src/kitemviews/kitemlistview.cpp

   1 /***************************************************************************
   2  *   Copyright (C) 2011 by Peter Penz <peter.penz19@gmail.com>             *
   3  *                                                                         *
   4  *   Based on the Itemviews NG project from Trolltech Labs:                *
   5  *   http://qt.gitorious.org/qt-labs/itemviews-ng                          *
   6  *                                                                         *
   7  *   This program is free software; you can redistribute it and/or modify  *
   8  *   it under the terms of the GNU General Public License as published by  *
   9  *   the Free Software Foundation; either version 2 of the License, or     *
  10  *   (at your option) any later version.                                   *
  11  *                                                                         *
  12  *   This program is distributed in the hope that it will be useful,       *
  13  *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
  14  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
  15  *   GNU General Public License for more details.                          *
  16  *                                                                         *
  17  *   You should have received a copy of the GNU General Public License     *
  18  *   along with this program; if not, write to the                         *
  19  *   Free Software Foundation, Inc.,                                       *
  20  *   51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA            *
  21  ***************************************************************************/
  22
  23 #include "kitemlistview.h"
  24
  25 #include "dolphindebug.h"
  26 #include "kitemlistcontainer.h"
  27 #include "kitemlistcontroller.h"
  28 #include "kitemlistheader.h"
  29 #include "kitemlistselectionmanager.h"
  30 #include "kitemlistviewaccessible.h"
  31 #include "kstandarditemlistwidget.h"
  32
  33 #include "private/kitemlistheaderwidget.h"
  34 #include "private/kitemlistrubberband.h"
  35 #include "private/kitemlistsizehintresolver.h"
  36 #include "private/kitemlistviewlayouter.h"
  37
  38 #include <QElapsedTimer>
  39 #include <QGraphicsSceneMouseEvent>
  40 #include <QGraphicsView>
  41 #include <QStyleOptionRubberBand>
  42 #include <QTimer>
  43
  44
  45 namespace {
  46     // Time in ms until reaching the autoscroll margin triggers
  47     // an initial autoscrolling
  48     const int InitialAutoScrollDelay = 700;
  49
  50     // Delay in ms for triggering the next autoscroll
  51     const int RepeatingAutoScrollDelay = 1000 / 60;
  52 }
  53
  54 #ifndef QT_NO_ACCESSIBILITY
  55 QAccessibleInterface* accessibleInterfaceFactory(const QString& key, QObject* object)
  56 {
  57     Q_UNUSED(key)
  58
  59     if (KItemListContainer* container = qobject_cast<KItemListContainer*>(object)) {
  60         return new KItemListContainerAccessible(container);
  61     } else if (KItemListView* view = qobject_cast<KItemListView*>(object)) {
  62         return new KItemListViewAccessible(view);
  63     }
  64
  65     return nullptr;
  66 }
  67 #endif
  68
  69 KItemListView::KItemListView(QGraphicsWidget* parent) :
  70     QGraphicsWidget(parent),
  71     m_enabledSelectionToggles(false),
  72     m_grouped(false),
  73     m_supportsItemExpanding(false),
  74     m_editingRole(false),
  75     m_activeTransactions(0),
  76     m_endTransactionAnimationHint(Animation),
  77     m_itemSize(),
  78     m_controller(nullptr),
  79     m_model(nullptr),
  80     m_visibleRoles(),
  81     m_widgetCreator(nullptr),
  82     m_groupHeaderCreator(nullptr),
  83     m_styleOption(),
  84     m_visibleItems(),
  85     m_visibleGroups(),
  86     m_visibleCells(),
  87     m_sizeHintResolver(nullptr),
  88     m_layouter(nullptr),
  89     m_animation(nullptr),
  90     m_layoutTimer(nullptr),
  91     m_oldScrollOffset(0),
  92     m_oldMaximumScrollOffset(0),
  93     m_oldItemOffset(0),
  94     m_oldMaximumItemOffset(0),
  95     m_skipAutoScrollForRubberBand(false),
  96     m_rubberBand(nullptr),
  97     m_mousePos(),
  98     m_autoScrollIncrement(0),
  99     m_autoScrollTimer(nullptr),
 100     m_header(nullptr),
 101     m_headerWidget(nullptr),
 102     m_dropIndicator()
 103 {
 104     setAcceptHoverEvents(true);
 105
 106     m_sizeHintResolver = new KItemListSizeHintResolver(this);
 107
 108     m_layouter = new KItemListViewLayouter(m_sizeHintResolver, this);
 109
 110     m_animation = new KItemListViewAnimation(this);
 111     connect(m_animation, &KItemListViewAnimation::finished,
 112             this, &KItemListView::slotAnimationFinished);
 113
 114     m_layoutTimer = new QTimer(this);
 115     m_layoutTimer->setInterval(300);
 116     m_layoutTimer->setSingleShot(true);
 117     connect(m_layoutTimer, &QTimer::timeout, this, &KItemListView::slotLayoutTimerFinished);
 118
 119     m_rubberBand = new KItemListRubberBand(this);
 120     connect(m_rubberBand, &KItemListRubberBand::activationChanged, this, &KItemListView::slotRubberBandActivationChanged);
 121
 122     m_headerWidget = new KItemListHeaderWidget(this);
 123     m_headerWidget->setVisible(false);
 124
 125     m_header = new KItemListHeader(this);
 126
 127 #ifndef QT_NO_ACCESSIBILITY
 128     QAccessible::installFactory(accessibleInterfaceFactory);
 129 #endif
 130
 131 }
 132
 133 KItemListView::~KItemListView()
 134 {
 135     // The group headers are children of the widgets created by
 136     // widgetCreator(). So it is mandatory to delete the group headers
 137     // first.
 138     delete m_groupHeaderCreator;
 139     m_groupHeaderCreator = nullptr;
 140
 141     delete m_widgetCreator;
 142     m_widgetCreator = nullptr;
 143
 144     delete m_sizeHintResolver;
 145     m_sizeHintResolver = nullptr;
 146 }
 147
 148 void KItemListView::setScrollOffset(qreal offset)
 149 {
 150     if (offset < 0) {
 151         offset = 0;
 152     }
 153
 154     const qreal previousOffset = m_layouter->scrollOffset();
 155     if (offset == previousOffset) {
 156         return;
 157     }
 158
 159     m_layouter->setScrollOffset(offset);
 160     m_animation->setScrollOffset(offset);
 161
 162     // Don't check whether the m_layoutTimer is active: Changing the
 163     // scroll offset must always trigger a synchronous layout, otherwise
 164     // the smooth-scrolling might get jerky.
 165     doLayout(NoAnimation);
 166     onScrollOffsetChanged(offset, previousOffset);
 167 }
 168
 169 qreal KItemListView::scrollOffset() const
 170 {
 171     return m_layouter->scrollOffset();
 172 }
 173
 174 qreal KItemListView::maximumScrollOffset() const
 175 {
 176     return m_layouter->maximumScrollOffset();
 177 }
 178
 179 void KItemListView::setItemOffset(qreal offset)
 180 {
 181     if (m_layouter->itemOffset() == offset) {
 182         return;
 183     }
 184
 185     m_layouter->setItemOffset(offset);
 186     if (m_headerWidget->isVisible()) {
 187         m_headerWidget->setOffset(offset);
 188     }
 189
 190     // Don't check whether the m_layoutTimer is active: Changing the
 191     // item offset must always trigger a synchronous layout, otherwise
 192     // the smooth-scrolling might get jerky.
 193     doLayout(NoAnimation);
 194 }
 195
 196 qreal KItemListView::itemOffset() const
 197 {
 198     return m_layouter->itemOffset();
 199 }
 200
 201 qreal KItemListView::maximumItemOffset() const
 202 {
 203     return m_layouter->maximumItemOffset();
 204 }
 205
 206 int KItemListView::maximumVisibleItems() const
 207 {
 208     return m_layouter->maximumVisibleItems();
 209 }
 210
 211 void KItemListView::setVisibleRoles(const QList<QByteArray>& roles)
 212 {
 213     const QList<QByteArray> previousRoles = m_visibleRoles;
 214     m_visibleRoles = roles;
 215     onVisibleRolesChanged(roles, previousRoles);
 216
 217     m_sizeHintResolver->clearCache();
 218     m_layouter->markAsDirty();
 219
 220     if (m_itemSize.isEmpty()) {
 221         m_headerWidget->setColumns(roles);
 222         updatePreferredColumnWidths();
 223         if (!m_headerWidget->automaticColumnResizing()) {
 224             // The column-width of new roles are still 0. Apply the preferred
 225             // column-width as default with.
 226             foreach (const QByteArray& role, m_visibleRoles) {
 227                 if (m_headerWidget->columnWidth(role) == 0) {
 228                     const qreal width = m_headerWidget->preferredColumnWidth(role);
 229                     m_headerWidget->setColumnWidth(role, width);
 230                 }
 231             }
 232
 233             applyColumnWidthsFromHeader();
 234         }
 235     }
 236
 237     const bool alternateBackgroundsChanged = m_itemSize.isEmpty() &&
 238                                              ((roles.count() > 1 && previousRoles.count() <= 1) ||
 239                                               (roles.count() <= 1 && previousRoles.count() > 1));
 240
 241     QHashIterator<int, KItemListWidget*> it(m_visibleItems);
 242     while (it.hasNext()) {
 243         it.next();
 244         KItemListWidget* widget = it.value();
 245         widget->setVisibleRoles(roles);
 246         if (alternateBackgroundsChanged) {
 247             updateAlternateBackgroundForWidget(widget);
 248         }
 249     }
 250
 251     doLayout(NoAnimation);
 252 }
 253
 254 QList<QByteArray> KItemListView::visibleRoles() const
 255 {
 256     return m_visibleRoles;
 257 }
 258
 259 void KItemListView::setAutoScroll(bool enabled)
 260 {
 261     if (enabled && !m_autoScrollTimer) {
 262         m_autoScrollTimer = new QTimer(this);
 263         m_autoScrollTimer->setSingleShot(true);
 264         connect(m_autoScrollTimer, &QTimer::timeout, this, &KItemListView::triggerAutoScrolling);
 265         m_autoScrollTimer->start(InitialAutoScrollDelay);
 266     } else if (!enabled && m_autoScrollTimer) {
 267         delete m_autoScrollTimer;
 268         m_autoScrollTimer = nullptr;
 269     }
 270 }
 271
 272 bool KItemListView::autoScroll() const
 273 {
 274     return m_autoScrollTimer != nullptr;
 275 }
 276
 277 void KItemListView::setEnabledSelectionToggles(bool enabled)
 278 {
 279     if (m_enabledSelectionToggles != enabled) {
 280         m_enabledSelectionToggles = enabled;
 281
 282         QHashIterator<int, KItemListWidget*> it(m_visibleItems);
 283         while (it.hasNext()) {
 284             it.next();
 285             it.value()->setEnabledSelectionToggle(enabled);
 286         }
 287     }
 288 }
 289
 290 bool KItemListView::enabledSelectionToggles() const
 291 {
 292     return m_enabledSelectionToggles;
 293 }
 294
 295 KItemListController* KItemListView::controller() const
 296 {
 297     return m_controller;
 298 }
 299
 300 KItemModelBase* KItemListView::model() const
 301 {
 302     return m_model;
 303 }
 304
 305 void KItemListView::setWidgetCreator(KItemListWidgetCreatorBase* widgetCreator)
 306 {
 307     delete m_widgetCreator;
 308     m_widgetCreator = widgetCreator;
 309 }
 310
 311 KItemListWidgetCreatorBase* KItemListView::widgetCreator() const
 312 {
 313     if (!m_widgetCreator) {
 314         m_widgetCreator = defaultWidgetCreator();
 315     }
 316     return m_widgetCreator;
 317 }
 318
 319 void KItemListView::setGroupHeaderCreator(KItemListGroupHeaderCreatorBase* groupHeaderCreator)
 320 {
 321     delete m_groupHeaderCreator;
 322     m_groupHeaderCreator = groupHeaderCreator;
 323 }
 324
 325 KItemListGroupHeaderCreatorBase* KItemListView::groupHeaderCreator() const
 326 {
 327     if (!m_groupHeaderCreator) {
 328         m_groupHeaderCreator = defaultGroupHeaderCreator();
 329     }
 330     return m_groupHeaderCreator;
 331 }
 332
 333 QSizeF KItemListView::itemSize() const
 334 {
 335     return m_itemSize;
 336 }
 337
 338 QSizeF KItemListView::itemSizeHint() const
 339 {
 340     return m_sizeHintResolver->minSizeHint();
 341 }
 342
 343 const KItemListStyleOption& KItemListView::styleOption() const
 344 {
 345     return m_styleOption;
 346 }
 347
 348 void KItemListView::setGeometry(const QRectF& rect)
 349 {
 350     QGraphicsWidget::setGeometry(rect);
 351
 352     if (!m_model) {
 353         return;
 354     }
 355
 356     const QSizeF newSize = rect.size();
 357     if (m_itemSize.isEmpty()) {
 358         m_headerWidget->resize(rect.width(), m_headerWidget->size().height());
 359         if (m_headerWidget->automaticColumnResizing()) {
 360             applyAutomaticColumnWidths();
 361         } else {
 362             const qreal requiredWidth = columnWidthsSum();
 363             const QSizeF dynamicItemSize(qMax(newSize.width(), requiredWidth),
 364                                          m_itemSize.height());
 365             m_layouter->setItemSize(dynamicItemSize);
 366         }
 367
 368         // Triggering a synchronous layout is fine from a performance point of view,
 369         // as with dynamic item sizes no moving animation must be done.
 370         m_layouter->setSize(newSize);
 371         doLayout(NoAnimation);
 372     } else {
 373         const bool animate = !changesItemGridLayout(newSize,
 374                                                     m_layouter->itemSize(),
 375                                                     m_layouter->itemMargin());
 376         m_layouter->setSize(newSize);
 377
 378         if (animate) {
 379             // Trigger an asynchronous relayout with m_layoutTimer to prevent
 380             // performance bottlenecks. If the timer is exceeded, an animated layout
 381             // will be triggered.
 382             if (!m_layoutTimer->isActive()) {
 383                 m_layoutTimer->start();
 384             }
 385         } else {
 386             m_layoutTimer->stop();
 387             doLayout(NoAnimation);
 388         }
 389     }
 390 }
 391
 392 qreal KItemListView::verticalPageStep() const
 393 {
 394     qreal headerHeight = 0;
 395     if (m_headerWidget->isVisible()) {
 396         headerHeight = m_headerWidget->size().height();
 397     }
 398     return size().height() - headerHeight;
 399 }
 400
 401 int KItemListView::itemAt(const QPointF& pos) const
 402 {
 403     QHashIterator<int, KItemListWidget*> it(m_visibleItems);
 404     while (it.hasNext()) {
 405         it.next();
 406
 407         const KItemListWidget* widget = it.value();
 408         const QPointF mappedPos = widget->mapFromItem(this, pos);
 409         if (widget->contains(mappedPos)) {
 410             return it.key();
 411         }
 412     }
 413
 414     return -1;
 415 }
 416
 417 bool KItemListView::isAboveSelectionToggle(int index, const QPointF& pos) const
 418 {
 419     if (!m_enabledSelectionToggles) {
 420         return false;
 421     }
 422
 423     const KItemListWidget* widget = m_visibleItems.value(index);
 424     if (widget) {
 425         const QRectF selectionToggleRect = widget->selectionToggleRect();
 426         if (!selectionToggleRect.isEmpty()) {
 427             const QPointF mappedPos = widget->mapFromItem(this, pos);
 428             return selectionToggleRect.contains(mappedPos);
 429         }
 430     }
 431     return false;
 432 }
 433
 434 bool KItemListView::isAboveExpansionToggle(int index, const QPointF& pos) const
 435 {
 436     const KItemListWidget* widget = m_visibleItems.value(index);
 437     if (widget) {
 438         const QRectF expansionToggleRect = widget->expansionToggleRect();
 439         if (!expansionToggleRect.isEmpty()) {
 440             const QPointF mappedPos = widget->mapFromItem(this, pos);
 441             return expansionToggleRect.contains(mappedPos);
 442         }
 443     }
 444     return false;
 445 }
 446
 447 bool KItemListView::isAboveText(int index, const QPointF &pos) const
 448 {
 449     const KItemListWidget* widget = m_visibleItems.value(index);
 450     if (widget) {
 451         const QRectF &textRect = widget->textRect();
 452         if (!textRect.isEmpty()) {
 453             const QPointF mappedPos = widget->mapFromItem(this, pos);
 454             return textRect.contains(mappedPos);
 455         }
 456     }
 457     return false;
 458 }
 459
 460 int KItemListView::firstVisibleIndex() const
 461 {
 462     return m_layouter->firstVisibleIndex();
 463 }
 464
 465 int KItemListView::lastVisibleIndex() const
 466 {
 467     return m_layouter->lastVisibleIndex();
 468 }
 469
 470 void KItemListView::calculateItemSizeHints(QVector<qreal>& logicalHeightHints, qreal& logicalWidthHint) const
 471 {
 472     widgetCreator()->calculateItemSizeHints(logicalHeightHints, logicalWidthHint, this);
 473 }
 474
 475 void KItemListView::setSupportsItemExpanding(bool supportsExpanding)
 476 {
 477     if (m_supportsItemExpanding != supportsExpanding) {
 478         m_supportsItemExpanding = supportsExpanding;
 479         updateSiblingsInformation();
 480         onSupportsItemExpandingChanged(supportsExpanding);
 481     }
 482 }
 483
 484 bool KItemListView::supportsItemExpanding() const
 485 {
 486     return m_supportsItemExpanding;
 487 }
 488
 489 QRectF KItemListView::itemRect(int index) const
 490 {
 491     return m_layouter->itemRect(index);
 492 }
 493
 494 QRectF KItemListView::itemContextRect(int index) const
 495 {
 496     QRectF contextRect;
 497
 498     const KItemListWidget* widget = m_visibleItems.value(index);
 499     if (widget) {
 500         contextRect = widget->iconRect() | widget->textRect();
 501         contextRect.translate(itemRect(index).topLeft());
 502     }
 503
 504     return contextRect;
 505 }
 506
 507 void KItemListView::scrollToItem(int index)
 508 {
 509     QRectF viewGeometry = geometry();
 510     if (m_headerWidget->isVisible()) {
 511         const qreal headerHeight = m_headerWidget->size().height();
 512         viewGeometry.adjust(0, headerHeight, 0, 0);
 513     }
 514     QRectF currentRect = itemRect(index);
 515
 516     // Fix for Bug 311099 - View the underscore when using Ctrl + PagDown
 517     currentRect.adjust(-m_styleOption.horizontalMargin, -m_styleOption.verticalMargin,
 518                         m_styleOption.horizontalMargin,  m_styleOption.verticalMargin);
 519
 520     if (!viewGeometry.contains(currentRect)) {
 521         qreal newOffset = scrollOffset();
 522         if (scrollOrientation() == Qt::Vertical) {
 523             if (currentRect.top() < viewGeometry.top()) {
 524                 newOffset += currentRect.top() - viewGeometry.top();
 525             } else if (currentRect.bottom() > viewGeometry.bottom()) {
 526                 newOffset += currentRect.bottom() - viewGeometry.bottom();
 527             }
 528         } else {
 529             if (currentRect.left() < viewGeometry.left()) {
 530                 newOffset += currentRect.left() - viewGeometry.left();
 531             } else if (currentRect.right() > viewGeometry.right()) {
 532                 newOffset += currentRect.right() - viewGeometry.right();
 533             }
 534         }
 535
 536         if (newOffset != scrollOffset()) {
 537             emit scrollTo(newOffset);
 538         }
 539     }
 540 }
 541
 542 void KItemListView::beginTransaction()
 543 {
 544     ++m_activeTransactions;
 545     if (m_activeTransactions == 1) {
 546         onTransactionBegin();
 547     }
 548 }
 549
 550 void KItemListView::endTransaction()
 551 {
 552     --m_activeTransactions;
 553     if (m_activeTransactions < 0) {
 554         m_activeTransactions = 0;
 555         qCWarning(DolphinDebug) << "Mismatch between beginTransaction()/endTransaction()";
 556     }
 557
 558     if (m_activeTransactions == 0) {
 559         onTransactionEnd();
 560         doLayout(m_endTransactionAnimationHint);
 561         m_endTransactionAnimationHint = Animation;
 562     }
 563 }
 564
 565 bool KItemListView::isTransactionActive() const
 566 {
 567     return m_activeTransactions > 0;
 568 }
 569
 570 void KItemListView::setHeaderVisible(bool visible)
 571 {
 572     if (visible && !m_headerWidget->isVisible()) {
 573         QStyleOptionHeader option;
 574         const QSize headerSize = style()->sizeFromContents(QStyle::CT_HeaderSection,
 575                                                            &option, QSize());
 576
 577         m_headerWidget->setPos(0, 0);
 578         m_headerWidget->resize(size().width(), headerSize.height());
 579         m_headerWidget->setModel(m_model);
 580         m_headerWidget->setColumns(m_visibleRoles);
 581         m_headerWidget->setZValue(1);
 582
 583         connect(m_headerWidget, &KItemListHeaderWidget::columnWidthChanged,
 584                 this, &KItemListView::slotHeaderColumnWidthChanged);
 585         connect(m_headerWidget, &KItemListHeaderWidget::columnMoved,
 586                 this, &KItemListView::slotHeaderColumnMoved);
 587         connect(m_headerWidget, &KItemListHeaderWidget::sortOrderChanged,
 588                 this, &KItemListView::sortOrderChanged);
 589         connect(m_headerWidget, &KItemListHeaderWidget::sortRoleChanged,
 590                 this, &KItemListView::sortRoleChanged);
 591
 592         m_layouter->setHeaderHeight(headerSize.height());
 593         m_headerWidget->setVisible(true);
 594     } else if (!visible && m_headerWidget->isVisible()) {
 595         disconnect(m_headerWidget, &KItemListHeaderWidget::columnWidthChanged,
 596                    this, &KItemListView::slotHeaderColumnWidthChanged);
 597         disconnect(m_headerWidget, &KItemListHeaderWidget::columnMoved,
 598                    this, &KItemListView::slotHeaderColumnMoved);
 599         disconnect(m_headerWidget, &KItemListHeaderWidget::sortOrderChanged,
 600                    this, &KItemListView::sortOrderChanged);
 601         disconnect(m_headerWidget, &KItemListHeaderWidget::sortRoleChanged,
 602                    this, &KItemListView::sortRoleChanged);
 603
 604         m_layouter->setHeaderHeight(0);
 605         m_headerWidget->setVisible(false);
 606     }
 607 }
 608
 609 bool KItemListView::isHeaderVisible() const
 610 {
 611     return m_headerWidget->isVisible();
 612 }
 613
 614 KItemListHeader* KItemListView::header() const
 615 {
 616     return m_header;
 617 }
 618
 619 QPixmap KItemListView::createDragPixmap(const KItemSet& indexes) const
 620 {
 621     QPixmap pixmap;
 622
 623     if (indexes.count() == 1) {
 624         KItemListWidget* item = m_visibleItems.value(indexes.first());
 625         QGraphicsView* graphicsView = scene()->views()[0];
 626         if (item && graphicsView) {
 627             pixmap = item->createDragPixmap(nullptr, graphicsView);
 628         }
 629     } else {
 630         // TODO: Not implemented yet. Probably extend the interface
 631         // from KItemListWidget::createDragPixmap() to return a pixmap
 632         // that can be used for multiple indexes.
 633     }
 634
 635     return pixmap;
 636 }
 637
 638 void KItemListView::editRole(int index, const QByteArray& role)
 639 {
 640     KStandardItemListWidget* widget = qobject_cast<KStandardItemListWidget *>(m_visibleItems.value(index));
 641     if (!widget || m_editingRole) {
 642         return;
 643     }
 644
 645     m_editingRole = true;
 646     widget->setEditedRole(role);
 647
 648     connect(widget, &KItemListWidget::roleEditingCanceled,
 649             this, &KItemListView::slotRoleEditingCanceled);
 650     connect(widget, &KItemListWidget::roleEditingFinished,
 651             this, &KItemListView::slotRoleEditingFinished);
 652
 653     connect(this, &KItemListView::scrollOffsetChanged,
 654             widget, &KStandardItemListWidget::finishRoleEditing);
 655 }
 656
 657 void KItemListView::paint(QPainter* painter, const QStyleOptionGraphicsItem* option, QWidget* widget)
 658 {
 659     QGraphicsWidget::paint(painter, option, widget);
 660
 661     if (m_rubberBand->isActive()) {
 662         QRectF rubberBandRect = QRectF(m_rubberBand->startPosition(),
 663                                        m_rubberBand->endPosition()).normalized();
 664
 665         const QPointF topLeft = rubberBandRect.topLeft();
 666         if (scrollOrientation() == Qt::Vertical) {
 667             rubberBandRect.moveTo(topLeft.x(), topLeft.y() - scrollOffset());
 668         } else {
 669             rubberBandRect.moveTo(topLeft.x() - scrollOffset(), topLeft.y());
 670         }
 671
 672         QStyleOptionRubberBand opt;
 673         initStyleOption(&opt);
 674         opt.shape = QRubberBand::Rectangle;
 675         opt.opaque = false;
 676         opt.rect = rubberBandRect.toRect();
 677         style()->drawControl(QStyle::CE_RubberBand, &opt, painter);
 678     }
 679
 680     if (!m_dropIndicator.isEmpty()) {
 681         const QRectF r = m_dropIndicator.toRect();
 682
 683         QColor color = palette().brush(QPalette::Normal, QPalette::Highlight).color();
 684         painter->setPen(color);
 685
 686         // TODO: The following implementation works only for a vertical scroll-orientation
 687         // and assumes a height of the m_draggingInsertIndicator of 1.
 688         Q_ASSERT(r.height() == 1);
 689         painter->drawLine(r.left() + 1, r.top(), r.right() - 1, r.top());
 690
 691         color.setAlpha(128);
 692         painter->setPen(color);
 693         painter->drawRect(r.left(), r.top() - 1, r.width() - 1, 2);
 694     }
 695 }
 696
 697 QVariant KItemListView::itemChange(GraphicsItemChange change, const QVariant &value)
 698 {
 699     if (change == QGraphicsItem::ItemSceneHasChanged && scene()) {
 700         if (!scene()->views().isEmpty()) {
 701             m_styleOption.palette = scene()->views().at(0)->palette();
 702         }
 703     }
 704     return QGraphicsItem::itemChange(change, value);
 705 }
 706
 707 void KItemListView::setItemSize(const QSizeF& size)
 708 {
 709     const QSizeF previousSize = m_itemSize;
 710     if (size == previousSize) {
 711         return;
 712     }
 713
 714     // Skip animations when the number of rows or columns
 715     // are changed in the grid layout. Although the animation
 716     // engine can handle this usecase, it looks obtrusive.
 717     const bool animate = !changesItemGridLayout(m_layouter->size(),
 718                                                 size,
 719                                                 m_layouter->itemMargin());
 720
 721     const bool alternateBackgroundsChanged = (m_visibleRoles.count() > 1) &&
 722                                              (( m_itemSize.isEmpty() && !size.isEmpty()) ||
 723                                               (!m_itemSize.isEmpty() && size.isEmpty()));
 724
 725     m_itemSize = size;
 726
 727     if (alternateBackgroundsChanged) {
 728         // For an empty item size alternate backgrounds are drawn if more than
 729         // one role is shown. Assure that the backgrounds for visible items are
 730         // updated when changing the size in this context.
 731         updateAlternateBackgrounds();
 732     }
 733
 734     if (size.isEmpty()) {
 735         if (m_headerWidget->automaticColumnResizing()) {
 736             updatePreferredColumnWidths();
 737         } else {
 738             // Only apply the changed height and respect the header widths
 739             // set by the user
 740             const qreal currentWidth = m_layouter->itemSize().width();
 741             const QSizeF newSize(currentWidth, size.height());
 742             m_layouter->setItemSize(newSize);
 743         }
 744     } else {
 745         m_layouter->setItemSize(size);
 746     }
 747
 748     m_sizeHintResolver->clearCache();
 749     doLayout(animate ? Animation : NoAnimation);
 750     onItemSizeChanged(size, previousSize);
 751 }
 752
 753 void KItemListView::setStyleOption(const KItemListStyleOption& option)
 754 {
 755     if (m_styleOption == option) {
 756         return;
 757     }
 758
 759     const KItemListStyleOption previousOption = m_styleOption;
 760     m_styleOption = option;
 761
 762     bool animate = true;
 763     const QSizeF margin(option.horizontalMargin, option.verticalMargin);
 764     if (margin != m_layouter->itemMargin()) {
 765         // Skip animations when the number of rows or columns
 766         // are changed in the grid layout. Although the animation
 767         // engine can handle this usecase, it looks obtrusive.
 768         animate = !changesItemGridLayout(m_layouter->size(),
 769                                          m_layouter->itemSize(),
 770                                          margin);
 771         m_layouter->setItemMargin(margin);
 772     }
 773
 774     if (m_grouped) {
 775         updateGroupHeaderHeight();
 776     }
 777
 778     if (animate &&
 779         (previousOption.maxTextLines != option.maxTextLines || previousOption.maxTextWidth != option.maxTextWidth)) {
 780         // Animating a change of the maximum text size just results in expensive
 781         // temporary eliding and clipping operations and does not look good visually.
 782         animate = false;
 783     }
 784
 785     QHashIterator<int, KItemListWidget*> it(m_visibleItems);
 786     while (it.hasNext()) {
 787         it.next();
 788         it.value()->setStyleOption(option);
 789     }
 790
 791     m_sizeHintResolver->clearCache();
 792     m_layouter->markAsDirty();
 793     doLayout(animate ? Animation : NoAnimation);
 794
 795     if (m_itemSize.isEmpty()) {
 796         updatePreferredColumnWidths();
 797     }
 798
 799     onStyleOptionChanged(option, previousOption);
 800 }
 801
 802 void KItemListView::setScrollOrientation(Qt::Orientation orientation)
 803 {
 804     const Qt::Orientation previousOrientation = m_layouter->scrollOrientation();
 805     if (orientation == previousOrientation) {
 806         return;
 807     }
 808
 809     m_layouter->setScrollOrientation(orientation);
 810     m_animation->setScrollOrientation(orientation);
 811     m_sizeHintResolver->clearCache();
 812
 813     if (m_grouped) {
 814         QMutableHashIterator<KItemListWidget*, KItemListGroupHeader*> it (m_visibleGroups);
 815         while (it.hasNext()) {
 816             it.next();
 817             it.value()->setScrollOrientation(orientation);
 818         }
 819         updateGroupHeaderHeight();
 820
 821     }
 822
 823     doLayout(NoAnimation);
 824
 825     onScrollOrientationChanged(orientation, previousOrientation);
 826     emit scrollOrientationChanged(orientation, previousOrientation);
 827 }
 828
 829 Qt::Orientation KItemListView::scrollOrientation() const
 830 {
 831     return m_layouter->scrollOrientation();
 832 }
 833
 834 KItemListWidgetCreatorBase* KItemListView::defaultWidgetCreator() const
 835 {
 836     return nullptr;
 837 }
 838
 839 KItemListGroupHeaderCreatorBase* KItemListView::defaultGroupHeaderCreator() const
 840 {
 841     return nullptr;
 842 }
 843
 844 void KItemListView::initializeItemListWidget(KItemListWidget* item)
 845 {
 846     Q_UNUSED(item)
 847 }
 848
 849 bool KItemListView::itemSizeHintUpdateRequired(const QSet<QByteArray>& changedRoles) const
 850 {
 851     Q_UNUSED(changedRoles)
 852     return true;
 853 }
 854
 855 void KItemListView::onControllerChanged(KItemListController* current, KItemListController* previous)
 856 {
 857     Q_UNUSED(current)
 858     Q_UNUSED(previous)
 859 }
 860
 861 void KItemListView::onModelChanged(KItemModelBase* current, KItemModelBase* previous)
 862 {
 863     Q_UNUSED(current)
 864     Q_UNUSED(previous)
 865 }
 866
 867 void KItemListView::onScrollOrientationChanged(Qt::Orientation current, Qt::Orientation previous)
 868 {
 869     Q_UNUSED(current)
 870     Q_UNUSED(previous)
 871 }
 872
 873 void KItemListView::onItemSizeChanged(const QSizeF& current, const QSizeF& previous)
 874 {
 875     Q_UNUSED(current)
 876     Q_UNUSED(previous)
 877 }
 878
 879 void KItemListView::onScrollOffsetChanged(qreal current, qreal previous)
 880 {
 881     Q_UNUSED(current)
 882     Q_UNUSED(previous)
 883 }
 884
 885 void KItemListView::onVisibleRolesChanged(const QList<QByteArray>& current, const QList<QByteArray>& previous)
 886 {
 887     Q_UNUSED(current)
 888     Q_UNUSED(previous)
 889 }
 890
 891 void KItemListView::onStyleOptionChanged(const KItemListStyleOption& current, const KItemListStyleOption& previous)
 892 {
 893     Q_UNUSED(current)
 894     Q_UNUSED(previous)
 895 }
 896
 897 void KItemListView::onSupportsItemExpandingChanged(bool supportsExpanding)
 898 {
 899     Q_UNUSED(supportsExpanding)
 900 }
 901
 902 void KItemListView::onTransactionBegin()
 903 {
 904 }
 905
 906 void KItemListView::onTransactionEnd()
 907 {
 908 }
 909
 910 bool KItemListView::event(QEvent* event)
 911 {
 912     switch (event->type()) {
 913     case QEvent::PaletteChange:
 914         updatePalette();
 915         break;
 916
 917     case QEvent::FontChange:
 918         updateFont();
 919         break;
 920
 921     default:
 922         // Forward all other events to the controller and handle them there
 923         if (!m_editingRole && m_controller && m_controller->processEvent(event, transform())) {
 924             event->accept();
 925             return true;
 926         }
 927     }
 928
 929     return QGraphicsWidget::event(event);
 930 }
 931
 932 void KItemListView::mousePressEvent(QGraphicsSceneMouseEvent* event)
 933 {
 934     m_mousePos = transform().map(event->pos());
 935     event->accept();
 936 }
 937
 938 void KItemListView::mouseMoveEvent(QGraphicsSceneMouseEvent* event)
 939 {
 940     QGraphicsWidget::mouseMoveEvent(event);
 941
 942     m_mousePos = transform().map(event->pos());
 943     if (m_autoScrollTimer && !m_autoScrollTimer->isActive()) {
 944         m_autoScrollTimer->start(InitialAutoScrollDelay);
 945     }
 946 }
 947
 948 void KItemListView::dragEnterEvent(QGraphicsSceneDragDropEvent* event)
 949 {
 950     event->setAccepted(true);
 951     setAutoScroll(true);
 952 }
 953
 954 void KItemListView::dragMoveEvent(QGraphicsSceneDragDropEvent* event)
 955 {
 956     QGraphicsWidget::dragMoveEvent(event);
 957
 958     m_mousePos = transform().map(event->pos());
 959     if (m_autoScrollTimer && !m_autoScrollTimer->isActive()) {
 960         m_autoScrollTimer->start(InitialAutoScrollDelay);
 961     }
 962 }
 963
 964 void KItemListView::dragLeaveEvent(QGraphicsSceneDragDropEvent* event)
 965 {
 966     QGraphicsWidget::dragLeaveEvent(event);
 967     setAutoScroll(false);
 968 }
 969
 970 void KItemListView::dropEvent(QGraphicsSceneDragDropEvent* event)
 971 {
 972     QGraphicsWidget::dropEvent(event);
 973     setAutoScroll(false);
 974 }
 975
 976 QList<KItemListWidget*> KItemListView::visibleItemListWidgets() const
 977 {
 978     return m_visibleItems.values();
 979 }
 980
 981 void KItemListView::updateFont()
 982 {
 983     if (scene() && !scene()->views().isEmpty()) {
 984         KItemListStyleOption option = styleOption();
 985         option.font = scene()->views().first()->font();
 986         option.fontMetrics = QFontMetrics(option.font);
 987
 988         setStyleOption(option);
 989     }
 990 }
 991
 992 void KItemListView::updatePalette()
 993 {
 994     if (scene() && !scene()->views().isEmpty()) {
 995         KItemListStyleOption option = styleOption();
 996         option.palette = scene()->views().first()->palette();
 997
 998         setStyleOption(option);
 999     }
1000 }
1001
1002 void KItemListView::slotItemsInserted(const KItemRangeList& itemRanges)
1003 {
1004     if (m_itemSize.isEmpty()) {
1005         updatePreferredColumnWidths(itemRanges);
1006     }
1007
1008     const bool hasMultipleRanges = (itemRanges.count() > 1);
1009     if (hasMultipleRanges) {
1010         beginTransaction();
1011     }
1012
1013     m_layouter->markAsDirty();
1014
1015     m_sizeHintResolver->itemsInserted(itemRanges);
1016
1017     int previouslyInsertedCount = 0;
1018     foreach (const KItemRange& range, itemRanges) {
1019         // range.index is related to the model before anything has been inserted.
1020         // As in each loop the current item-range gets inserted the index must
1021         // be increased by the already previously inserted items.
1022         const int index = range.index + previouslyInsertedCount;
1023         const int count = range.count;
1024         if (index < 0 || count <= 0) {
1025             qCWarning(DolphinDebug) << "Invalid item range (index:" << index << ", count:" << count << ")";
1026             continue;
1027         }
1028         previouslyInsertedCount += count;
1029
1030         // Determine which visible items must be moved
1031         QList<int> itemsToMove;
1032         QHashIterator<int, KItemListWidget*> it(m_visibleItems);
1033         while (it.hasNext()) {
1034             it.next();
1035             const int visibleItemIndex = it.key();
1036             if (visibleItemIndex >= index) {
1037                 itemsToMove.append(visibleItemIndex);
1038             }
1039         }
1040
1041         // Update the indexes of all KItemListWidget instances that are located
1042         // after the inserted items. It is important to adjust the indexes in the order
1043         // from the highest index to the lowest index to prevent overlaps when setting the new index.
1044         std::sort(itemsToMove.begin(), itemsToMove.end());
1045         for (int i = itemsToMove.count() - 1; i >= 0; --i) {
1046             KItemListWidget* widget = m_visibleItems.value(itemsToMove[i]);
1047             Q_ASSERT(widget);
1048             const int newIndex = widget->index() + count;
1049             if (hasMultipleRanges) {
1050                 setWidgetIndex(widget, newIndex);
1051             } else {
1052                 // Try to animate the moving of the item
1053                 moveWidgetToIndex(widget, newIndex);
1054             }
1055         }
1056
1057         if (m_model->count() == count && m_activeTransactions == 0) {
1058             // Check whether a scrollbar is required to show the inserted items. In this case
1059             // the size of the layouter will be decreased before calling doLayout(): This prevents
1060             // an unnecessary temporary animation due to the geometry change of the inserted scrollbar.
1061             const bool verticalScrollOrientation = (scrollOrientation() == Qt::Vertical);
1062             const bool decreaseLayouterSize = ( verticalScrollOrientation && maximumScrollOffset() > size().height()) ||
1063                                               (!verticalScrollOrientation && maximumScrollOffset() > size().width());
1064             if (decreaseLayouterSize) {
1065                 const int scrollBarExtent = style()->pixelMetric(QStyle::PM_ScrollBarExtent);
1066
1067                 int scrollbarSpacing = 0;
1068                 if (style()->styleHint(QStyle::SH_ScrollView_FrameOnlyAroundContents)) {
1069                     scrollbarSpacing = style()->pixelMetric(QStyle::PM_ScrollView_ScrollBarSpacing);
1070                 }
1071
1072                 QSizeF layouterSize = m_layouter->size();
1073                 if (verticalScrollOrientation) {
1074                     layouterSize.rwidth() -= scrollBarExtent + scrollbarSpacing;
1075                 } else {
1076                     layouterSize.rheight() -= scrollBarExtent + scrollbarSpacing;
1077                 }
1078                 m_layouter->setSize(layouterSize);
1079             }
1080         }
1081
1082         if (!hasMultipleRanges) {
1083             doLayout(animateChangedItemCount(count) ? Animation : NoAnimation, index, count);
1084             updateSiblingsInformation();
1085         }
1086     }
1087
1088     if (m_controller) {
1089         m_controller->selectionManager()->itemsInserted(itemRanges);
1090     }
1091
1092     if (hasMultipleRanges) {
1093         m_endTransactionAnimationHint = NoAnimation;
1094         endTransaction();
1095
1096         updateSiblingsInformation();
1097     }
1098
1099     if (m_grouped && (hasMultipleRanges || itemRanges.first().count < m_model->count())) {
1100         // In case if items of the same group have been inserted before an item that
1101         // currently represents the first item of the group, the group header of
1102         // this item must be removed.
1103         updateVisibleGroupHeaders();
1104     }
1105
1106     if (useAlternateBackgrounds()) {
1107         updateAlternateBackgrounds();
1108     }
1109 }
1110
1111 void KItemListView::slotItemsRemoved(const KItemRangeList& itemRanges)
1112 {
1113     if (m_itemSize.isEmpty()) {
1114         // Don't pass the item-range: The preferred column-widths of
1115         // all items must be adjusted when removing items.
1116         updatePreferredColumnWidths();
1117     }
1118
1119     const bool hasMultipleRanges = (itemRanges.count() > 1);
1120     if (hasMultipleRanges) {
1121         beginTransaction();
1122     }
1123
1124     m_layouter->markAsDirty();
1125
1126     m_sizeHintResolver->itemsRemoved(itemRanges);
1127
1128     for (int i = itemRanges.count() - 1; i >= 0; --i) {
1129         const KItemRange& range = itemRanges[i];
1130         const int index = range.index;
1131         const int count = range.count;
1132         if (index < 0 || count <= 0) {
1133             qCWarning(DolphinDebug) << "Invalid item range (index:" << index << ", count:" << count << ")";
1134             continue;
1135         }
1136
1137         const int firstRemovedIndex = index;
1138         const int lastRemovedIndex = index + count - 1;
1139
1140         // Remember which items have to be moved because they are behind the removed range.
1141         QVector<int> itemsToMove;
1142
1143         // Remove all KItemListWidget instances that got deleted
1144         foreach (KItemListWidget* widget, m_visibleItems) {
1145             const int i = widget->index();
1146             if (i < firstRemovedIndex) {
1147                 continue;
1148             } else if (i > lastRemovedIndex) {
1149                 itemsToMove.append(i);
1150                 continue;
1151             }
1152
1153             m_animation->stop(widget);
1154             // Stopping the animation might lead to recycling the widget if
1155             // it is invisible (see slotAnimationFinished()).
1156             // Check again whether it is still visible:
1157             if (!m_visibleItems.contains(i)) {
1158                 continue;
1159             }
1160
1161             if (m_model->count() == 0 || hasMultipleRanges || !animateChangedItemCount(count)) {
1162                 // Remove the widget without animation
1163                 recycleWidget(widget);
1164             } else {
1165                 // Animate the removing of the items. Special case: When removing an item there
1166                 // is no valid model index available anymore. For the
1167                 // remove-animation the item gets removed from m_visibleItems but the widget
1168                 // will stay alive until the animation has been finished and will
1169                 // be recycled (deleted) in KItemListView::slotAnimationFinished().
1170                 m_visibleItems.remove(i);
1171                 widget->setIndex(-1);
1172                 m_animation->start(widget, KItemListViewAnimation::DeleteAnimation);
1173             }
1174         }
1175
1176         // Update the indexes of all KItemListWidget instances that are located
1177         // after the deleted items. It is important to update them in ascending
1178         // order to prevent overlaps when setting the new index.
1179         std::sort(itemsToMove.begin(), itemsToMove.end());
1180         foreach (int i, itemsToMove) {
1181             KItemListWidget* widget = m_visibleItems.value(i);
1182             Q_ASSERT(widget);
1183             const int newIndex = i - count;
1184             if (hasMultipleRanges) {
1185                 setWidgetIndex(widget, newIndex);
1186             } else {
1187                 // Try to animate the moving of the item
1188                 moveWidgetToIndex(widget, newIndex);
1189             }
1190         }
1191
1192         if (!hasMultipleRanges) {
1193             // The decrease-layout-size optimization in KItemListView::slotItemsInserted()
1194             // assumes an updated geometry. If items are removed during an active transaction,
1195             // the transaction will be temporary deactivated so that doLayout() triggers a
1196             // geometry update if necessary.
1197             const int activeTransactions = m_activeTransactions;
1198             m_activeTransactions = 0;
1199             doLayout(animateChangedItemCount(count) ? Animation : NoAnimation, index, -count);
1200             m_activeTransactions = activeTransactions;
1201             updateSiblingsInformation();
1202         }
1203     }
1204
1205     if (m_controller) {
1206         m_controller->selectionManager()->itemsRemoved(itemRanges);
1207     }
1208
1209     if (hasMultipleRanges) {
1210         m_endTransactionAnimationHint = NoAnimation;
1211         endTransaction();
1212         updateSiblingsInformation();
1213     }
1214
1215     if (m_grouped && (hasMultipleRanges || m_model->count() > 0)) {
1216         // In case if the first item of a group has been removed, the group header
1217         // must be applied to the next visible item.
1218         updateVisibleGroupHeaders();
1219     }
1220
1221     if (useAlternateBackgrounds()) {
1222         updateAlternateBackgrounds();
1223     }
1224 }
1225
1226 void KItemListView::slotItemsMoved(const KItemRange& itemRange, const QList<int>& movedToIndexes)
1227 {
1228     m_sizeHintResolver->itemsMoved(itemRange, movedToIndexes);
1229     m_layouter->markAsDirty();
1230
1231     if (m_controller) {
1232         m_controller->selectionManager()->itemsMoved(itemRange, movedToIndexes);
1233     }
1234
1235     const int firstVisibleMovedIndex = qMax(firstVisibleIndex(), itemRange.index);
1236     const int lastVisibleMovedIndex = qMin(lastVisibleIndex(), itemRange.index + itemRange.count - 1);
1237
1238     for (int index = firstVisibleMovedIndex; index <= lastVisibleMovedIndex; ++index) {
1239         KItemListWidget* widget = m_visibleItems.value(index);
1240         if (widget) {
1241             updateWidgetProperties(widget, index);
1242             initializeItemListWidget(widget);
1243         }
1244     }
1245
1246     doLayout(NoAnimation);
1247     updateSiblingsInformation();
1248 }
1249
1250 void KItemListView::slotItemsChanged(const KItemRangeList& itemRanges,
1251                                      const QSet<QByteArray>& roles)
1252 {
1253     const bool updateSizeHints = itemSizeHintUpdateRequired(roles);
1254     if (updateSizeHints && m_itemSize.isEmpty()) {
1255         updatePreferredColumnWidths(itemRanges);
1256     }
1257
1258     foreach (const KItemRange& itemRange, itemRanges) {
1259         const int index = itemRange.index;
1260         const int count = itemRange.count;
1261
1262         if (updateSizeHints) {
1263             m_sizeHintResolver->itemsChanged(index, count, roles);
1264             m_layouter->markAsDirty();
1265
1266             if (!m_layoutTimer->isActive()) {
1267                 m_layoutTimer->start();
1268             }
1269         }
1270
1271         // Apply the changed roles to the visible item-widgets
1272         const int lastIndex = index + count - 1;
1273         for (int i = index; i <= lastIndex; ++i) {
1274             KItemListWidget* widget = m_visibleItems.value(i);
1275             if (widget) {
1276                 widget->setData(m_model->data(i), roles);
1277             }
1278         }
1279
1280         if (m_grouped && roles.contains(m_model->sortRole())) {
1281             // The sort-role has been changed which might result
1282             // in modified group headers
1283             updateVisibleGroupHeaders();
1284             doLayout(NoAnimation);
1285         }
1286
1287         QAccessibleTableModelChangeEvent ev(this, QAccessibleTableModelChangeEvent::DataChanged);
1288         ev.setFirstRow(itemRange.index);
1289         ev.setLastRow(itemRange.index + itemRange.count);
1290         QAccessible::updateAccessibility(&ev);
1291     }
1292 }
1293
1294 void KItemListView::slotGroupsChanged()
1295 {
1296     updateVisibleGroupHeaders();
1297     doLayout(NoAnimation);
1298     updateSiblingsInformation();
1299 }
1300
1301 void KItemListView::slotGroupedSortingChanged(bool current)
1302 {
1303     m_grouped = current;
1304     m_layouter->markAsDirty();
1305
1306     if (m_grouped) {
1307         updateGroupHeaderHeight();
1308     } else {
1309         // Clear all visible headers. Note that the QHashIterator takes a copy of
1310         // m_visibleGroups. Therefore, it remains valid even if items are removed
1311         // from m_visibleGroups in recycleGroupHeaderForWidget().
1312         QHashIterator<KItemListWidget*, KItemListGroupHeader*> it(m_visibleGroups);
1313         while (it.hasNext()) {
1314             it.next();
1315             recycleGroupHeaderForWidget(it.key());
1316         }
1317         Q_ASSERT(m_visibleGroups.isEmpty());
1318     }
1319
1320     if (useAlternateBackgrounds()) {
1321         // Changing the group mode requires to update the alternate backgrounds
1322         // as with the enabled group mode the altering is done on base of the first
1323         // group item.
1324         updateAlternateBackgrounds();
1325     }
1326     updateSiblingsInformation();
1327     doLayout(NoAnimation);
1328 }
1329
1330 void KItemListView::slotSortOrderChanged(Qt::SortOrder current, Qt::SortOrder previous)
1331 {
1332     Q_UNUSED(current)
1333     Q_UNUSED(previous)
1334     if (m_grouped) {
1335         updateVisibleGroupHeaders();
1336         doLayout(NoAnimation);
1337     }
1338 }
1339
1340 void KItemListView::slotSortRoleChanged(const QByteArray& current, const QByteArray& previous)
1341 {
1342     Q_UNUSED(current)
1343     Q_UNUSED(previous)
1344     if (m_grouped) {
1345         updateVisibleGroupHeaders();
1346         doLayout(NoAnimation);
1347     }
1348 }
1349
1350 void KItemListView::slotCurrentChanged(int current, int previous)
1351 {
1352     Q_UNUSED(previous)
1353
1354     // In SingleSelection mode (e.g., in the Places Panel), the current item is
1355     // always the selected item. It is not necessary to highlight the current item then.
1356     if (m_controller->selectionBehavior() != KItemListController::SingleSelection) {
1357         KItemListWidget* previousWidget = m_visibleItems.value(previous, nullptr);
1358         if (previousWidget) {
1359             previousWidget->setCurrent(false);
1360         }
1361
1362         KItemListWidget* currentWidget = m_visibleItems.value(current, nullptr);
1363         if (currentWidget) {
1364             currentWidget->setCurrent(true);
1365         }
1366     }
1367
1368     QAccessibleEvent ev(this, QAccessible::Focus);
1369     ev.setChild(current);
1370     QAccessible::updateAccessibility(&ev);
1371 }
1372
1373 void KItemListView::slotSelectionChanged(const KItemSet& current, const KItemSet& previous)
1374 {
1375     Q_UNUSED(previous)
1376
1377     QHashIterator<int, KItemListWidget*> it(m_visibleItems);
1378     while (it.hasNext()) {
1379         it.next();
1380         const int index = it.key();
1381         KItemListWidget* widget = it.value();
1382         widget->setSelected(current.contains(index));
1383     }
1384 }
1385
1386 void KItemListView::slotAnimationFinished(QGraphicsWidget* widget,
1387                                           KItemListViewAnimation::AnimationType type)
1388 {
1389     KItemListWidget* itemListWidget = qobject_cast<KItemListWidget*>(widget);
1390     Q_ASSERT(itemListWidget);
1391
1392     switch (type) {
1393     case KItemListViewAnimation::DeleteAnimation: {
1394         // As we recycle the widget in this case it is important to assure that no
1395         // other animation has been started. This is a convention in KItemListView and
1396         // not a requirement defined by KItemListViewAnimation.
1397         Q_ASSERT(!m_animation->isStarted(itemListWidget));
1398
1399         // All KItemListWidgets that are animated by the DeleteAnimation are not maintained
1400         // by m_visibleWidgets and must be deleted manually after the animation has
1401         // been finished.
1402         recycleGroupHeaderForWidget(itemListWidget);
1403         widgetCreator()->recycle(itemListWidget);
1404         break;
1405     }
1406
1407     case KItemListViewAnimation::CreateAnimation:
1408     case KItemListViewAnimation::MovingAnimation:
1409     case KItemListViewAnimation::ResizeAnimation: {
1410         const int index = itemListWidget->index();
1411         const bool invisible = (index < m_layouter->firstVisibleIndex()) ||
1412                                (index > m_layouter->lastVisibleIndex());
1413         if (invisible && !m_animation->isStarted(itemListWidget)) {
1414             recycleWidget(itemListWidget);
1415         }
1416         break;
1417     }
1418
1419     default: break;
1420     }
1421 }
1422
1423 void KItemListView::slotLayoutTimerFinished()
1424 {
1425     m_layouter->setSize(geometry().size());
1426     doLayout(Animation);
1427 }
1428
1429 void KItemListView::slotRubberBandPosChanged()
1430 {
1431     update();
1432 }
1433
1434 void KItemListView::slotRubberBandActivationChanged(bool active)
1435 {
1436     if (active) {
1437         connect(m_rubberBand, &KItemListRubberBand::startPositionChanged, this, &KItemListView::slotRubberBandPosChanged);
1438         connect(m_rubberBand, &KItemListRubberBand::endPositionChanged, this, &KItemListView::slotRubberBandPosChanged);
1439         m_skipAutoScrollForRubberBand = true;
1440     } else {
1441         disconnect(m_rubberBand, &KItemListRubberBand::startPositionChanged, this, &KItemListView::slotRubberBandPosChanged);
1442         disconnect(m_rubberBand, &KItemListRubberBand::endPositionChanged, this, &KItemListView::slotRubberBandPosChanged);
1443         m_skipAutoScrollForRubberBand = false;
1444     }
1445
1446     update();
1447 }
1448
1449 void KItemListView::slotHeaderColumnWidthChanged(const QByteArray& role,
1450                                                  qreal currentWidth,
1451                                                  qreal previousWidth)
1452 {
1453     Q_UNUSED(role)
1454     Q_UNUSED(currentWidth)
1455     Q_UNUSED(previousWidth)
1456
1457     m_headerWidget->setAutomaticColumnResizing(false);
1458     applyColumnWidthsFromHeader();
1459     doLayout(NoAnimation);
1460 }
1461
1462 void KItemListView::slotHeaderColumnMoved(const QByteArray& role,
1463                                           int currentIndex,
1464                                           int previousIndex)
1465 {
1466     Q_ASSERT(m_visibleRoles[previousIndex] == role);
1467
1468     const QList<QByteArray> previous = m_visibleRoles;
1469
1470     QList<QByteArray> current = m_visibleRoles;
1471     current.removeAt(previousIndex);
1472     current.insert(currentIndex, role);
1473
1474     setVisibleRoles(current);
1475
1476     emit visibleRolesChanged(current, previous);
1477 }
1478
1479 void KItemListView::triggerAutoScrolling()
1480 {
1481     if (!m_autoScrollTimer) {
1482         return;
1483     }
1484
1485     int pos = 0;
1486     int visibleSize = 0;
1487     if (scrollOrientation() == Qt::Vertical) {
1488         pos = m_mousePos.y();
1489         visibleSize = size().height();
1490     } else {
1491         pos = m_mousePos.x();
1492         visibleSize = size().width();
1493     }
1494
1495     if (m_autoScrollTimer->interval() == InitialAutoScrollDelay) {
1496         m_autoScrollIncrement = 0;
1497     }
1498
1499     m_autoScrollIncrement = calculateAutoScrollingIncrement(pos, visibleSize, m_autoScrollIncrement);
1500     if (m_autoScrollIncrement == 0) {
1501         // The mouse position is not above an autoscroll margin (the autoscroll timer
1502         // will be restarted in mouseMoveEvent())
1503         m_autoScrollTimer->stop();
1504         return;
1505     }
1506
1507     if (m_rubberBand->isActive() && m_skipAutoScrollForRubberBand) {
1508         // If a rubberband selection is ongoing the autoscrolling may only get triggered
1509         // if the direction of the rubberband is similar to the autoscroll direction. This
1510         // prevents that starting to create a rubberband within the autoscroll margins starts
1511         // an autoscrolling.
1512
1513         const qreal minDiff = 4; // Ignore any autoscrolling if the rubberband is very small
1514         const qreal diff = (scrollOrientation() == Qt::Vertical)
1515                            ? m_rubberBand->endPosition().y() - m_rubberBand->startPosition().y()
1516                            : m_rubberBand->endPosition().x() - m_rubberBand->startPosition().x();
1517         if (qAbs(diff) < minDiff || (m_autoScrollIncrement < 0 && diff > 0) || (m_autoScrollIncrement > 0 && diff < 0)) {
1518             // The rubberband direction is different from the scroll direction (e.g. the rubberband has
1519             // been moved up although the autoscroll direction might be down)
1520             m_autoScrollTimer->stop();
1521             return;
1522         }
1523     }
1524
1525     // As soon as the autoscrolling has been triggered at least once despite having an active rubberband,
1526     // the autoscrolling may not get skipped anymore until a new rubberband is created
1527     m_skipAutoScrollForRubberBand = false;
1528
1529     const qreal maxVisibleOffset = qMax(qreal(0), maximumScrollOffset() - visibleSize);
1530     const qreal newScrollOffset = qMin(scrollOffset() + m_autoScrollIncrement, maxVisibleOffset);
1531     setScrollOffset(newScrollOffset);
1532
1533     // Trigger the autoscroll timer which will periodically call
1534     // triggerAutoScrolling()
1535     m_autoScrollTimer->start(RepeatingAutoScrollDelay);
1536 }
1537
1538 void KItemListView::slotGeometryOfGroupHeaderParentChanged()
1539 {
1540     KItemListWidget* widget = qobject_cast<KItemListWidget*>(sender());
1541     Q_ASSERT(widget);
1542     KItemListGroupHeader* groupHeader = m_visibleGroups.value(widget);
1543     Q_ASSERT(groupHeader);
1544     updateGroupHeaderLayout(widget);
1545 }
1546
1547 void KItemListView::slotRoleEditingCanceled(int index, const QByteArray& role, const QVariant& value)
1548 {
1549     disconnectRoleEditingSignals(index);
1550
1551     emit roleEditingCanceled(index, role, value);
1552     m_editingRole = false;
1553 }
1554
1555 void KItemListView::slotRoleEditingFinished(int index, const QByteArray& role, const QVariant& value)
1556 {
1557     disconnectRoleEditingSignals(index);
1558
1559     emit roleEditingFinished(index, role, value);
1560     m_editingRole = false;
1561 }
1562
1563 void KItemListView::setController(KItemListController* controller)
1564 {
1565     if (m_controller != controller) {
1566         KItemListController* previous = m_controller;
1567         if (previous) {
1568             KItemListSelectionManager* selectionManager = previous->selectionManager();
1569             disconnect(selectionManager, &KItemListSelectionManager::currentChanged, this, &KItemListView::slotCurrentChanged);
1570             disconnect(selectionManager, &KItemListSelectionManager::selectionChanged, this, &KItemListView::slotSelectionChanged);
1571         }
1572
1573         m_controller = controller;
1574
1575         if (controller) {
1576             KItemListSelectionManager* selectionManager = controller->selectionManager();
1577             connect(selectionManager, &KItemListSelectionManager::currentChanged, this, &KItemListView::slotCurrentChanged);
1578             connect(selectionManager, &KItemListSelectionManager::selectionChanged, this, &KItemListView::slotSelectionChanged);
1579         }
1580
1581         onControllerChanged(controller, previous);
1582     }
1583 }
1584
1585 void KItemListView::setModel(KItemModelBase* model)
1586 {
1587     if (m_model == model) {
1588         return;
1589     }
1590
1591     KItemModelBase* previous = m_model;
1592
1593     if (m_model) {
1594         disconnect(m_model, &KItemModelBase::itemsChanged,
1595                    this,    &KItemListView::slotItemsChanged);
1596         disconnect(m_model, &KItemModelBase::itemsInserted,
1597                    this,    &KItemListView::slotItemsInserted);
1598         disconnect(m_model, &KItemModelBase::itemsRemoved,
1599                    this,    &KItemListView::slotItemsRemoved);
1600         disconnect(m_model, &KItemModelBase::itemsMoved,
1601                    this,    &KItemListView::slotItemsMoved);
1602         disconnect(m_model, &KItemModelBase::groupsChanged,
1603                    this,    &KItemListView::slotGroupsChanged);
1604         disconnect(m_model, &KItemModelBase::groupedSortingChanged,
1605                    this,    &KItemListView::slotGroupedSortingChanged);
1606         disconnect(m_model, &KItemModelBase::sortOrderChanged,
1607                    this,    &KItemListView::slotSortOrderChanged);
1608         disconnect(m_model, &KItemModelBase::sortRoleChanged,
1609                    this,    &KItemListView::slotSortRoleChanged);
1610
1611         m_sizeHintResolver->itemsRemoved(KItemRangeList() << KItemRange(0, m_model->count()));
1612     }
1613
1614     m_model = model;
1615     m_layouter->setModel(model);
1616     m_grouped = model->groupedSorting();
1617
1618     if (m_model) {
1619         connect(m_model, &KItemModelBase::itemsChanged,
1620                 this,    &KItemListView::slotItemsChanged);
1621         connect(m_model, &KItemModelBase::itemsInserted,
1622                 this,    &KItemListView::slotItemsInserted);
1623         connect(m_model, &KItemModelBase::itemsRemoved,
1624                 this,    &KItemListView::slotItemsRemoved);
1625         connect(m_model, &KItemModelBase::itemsMoved,
1626                 this,    &KItemListView::slotItemsMoved);
1627         connect(m_model, &KItemModelBase::groupsChanged,
1628                 this,    &KItemListView::slotGroupsChanged);
1629         connect(m_model, &KItemModelBase::groupedSortingChanged,
1630                 this,    &KItemListView::slotGroupedSortingChanged);
1631         connect(m_model, &KItemModelBase::sortOrderChanged,
1632                 this,    &KItemListView::slotSortOrderChanged);
1633         connect(m_model, &KItemModelBase::sortRoleChanged,
1634                 this,    &KItemListView::slotSortRoleChanged);
1635
1636         const int itemCount = m_model->count();
1637         if (itemCount > 0) {
1638             slotItemsInserted(KItemRangeList() << KItemRange(0, itemCount));
1639         }
1640     }
1641
1642     onModelChanged(model, previous);
1643 }
1644
1645 KItemListRubberBand* KItemListView::rubberBand() const
1646 {
1647     return m_rubberBand;
1648 }
1649
1650 void KItemListView::doLayout(LayoutAnimationHint hint, int changedIndex, int changedCount)
1651 {
1652     if (m_layoutTimer->isActive()) {
1653         m_layoutTimer->stop();
1654     }
1655
1656     if (m_activeTransactions > 0) {
1657         if (hint == NoAnimation) {
1658             // As soon as at least one property change should be done without animation,
1659             // the whole transaction will be marked as not animated.
1660             m_endTransactionAnimationHint = NoAnimation;
1661         }
1662         return;
1663     }
1664
1665     if (!m_model || m_model->count() < 0) {
1666         return;
1667     }
1668
1669     int firstVisibleIndex = m_layouter->firstVisibleIndex();
1670     if (firstVisibleIndex < 0) {
1671         emitOffsetChanges();
1672         return;
1673     }
1674
1675     // Do a sanity check of the scroll-offset property: When properties of the itemlist-view have been changed
1676     // it might be possible that the maximum offset got changed too. Assure that the full visible range
1677     // is still shown if the maximum offset got decreased.
1678     const qreal visibleOffsetRange = (scrollOrientation() == Qt::Horizontal) ? size().width() : size().height();
1679     const qreal maxOffsetToShowFullRange = maximumScrollOffset() - visibleOffsetRange;
1680     if (scrollOffset() > maxOffsetToShowFullRange) {
1681         m_layouter->setScrollOffset(qMax(qreal(0), maxOffsetToShowFullRange));
1682         firstVisibleIndex = m_layouter->firstVisibleIndex();
1683     }
1684
1685     const int lastVisibleIndex = m_layouter->lastVisibleIndex();
1686
1687     int firstSibblingIndex = -1;
1688     int lastSibblingIndex = -1;
1689     const bool supportsExpanding = supportsItemExpanding();
1690
1691     QList<int> reusableItems = recycleInvisibleItems(firstVisibleIndex, lastVisibleIndex, hint);
1692
1693     // Assure that for each visible item a KItemListWidget is available. KItemListWidget
1694     // instances from invisible items are reused. If no reusable items are
1695     // found then new KItemListWidget instances get created.
1696     const bool animate = (hint == Animation);
1697     for (int i = firstVisibleIndex; i <= lastVisibleIndex; ++i) {
1698         bool applyNewPos = true;
1699         bool wasHidden = false;
1700
1701         const QRectF itemBounds = m_layouter->itemRect(i);
1702         const QPointF newPos = itemBounds.topLeft();
1703         KItemListWidget* widget = m_visibleItems.value(i);
1704         if (!widget) {
1705             wasHidden = true;
1706             if (!reusableItems.isEmpty()) {
1707                 // Reuse a KItemListWidget instance from an invisible item
1708                 const int oldIndex = reusableItems.takeLast();
1709                 widget = m_visibleItems.value(oldIndex);
1710                 setWidgetIndex(widget, i);
1711                 updateWidgetProperties(widget, i);
1712                 initializeItemListWidget(widget);
1713             } else {
1714                 // No reusable KItemListWidget instance is available, create a new one
1715                 widget = createWidget(i);
1716             }
1717             widget->resize(itemBounds.size());
1718
1719             if (animate && changedCount < 0) {
1720                 // Items have been deleted.
1721                 if (i >= changedIndex) {
1722                     // The item is located behind the removed range. Move the
1723                     // created item to the imaginary old position outside the
1724                     // view. It will get animated to the new position later.
1725                     const int previousIndex = i - changedCount;
1726                     const QRectF itemRect = m_layouter->itemRect(previousIndex);
1727                     if (itemRect.isEmpty()) {
1728                         const QPointF invisibleOldPos = (scrollOrientation() == Qt::Vertical)
1729                                                         ? QPointF(0, size().height()) : QPointF(size().width(), 0);
1730                         widget->setPos(invisibleOldPos);
1731                     } else {
1732                         widget->setPos(itemRect.topLeft());
1733                     }
1734                     applyNewPos = false;
1735                 }
1736             }
1737
1738             if (supportsExpanding && changedCount == 0) {
1739                 if (firstSibblingIndex < 0) {
1740                     firstSibblingIndex = i;
1741                 }
1742                 lastSibblingIndex = i;
1743             }
1744         }
1745
1746         if (animate) {
1747             if (m_animation->isStarted(widget, KItemListViewAnimation::MovingAnimation)) {
1748                 m_animation->start(widget,  KItemListViewAnimation::MovingAnimation, newPos);
1749                 applyNewPos = false;
1750             }
1751
1752             const bool itemsRemoved = (changedCount < 0);
1753             const bool itemsInserted = (changedCount > 0);
1754             if (itemsRemoved && (i >= changedIndex)) {
1755                 // The item is located after the removed items. Animate the moving of the position.
1756                 applyNewPos = !moveWidget(widget, newPos);
1757             } else if (itemsInserted && i >= changedIndex) {
1758                 // The item is located after the first inserted item
1759                 if (i <= changedIndex + changedCount - 1) {
1760                     // The item is an inserted item. Animate the appearing of the item.
1761                     // For performance reasons no animation is done when changedCount is equal
1762                     // to all available items.
1763                     if (changedCount < m_model->count()) {
1764                         m_animation->start(widget, KItemListViewAnimation::CreateAnimation);
1765                     }
1766                 } else if (!m_animation->isStarted(widget, KItemListViewAnimation::CreateAnimation)) {
1767                     // The item was already there before, so animate the moving of the position.
1768                     // No moving animation is done if the item is animated by a create animation: This
1769                     // prevents a "move animation mess" when inserting several ranges in parallel.
1770                     applyNewPos = !moveWidget(widget, newPos);
1771                 }
1772             } else if (!itemsRemoved && !itemsInserted && !wasHidden) {
1773                 // The size of the view might have been changed. Animate the moving of the position.
1774                 applyNewPos = !moveWidget(widget, newPos);
1775             }
1776         } else {
1777             m_animation->stop(widget);
1778         }
1779
1780         if (applyNewPos) {
1781             widget->setPos(newPos);
1782         }
1783
1784         Q_ASSERT(widget->index() == i);
1785         widget->setVisible(true);
1786
1787         if (widget->size() != itemBounds.size()) {
1788             // Resize the widget for the item to the changed size.
1789             if (animate) {
1790                 // If a dynamic item size is used then no animation is done in the direction
1791                 // of the dynamic size.
1792                 if (m_itemSize.width() <= 0) {
1793                     // The width is dynamic, apply the new width without animation.
1794                     widget->resize(itemBounds.width(), widget->size().height());
1795                 } else if (m_itemSize.height() <= 0) {
1796                     // The height is dynamic, apply the new height without animation.
1797                     widget->resize(widget->size().width(), itemBounds.height());
1798                 }
1799                 m_animation->start(widget, KItemListViewAnimation::ResizeAnimation, itemBounds.size());
1800             } else {
1801                 widget->resize(itemBounds.size());
1802             }
1803         }
1804
1805         // Updating the cell-information must be done as last step: The decision whether the
1806         // moving-animation should be started at all is based on the previous cell-information.
1807         const Cell cell(m_layouter->itemColumn(i), m_layouter->itemRow(i));
1808         m_visibleCells.insert(i, cell);
1809     }
1810
1811     // Delete invisible KItemListWidget instances that have not been reused
1812     foreach (int index, reusableItems) {
1813         recycleWidget(m_visibleItems.value(index));
1814     }
1815
1816     if (supportsExpanding && firstSibblingIndex >= 0) {
1817         Q_ASSERT(lastSibblingIndex >= 0);
1818         updateSiblingsInformation(firstSibblingIndex, lastSibblingIndex);
1819     }
1820
1821     if (m_grouped) {
1822         // Update the layout of all visible group headers
1823         QHashIterator<KItemListWidget*, KItemListGroupHeader*> it(m_visibleGroups);
1824         while (it.hasNext()) {
1825             it.next();
1826             updateGroupHeaderLayout(it.key());
1827         }
1828     }
1829
1830     emitOffsetChanges();
1831 }
1832
1833 QList<int> KItemListView::recycleInvisibleItems(int firstVisibleIndex,
1834                                                 int lastVisibleIndex,
1835                                                 LayoutAnimationHint hint)
1836 {
1837     // Determine all items that are completely invisible and might be
1838     // reused for items that just got (at least partly) visible. If the
1839     // animation hint is set to 'Animation' items that do e.g. an animated
1840     // moving of their position are not marked as invisible: This assures
1841     // that a scrolling inside the view can be done without breaking an animation.
1842
1843     QList<int> items;
1844
1845     QHashIterator<int, KItemListWidget*> it(m_visibleItems);
1846     while (it.hasNext()) {
1847         it.next();
1848
1849         KItemListWidget* widget = it.value();
1850         const int index = widget->index();
1851         const bool invisible = (index < firstVisibleIndex) || (index > lastVisibleIndex);
1852
1853         if (invisible) {
1854             if (m_animation->isStarted(widget)) {
1855                 if (hint == NoAnimation) {
1856                     // Stopping the animation will call KItemListView::slotAnimationFinished()
1857                     // and the widget will be recycled if necessary there.
1858                     m_animation->stop(widget);
1859                 }
1860             } else {
1861                 widget->setVisible(false);
1862                 items.append(index);
1863
1864                 if (m_grouped) {
1865                     recycleGroupHeaderForWidget(widget);
1866                 }
1867             }
1868         }
1869     }
1870
1871     return items;
1872 }
1873
1874 bool KItemListView::moveWidget(KItemListWidget* widget,const QPointF& newPos)
1875 {
1876     if (widget->pos() == newPos) {
1877         return false;
1878     }
1879
1880     bool startMovingAnim = false;
1881
1882     if (m_itemSize.isEmpty()) {
1883         // The items are not aligned in a grid but either as columns or rows.
1884         startMovingAnim = true;
1885     } else {
1886         // When having a grid the moving-animation should only be started, if it is done within
1887         // one row in the vertical scroll-orientation or one column in the horizontal scroll-orientation.
1888         // Otherwise instead of a moving-animation a create-animation on the new position will be used
1889         // instead. This is done to prevent overlapping (and confusing) moving-animations.
1890         const int index = widget->index();
1891         const Cell cell = m_visibleCells.value(index);
1892         if (cell.column >= 0 && cell.row >= 0) {
1893             if (scrollOrientation() == Qt::Vertical) {
1894                 startMovingAnim = (cell.row == m_layouter->itemRow(index));
1895             } else {
1896                 startMovingAnim = (cell.column == m_layouter->itemColumn(index));
1897             }
1898         }
1899     }
1900
1901     if (startMovingAnim) {
1902         m_animation->start(widget, KItemListViewAnimation::MovingAnimation, newPos);
1903         return true;
1904     }
1905
1906     m_animation->stop(widget);
1907     m_animation->start(widget, KItemListViewAnimation::CreateAnimation);
1908     return false;
1909 }
1910
1911 void KItemListView::emitOffsetChanges()
1912 {
1913     const qreal newScrollOffset = m_layouter->scrollOffset();
1914     if (m_oldScrollOffset != newScrollOffset) {
1915         emit scrollOffsetChanged(newScrollOffset, m_oldScrollOffset);
1916         m_oldScrollOffset = newScrollOffset;
1917     }
1918
1919     const qreal newMaximumScrollOffset = m_layouter->maximumScrollOffset();
1920     if (m_oldMaximumScrollOffset != newMaximumScrollOffset) {
1921         emit maximumScrollOffsetChanged(newMaximumScrollOffset, m_oldMaximumScrollOffset);
1922         m_oldMaximumScrollOffset = newMaximumScrollOffset;
1923     }
1924
1925     const qreal newItemOffset = m_layouter->itemOffset();
1926     if (m_oldItemOffset != newItemOffset) {
1927         emit itemOffsetChanged(newItemOffset, m_oldItemOffset);
1928         m_oldItemOffset = newItemOffset;
1929     }
1930
1931     const qreal newMaximumItemOffset = m_layouter->maximumItemOffset();
1932     if (m_oldMaximumItemOffset != newMaximumItemOffset) {
1933         emit maximumItemOffsetChanged(newMaximumItemOffset, m_oldMaximumItemOffset);
1934         m_oldMaximumItemOffset = newMaximumItemOffset;
1935     }
1936 }
1937
1938 KItemListWidget* KItemListView::createWidget(int index)
1939 {
1940     KItemListWidget* widget = widgetCreator()->create(this);
1941     widget->setFlag(QGraphicsItem::ItemStacksBehindParent);
1942
1943     m_visibleItems.insert(index, widget);
1944     m_visibleCells.insert(index, Cell());
1945     updateWidgetProperties(widget, index);
1946     initializeItemListWidget(widget);
1947     return widget;
1948 }
1949
1950 void KItemListView::recycleWidget(KItemListWidget* widget)
1951 {
1952     if (m_grouped) {
1953         recycleGroupHeaderForWidget(widget);
1954     }
1955
1956     const int index = widget->index();
1957     m_visibleItems.remove(index);
1958     m_visibleCells.remove(index);
1959
1960     widgetCreator()->recycle(widget);
1961 }
1962
1963 void KItemListView::setWidgetIndex(KItemListWidget* widget, int index)
1964 {
1965     const int oldIndex = widget->index();
1966     m_visibleItems.remove(oldIndex);
1967     m_visibleCells.remove(oldIndex);
1968
1969     m_visibleItems.insert(index, widget);
1970     m_visibleCells.insert(index, Cell());
1971
1972     widget->setIndex(index);
1973 }
1974
1975 void KItemListView::moveWidgetToIndex(KItemListWidget* widget, int index)
1976 {
1977     const int oldIndex = widget->index();
1978     const Cell oldCell = m_visibleCells.value(oldIndex);
1979
1980     setWidgetIndex(widget, index);
1981
1982     const Cell newCell(m_layouter->itemColumn(index), m_layouter->itemRow(index));
1983     const bool vertical = (scrollOrientation() == Qt::Vertical);
1984     const bool updateCell = (vertical  && oldCell.row    == newCell.row) ||
1985                             (!vertical && oldCell.column == newCell.column);
1986     if (updateCell) {
1987         m_visibleCells.insert(index, newCell);
1988     }
1989 }
1990
1991 void KItemListView::setLayouterSize(const QSizeF& size, SizeType sizeType)
1992 {
1993     switch (sizeType) {
1994     case LayouterSize: m_layouter->setSize(size); break;
1995     case ItemSize: m_layouter->setItemSize(size); break;
1996     default: break;
1997     }
1998 }
1999
2000 void KItemListView::updateWidgetProperties(KItemListWidget* widget, int index)
2001 {
2002     widget->setVisibleRoles(m_visibleRoles);
2003     updateWidgetColumnWidths(widget);
2004     widget->setStyleOption(m_styleOption);
2005
2006     const KItemListSelectionManager* selectionManager = m_controller->selectionManager();
2007
2008     // In SingleSelection mode (e.g., in the Places Panel), the current item is
2009     // always the selected item. It is not necessary to highlight the current item then.
2010     if (m_controller->selectionBehavior() != KItemListController::SingleSelection) {
2011         widget->setCurrent(index == selectionManager->currentItem());
2012     }
2013     widget->setSelected(selectionManager->isSelected(index));
2014     widget->setHovered(false);
2015     widget->setEnabledSelectionToggle(enabledSelectionToggles());
2016     widget->setIndex(index);
2017     widget->setData(m_model->data(index));
2018     widget->setSiblingsInformation(QBitArray());
2019     updateAlternateBackgroundForWidget(widget);
2020
2021     if (m_grouped) {
2022         updateGroupHeaderForWidget(widget);
2023     }
2024 }
2025
2026 void KItemListView::updateGroupHeaderForWidget(KItemListWidget* widget)
2027 {
2028     Q_ASSERT(m_grouped);
2029
2030     const int index = widget->index();
2031     if (!m_layouter->isFirstGroupItem(index)) {
2032         // The widget does not represent the first item of a group
2033         // and hence requires no header
2034         recycleGroupHeaderForWidget(widget);
2035         return;
2036     }
2037
2038     const QList<QPair<int, QVariant> > groups = model()->groups();
2039     if (groups.isEmpty() || !groupHeaderCreator()) {
2040         return;
2041     }
2042
2043     KItemListGroupHeader* groupHeader = m_visibleGroups.value(widget);
2044     if (!groupHeader) {
2045         groupHeader = groupHeaderCreator()->create(this);
2046         groupHeader->setParentItem(widget);
2047         m_visibleGroups.insert(widget, groupHeader);
2048         connect(widget, &KItemListWidget::geometryChanged, this, &KItemListView::slotGeometryOfGroupHeaderParentChanged);
2049     }
2050     Q_ASSERT(groupHeader->parentItem() == widget);
2051
2052     const int groupIndex = groupIndexForItem(index);
2053     Q_ASSERT(groupIndex >= 0);
2054     groupHeader->setData(groups.at(groupIndex).second);
2055     groupHeader->setRole(model()->sortRole());
2056     groupHeader->setStyleOption(m_styleOption);
2057     groupHeader->setScrollOrientation(scrollOrientation());
2058     groupHeader->setItemIndex(index);
2059
2060     groupHeader->show();
2061 }
2062
2063 void KItemListView::updateGroupHeaderLayout(KItemListWidget* widget)
2064 {
2065     KItemListGroupHeader* groupHeader = m_visibleGroups.value(widget);
2066     Q_ASSERT(groupHeader);
2067
2068     const int index = widget->index();
2069     const QRectF groupHeaderRect = m_layouter->groupHeaderRect(index);
2070     const QRectF itemRect = m_layouter->itemRect(index);
2071
2072     // The group-header is a child of the itemlist widget. Translate the
2073     // group header position to the relative position.
2074     if (scrollOrientation() == Qt::Vertical) {
2075         // In the vertical scroll orientation the group header should always span
2076         // the whole width no matter which temporary position the parent widget
2077         // has. In this case the x-position and width will be adjusted manually.
2078         const qreal x = -widget->x() - itemOffset();
2079         const qreal width = maximumItemOffset();
2080         groupHeader->setPos(x, -groupHeaderRect.height());
2081         groupHeader->resize(width, groupHeaderRect.size().height());
2082     } else {
2083         groupHeader->setPos(groupHeaderRect.x() - itemRect.x(), -widget->y());
2084         groupHeader->resize(groupHeaderRect.size());
2085     }
2086 }
2087
2088 void KItemListView::recycleGroupHeaderForWidget(KItemListWidget* widget)
2089 {
2090     KItemListGroupHeader* header = m_visibleGroups.value(widget);
2091     if (header) {
2092         header->setParentItem(nullptr);
2093         groupHeaderCreator()->recycle(header);
2094         m_visibleGroups.remove(widget);
2095         disconnect(widget, &KItemListWidget::geometryChanged, this, &KItemListView::slotGeometryOfGroupHeaderParentChanged);
2096     }
2097 }
2098
2099 void KItemListView::updateVisibleGroupHeaders()
2100 {
2101     Q_ASSERT(m_grouped);
2102     m_layouter->markAsDirty();
2103
2104     QHashIterator<int, KItemListWidget*> it(m_visibleItems);
2105     while (it.hasNext()) {
2106         it.next();
2107         updateGroupHeaderForWidget(it.value());
2108     }
2109 }
2110
2111 int KItemListView::groupIndexForItem(int index) const
2112 {
2113     Q_ASSERT(m_grouped);
2114
2115     const QList<QPair<int, QVariant> > groups = model()->groups();
2116     if (groups.isEmpty()) {
2117         return -1;
2118     }
2119
2120     int min = 0;
2121     int max = groups.count() - 1;
2122     int mid = 0;
2123     do {
2124         mid = (min + max) / 2;
2125         if (index > groups[mid].first) {
2126             min = mid + 1;
2127         } else {
2128             max = mid - 1;
2129         }
2130     } while (groups[mid].first != index && min <= max);
2131
2132     if (min > max) {
2133         while (groups[mid].first > index && mid > 0) {
2134             --mid;
2135         }
2136     }
2137
2138     return mid;
2139 }
2140
2141 void KItemListView::updateAlternateBackgrounds()
2142 {
2143     QHashIterator<int, KItemListWidget*> it(m_visibleItems);
2144     while (it.hasNext()) {
2145         it.next();
2146         updateAlternateBackgroundForWidget(it.value());
2147     }
2148 }
2149
2150 void KItemListView::updateAlternateBackgroundForWidget(KItemListWidget* widget)
2151 {
2152     bool enabled = useAlternateBackgrounds();
2153     if (enabled) {
2154         const int index = widget->index();
2155         enabled = (index & 0x1) > 0;
2156         if (m_grouped) {
2157             const int groupIndex = groupIndexForItem(index);
2158             if (groupIndex >= 0) {
2159                 const QList<QPair<int, QVariant> > groups = model()->groups();
2160                 const int indexOfFirstGroupItem = groups[groupIndex].first;
2161                 const int relativeIndex = index - indexOfFirstGroupItem;
2162                 enabled = (relativeIndex & 0x1) > 0;
2163             }
2164         }
2165     }
2166     widget->setAlternateBackground(enabled);
2167 }
2168
2169 bool KItemListView::useAlternateBackgrounds() const
2170 {
2171     return m_itemSize.isEmpty() && m_visibleRoles.count() > 1;
2172 }
2173
2174 QHash<QByteArray, qreal> KItemListView::preferredColumnWidths(const KItemRangeList& itemRanges) const
2175 {
2176     QElapsedTimer timer;
2177     timer.start();
2178
2179     QHash<QByteArray, qreal> widths;
2180
2181     // Calculate the minimum width for each column that is required
2182     // to show the headline unclipped.
2183     const QFontMetricsF fontMetrics(m_headerWidget->font());
2184     const int gripMargin   = m_headerWidget->style()->pixelMetric(QStyle::PM_HeaderGripMargin);
2185     const int headerMargin = m_headerWidget->style()->pixelMetric(QStyle::PM_HeaderMargin);
2186     foreach (const QByteArray& visibleRole, visibleRoles()) {
2187         const QString headerText = m_model->roleDescription(visibleRole);
2188         const qreal headerWidth = fontMetrics.width(headerText) + gripMargin + headerMargin * 2;
2189         widths.insert(visibleRole, headerWidth);
2190     }
2191
2192     // Calculate the preferred column withs for each item and ignore values
2193     // smaller than the width for showing the headline unclipped.
2194     const KItemListWidgetCreatorBase* creator = widgetCreator();
2195     int calculatedItemCount = 0;
2196     bool maxTimeExceeded = false;
2197     foreach (const KItemRange& itemRange, itemRanges) {
2198         const int startIndex = itemRange.index;
2199         const int endIndex = startIndex + itemRange.count - 1;
2200
2201         for (int i = startIndex; i <= endIndex; ++i) {
2202             foreach (const QByteArray& visibleRole, visibleRoles()) {
2203                 qreal maxWidth = widths.value(visibleRole, 0);
2204                 const qreal width = creator->preferredRoleColumnWidth(visibleRole, i, this);
2205                 maxWidth = qMax(width, maxWidth);
2206                 widths.insert(visibleRole, maxWidth);
2207             }
2208
2209             if (calculatedItemCount > 100 && timer.elapsed() > 200) {
2210                 // When having several thousands of items calculating the sizes can get
2211                 // very expensive. We accept a possibly too small role-size in favour
2212                 // of having no blocking user interface.
2213                 maxTimeExceeded = true;
2214                 break;
2215             }
2216             ++calculatedItemCount;
2217         }
2218         if (maxTimeExceeded) {
2219             break;
2220         }
2221     }
2222
2223     return widths;
2224 }
2225
2226 void KItemListView::applyColumnWidthsFromHeader()
2227 {
2228     // Apply the new size to the layouter
2229     const qreal requiredWidth = columnWidthsSum();
2230     const QSizeF dynamicItemSize(qMax(size().width(), requiredWidth),
2231                                  m_itemSize.height());
2232     m_layouter->setItemSize(dynamicItemSize);
2233
2234     // Update the role sizes for all visible widgets
2235     QHashIterator<int, KItemListWidget*> it(m_visibleItems);
2236     while (it.hasNext()) {
2237         it.next();
2238         updateWidgetColumnWidths(it.value());
2239     }
2240 }
2241
2242 void KItemListView::updateWidgetColumnWidths(KItemListWidget* widget)
2243 {
2244     foreach (const QByteArray& role, m_visibleRoles) {
2245         widget->setColumnWidth(role, m_headerWidget->columnWidth(role));
2246     }
2247 }
2248
2249 void KItemListView::updatePreferredColumnWidths(const KItemRangeList& itemRanges)
2250 {
2251     Q_ASSERT(m_itemSize.isEmpty());
2252     const int itemCount = m_model->count();
2253     int rangesItemCount = 0;
2254     foreach (const KItemRange& range, itemRanges) {
2255         rangesItemCount += range.count;
2256     }
2257
2258     if (itemCount == rangesItemCount) {
2259         const QHash<QByteArray, qreal> preferredWidths = preferredColumnWidths(itemRanges);
2260         foreach (const QByteArray& role, m_visibleRoles) {
2261             m_headerWidget->setPreferredColumnWidth(role, preferredWidths.value(role));
2262         }
2263     } else {
2264         // Only a sub range of the roles need to be determined.
2265         // The chances are good that the widths of the sub ranges
2266         // already fit into the available widths and hence no
2267         // expensive update might be required.
2268         bool changed = false;
2269
2270         const QHash<QByteArray, qreal> updatedWidths = preferredColumnWidths(itemRanges);
2271         QHashIterator<QByteArray, qreal> it(updatedWidths);
2272         while (it.hasNext()) {
2273             it.next();
2274             const QByteArray& role = it.key();
2275             const qreal updatedWidth = it.value();
2276             const qreal currentWidth = m_headerWidget->preferredColumnWidth(role);
2277             if (updatedWidth > currentWidth) {
2278                 m_headerWidget->setPreferredColumnWidth(role, updatedWidth);
2279                 changed = true;
2280             }
2281         }
2282
2283         if (!changed) {
2284             // All the updated sizes are smaller than the current sizes and no change
2285             // of the stretched roles-widths is required
2286             return;
2287         }
2288     }
2289
2290     if (m_headerWidget->automaticColumnResizing()) {
2291         applyAutomaticColumnWidths();
2292     }
2293 }
2294
2295 void KItemListView::updatePreferredColumnWidths()
2296 {
2297     if (m_model) {
2298         updatePreferredColumnWidths(KItemRangeList() << KItemRange(0, m_model->count()));
2299     }
2300 }
2301
2302 void KItemListView::applyAutomaticColumnWidths()
2303 {
2304     Q_ASSERT(m_itemSize.isEmpty());
2305     Q_ASSERT(m_headerWidget->automaticColumnResizing());
2306     if (m_visibleRoles.isEmpty()) {
2307         return;
2308     }
2309
2310     // Calculate the maximum size of an item by considering the
2311     // visible role sizes and apply them to the layouter. If the
2312     // size does not use the available view-size the size of the
2313     // first role will get stretched.
2314
2315     foreach (const QByteArray& role, m_visibleRoles) {
2316         const qreal preferredWidth = m_headerWidget->preferredColumnWidth(role);
2317         m_headerWidget->setColumnWidth(role, preferredWidth);
2318     }
2319
2320     const QByteArray firstRole = m_visibleRoles.first();
2321     qreal firstColumnWidth = m_headerWidget->columnWidth(firstRole);
2322     QSizeF dynamicItemSize = m_itemSize;
2323
2324     qreal requiredWidth = columnWidthsSum();
2325     const qreal availableWidth = size().width();
2326     if (requiredWidth < availableWidth) {
2327         // Stretch the first column to use the whole remaining width
2328         firstColumnWidth += availableWidth - requiredWidth;
2329         m_headerWidget->setColumnWidth(firstRole, firstColumnWidth);
2330     } else if (requiredWidth > availableWidth && m_visibleRoles.count() > 1) {
2331         // Shrink the first column to be able to show as much other
2332         // columns as possible
2333         qreal shrinkedFirstColumnWidth = firstColumnWidth - requiredWidth + availableWidth;
2334
2335         // TODO: A proper calculation of the minimum width depends on the implementation
2336         // of KItemListWidget. Probably a kind of minimum size-hint should be introduced
2337         // later.
2338         const qreal minWidth = qMin(firstColumnWidth, qreal(m_styleOption.iconSize * 2 + 200));
2339         if (shrinkedFirstColumnWidth < minWidth) {
2340             shrinkedFirstColumnWidth = minWidth;
2341         }
2342
2343         m_headerWidget->setColumnWidth(firstRole, shrinkedFirstColumnWidth);
2344         requiredWidth -= firstColumnWidth - shrinkedFirstColumnWidth;
2345     }
2346
2347     dynamicItemSize.rwidth() = qMax(requiredWidth, availableWidth);
2348
2349     m_layouter->setItemSize(dynamicItemSize);
2350
2351     // Update the role sizes for all visible widgets
2352     QHashIterator<int, KItemListWidget*> it(m_visibleItems);
2353     while (it.hasNext()) {
2354         it.next();
2355         updateWidgetColumnWidths(it.value());
2356     }
2357 }
2358
2359 qreal KItemListView::columnWidthsSum() const
2360 {
2361     qreal widthsSum = 0;
2362     foreach (const QByteArray& role, m_visibleRoles) {
2363         widthsSum += m_headerWidget->columnWidth(role);
2364     }
2365     return widthsSum;
2366 }
2367
2368 QRectF KItemListView::headerBoundaries() const
2369 {
2370     return m_headerWidget->isVisible() ? m_headerWidget->geometry() : QRectF();
2371 }
2372
2373 bool KItemListView::changesItemGridLayout(const QSizeF& newGridSize,
2374                                           const QSizeF& newItemSize,
2375                                           const QSizeF& newItemMargin) const
2376 {
2377     if (newItemSize.isEmpty() || newGridSize.isEmpty()) {
2378         return false;
2379     }
2380
2381     if (m_layouter->scrollOrientation() == Qt::Vertical) {
2382         const qreal itemWidth = m_layouter->itemSize().width();
2383         if (itemWidth > 0) {
2384             const int newColumnCount = itemsPerSize(newGridSize.width(),
2385                                                     newItemSize.width(),
2386                                                     newItemMargin.width());
2387             if (m_model->count() > newColumnCount) {
2388                 const int oldColumnCount = itemsPerSize(m_layouter->size().width(),
2389                                                         itemWidth,
2390                                                         m_layouter->itemMargin().width());
2391                 return oldColumnCount != newColumnCount;
2392             }
2393         }
2394     } else {
2395         const qreal itemHeight = m_layouter->itemSize().height();
2396         if (itemHeight > 0) {
2397             const int newRowCount = itemsPerSize(newGridSize.height(),
2398                                                  newItemSize.height(),
2399                                                  newItemMargin.height());
2400             if (m_model->count() > newRowCount) {
2401                 const int oldRowCount = itemsPerSize(m_layouter->size().height(),
2402                                                      itemHeight,
2403                                                      m_layouter->itemMargin().height());
2404                 return oldRowCount != newRowCount;
2405             }
2406         }
2407     }
2408
2409     return false;
2410 }
2411
2412 bool KItemListView::animateChangedItemCount(int changedItemCount) const
2413 {
2414     if (m_itemSize.isEmpty()) {
2415         // We have only columns or only rows, but no grid: An animation is usually
2416         // welcome when inserting or removing items.
2417         return !supportsItemExpanding();
2418     }
2419
2420     if (m_layouter->size().isEmpty() || m_layouter->itemSize().isEmpty()) {
2421         return false;
2422     }
2423
2424     const int maximum = (scrollOrientation() == Qt::Vertical)
2425                         ? m_layouter->size().width()  / m_layouter->itemSize().width()
2426                         : m_layouter->size().height() / m_layouter->itemSize().height();
2427     // Only animate if up to 2/3 of a row or column are inserted or removed
2428     return changedItemCount <= maximum * 2 / 3;
2429 }
2430
2431
2432 bool KItemListView::scrollBarRequired(const QSizeF& size) const
2433 {
2434     const QSizeF oldSize = m_layouter->size();
2435
2436     m_layouter->setSize(size);
2437     const qreal maxOffset = m_layouter->maximumScrollOffset();
2438     m_layouter->setSize(oldSize);
2439
2440     return m_layouter->scrollOrientation() == Qt::Vertical ? maxOffset > size.height()
2441                                                            : maxOffset > size.width();
2442 }
2443
2444 int KItemListView::showDropIndicator(const QPointF& pos)
2445 {
2446     QHashIterator<int, KItemListWidget*> it(m_visibleItems);
2447     while (it.hasNext()) {
2448         it.next();
2449         const KItemListWidget* widget = it.value();
2450
2451         const QPointF mappedPos = widget->mapFromItem(this, pos);
2452         const QRectF rect = itemRect(widget->index());
2453         if (mappedPos.y() >= 0 && mappedPos.y() <= rect.height()) {
2454             if (m_model->supportsDropping(widget->index())) {
2455                 // Keep 30% of the rectangle as the gap instead of always having a fixed gap
2456                 const int gap = qMax(qreal(4.0), qreal(0.3) * rect.height());
2457                 if (mappedPos.y() >= gap && mappedPos.y() <= rect.height() - gap) {
2458                     return -1;
2459                 }
2460             }
2461
2462             const bool isAboveItem = (mappedPos.y () < rect.height() / 2);
2463             const qreal y = isAboveItem ? rect.top() : rect.bottom();
2464
2465             const QRectF draggingInsertIndicator(rect.left(), y, rect.width(), 1);
2466             if (m_dropIndicator != draggingInsertIndicator) {
2467                 m_dropIndicator = draggingInsertIndicator;
2468                 update();
2469             }
2470
2471             int index = widget->index();
2472             if (!isAboveItem) {
2473                 ++index;
2474             }
2475             return index;
2476         }
2477     }
2478
2479     const QRectF firstItemRect = itemRect(firstVisibleIndex());
2480     return (pos.y() <= firstItemRect.top()) ? 0 : -1;
2481 }
2482
2483 void KItemListView::hideDropIndicator()
2484 {
2485     if (!m_dropIndicator.isNull()) {
2486         m_dropIndicator = QRectF();
2487         update();
2488     }
2489 }
2490
2491 void KItemListView::updateGroupHeaderHeight()
2492 {
2493     qreal groupHeaderHeight = m_styleOption.fontMetrics.height();
2494     qreal groupHeaderMargin = 0;
2495
2496     if (scrollOrientation() == Qt::Horizontal) {
2497         // The vertical margin above and below the header should be
2498         // equal to the horizontal margin, not the vertical margin
2499         // from m_styleOption.
2500         groupHeaderHeight += 2 * m_styleOption.horizontalMargin;
2501         groupHeaderMargin = m_styleOption.horizontalMargin;
2502     } else if (m_itemSize.isEmpty()){
2503         groupHeaderHeight += 4 * m_styleOption.padding;
2504         groupHeaderMargin = m_styleOption.iconSize / 2;
2505     } else {
2506         groupHeaderHeight += 2 * m_styleOption.padding + m_styleOption.verticalMargin;
2507         groupHeaderMargin = m_styleOption.iconSize / 4;
2508     }
2509     m_layouter->setGroupHeaderHeight(groupHeaderHeight);
2510     m_layouter->setGroupHeaderMargin(groupHeaderMargin);
2511
2512     updateVisibleGroupHeaders();
2513 }
2514
2515 void KItemListView::updateSiblingsInformation(int firstIndex, int lastIndex)
2516 {
2517     if (!supportsItemExpanding() || !m_model) {
2518         return;
2519     }
2520
2521     if (firstIndex < 0 || lastIndex < 0) {
2522         firstIndex = m_layouter->firstVisibleIndex();
2523         lastIndex  = m_layouter->lastVisibleIndex();
2524     } else {
2525         const bool isRangeVisible = (firstIndex <= m_layouter->lastVisibleIndex() &&
2526                                      lastIndex  >= m_layouter->firstVisibleIndex());
2527         if (!isRangeVisible) {
2528             return;
2529         }
2530     }
2531
2532     int previousParents = 0;
2533     QBitArray previousSiblings;
2534
2535     // The rootIndex describes the first index where the siblings get
2536     // calculated from. For the calculation the upper most parent item
2537     // is required. For performance reasons it is checked first whether
2538     // the visible items before or after the current range already
2539     // contain a siblings information which can be used as base.
2540     int rootIndex = firstIndex;
2541
2542     KItemListWidget* widget = m_visibleItems.value(firstIndex - 1);
2543     if (!widget) {
2544         // There is no visible widget before the range, check whether there
2545         // is one after the range:
2546         widget = m_visibleItems.value(lastIndex + 1);
2547         if (widget) {
2548             // The sibling information of the widget may only be used if
2549             // all items of the range have the same number of parents.
2550             const int parents = m_model->expandedParentsCount(lastIndex + 1);
2551             for (int i = lastIndex; i >= firstIndex; --i) {
2552                 if (m_model->expandedParentsCount(i) != parents) {
2553                     widget = nullptr;
2554                     break;
2555                 }
2556             }
2557         }
2558     }
2559
2560     if (widget) {
2561         // Performance optimization: Use the sibling information of the visible
2562         // widget beside the given range.
2563         previousSiblings = widget->siblingsInformation();
2564         if (previousSiblings.isEmpty()) {
2565             return;
2566         }
2567         previousParents = previousSiblings.count() - 1;
2568         previousSiblings.truncate(previousParents);
2569     } else {
2570         // Potentially slow path: Go back to the upper most parent of firstIndex
2571         // to be able to calculate the initial value for the siblings.
2572         while (rootIndex > 0 && m_model->expandedParentsCount(rootIndex) > 0) {
2573             --rootIndex;
2574         }
2575     }
2576
2577     Q_ASSERT(previousParents >= 0);
2578     for (int i = rootIndex; i <= lastIndex; ++i) {
2579         // Update the parent-siblings in case if the current item represents
2580         // a child or an upper parent.
2581         const int currentParents = m_model->expandedParentsCount(i);
2582         Q_ASSERT(currentParents >= 0);
2583         if (previousParents < currentParents) {
2584             previousParents = currentParents;
2585             previousSiblings.resize(currentParents);
2586             previousSiblings.setBit(currentParents - 1, hasSiblingSuccessor(i - 1));
2587         } else if (previousParents > currentParents) {
2588             previousParents = currentParents;
2589             previousSiblings.truncate(currentParents);
2590         }
2591
2592         if (i >= firstIndex) {
2593             // The index represents a visible item. Apply the parent-siblings
2594             // and update the sibling of the current item.
2595             KItemListWidget* widget = m_visibleItems.value(i);
2596             if (!widget) {
2597                 continue;
2598             }
2599
2600             QBitArray siblings = previousSiblings;
2601             siblings.resize(siblings.count() + 1);
2602             siblings.setBit(siblings.count() - 1, hasSiblingSuccessor(i));
2603
2604             widget->setSiblingsInformation(siblings);
2605         }
2606     }
2607 }
2608
2609 bool KItemListView::hasSiblingSuccessor(int index) const
2610 {
2611     bool hasSuccessor = false;
2612     const int parentsCount = m_model->expandedParentsCount(index);
2613     int successorIndex = index + 1;
2614
2615     // Search the next sibling
2616     const int itemCount = m_model->count();
2617     while (successorIndex < itemCount) {
2618         const int currentParentsCount = m_model->expandedParentsCount(successorIndex);
2619         if (currentParentsCount == parentsCount) {
2620             hasSuccessor = true;
2621             break;
2622         } else if (currentParentsCount < parentsCount) {
2623             break;
2624         }
2625         ++successorIndex;
2626     }
2627
2628     if (m_grouped && hasSuccessor) {
2629         // If the sibling is part of another group, don't mark it as
2630         // successor as the group header is between the sibling connections.
2631         for (int i = index + 1; i <= successorIndex; ++i) {
2632             if (m_layouter->isFirstGroupItem(i)) {
2633                 hasSuccessor = false;
2634                 break;
2635             }
2636         }
2637     }
2638
2639     return hasSuccessor;
2640 }
2641
2642 void KItemListView::disconnectRoleEditingSignals(int index)
2643 {
2644     KStandardItemListWidget* widget = qobject_cast<KStandardItemListWidget *>(m_visibleItems.value(index));
2645     if (!widget) {
2646         return;
2647     }
2648
2649     disconnect(widget, &KItemListWidget::roleEditingCanceled, this, nullptr);
2650     disconnect(widget, &KItemListWidget::roleEditingFinished, this, nullptr);
2651     disconnect(this, &KItemListView::scrollOffsetChanged, widget, nullptr);
2652 }
2653
2654 int KItemListView::calculateAutoScrollingIncrement(int pos, int range, int oldInc)
2655 {
2656     int inc = 0;
2657
2658     const int minSpeed = 4;
2659     const int maxSpeed = 128;
2660     const int speedLimiter = 96;
2661     const int autoScrollBorder = 64;
2662
2663     // Limit the increment that is allowed to be added in comparison to 'oldInc'.
2664     // This assures that the autoscrolling speed grows gradually.
2665     const int incLimiter = 1;
2666
2667     if (pos < autoScrollBorder) {
2668         inc = -minSpeed + qAbs(pos - autoScrollBorder) * (pos - autoScrollBorder) / speedLimiter;
2669         inc = qMax(inc, -maxSpeed);
2670         inc = qMax(inc, oldInc - incLimiter);
2671     } else if (pos > range - autoScrollBorder) {
2672         inc = minSpeed + qAbs(pos - range + autoScrollBorder) * (pos - range + autoScrollBorder) / speedLimiter;
2673         inc = qMin(inc, maxSpeed);
2674         inc = qMin(inc, oldInc + incLimiter);
2675     }
2676
2677     return inc;
2678 }
2679
2680 int KItemListView::itemsPerSize(qreal size, qreal itemSize, qreal itemMargin)
2681 {
2682     const qreal availableSize = size - itemMargin;
2683     const int count = availableSize / (itemSize + itemMargin);
2684     return count;
2685 }
2686
2687
2688
2689 KItemListCreatorBase::~KItemListCreatorBase()
2690 {
2691     qDeleteAll(m_recycleableWidgets);
2692     qDeleteAll(m_createdWidgets);
2693 }
2694
2695 void KItemListCreatorBase::addCreatedWidget(QGraphicsWidget* widget)
2696 {
2697     m_createdWidgets.insert(widget);
2698 }
2699
2700 void KItemListCreatorBase::pushRecycleableWidget(QGraphicsWidget* widget)
2701 {
2702     Q_ASSERT(m_createdWidgets.contains(widget));
2703     m_createdWidgets.remove(widget);
2704
2705     if (m_recycleableWidgets.count() < 100) {
2706         m_recycleableWidgets.append(widget);
2707         widget->setVisible(false);
2708     } else {
2709         delete widget;
2710     }
2711 }
2712
2713 QGraphicsWidget* KItemListCreatorBase::popRecycleableWidget()
2714 {
2715     if (m_recycleableWidgets.isEmpty()) {
2716         return nullptr;
2717     }
2718
2719     QGraphicsWidget* widget = m_recycleableWidgets.takeLast();
2720     m_createdWidgets.insert(widget);
2721     return widget;
2722 }
2723
2724 KItemListWidgetCreatorBase::~KItemListWidgetCreatorBase()
2725 {
2726 }
2727
2728 void KItemListWidgetCreatorBase::recycle(KItemListWidget* widget)
2729 {
2730     widget->setParentItem(nullptr);
2731     widget->setOpacity(1.0);
2732     pushRecycleableWidget(widget);
2733 }
2734
2735 KItemListGroupHeaderCreatorBase::~KItemListGroupHeaderCreatorBase()
2736 {
2737 }
2738
2739 void KItemListGroupHeaderCreatorBase::recycle(KItemListGroupHeader* header)
2740 {
2741     header->setOpacity(1.0);
2742     pushRecycleableWidget(header);
2743 }
2744