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