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