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