201     const int index = widget->index();
2202     const QRectF groupHeaderRect = m_layouter->groupHeaderRect(index);
2203     const QRectF itemRect = m_layouter->itemRect(index);
2204
2205     // The group-header is a child of the itemlist widget. Translate the
2206     // group header position to the relative position.
2207     if (scrollOrientation() == Qt::Vertical) {
2208         // In the vertical scroll orientation the group header should always span
2209         // the whole width no matter which temporary position the parent widget
2210         // has. In this case the x-position and width will be adjusted manually.
2211         const qreal x = -widget->x() - itemOffset();
2212         const qreal width = maximumItemOffset();
2213         groupHeader->setPos(x, -groupHeaderRect.height());
2214         groupHeader->resize(width, groupHeaderRect.size().height());
2215     } else {
2216         groupHeader->setPos(groupHeaderRect.x() - itemRect.x(), -widget->y());
2217         groupHeader->resize(groupHeaderRect.size());
2218     }
2219 }
2220
2221 void KItemListView::recycleGroupHeaderForWidget(KItemListWidget *widget)
2222 {
2223     KItemListGroupHeader *header = m_visibleGroups.value(widget);
2224     if (header) {
2225         header->setParentItem(nullptr);
2226         groupHeaderCreator()->recycle(header);
2227         m_visibleGroups.remove(widget);
2228         disconnect(widget, &KItemListWidget::geometryChanged, this, &KItemListView::slotGeometryOfGroupHeaderParentChanged);
2229     }
2230 }
2231
2232 void KItemListView::updateVisibleGroupHeaders()
2233 {
2234     Q_ASSERT(m_grouped);
2235     m_layouter->markAsDirty();
2236
2237     QHashIterator<int, KItemListWidget *> it(m_visibleItems);
2238     while (it.hasNext()) {
2239         it.next();
2240         updateGroupHeaderForWidget(it.value());
2241     }
2242 }
2243
2244 int KItemListView::groupIndexForItem(int index) const
2245 {
2246     Q_ASSERT(m_grouped);
2247
2248     const QList<QPair<int, QVariant>> groups = model()->groups();
2249     if (groups.isEmpty()) {
2250         return -1;
2251     }
2252
2253     int min = 0;
2254     int max = groups.count() - 1;
2255     int mid = 0;
2256     do {
2257         mid = (min + max) / 2;
2258         if (index > groups[mid].first) {
2259             min = mid + 1;
2260         } else {
2261             max = mid - 1;
2262         }
2263     } while (groups[mid].first != index && min <= max);
2264
2265     if (min > max) {
2266         while (groups[mid].first > index && mid > 0) {
2267             --mid;
2268         }
2269     }
2270
2271     return mid;
2272 }
2273
2274 void KItemListView::updateAlternateBackgrounds()
2275 {
2276     QHashIterator<int, KItemListWidget *> it(m_visibleItems);
2277     while (it.hasNext()) {
2278         it.next();
2279         updateAlternateBackgroundForWidget(it.value());
2280     }
2281 }
2282
2283 void KItemListView::updateAlternateBackgroundForWidget(KItemListWidget *widget)
2284 {
2285     bool enabled = useAlternateBackgrounds();
2286     if (enabled) {
2287         const int index = widget->index();
2288         enabled = (index & 0x1) > 0;
2289         if (m_grouped) {
2290             const int groupIndex = groupIndexForItem(index);
2291             if (groupIndex >= 0) {
2292                 const QList<QPair<int, QVariant>> groups = model()->groups();
2293                 const int indexOfFirstGroupItem = groups[groupIndex].first;
2294                 const int relativeIndex = index - indexOfFirstGroupItem;
2295                 enabled = (relativeIndex & 0x1) > 0;
2296             }
2297         }
2298     }
2299     widget->setAlternateBackground(enabled);
2300 }
2301
2302 bool KItemListView::useAlternateBackgrounds() const
2303 {
2304     return m_alternateBackgrounds && m_itemSize.isEmpty();
2305 }
2306
2307 QHash<QByteArray, qreal> KItemListView::preferredColumnWidths(const KItemRangeList &itemRanges) const
2308 {
2309     QElapsedTimer timer;
2310     timer.start();
2311
2312     QHash<QByteArray, qreal> widths;
2313
2314     // Calculate the minimum width for each column that is required
2315     // to show the headline unclipped.
2316     const QFontMetricsF fontMetrics(m_headerWidget->font());
2317     const int gripMargin = m_headerWidget->style()->pixelMetric(QStyle::PM_HeaderGripMargin);
2318     const int headerMargin = m_headerWidget->style()->pixelMetric(QStyle::PM_HeaderMargin);
2319     for (const QByteArray &visibleRole : std::as_const(m_visibleRoles)) {
2320         const QString headerText = m_model->roleDescription(visibleRole);
2321         const qreal headerWidth = fontMetrics.horizontalAdvance(headerText) + gripMargin + headerMargin * 2;
2322         widths.insert(visibleRole, headerWidth);
2323     }
2324
2325     // Calculate the preferred column widths for each item and ignore values
2326     // smaller than the width for showing the headline unclipped.
2327     const KItemListWidgetCreatorBase *creator = widgetCreator();
2328     int calculatedItemCount = 0;
2329     bool maxTimeExceeded = false;
2330     for (const KItemRange &itemRange : itemRanges) {
2331         const int startIndex = itemRange.index;
2332         const int endIndex = startIndex + itemRange.count - 1;
2333
2334         for (int i = startIndex; i <= endIndex; ++i) {
2335             for (const QByteArray &visibleRole : std::as_const(m_visibleRoles)) {
2336                 qreal maxWidth = widths.value(visibleRole, 0);
2337                 const qreal width = creator->preferredRoleColumnWidth(visibleRole, i, this);
2338                 maxWidth = qMax(width, maxWidth);
2339                 widths.insert(visibleRole, maxWidth);
2340             }
2341
2342             if (calculatedItemCount > 100 && timer.elapsed() > 200) {
2343                 // When having several thousands of items calculating the sizes can get
2344                 // very expensive. We accept a possibly too small role-size in favour
2345                 // of having no blocking user interface.
2346                 maxTimeExceeded = true;
2347                 break;
2348             }
2349             ++calculatedItemCount;
2350         }
2351         if (maxTimeExceeded) {
2352             break;
2353         }
2354     }
2355
2356     return widths;
2357 }
2358
2359 void KItemListView::applyColumnWidthsFromHeader()
2360 {
2361     // Apply the new size to the layouter
2362     const qreal requiredWidth = columnWidthsSum() + 2 * m_headerWidget->sidePadding();
2363     const QSizeF dynamicItemSize(qMax(size().width(), requiredWidth), m_itemSize.height());
2364     m_layouter->setItemSize(dynamicItemSize);
2365
2366     // Update the role sizes for all visible widgets
2367     QHashIterator<int, KItemListWidget *> it(m_visibleItems);
2368     while (it.hasNext()) {
2369         it.next();
2370         updateWidgetColumnWidths(it.value());
2371     }
2372 }
2373
2374 void KItemListView::updateWidgetColumnWidths(KItemListWidget *widget)
2375 {
2376     for (const QByteArray &role : std::as_const(m_visibleRoles)) {
2377         widget->setColumnWidth(role, m_headerWidget->columnWidth(role));
2378     }
2379     widget->setSidePadding(m_headerWidget->sidePadding());
2380 }
2381
2382 void KItemListView::updatePreferredColumnWidths(const KItemRangeList &itemRanges)
2383 {
2384     Q_ASSERT(m_itemSize.isEmpty());
2385     const int itemCount = m_model->count();
2386     int rangesItemCount = 0;
2387     for (const KItemRange &range : itemRanges) {
2388         rangesItemCount += range.count;
2389     }
2390
2391     if (itemCount == rangesItemCount) {
2392         const QHash<QByteArray, qreal> preferredWidths = preferredColumnWidths(itemRanges);
2393         for (const QByteArray &role : std::as_const(m_visibleRoles)) {
2394             m_headerWidget->setPreferredColumnWidth(role, preferredWidths.value(role));
2395         }
2396     } else {
2397         // Only a sub range of the roles need to be determined.
2398         // The chances are good that the widths of the sub ranges
2399         // already fit into the available widths and hence no
2400         // expensive update might be required.
2401         bool changed = false;
2402
2403         const QHash<QByteArray, qreal> updatedWidths = preferredColumnWidths(itemRanges);
2404         QHashIterator<QByteArray, qreal> it(updatedWidths);
2405         while (it.hasNext()) {
2406             it.next();
2407             const QByteArray &role = it.key();
2408             const qreal updatedWidth = it.value();
2409             const qreal currentWidth = m_headerWidget->preferredColumnWidth(role);
2410             if (updatedWidth > currentWidth) {
2411                 m_headerWidget->setPreferredColumnWidth(role, updatedWidth);
2412                 changed = true;
2413             }
2414         }
2415
2416         if (!changed) {
2417             // All the updated sizes are smaller than the current sizes and no change
2418             // of the stretched roles-widths is required
2419             return;
2420         }
2421     }
2422
2423     if (m_headerWidget->automaticColumnResizing()) {
2424         applyAutomaticColumnWidths();
2425     }
2426 }
2427
2428 void KItemListView::updatePreferredColumnWidths()
2429 {
2430     if (m_model) {
2431         updatePreferredColumnWidths(KItemRangeList() << KItemRange(0, m_model->count()));
2432     }
2433 }
2434
2435 void KItemListView::applyAutomaticColumnWidths()
2436 {
2437     Q_ASSERT(m_itemSize.isEmpty());
2438     Q_ASSERT(m_headerWidget->automaticColumnResizing());
2439     if (m_visibleRoles.isEmpty()) {
2440         return;
2441     }
2442
2443     // Calculate the maximum size of an item by considering the
2444     // visible role sizes and apply them to the layouter. If the
2445     // size does not use the available view-size the size of the
2446     // first role will get stretched.
2447
2448     for (const QByteArray &role : std::as_const(m_visibleRoles)) {
2449         const qreal preferredWidth = m_headerWidget->preferredColumnWidth(role);
2450         m_headerWidget->setColumnWidth(role, preferredWidth);
2451     }
2452
2453     const QByteArray firstRole = m_visibleRoles.first();
2454     qreal firstColumnWidth = m_headerWidget->columnWidth(firstRole);
2455     QSizeF dynamicItemSize = m_itemSize;
2456
2457     qreal requiredWidth = columnWidthsSum() + 2 * m_headerWidget->sidePadding(); // Adding the padding a second time so we have the same padding
2458     // symmetrically on both sides of the view. This improves UX, looks better and increases the chances of users figuring out that the padding
2459     // area can be used for deselecting and dropping files.
2460     const qreal availableWidth = size().width();
2461     if (requiredWidth < availableWidth) {
2462         // Stretch the first column to use the whole remaining width
2463         firstColumnWidth += availableWidth - requiredWidth;
2464         m_headerWidget->setColumnWidth(firstRole, firstColumnWidth);
2465     } else if (requiredWidth > availableWidth && m_visibleRoles.count() > 1) {
2466         // Shrink the first column to be able to show as much other
2467         // columns as possible
2468         qreal shrinkedFirstColumnWidth = firstColumnWidth - requiredWidth + availableWidth;
2469
2470         // TODO: A proper calculation of the minimum width depends on the implementation
2471         // of KItemListWidget. Probably a kind of minimum size-hint should be introduced
2472         // later.
2473         const qreal minWidth = qMin(firstColumnWidth, qreal(m_styleOption.iconSize * 2 + 200));
2474         if (shrinkedFirstColumnWidth < minWidth) {
2475             shrinkedFirstColumnWidth = minWidth;
2476         }
2477
2478         m_headerWidget->setColumnWidth(firstRole, shrinkedFirstColumnWidth);
2479         requiredWidth -= firstColumnWidth - shrinkedFirstColumnWidth;
2480     }
2481
2482     dynamicItemSize.rwidth() = qMax(requiredWidth, availableWidth);
2483
2484     m_layouter->setItemSize(dynamicItemSize);
2485
2486     // Update the role sizes for all visible widgets
2487     QHashIterator<int, KItemListWidget *> it(m_visibleItems);
2488     while (it.hasNext()) {
2489         it.next();
2490         updateWidgetColumnWidths(it.value());
2491     }
2492 }
2493
2494 qreal KItemListView::columnWidthsSum() const
2495 {
2496     qreal widthsSum = 0;
2497     for (const QByteArray &role : std::as_const(m_visibleRoles)) {
2498         widthsSum += m_headerWidget->columnWidth(role);
2499     }
2500     return widthsSum;
2501 }
2502
2503 QRectF KItemListView::headerBoundaries() const
2504 {
2505     return m_headerWidget->isVisible() ? m_headerWidget->geometry() : QRectF();
2506 }
2507
2508 bool KItemListView::changesItemGridLayout(const QSizeF &newGridSize, const QSizeF &newItemSize, const QSizeF &newItemMargin) const
2509 {
2510     if (newItemSize.isEmpty() || newGridSize.isEmpty()) {
2511         return false;
2512     }
2513
2514     if (m_layouter->scrollOrientation() == Qt::Vertical) {
2515         const qreal itemWidth = m_layouter->itemSize().width();
2516         if (itemWidth > 0) {
2517             const int newColumnCount = itemsPerSize(newGridSize.width(), newItemSize.width(), newItemMargin.width());
2518             if (m_model->count() > newColumnCount) {
2519                 const int oldColumnCount = itemsPerSize(m_layouter->size().width(), itemWidth, m_layouter->itemMargin().width());
2520                 return oldColumnCount != newColumnCount;
2521             }
2522         }
2523     } else {
2524         const qreal itemHeight = m_layouter->itemSize().height();
2525         if (itemHeight > 0) {
2526             const int newRowCount = itemsPerSize(newGridSize.height(), newItemSize.height(), newItemMargin.height());
2527             if (m_model->count() > newRowCount) {
2528                 const int oldRowCount = itemsPerSize(m_layouter->size().height(), itemHeight, m_layouter->itemMargin().height());
2529                 return oldRowCount != newRowCount;
2530             }
2531         }
2532     }
2533
2534     return false;
2535 }
2536
2537 bool KItemListView::animateChangedItemCount(int changedItemCount) const
2538 {
2539     if (m_itemSize.isEmpty()) {
2540         // We have only columns or only rows, but no grid: An animation is usually
2541         // welcome when inserting or removing items.
2542         return !supportsItemExpanding();
2543     }
2544
2545     if (m_layouter->size().isEmpty() || m_layouter->itemSize().isEmpty()) {
2546         return false;
2547     }
2548
2549     const int maximum = (scrollOrientation() == Qt::Vertical) ? m_layouter->size().width() / m_layouter->itemSize().width()
2550                                                               : m_layouter->size().height() / m_layouter->itemSize().height();
2551     // Only animate if up to 2/3 of a row or column are inserted or removed
2552     return changedItemCount <= maximum * 2 / 3;
2553 }
2554
2555 bool KItemListView::scrollBarRequired(const QSizeF &size) const
2556 {
2557     const QSizeF oldSize = m_layouter->size();
2558
2559     m_layouter->setSize(size);
2560     const qreal maxOffset = m_layouter->maximumScrollOffset();
2561     m_layouter->setSize(oldSize);
2562
2563     return m_layouter->scrollOrientation() == Qt::Vertical ? maxOffset > size.height() : maxOffset > size.width();
2564 }
2565
2566 int KItemListView::showDropIndicator(const QPointF &pos)
2567 {
2568     QHashIterator<int, KItemListWidget *> it(m_visibleItems);
2569     while (it.hasNext()) {
2570         it.next();
2571         const KItemListWidget *widget = it.value();
2572
2573         const QPointF mappedPos = widget->mapFromItem(this, pos);
2574         const QRectF rect = itemRect(widget->index());
2575         if (mappedPos.y() >= 0 && mappedPos.y() <= rect.height()) {
2576             if (m_model->supportsDropping(widget->index())) {
2577                 // Keep 30% of the rectangle as the gap instead of always having a fixed gap
2578                 const int gap = qMax(qreal(4.0), qreal(0.3) * rect.height());
2579                 if (mappedPos.y() >= gap && mappedPos.y() <= rect.height() - gap) {
2580                     return -1;
2581                 }
2582             }
2583
2584             const bool isAboveItem = (mappedPos.y() < rect.height() / 2);
2585             const qreal y = isAboveItem ? rect.top() : rect.bottom();
2586
2587             const QRectF draggingInsertIndicator(rect.left(), y, rect.width(), 1);
2588             if (m_dropIndicator != draggingInsertIndicator) {
2589                 m_dropIndicator = draggingInsertIndicator;
2590                 update();
2591             }
2592
2593             int index = widget->index();
2594             if (!isAboveItem) {
2595                 ++index;
2596             }
2597             return index;
2598         }
2599     }
2600
2601     const QRectF firstItemRect = itemRect(firstVisibleIndex());
2602     return (pos.y() <= firstItemRect.top()) ? 0 : -1;
2603 }
2604
2605 void KItemListView::hideDropIndicator()
2606 {
2607     if (!m_dropIndicator.isNull()) {
2608         m_dropIndicator = QRectF();
2609         update();
2610     }
2611 }
2612
2613 void KItemListView::updateGroupHeaderHeight()
2614 {
2615     qreal groupHeaderHeight = m_styleOption.fontMetrics.height();
2616     qreal groupHeaderMargin = 0;
2617
2618     if (scrollOrientation() == Qt::Horizontal) {
2619         // The vertical margin above and below the header should be
2620         // equal to the horizontal margin, not the vertical margin
2621         // from m_styleOption.
2622         groupHeaderHeight += 2 * m_styleOption.horizontalMargin;
2623         groupHeaderMargin = m_styleOption.horizontalMargin;
2624     } else if (m_itemSize.isEmpty()) {
2625         groupHeaderHeight += 4 * m_styleOption.padding;
2626         groupHeaderMargin = m_styleOption.iconSize / 2;
2627     } else {
2628         groupHeaderHeight += 2 * m_styleOption.padding + m_styleOption.verticalMargin;
2629         groupHeaderMargin = m_styleOption.iconSize / 4;
2630     }
2631     m_layouter->setGroupHeaderHeight(groupHeaderHeight);
2632     m_layouter->setGroupHeaderMargin(groupHeaderMargin);
2633
2634     updateVisibleGroupHeaders();
2635 }
2636
2637 void KItemListView::updateSiblingsInformation(int firstIndex, int lastIndex)
2638 {
2639     if (!supportsItemExpanding() || !m_model) {
2640         return;
2641     }
2642
2643     if (firstIndex < 0 || lastIndex < 0) {
2644         firstIndex = m_layouter->firstVisibleIndex();
2645         lastIndex = m_layouter->lastVisibleIndex();
2646     } else {
2647         const bool isRangeVisible = (firstIndex <= m_layouter->lastVisibleIndex() && lastIndex >= m_layouter->firstVisibleIndex());
2648         if (!isRangeVisible) {
2649             return;
2650         }
2651     }
2652
2653     int previousParents = 0;
2654     QBitArray previousSiblings;
2655
2656     // The rootIndex describes the first index where the siblings get
2657     // calculated from. For the calculation the upper most parent item
2658     // is required. For performance reasons it is checked first whether
2659     // the visible items before or after the current range already
2660     // contain a siblings information which can be used as base.
2661     int rootIndex = firstIndex;
2662
2663     KItemListWidget *widget = m_visibleItems.value(firstIndex - 1);
2664     if (!widget) {
2665         // There is no visible widget before the range, check whether there
2666         // is one after the range:
2667         widget = m_visibleItems.value(lastIndex + 1);
2668         if (widget) {
2669             // The sibling information of the widget may only be used if
2670             // all items of the range have the same number of parents.
2671             const int parents = m_model->expandedParentsCount(lastIndex + 1);
2672             for (int i = lastIndex; i >= firstIndex; --i) {
2673                 if (m_model->expandedParentsCount(i) != parents) {
2674                     widget = nullptr;
2675                     break;
2676                 }
2677             }
2678         }
2679     }
2680
2681     if (widget) {
2682         // Performance optimization: Use the sibling information of the visible
2683         // widget beside the given range.
2684         previousSiblings = widget->siblingsInformation();
2685         if (previousSiblings.isEmpty()) {
2686             return;
2687         }
2688         previousParents = previousSiblings.count() - 1;
2689         previousSiblings.truncate(previousParents);
2690     } else {
2691         // Potentially slow path: Go back to the upper most parent of firstIndex
2692         // to be able to calculate the initial value for the siblings.
2693         while (rootIndex > 0 && m_model->expandedParentsCount(rootIndex) > 0) {
2694             --rootIndex;
2695         }
2696     }
2697
2698     Q_ASSERT(previousParents >= 0);
2699     for (int i = rootIndex; i <= lastIndex; ++i) {
2700         // Update the parent-siblings in case if the current item represents
2701         // a child or an upper parent.
2702         const int currentParents = m_model->expandedParentsCount(i);
2703         Q_ASSERT(currentParents >= 0);
2704         if (previousParents < currentParents) {
2705             previousParents = currentParents;
2706             previousSiblings.resize(currentParents);
2707             previousSiblings.setBit(currentParents - 1, hasSiblingSuccessor(i - 1));
2708         } else if (previousParents > currentParents) {
2709             previousParents = currentParents;
2710             previousSiblings.truncate(currentParents);
2711         }
2712
2713         if (i >= firstIndex) {
2714             // The index represents a visible item. Apply the parent-siblings
2715             // and update the sibling of the current item.
2716             KItemListWidget *widget = m_visibleItems.value(i);
2717             if (!widget) {
2718                 continue;
2719             }
2720
2721             QBitArray siblings = previousSiblings;
2722             siblings.resize(siblings.count() + 1);
2723             siblings.setBit(siblings.count() - 1, hasSiblingSuccessor(i));
2724
2725             widget->setSiblingsInformation(siblings);
2726         }
2727     }
2728 }
2729
2730 bool KItemListView::hasSiblingSuccessor(int index) const
2731 {
2732     bool hasSuccessor = false;
2733     const int parentsCount = m_model->expandedParentsCount(index);
2734     int successorIndex = index + 1;
2735
2736     // Search the next sibling
2737     const int itemCount = m_model->count();
2738     while (successorIndex < itemCount) {
2739         const int currentParentsCount = m_model->expandedParentsCount(successorIndex);
2740         if (currentParentsCount == parentsCount) {
2741             hasSuccessor = true;
2742             break;
2743         } else if (currentParentsCount < parentsCount) {
2744             break;
2745         }
2746         ++successorIndex;
2747     }
2748
2749     if (m_grouped && hasSuccessor) {
2750         // If the sibling is part of another group, don't mark it as
2751         // successor as the group header is between the sibling connections.
2752         for (int i = index + 1; i <= successorIndex; ++i) {
2753             if (m_layouter->isFirstGroupItem(i)) {
2754                 hasSuccessor = false;
2755                 break;
2756             }
2757         }
2758     }
2759
2760     return hasSuccessor;
2761 }
2762
2763 void KItemListView::disconnectRoleEditingSignals(int index)
2764 {
2765     KStandardItemListWidget *widget = qobject_cast<KStandardItemListWidget *>(m_visibleItems.value(index));
2766     if (!widget) {
2767         return;
2768     }
2769
2770     disconnect(widget, &KItemListWidget::roleEditingCanceled, this, nullptr);
2771     disconnect(widget, &KItemListWidget::roleEditingFinished, this, nullptr);
2772     disconnect(this, &KItemListView::scrollOffsetChanged, widget, nullptr);
2773 }
2774
2775 int KItemListView::calculateAutoScrollingIncrement(int pos, int range, int oldInc)
2776 {
2777     int inc = 0;
2778
2779     const int minSpeed = 4;
2780     const int maxSpeed = 128;
2781     const int speedLimiter = 96;
2782     const int autoScrollBorder = 64;
2783
2784     // Limit the increment that is allowed to be added in comparison to 'oldInc'.
2785     // This assures that the autoscrolling speed grows gradually.
2786     const int incLimiter = 1;
2787
2788     if (pos < autoScrollBorder) {
2789         inc = -minSpeed + qAbs(pos - autoScrollBorder) * (pos - autoScrollBorder) / speedLimiter;
2790         inc = qMax(inc, -maxSpeed);
2791         inc = qMax(inc, oldInc - incLimiter);
2792     } else if (pos > range - autoScrollBorder) {
2793         inc = minSpeed + qAbs(pos - range + autoScrollBorder) * (pos - range + autoScrollBorder) / speedLimiter;
2794         inc = qMin(inc, maxSpeed);
2795         inc = qMin(inc, oldInc + incLimiter);
2796     }
2797
2798     return inc;
2799 }
2800
2801 int KItemListView::itemsPerSize(qreal size, qreal itemSize, qreal itemMargin)
2802 {
2803     const qreal availableSize = size - itemMargin;
2804     const int count = availableSize / (itemSize + itemMargin);
2805     return count;
2806 }
2807
2808 KItemListCreatorBase::~KItemListCreatorBase()
2809 {
2810     qDeleteAll(m_recycleableWidgets);
2811     qDeleteAll(m_createdWidgets);
2812 }
2813
2814 void KItemListCreatorBase::addCreatedWidget(QGraphicsWidget *widget)
2815 {
2816     m_createdWidgets.insert(widget);
2817 }
2818
2819 void KItemListCreatorBase::pushRecycleableWidget(QGraphicsWidget *widget)
2820 {
2821     Q_ASSERT(m_createdWidgets.contains(widget));
2822     m_createdWidgets.remove(widget);
2823
2824     if (m_recycleableWidgets.count() < 100) {
2825         m_recycleableWidgets.append(widget);
2826         widget->setVisible(false);
2827     } else {
2828         delete widget;
2829     }
2830 }
2831
2832 QGraphicsWidget *KItemListCreatorBase::popRecycleableWidget()
2833 {
2834     if (m_recycleableWidgets.isEmpty()) {
2835         return nullptr;
2836     }
2837
2838     QGraphicsWidget *widget = m_recycleableWidgets.takeLast();
2839     m_createdWidgets.insert(widget);
2840     return widget;
2841 }
2842
2843 KItemListWidgetCreatorBase::~KItemListWidgetCreatorBase()
2844 {
2845 }
2846
2847 void KItemListWidgetCreatorBase::recycle(KItemListWidget *widget)
2848 {
2849     widget->setParentItem(nullptr);
2850     widget->setOpacity(1.0);
2851     pushRecycleableWidget(widget);
2852 }
2853
2854 KItemListGroupHeaderCreatorBase::~KItemListGroupHeaderCreatorBase()
2855 {
2856 }
2857
2858 void KItemListGroupHeaderCreatorBase::recycle(KItemListGroupHeader *header)
2859 {
2860     header->setOpacity(1.0);
2861     pushRecycleableWidget(header);
2862 }
2863
2864 #include "moc_kitemlistview.cpp"