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