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 "kitemlistcontroller.h"
  26 #include "kitemlistheader_p.h"
  27 #include "kitemlistrubberband_p.h"
  28 #include "kitemlistselectionmanager.h"
  29 #include "kitemlistsizehintresolver_p.h"
  30 #include "kitemlistviewlayouter_p.h"
  31 #include "kitemlistviewanimation_p.h"
  32 #include "kitemlistwidget.h"
  33
  34 #include <KDebug>
  35
  36 #include <QCursor>
  37 #include <QGraphicsSceneMouseEvent>
  38 #include <QPainter>
  39 #include <QPropertyAnimation>
  40 #include <QStyle>
  41 #include <QStyleOptionRubberBand>
  42 #include <QTimer>
  43
  44 namespace {
  45     // Time in ms until reaching the autoscroll margin triggers
  46     // an initial autoscrolling
  47     const int InitialAutoScrollDelay = 700;
  48
  49     // Delay in ms for triggering the next autoscroll
  50     const int RepeatingAutoScrollDelay = 1000 / 60;
  51 }
  52
  53 KItemListView::KItemListView(QGraphicsWidget* parent) :
  54     QGraphicsWidget(parent),
  55     m_enabledSelectionToggles(false),
  56     m_grouped(false),
  57     m_activeTransactions(0),
  58     m_itemSize(),
  59     m_controller(0),
  60     m_model(0),
  61     m_visibleRoles(),
  62     m_visibleRolesSizes(),
  63     m_stretchedVisibleRolesSizes(),
  64     m_widgetCreator(0),
  65     m_groupHeaderCreator(0),
  66     m_styleOption(),
  67     m_visibleItems(),
  68     m_visibleGroups(),
  69     m_sizeHintResolver(0),
  70     m_layouter(0),
  71     m_animation(0),
  72     m_layoutTimer(0),
  73     m_oldScrollOffset(0),
  74     m_oldMaximumScrollOffset(0),
  75     m_oldItemOffset(0),
  76     m_oldMaximumItemOffset(0),
  77     m_skipAutoScrollForRubberBand(false),
  78     m_rubberBand(0),
  79     m_mousePos(),
  80     m_autoScrollIncrement(0),
  81     m_autoScrollTimer(0),
  82     m_header(0),
  83     m_useHeaderWidths(false)
  84 {
  85     setAcceptHoverEvents(true);
  86
  87     m_sizeHintResolver = new KItemListSizeHintResolver(this);
  88
  89     m_layouter = new KItemListViewLayouter(this);
  90     m_layouter->setSizeHintResolver(m_sizeHintResolver);
  91
  92     m_animation = new KItemListViewAnimation(this);
  93     connect(m_animation, SIGNAL(finished(QGraphicsWidget*,KItemListViewAnimation::AnimationType)),
  94             this, SLOT(slotAnimationFinished(QGraphicsWidget*,KItemListViewAnimation::AnimationType)));
  95
  96     m_layoutTimer = new QTimer(this);
  97     m_layoutTimer->setInterval(300);
  98     m_layoutTimer->setSingleShot(true);
  99     connect(m_layoutTimer, SIGNAL(timeout()), this, SLOT(slotLayoutTimerFinished()));
 100
 101     m_rubberBand = new KItemListRubberBand(this);
 102     connect(m_rubberBand, SIGNAL(activationChanged(bool)), this, SLOT(slotRubberBandActivationChanged(bool)));
 103 }
 104
 105 KItemListView::~KItemListView()
 106 {
 107     delete m_sizeHintResolver;
 108     m_sizeHintResolver = 0;
 109 }
 110
 111 void KItemListView::setScrollOrientation(Qt::Orientation orientation)
 112 {
 113     const Qt::Orientation previousOrientation = m_layouter->scrollOrientation();
 114     if (orientation == previousOrientation) {
 115         return;
 116     }
 117
 118     m_layouter->setScrollOrientation(orientation);
 119     m_animation->setScrollOrientation(orientation);
 120     m_sizeHintResolver->clearCache();
 121
 122     if (m_grouped) {
 123         QMutableHashIterator<KItemListWidget*, KItemListGroupHeader*> it (m_visibleGroups);
 124         while (it.hasNext()) {
 125             it.next();
 126             it.value()->setScrollOrientation(orientation);
 127         }
 128     }
 129
 130     doLayout(Animation, 0, 0);
 131
 132     onScrollOrientationChanged(orientation, previousOrientation);
 133     emit scrollOrientationChanged(orientation, previousOrientation);
 134 }
 135
 136 Qt::Orientation KItemListView::scrollOrientation() const
 137 {
 138     return m_layouter->scrollOrientation();
 139 }
 140
 141 void KItemListView::setItemSize(const QSizeF& itemSize)
 142 {
 143     const QSizeF previousSize = m_itemSize;
 144     if (itemSize == previousSize) {
 145         return;
 146     }
 147
 148     m_itemSize = itemSize;
 149
 150     const bool emptySize = itemSize.isEmpty();
 151     if (emptySize) {
 152         updateVisibleRolesSizes();
 153     } else {
 154         if (itemSize.width() < previousSize.width() || itemSize.height() < previousSize.height()) {
 155             prepareLayoutForIncreasedItemCount(itemSize, ItemSize);
 156         } else {
 157             m_layouter->setItemSize(itemSize);
 158         }
 159     }
 160
 161     m_sizeHintResolver->clearCache();
 162     doLayout(Animation, 0, 0);
 163     onItemSizeChanged(itemSize, previousSize);
 164 }
 165
 166 QSizeF KItemListView::itemSize() const
 167 {
 168     return m_itemSize;
 169 }
 170
 171 void KItemListView::setScrollOffset(qreal offset)
 172 {
 173     if (offset < 0) {
 174         offset = 0;
 175     }
 176
 177     const qreal previousOffset = m_layouter->scrollOffset();
 178     if (offset == previousOffset) {
 179         return;
 180     }
 181
 182     m_layouter->setScrollOffset(offset);
 183     m_animation->setScrollOffset(offset);
 184     if (!m_layoutTimer->isActive()) {
 185         doLayout(NoAnimation, 0, 0);
 186     }
 187     onScrollOffsetChanged(offset, previousOffset);
 188 }
 189
 190 qreal KItemListView::scrollOffset() const
 191 {
 192     return m_layouter->scrollOffset();
 193 }
 194
 195 qreal KItemListView::maximumScrollOffset() const
 196 {
 197     return m_layouter->maximumScrollOffset();
 198 }
 199
 200 void KItemListView::setItemOffset(qreal offset)
 201 {
 202     m_layouter->setItemOffset(offset);
 203     if (m_header) {
 204         m_header->setPos(-offset, 0);
 205     }
 206     if (!m_layoutTimer->isActive()) {
 207         doLayout(NoAnimation, 0, 0);
 208     }
 209 }
 210
 211 qreal KItemListView::itemOffset() const
 212 {
 213     return m_layouter->itemOffset();
 214 }
 215
 216 qreal KItemListView::maximumItemOffset() const
 217 {
 218     return m_layouter->maximumItemOffset();
 219 }
 220
 221 void KItemListView::setVisibleRoles(const QList<QByteArray>& roles)
 222 {
 223     const QList<QByteArray> previousRoles = m_visibleRoles;
 224     m_visibleRoles = roles;
 225
 226     QHashIterator<int, KItemListWidget*> it(m_visibleItems);
 227     while (it.hasNext()) {
 228         it.next();
 229         KItemListWidget* widget = it.value();
 230         widget->setVisibleRoles(roles);
 231         widget->setVisibleRolesSizes(m_stretchedVisibleRolesSizes);
 232     }
 233
 234     m_sizeHintResolver->clearCache();
 235     m_layouter->markAsDirty();
 236
 237     if (m_header) {
 238         m_header->setVisibleRoles(roles);
 239         m_header->setVisibleRolesWidths(headerRolesWidths());
 240         m_useHeaderWidths = false;
 241     }
 242
 243     updateVisibleRolesSizes();
 244     doLayout(Animation, 0, 0);
 245
 246     onVisibleRolesChanged(roles, previousRoles);
 247 }
 248
 249 QList<QByteArray> KItemListView::visibleRoles() const
 250 {
 251     return m_visibleRoles;
 252 }
 253
 254 void KItemListView::setAutoScroll(bool enabled)
 255 {
 256     if (enabled && !m_autoScrollTimer) {
 257         m_autoScrollTimer = new QTimer(this);
 258         m_autoScrollTimer->setSingleShot(false);
 259         connect(m_autoScrollTimer, SIGNAL(timeout()), this, SLOT(triggerAutoScrolling()));
 260         m_autoScrollTimer->start(InitialAutoScrollDelay);
 261     } else if (!enabled && m_autoScrollTimer) {
 262         delete m_autoScrollTimer;
 263         m_autoScrollTimer = 0;
 264     }
 265
 266 }
 267
 268 bool KItemListView::autoScroll() const
 269 {
 270     return m_autoScrollTimer != 0;
 271 }
 272
 273 void KItemListView::setEnabledSelectionToggles(bool enabled)
 274 {
 275     if (m_enabledSelectionToggles != enabled) {
 276         m_enabledSelectionToggles = enabled;
 277
 278         QHashIterator<int, KItemListWidget*> it(m_visibleItems);
 279         while (it.hasNext()) {
 280             it.next();
 281             it.value()->setEnabledSelectionToggle(enabled);
 282         }
 283     }
 284 }
 285
 286 bool KItemListView::enabledSelectionToggles() const
 287 {
 288     return m_enabledSelectionToggles;
 289 }
 290
 291 KItemListController* KItemListView::controller() const
 292 {
 293     return m_controller;
 294 }
 295
 296 KItemModelBase* KItemListView::model() const
 297 {
 298     return m_model;
 299 }
 300
 301 void KItemListView::setWidgetCreator(KItemListWidgetCreatorBase* widgetCreator)
 302 {
 303     m_widgetCreator = widgetCreator;
 304 }
 305
 306 KItemListWidgetCreatorBase* KItemListView::widgetCreator() const
 307 {
 308     return m_widgetCreator;
 309 }
 310
 311 void KItemListView::setGroupHeaderCreator(KItemListGroupHeaderCreatorBase* groupHeaderCreator)
 312 {
 313     m_groupHeaderCreator = groupHeaderCreator;
 314 }
 315
 316 KItemListGroupHeaderCreatorBase* KItemListView::groupHeaderCreator() const
 317 {
 318     return m_groupHeaderCreator;
 319 }
 320
 321 void KItemListView::setStyleOption(const KItemListStyleOption& option)
 322 {
 323     const KItemListStyleOption previousOption = m_styleOption;
 324     m_styleOption = option;
 325
 326     QHashIterator<int, KItemListWidget*> it(m_visibleItems);
 327     while (it.hasNext()) {
 328         it.next();
 329         it.value()->setStyleOption(option);
 330     }
 331
 332     m_sizeHintResolver->clearCache();
 333     doLayout(Animation, 0, 0);
 334     onStyleOptionChanged(option, previousOption);
 335 }
 336
 337 const KItemListStyleOption& KItemListView::styleOption() const
 338 {
 339     return m_styleOption;
 340 }
 341
 342 void KItemListView::setGeometry(const QRectF& rect)
 343 {
 344     QGraphicsWidget::setGeometry(rect);
 345
 346     if (!m_model) {
 347         return;
 348     }
 349
 350     if (m_model->count() > 0) {
 351         prepareLayoutForIncreasedItemCount(rect.size(), LayouterSize);
 352     } else {
 353         m_layouter->setSize(rect.size());
 354     }
 355
 356     if (!m_layoutTimer->isActive()) {
 357         m_layoutTimer->start();
 358     }
 359
 360     // Changing the geometry does not require to do an expensive
 361     // update of the visible-roles sizes, only the stretched sizes
 362     // need to be adjusted to the new size.
 363     updateStretchedVisibleRolesSizes();
 364 }
 365
 366 int KItemListView::itemAt(const QPointF& pos) const
 367 {
 368     QHashIterator<int, KItemListWidget*> it(m_visibleItems);
 369     while (it.hasNext()) {
 370         it.next();
 371
 372         const KItemListWidget* widget = it.value();
 373         const QPointF mappedPos = widget->mapFromItem(this, pos);
 374         if (widget->contains(mappedPos)) {
 375             return it.key();
 376         }
 377     }
 378
 379     return -1;
 380 }
 381
 382 bool KItemListView::isAboveSelectionToggle(int index, const QPointF& pos) const
 383 {
 384     const KItemListWidget* widget = m_visibleItems.value(index);
 385     if (widget) {
 386         const QRectF selectionToggleRect = widget->selectionToggleRect();
 387         if (!selectionToggleRect.isEmpty()) {
 388             const QPointF mappedPos = widget->mapFromItem(this, pos);
 389             return selectionToggleRect.contains(mappedPos);
 390         }
 391     }
 392     return false;
 393 }
 394
 395 bool KItemListView::isAboveExpansionToggle(int index, const QPointF& pos) const
 396 {
 397     const KItemListWidget* widget = m_visibleItems.value(index);
 398     if (widget) {
 399         const QRectF expansionToggleRect = widget->expansionToggleRect();
 400         if (!expansionToggleRect.isEmpty()) {
 401             const QPointF mappedPos = widget->mapFromItem(this, pos);
 402             return expansionToggleRect.contains(mappedPos);
 403         }
 404     }
 405     return false;
 406 }
 407
 408 int KItemListView::firstVisibleIndex() const
 409 {
 410     return m_layouter->firstVisibleIndex();
 411 }
 412
 413 int KItemListView::lastVisibleIndex() const
 414 {
 415     return m_layouter->lastVisibleIndex();
 416 }
 417
 418 QSizeF KItemListView::itemSizeHint(int index) const
 419 {
 420     Q_UNUSED(index);
 421     return itemSize();
 422 }
 423
 424 QHash<QByteArray, QSizeF> KItemListView::visibleRolesSizes(const KItemRangeList& itemRanges) const
 425 {
 426     Q_UNUSED(itemRanges);
 427     return QHash<QByteArray, QSizeF>();
 428 }
 429
 430 bool KItemListView::supportsItemExpanding() const
 431 {
 432     return false;
 433 }
 434
 435 QRectF KItemListView::itemRect(int index) const
 436 {
 437     return m_layouter->itemRect(index);
 438 }
 439
 440 void KItemListView::scrollToItem(int index)
 441 {
 442     const QRectF viewGeometry = geometry();
 443     const QRectF currentRect = itemRect(index);
 444
 445     if (!viewGeometry.contains(currentRect)) {
 446         qreal newOffset = scrollOffset();
 447         if (currentRect.top() < viewGeometry.top()) {
 448             Q_ASSERT(scrollOrientation() == Qt::Vertical);
 449             newOffset += currentRect.top() - viewGeometry.top();
 450         } else if ((currentRect.bottom() > viewGeometry.bottom())) {
 451             Q_ASSERT(scrollOrientation() == Qt::Vertical);
 452             newOffset += currentRect.bottom() - viewGeometry.bottom();
 453         } else if (currentRect.left() < viewGeometry.left()) {
 454             if (scrollOrientation() == Qt::Horizontal) {
 455                 newOffset += currentRect.left() - viewGeometry.left();
 456             }
 457         } else if ((currentRect.right() > viewGeometry.right())) {
 458             if (scrollOrientation() == Qt::Horizontal) {
 459                 newOffset += currentRect.right() - viewGeometry.right();
 460             }
 461         }
 462
 463         if (newOffset != scrollOffset()) {
 464             emit scrollTo(newOffset);
 465         }
 466     }
 467 }
 468
 469 int KItemListView::itemsPerOffset() const
 470 {
 471     return m_layouter->itemsPerOffset();
 472 }
 473
 474 void KItemListView::beginTransaction()
 475 {
 476     ++m_activeTransactions;
 477     if (m_activeTransactions == 1) {
 478         onTransactionBegin();
 479     }
 480 }
 481
 482 void KItemListView::endTransaction()
 483 {
 484     --m_activeTransactions;
 485     if (m_activeTransactions < 0) {
 486         m_activeTransactions = 0;
 487         kWarning() << "Mismatch between beginTransaction()/endTransaction()";
 488     }
 489
 490     if (m_activeTransactions == 0) {
 491         onTransactionEnd();
 492         doLayout(Animation, 0, 0);
 493     }
 494 }
 495
 496 bool KItemListView::isTransactionActive() const
 497 {
 498     return m_activeTransactions > 0;
 499 }
 500
 501
 502 void KItemListView::setHeaderShown(bool show)
 503 {
 504
 505     if (show && !m_header) {
 506         m_header = new KItemListHeader(this);
 507         m_header->setPos(0, 0);
 508         m_header->setModel(m_model);
 509         m_header->setVisibleRoles(m_visibleRoles);
 510         m_header->setVisibleRolesWidths(headerRolesWidths());
 511         m_header->setZValue(1);
 512
 513         m_useHeaderWidths = false;
 514
 515         connect(m_header, SIGNAL(visibleRoleWidthChanged(QByteArray,qreal,qreal)),
 516                 this, SLOT(slotVisibleRoleWidthChanged(QByteArray,qreal,qreal)));
 517
 518         m_layouter->setHeaderHeight(m_header->size().height());
 519     } else if (!show && m_header) {
 520         delete m_header;
 521         m_header = 0;
 522         m_useHeaderWidths = false;
 523         m_layouter->setHeaderHeight(0);
 524     }
 525 }
 526
 527 bool KItemListView::isHeaderShown() const
 528 {
 529     return m_header != 0;
 530 }
 531
 532 QPixmap KItemListView::createDragPixmap(const QSet<int>& indexes) const
 533 {
 534     Q_UNUSED(indexes);
 535     return QPixmap();
 536 }
 537
 538 void KItemListView::paint(QPainter* painter, const QStyleOptionGraphicsItem* option, QWidget* widget)
 539 {
 540     QGraphicsWidget::paint(painter, option, widget);
 541
 542     if (m_rubberBand->isActive()) {
 543         QRectF rubberBandRect = QRectF(m_rubberBand->startPosition(),
 544                                        m_rubberBand->endPosition()).normalized();
 545
 546         const QPointF topLeft = rubberBandRect.topLeft();
 547         if (scrollOrientation() == Qt::Vertical) {
 548             rubberBandRect.moveTo(topLeft.x(), topLeft.y() - scrollOffset());
 549         } else {
 550             rubberBandRect.moveTo(topLeft.x() - scrollOffset(), topLeft.y());
 551         }
 552
 553         QStyleOptionRubberBand opt;
 554         opt.initFrom(widget);
 555         opt.shape = QRubberBand::Rectangle;
 556         opt.opaque = false;
 557         opt.rect = rubberBandRect.toRect();
 558         style()->drawControl(QStyle::CE_RubberBand, &opt, painter);
 559     }
 560 }
 561
 562 void KItemListView::initializeItemListWidget(KItemListWidget* item)
 563 {
 564     Q_UNUSED(item);
 565 }
 566
 567 bool KItemListView::itemSizeHintUpdateRequired(const QSet<QByteArray>& changedRoles) const
 568 {
 569     Q_UNUSED(changedRoles);
 570     return true;
 571 }
 572
 573 void KItemListView::onControllerChanged(KItemListController* current, KItemListController* previous)
 574 {
 575     Q_UNUSED(current);
 576     Q_UNUSED(previous);
 577 }
 578
 579 void KItemListView::onModelChanged(KItemModelBase* current, KItemModelBase* previous)
 580 {
 581     Q_UNUSED(current);
 582     Q_UNUSED(previous);
 583 }
 584
 585 void KItemListView::onScrollOrientationChanged(Qt::Orientation current, Qt::Orientation previous)
 586 {
 587     Q_UNUSED(current);
 588     Q_UNUSED(previous);
 589 }
 590
 591 void KItemListView::onItemSizeChanged(const QSizeF& current, const QSizeF& previous)
 592 {
 593     Q_UNUSED(current);
 594     Q_UNUSED(previous);
 595 }
 596
 597 void KItemListView::onScrollOffsetChanged(qreal current, qreal previous)
 598 {
 599     Q_UNUSED(current);
 600     Q_UNUSED(previous);
 601 }
 602
 603 void KItemListView::onVisibleRolesChanged(const QList<QByteArray>& current, const QList<QByteArray>& previous)
 604 {
 605     Q_UNUSED(current);
 606     Q_UNUSED(previous);
 607 }
 608
 609 void KItemListView::onStyleOptionChanged(const KItemListStyleOption& current, const KItemListStyleOption& previous)
 610 {
 611     Q_UNUSED(current);
 612     Q_UNUSED(previous);
 613 }
 614
 615 void KItemListView::onTransactionBegin()
 616 {
 617 }
 618
 619 void KItemListView::onTransactionEnd()
 620 {
 621 }
 622
 623 bool KItemListView::event(QEvent* event)
 624 {
 625     // Forward all events to the controller and handle them there
 626     if (m_controller && m_controller->processEvent(event, transform())) {
 627         event->accept();
 628         return true;
 629     }
 630     return QGraphicsWidget::event(event);
 631 }
 632
 633 void KItemListView::mousePressEvent(QGraphicsSceneMouseEvent* event)
 634 {
 635     m_mousePos = transform().map(event->pos());
 636     event->accept();
 637 }
 638
 639 void KItemListView::mouseMoveEvent(QGraphicsSceneMouseEvent* event)
 640 {
 641     QGraphicsWidget::mouseMoveEvent(event);
 642
 643     m_mousePos = transform().map(event->pos());
 644     if (m_autoScrollTimer && !m_autoScrollTimer->isActive()) {
 645         m_autoScrollTimer->start(InitialAutoScrollDelay);
 646     }
 647 }
 648
 649 void KItemListView::dragEnterEvent(QGraphicsSceneDragDropEvent* event)
 650 {
 651     event->setAccepted(true);
 652     setAutoScroll(true);
 653 }
 654
 655 void KItemListView::dragMoveEvent(QGraphicsSceneDragDropEvent *event)
 656 {
 657     QGraphicsWidget::dragMoveEvent(event);
 658
 659     m_mousePos = transform().map(event->pos());
 660     if (m_autoScrollTimer && !m_autoScrollTimer->isActive()) {
 661         m_autoScrollTimer->start(InitialAutoScrollDelay);
 662     }
 663 }
 664
 665 void KItemListView::dragLeaveEvent(QGraphicsSceneDragDropEvent *event)
 666 {
 667     QGraphicsWidget::dragLeaveEvent(event);
 668     setAutoScroll(false);
 669 }
 670
 671 void KItemListView::dropEvent(QGraphicsSceneDragDropEvent* event)
 672 {
 673     QGraphicsWidget::dropEvent(event);
 674     setAutoScroll(false);
 675 }
 676
 677 QList<KItemListWidget*> KItemListView::visibleItemListWidgets() const
 678 {
 679     return m_visibleItems.values();
 680 }
 681
 682 void KItemListView::resizeEvent(QGraphicsSceneResizeEvent* event)
 683 {
 684     QGraphicsWidget::resizeEvent(event);
 685     if (m_itemSize.isEmpty() && m_useHeaderWidths) {
 686         QSizeF dynamicItemSize = m_layouter->itemSize();
 687         const QSizeF newSize = event->newSize();
 688
 689         if (m_itemSize.width() < 0) {
 690             const qreal requiredWidth = visibleRolesSizesWidthSum();
 691             if (newSize.width() > requiredWidth) {
 692                 dynamicItemSize.setWidth(newSize.width());
 693             }
 694             const qreal headerWidth = qMax(newSize.width(), requiredWidth);
 695             m_header->resize(headerWidth, m_header->size().height());
 696         }
 697
 698         if (m_itemSize.height() < 0) {
 699             const qreal requiredHeight = visibleRolesSizesHeightSum();
 700             if (newSize.height() > requiredHeight) {
 701                 dynamicItemSize.setHeight(newSize.height());
 702             }
 703             // TODO: KItemListHeader is not prepared for vertical alignment
 704         }
 705
 706         m_layouter->setItemSize(dynamicItemSize);
 707     }
 708 }
 709
 710 void KItemListView::slotItemsInserted(const KItemRangeList& itemRanges)
 711 {
 712     updateVisibleRolesSizes(itemRanges);
 713
 714     const bool hasMultipleRanges = (itemRanges.count() > 1);
 715     if (hasMultipleRanges) {
 716         beginTransaction();
 717     }
 718
 719     int previouslyInsertedCount = 0;
 720     foreach (const KItemRange& range, itemRanges) {
 721         // range.index is related to the model before anything has been inserted.
 722         // As in each loop the current item-range gets inserted the index must
 723         // be increased by the already previously inserted items.
 724         const int index = range.index + previouslyInsertedCount;
 725         const int count = range.count;
 726         if (index < 0 || count <= 0) {
 727             kWarning() << "Invalid item range (index:" << index << ", count:" << count << ")";
 728             continue;
 729         }
 730         previouslyInsertedCount += count;
 731
 732         m_sizeHintResolver->itemsInserted(index, count);
 733
 734         // Determine which visible items must be moved
 735         QList<int> itemsToMove;
 736         QHashIterator<int, KItemListWidget*> it(m_visibleItems);
 737         while (it.hasNext()) {
 738             it.next();
 739             const int visibleItemIndex = it.key();
 740             if (visibleItemIndex >= index) {
 741                 itemsToMove.append(visibleItemIndex);
 742             }
 743         }
 744
 745         // Update the indexes of all KItemListWidget instances that are located
 746         // after the inserted items. It is important to adjust the indexes in the order
 747         // from the highest index to the lowest index to prevent overlaps when setting the new index.
 748         qSort(itemsToMove);
 749         for (int i = itemsToMove.count() - 1; i >= 0; --i) {
 750             KItemListWidget* widget = m_visibleItems.value(itemsToMove[i]);
 751             Q_ASSERT(widget);
 752             setWidgetIndex(widget, widget->index() + count);
 753         }
 754
 755         m_layouter->markAsDirty();
 756         if (m_model->count() == count && maximumScrollOffset() > size().height()) {
 757             kDebug() << "Scrollbar required, skipping layout";
 758             const int scrollBarExtent = style()->pixelMetric(QStyle::PM_ScrollBarExtent);
 759             QSizeF layouterSize = m_layouter->size();
 760             if (scrollOrientation() == Qt::Vertical) {
 761                 layouterSize.rwidth() -= scrollBarExtent;
 762             } else {
 763                 layouterSize.rheight() -= scrollBarExtent;
 764             }
 765             m_layouter->setSize(layouterSize);
 766         }
 767
 768         if (!hasMultipleRanges) {
 769             doLayout(Animation, index, count);
 770         }
 771     }
 772
 773     if (m_controller) {
 774         m_controller->selectionManager()->itemsInserted(itemRanges);
 775     }
 776
 777     if (hasMultipleRanges) {
 778         endTransaction();
 779     }
 780 }
 781
 782 void KItemListView::slotItemsRemoved(const KItemRangeList& itemRanges)
 783 {
 784     updateVisibleRolesSizes();
 785
 786     const bool hasMultipleRanges = (itemRanges.count() > 1);
 787     if (hasMultipleRanges) {
 788         beginTransaction();
 789     }
 790
 791     for (int i = itemRanges.count() - 1; i >= 0; --i) {
 792         const KItemRange& range = itemRanges.at(i);
 793         const int index = range.index;
 794         const int count = range.count;
 795         if (index < 0 || count <= 0) {
 796             kWarning() << "Invalid item range (index:" << index << ", count:" << count << ")";
 797             continue;
 798         }
 799
 800         m_sizeHintResolver->itemsRemoved(index, count);
 801
 802         const int firstRemovedIndex = index;
 803         const int lastRemovedIndex = index + count - 1;
 804         const int lastIndex = m_model->count() + count - 1;
 805
 806         // Remove all KItemListWidget instances that got deleted
 807         for (int i = firstRemovedIndex; i <= lastRemovedIndex; ++i) {
 808             KItemListWidget* widget = m_visibleItems.value(i);
 809             if (!widget) {
 810                 continue;
 811             }
 812
 813             m_animation->stop(widget);
 814             // Stopping the animation might lead to recycling the widget if
 815             // it is invisible (see slotAnimationFinished()).
 816             // Check again whether it is still visible:
 817             if (!m_visibleItems.contains(i)) {
 818                 continue;
 819             }
 820
 821             if (m_model->count() == 0) {
 822                 // For performance reasons no animation is done when all items have
 823                 // been removed.
 824                 recycleWidget(widget);
 825             } else {
 826                 // Animate the removing of the items. Special case: When removing an item there
 827                 // is no valid model index available anymore. For the
 828                 // remove-animation the item gets removed from m_visibleItems but the widget
 829                 // will stay alive until the animation has been finished and will
 830                 // be recycled (deleted) in KItemListView::slotAnimationFinished().
 831                 m_visibleItems.remove(i);
 832                 widget->setIndex(-1);
 833                 m_animation->start(widget, KItemListViewAnimation::DeleteAnimation);
 834             }
 835         }
 836
 837         // Update the indexes of all KItemListWidget instances that are located
 838         // after the deleted items
 839         for (int i = lastRemovedIndex + 1; i <= lastIndex; ++i) {
 840             KItemListWidget* widget = m_visibleItems.value(i);
 841             if (widget) {
 842                 const int newIndex = i - count;
 843                 setWidgetIndex(widget, newIndex);
 844             }
 845         }
 846
 847         m_layouter->markAsDirty();
 848         if (!hasMultipleRanges) {
 849             doLayout(Animation, index, -count);
 850         }
 851     }
 852
 853     if (m_controller) {
 854         m_controller->selectionManager()->itemsRemoved(itemRanges);
 855     }
 856
 857     if (hasMultipleRanges) {
 858         endTransaction();
 859     }
 860 }
 861
 862 void KItemListView::slotItemsMoved(const KItemRange& itemRange, const QList<int>& movedToIndexes)
 863 {
 864     m_sizeHintResolver->itemsMoved(itemRange.index, itemRange.count);
 865     m_layouter->markAsDirty();
 866
 867     if (m_controller) {
 868         m_controller->selectionManager()->itemsMoved(itemRange, movedToIndexes);
 869     }
 870
 871     const int firstVisibleMovedIndex = qMax(firstVisibleIndex(), itemRange.index);
 872     const int lastVisibleMovedIndex = qMin(lastVisibleIndex(), itemRange.index + itemRange.count - 1);
 873
 874     for (int index = firstVisibleMovedIndex; index <= lastVisibleMovedIndex; ++index) {
 875         KItemListWidget* widget = m_visibleItems.value(index);
 876         if (widget) {
 877             updateWidgetProperties(widget, index);
 878             if (m_grouped) {
 879                 updateGroupHeaderForWidget(widget);
 880             }
 881             initializeItemListWidget(widget);
 882         }
 883     }
 884
 885     doLayout(NoAnimation, 0, 0);
 886 }
 887
 888 void KItemListView::slotItemsChanged(const KItemRangeList& itemRanges,
 889                                      const QSet<QByteArray>& roles)
 890 {
 891     const bool updateSizeHints = itemSizeHintUpdateRequired(roles);
 892     if (updateSizeHints) {
 893         updateVisibleRolesSizes(itemRanges);
 894     }
 895
 896     foreach (const KItemRange& itemRange, itemRanges) {
 897         const int index = itemRange.index;
 898         const int count = itemRange.count;
 899
 900         if (updateSizeHints) {
 901             m_sizeHintResolver->itemsChanged(index, count, roles);
 902             m_layouter->markAsDirty();
 903
 904             if (!m_layoutTimer->isActive()) {
 905                 m_layoutTimer->start();
 906             }
 907         }
 908
 909         // Apply the changed roles to the visible item-widgets
 910         const int lastIndex = index + count - 1;
 911         for (int i = index; i <= lastIndex; ++i) {
 912             KItemListWidget* widget = m_visibleItems.value(i);
 913             if (widget) {
 914                 widget->setData(m_model->data(i), roles);
 915             }
 916         }
 917
 918         if (m_grouped && roles.contains(m_model->sortRole())) {
 919             // The sort-role has been changed which might result
 920             // in modified group headers
 921             updateVisibleGroupHeaders();
 922             doLayout(NoAnimation, 0, 0);
 923         }
 924     }
 925 }
 926
 927 void KItemListView::slotGroupedSortingChanged(bool current)
 928 {
 929     m_grouped = current;
 930     m_layouter->markAsDirty();
 931
 932     if (m_grouped) {
 933         // Apply the height of the header to the layouter
 934         const qreal groupHeaderHeight = m_styleOption.fontMetrics.height() +
 935                                         m_styleOption.margin * 2;
 936         m_layouter->setGroupHeaderHeight(groupHeaderHeight);
 937
 938         updateVisibleGroupHeaders();
 939     } else {
 940         // Clear all visible headers
 941         QMutableHashIterator<KItemListWidget*, KItemListGroupHeader*> it (m_visibleGroups);
 942         while (it.hasNext()) {
 943             it.next();
 944             recycleGroupHeaderForWidget(it.key());
 945         }
 946         Q_ASSERT(m_visibleGroups.isEmpty());
 947     }
 948
 949     doLayout(Animation, 0, 0);
 950 }
 951
 952 void KItemListView::slotSortOrderChanged(Qt::SortOrder current, Qt::SortOrder previous)
 953 {
 954     Q_UNUSED(current);
 955     Q_UNUSED(previous);
 956     if (m_grouped) {
 957         updateVisibleGroupHeaders();
 958         doLayout(Animation, 0, 0);
 959     }
 960 }
 961
 962 void KItemListView::slotSortRoleChanged(const QByteArray& current, const QByteArray& previous)
 963 {
 964     Q_UNUSED(current);
 965     Q_UNUSED(previous);
 966     if (m_grouped) {
 967         updateVisibleGroupHeaders();
 968         doLayout(Animation, 0, 0);
 969     }
 970 }
 971
 972 void KItemListView::slotCurrentChanged(int current, int previous)
 973 {
 974     Q_UNUSED(previous);
 975
 976     KItemListWidget* previousWidget = m_visibleItems.value(previous, 0);
 977     if (previousWidget) {
 978         Q_ASSERT(previousWidget->isCurrent());
 979         previousWidget->setCurrent(false);
 980     }
 981
 982     KItemListWidget* currentWidget = m_visibleItems.value(current, 0);
 983     if (currentWidget) {
 984         Q_ASSERT(!currentWidget->isCurrent());
 985         currentWidget->setCurrent(true);
 986     }
 987 }
 988
 989 void KItemListView::slotSelectionChanged(const QSet<int>& current, const QSet<int>& previous)
 990 {
 991     Q_UNUSED(previous);
 992
 993     QHashIterator<int, KItemListWidget*> it(m_visibleItems);
 994     while (it.hasNext()) {
 995         it.next();
 996         const int index = it.key();
 997         KItemListWidget* widget = it.value();
 998         widget->setSelected(current.contains(index));
 999     }
1000 }
1001
1002 void KItemListView::slotAnimationFinished(QGraphicsWidget* widget,
1003                                           KItemListViewAnimation::AnimationType type)
1004 {
1005     KItemListWidget* itemListWidget = qobject_cast<KItemListWidget*>(widget);
1006     Q_ASSERT(itemListWidget);
1007
1008     switch (type) {
1009     case KItemListViewAnimation::DeleteAnimation: {
1010         // As we recycle the widget in this case it is important to assure that no
1011         // other animation has been started. This is a convention in KItemListView and
1012         // not a requirement defined by KItemListViewAnimation.
1013         Q_ASSERT(!m_animation->isStarted(itemListWidget));
1014
1015         // All KItemListWidgets that are animated by the DeleteAnimation are not maintained
1016         // by m_visibleWidgets and must be deleted manually after the animation has
1017         // been finished.
1018         recycleGroupHeaderForWidget(itemListWidget);
1019         m_widgetCreator->recycle(itemListWidget);
1020         break;
1021     }
1022
1023     case KItemListViewAnimation::CreateAnimation:
1024     case KItemListViewAnimation::MovingAnimation:
1025     case KItemListViewAnimation::ResizeAnimation: {
1026         const int index = itemListWidget->index();
1027         const bool invisible = (index < m_layouter->firstVisibleIndex()) ||
1028                                (index > m_layouter->lastVisibleIndex());
1029         if (invisible && !m_animation->isStarted(itemListWidget)) {
1030             recycleWidget(itemListWidget);
1031         }
1032         break;
1033     }
1034
1035     default: break;
1036     }
1037 }
1038
1039 void KItemListView::slotLayoutTimerFinished()
1040 {
1041     m_layouter->setSize(geometry().size());
1042     doLayout(Animation, 0, 0);
1043 }
1044
1045 void KItemListView::slotRubberBandPosChanged()
1046 {
1047     update();
1048 }
1049
1050 void KItemListView::slotRubberBandActivationChanged(bool active)
1051 {
1052     if (active) {
1053         connect(m_rubberBand, SIGNAL(startPositionChanged(QPointF,QPointF)), this, SLOT(slotRubberBandPosChanged()));
1054         connect(m_rubberBand, SIGNAL(endPositionChanged(QPointF,QPointF)), this, SLOT(slotRubberBandPosChanged()));
1055         m_skipAutoScrollForRubberBand = true;
1056     } else {
1057         disconnect(m_rubberBand, SIGNAL(startPositionChanged(QPointF,QPointF)), this, SLOT(slotRubberBandPosChanged()));
1058         disconnect(m_rubberBand, SIGNAL(endPositionChanged(QPointF,QPointF)), this, SLOT(slotRubberBandPosChanged()));
1059         m_skipAutoScrollForRubberBand = false;
1060     }
1061
1062     update();
1063 }
1064
1065 void KItemListView::slotVisibleRoleWidthChanged(const QByteArray& role,
1066                                                 qreal currentWidth,
1067                                                 qreal previousWidth)
1068 {
1069     Q_UNUSED(previousWidth);
1070
1071     m_useHeaderWidths = true;
1072
1073     if (m_visibleRolesSizes.contains(role)) {
1074         QSizeF roleSize = m_visibleRolesSizes.value(role);
1075         roleSize.setWidth(currentWidth);
1076         m_visibleRolesSizes.insert(role, roleSize);
1077         m_stretchedVisibleRolesSizes.insert(role, roleSize);
1078
1079         // Apply the new size to the layouter
1080         QSizeF dynamicItemSize = m_itemSize;
1081         if (dynamicItemSize.width() < 0) {
1082             const qreal requiredWidth = visibleRolesSizesWidthSum();
1083             dynamicItemSize.setWidth(qMax(size().width(), requiredWidth));
1084         }
1085         if (dynamicItemSize.height() < 0) {
1086             const qreal requiredHeight = visibleRolesSizesHeightSum();
1087             dynamicItemSize.setHeight(qMax(size().height(), requiredHeight));
1088         }
1089
1090         m_layouter->setItemSize(dynamicItemSize);
1091
1092         // Update the role sizes for all visible widgets
1093         foreach (KItemListWidget* widget, visibleItemListWidgets()) {
1094             widget->setVisibleRolesSizes(m_stretchedVisibleRolesSizes);
1095         }
1096
1097         doLayout(Animation, 0, 0);
1098     }
1099 }
1100
1101 void KItemListView::triggerAutoScrolling()
1102 {
1103     if (!m_autoScrollTimer) {
1104         return;
1105     }
1106
1107     int pos = 0;
1108     int visibleSize = 0;
1109     if (scrollOrientation() == Qt::Vertical) {
1110         pos = m_mousePos.y();
1111         visibleSize = size().height();
1112     } else {
1113         pos = m_mousePos.x();
1114         visibleSize = size().width();
1115     }
1116
1117     if (m_autoScrollTimer->interval() == InitialAutoScrollDelay) {
1118         m_autoScrollIncrement = 0;
1119     }
1120
1121     m_autoScrollIncrement = calculateAutoScrollingIncrement(pos, visibleSize, m_autoScrollIncrement);
1122     if (m_autoScrollIncrement == 0) {
1123         // The mouse position is not above an autoscroll margin (the autoscroll timer
1124         // will be restarted in mouseMoveEvent())
1125         m_autoScrollTimer->stop();
1126         return;
1127     }
1128
1129     if (m_rubberBand->isActive() && m_skipAutoScrollForRubberBand) {
1130         // If a rubberband selection is ongoing the autoscrolling may only get triggered
1131         // if the direction of the rubberband is similar to the autoscroll direction. This
1132         // prevents that starting to create a rubberband within the autoscroll margins starts
1133         // an autoscrolling.
1134
1135         const qreal minDiff = 4; // Ignore any autoscrolling if the rubberband is very small
1136         const qreal diff = (scrollOrientation() == Qt::Vertical)
1137                            ? m_rubberBand->endPosition().y() - m_rubberBand->startPosition().y()
1138                            : m_rubberBand->endPosition().x() - m_rubberBand->startPosition().x();
1139         if (qAbs(diff) < minDiff || (m_autoScrollIncrement < 0 && diff > 0) || (m_autoScrollIncrement > 0 && diff < 0)) {
1140             // The rubberband direction is different from the scroll direction (e.g. the rubberband has
1141             // been moved up although the autoscroll direction might be down)
1142             m_autoScrollTimer->stop();
1143             return;
1144         }
1145     }
1146
1147     // As soon as the autoscrolling has been triggered at least once despite having an active rubberband,
1148     // the autoscrolling may not get skipped anymore until a new rubberband is created
1149     m_skipAutoScrollForRubberBand = false;
1150
1151     setScrollOffset(scrollOffset() + m_autoScrollIncrement);
1152
1153    // Trigger the autoscroll timer which will periodically call
1154    // triggerAutoScrolling()
1155    m_autoScrollTimer->start(RepeatingAutoScrollDelay);
1156 }
1157
1158 void KItemListView::setController(KItemListController* controller)
1159 {
1160     if (m_controller != controller) {
1161         KItemListController* previous = m_controller;
1162         if (previous) {
1163             KItemListSelectionManager* selectionManager = previous->selectionManager();
1164             disconnect(selectionManager, SIGNAL(currentChanged(int,int)), this, SLOT(slotCurrentChanged(int,int)));
1165             disconnect(selectionManager, SIGNAL(selectionChanged(QSet<int>,QSet<int>)), this, SLOT(slotSelectionChanged(QSet<int>,QSet<int>)));
1166         }
1167
1168         m_controller = controller;
1169
1170         if (controller) {
1171             KItemListSelectionManager* selectionManager = controller->selectionManager();
1172             connect(selectionManager, SIGNAL(currentChanged(int,int)), this, SLOT(slotCurrentChanged(int,int)));
1173             connect(selectionManager, SIGNAL(selectionChanged(QSet<int>,QSet<int>)), this, SLOT(slotSelectionChanged(QSet<int>,QSet<int>)));
1174         }
1175
1176         onControllerChanged(controller, previous);
1177     }
1178 }
1179
1180 void KItemListView::setModel(KItemModelBase* model)
1181 {
1182     if (m_model == model) {
1183         return;
1184     }
1185
1186     KItemModelBase* previous = m_model;
1187
1188     if (m_model) {
1189         disconnect(m_model, SIGNAL(itemsChanged(KItemRangeList,QSet<QByteArray>)),
1190                    this,    SLOT(slotItemsChanged(KItemRangeList,QSet<QByteArray>)));
1191         disconnect(m_model, SIGNAL(itemsInserted(KItemRangeList)),
1192                    this,    SLOT(slotItemsInserted(KItemRangeList)));
1193         disconnect(m_model, SIGNAL(itemsRemoved(KItemRangeList)),
1194                    this,    SLOT(slotItemsRemoved(KItemRangeList)));
1195         disconnect(m_model, SIGNAL(itemsMoved(KItemRange,QList<int>)),
1196                    this,    SLOT(slotItemsMoved(KItemRange,QList<int>)));
1197         disconnect(m_model, SIGNAL(groupedSortingChanged(bool)),
1198                    this,    SLOT(slotGroupedSortingChanged(bool)));
1199         disconnect(m_model, SIGNAL(sortOrderChanged(Qt::SortOrder,Qt::SortOrder)),
1200                    this,    SLOT(slotSortOrderChanged(Qt::SortOrder,Qt::SortOrder)));
1201         disconnect(m_model, SIGNAL(sortRoleChanged(QByteArray,QByteArray)),
1202                    this,    SLOT(slotSortRoleChanged(QByteArray,QByteArray)));
1203     }
1204
1205     m_model = model;
1206     m_layouter->setModel(model);
1207     m_grouped = model->groupedSorting();
1208
1209     if (m_model) {
1210         connect(m_model, SIGNAL(itemsChanged(KItemRangeList,QSet<QByteArray>)),
1211                 this,    SLOT(slotItemsChanged(KItemRangeList,QSet<QByteArray>)));
1212         connect(m_model, SIGNAL(itemsInserted(KItemRangeList)),
1213                 this,    SLOT(slotItemsInserted(KItemRangeList)));
1214         connect(m_model, SIGNAL(itemsRemoved(KItemRangeList)),
1215                 this,    SLOT(slotItemsRemoved(KItemRangeList)));
1216         connect(m_model, SIGNAL(itemsMoved(KItemRange,QList<int>)),
1217                 this,    SLOT(slotItemsMoved(KItemRange,QList<int>)));
1218         connect(m_model, SIGNAL(groupedSortingChanged(bool)),
1219                 this,    SLOT(slotGroupedSortingChanged(bool)));
1220         connect(m_model, SIGNAL(sortOrderChanged(Qt::SortOrder,Qt::SortOrder)),
1221                 this,    SLOT(slotSortOrderChanged(Qt::SortOrder,Qt::SortOrder)));
1222         connect(m_model, SIGNAL(sortRoleChanged(QByteArray,QByteArray)),
1223                 this,    SLOT(slotSortRoleChanged(QByteArray,QByteArray)));
1224     }
1225
1226     onModelChanged(model, previous);
1227 }
1228
1229 KItemListRubberBand* KItemListView::rubberBand() const
1230 {
1231     return m_rubberBand;
1232 }
1233
1234 void KItemListView::doLayout(LayoutAnimationHint hint, int changedIndex, int changedCount)
1235 {
1236     if (m_layoutTimer->isActive()) {
1237         kDebug() << "Stopping layout timer, synchronous layout requested";
1238         m_layoutTimer->stop();
1239     }
1240
1241     if (!m_model || m_model->count() < 0 || m_activeTransactions > 0) {
1242         return;
1243     }
1244
1245     const int firstVisibleIndex = m_layouter->firstVisibleIndex();
1246     const int lastVisibleIndex = m_layouter->lastVisibleIndex();
1247     if (firstVisibleIndex < 0) {
1248         emitOffsetChanges();
1249         return;
1250     }
1251
1252     // Do a sanity check of the scroll-offset property: When properties of the itemlist-view have been changed
1253     // it might be possible that the maximum offset got changed too. Assure that the full visible range
1254     // is still shown if the maximum offset got decreased.
1255     const qreal visibleOffsetRange = (scrollOrientation() == Qt::Horizontal) ? size().width() : size().height();
1256     const qreal maxOffsetToShowFullRange = maximumScrollOffset() - visibleOffsetRange;
1257     if (scrollOffset() > maxOffsetToShowFullRange) {
1258         m_layouter->setScrollOffset(qMax(qreal(0), maxOffsetToShowFullRange));
1259     }
1260
1261     // Determine all items that are completely invisible and might be
1262     // reused for items that just got (at least partly) visible.
1263     // Items that do e.g. an animated moving of their position are not
1264     // marked as invisible: This assures that a scrolling inside the view
1265     // can be done without breaking an animation.
1266     QList<int> reusableItems;
1267     QHashIterator<int, KItemListWidget*> it(m_visibleItems);
1268     while (it.hasNext()) {
1269         it.next();
1270         KItemListWidget* widget = it.value();
1271         const int index = widget->index();
1272         const bool invisible = (index < firstVisibleIndex) || (index > lastVisibleIndex);
1273         if (invisible && !m_animation->isStarted(widget)) {
1274             widget->setVisible(false);
1275             reusableItems.append(index);
1276
1277             if (m_grouped) {
1278                 recycleGroupHeaderForWidget(widget);
1279             }
1280         }
1281     }
1282
1283     // Assure that for each visible item a KItemListWidget is available. KItemListWidget
1284     // instances from invisible items are reused. If no reusable items are
1285     // found then new KItemListWidget instances get created.
1286     const bool animate = (hint == Animation);
1287     for (int i = firstVisibleIndex; i <= lastVisibleIndex; ++i) {
1288         bool applyNewPos = true;
1289         bool wasHidden = false;
1290
1291         const QRectF itemBounds = m_layouter->itemRect(i);
1292         const QPointF newPos = itemBounds.topLeft();
1293         KItemListWidget* widget = m_visibleItems.value(i);
1294         if (!widget) {
1295             wasHidden = true;
1296             if (!reusableItems.isEmpty()) {
1297                 // Reuse a KItemListWidget instance from an invisible item
1298                 const int oldIndex = reusableItems.takeLast();
1299                 widget = m_visibleItems.value(oldIndex);
1300                 setWidgetIndex(widget, i);
1301
1302                 if (m_grouped) {
1303                     updateGroupHeaderForWidget(widget);
1304                 }
1305             } else {
1306                 // No reusable KItemListWidget instance is available, create a new one
1307                 widget = createWidget(i);
1308             }
1309             widget->resize(itemBounds.size());
1310
1311             if (animate && changedCount < 0) {
1312                 // Items have been deleted, move the created item to the
1313                 // imaginary old position.
1314                 const QRectF itemRect = m_layouter->itemRect(i - changedCount);
1315                 if (itemRect.isEmpty()) {
1316                     const QPointF invisibleOldPos = (scrollOrientation() == Qt::Vertical)
1317                                                     ? QPointF(0, size().height()) : QPointF(size().width(), 0);
1318                     widget->setPos(invisibleOldPos);
1319                 } else {
1320                     widget->setPos(itemRect.topLeft());
1321                 }
1322                 applyNewPos = false;
1323             }
1324         } else if (m_animation->isStarted(widget, KItemListViewAnimation::MovingAnimation)) {
1325             applyNewPos = false;
1326         }
1327
1328         if (animate) {
1329             const bool itemsRemoved = (changedCount < 0);
1330             const bool itemsInserted = (changedCount > 0);
1331
1332             if (itemsRemoved && (i >= changedIndex + changedCount + 1)) {
1333                 // The item is located after the removed items. Animate the moving of the position.
1334                 m_animation->start(widget, KItemListViewAnimation::MovingAnimation, newPos);
1335                 applyNewPos = false;
1336             } else if (itemsInserted && i >= changedIndex) {
1337                 // The item is located after the first inserted item
1338                 if (i <= changedIndex + changedCount - 1) {
1339                     // The item is an inserted item. Animate the appearing of the item.
1340                     // For performance reasons no animation is done when changedCount is equal
1341                     // to all available items.
1342                     if (changedCount < m_model->count()) {
1343                         m_animation->start(widget, KItemListViewAnimation::CreateAnimation);
1344                     }
1345                 } else if (!m_animation->isStarted(widget, KItemListViewAnimation::CreateAnimation)) {
1346                     // The item was already there before, so animate the moving of the position.
1347                     // No moving animation is done if the item is animated by a create animation: This
1348                     // prevents a "move animation mess" when inserting several ranges in parallel.
1349                     m_animation->start(widget, KItemListViewAnimation::MovingAnimation, newPos);
1350                     applyNewPos = false;
1351                 }
1352             } else if (!itemsRemoved && !itemsInserted && !wasHidden) {
1353                 // The size of the view might have been changed. Animate the moving of the position.
1354                 m_animation->start(widget, KItemListViewAnimation::MovingAnimation, newPos);
1355                 applyNewPos = false;
1356             }
1357         }
1358
1359         if (applyNewPos) {
1360             widget->setPos(newPos);
1361         }
1362
1363         Q_ASSERT(widget->index() == i);
1364         widget->setVisible(true);
1365
1366         if (widget->size() != itemBounds.size()) {
1367             if (animate) {
1368                 m_animation->start(widget, KItemListViewAnimation::ResizeAnimation, itemBounds.size());
1369             } else {
1370                 widget->resize(itemBounds.size());
1371             }
1372         }
1373     }
1374
1375     // Delete invisible KItemListWidget instances that have not been reused
1376     foreach (int index, reusableItems) {
1377         recycleWidget(m_visibleItems.value(index));
1378     }
1379
1380     if (m_grouped) {
1381         // Update the layout of all visible group headers
1382         QHashIterator<KItemListWidget*, KItemListGroupHeader*> it(m_visibleGroups);
1383         while (it.hasNext()) {
1384             it.next();
1385             updateGroupHeaderLayout(it.key());
1386         }
1387     }
1388
1389     emitOffsetChanges();
1390 }
1391
1392 void KItemListView::emitOffsetChanges()
1393 {
1394     const qreal newScrollOffset = m_layouter->scrollOffset();
1395     if (m_oldScrollOffset != newScrollOffset) {
1396         emit scrollOffsetChanged(newScrollOffset, m_oldScrollOffset);
1397         m_oldScrollOffset = newScrollOffset;
1398     }
1399
1400     const qreal newMaximumScrollOffset = m_layouter->maximumScrollOffset();
1401     if (m_oldMaximumScrollOffset != newMaximumScrollOffset) {
1402         emit maximumScrollOffsetChanged(newMaximumScrollOffset, m_oldMaximumScrollOffset);
1403         m_oldMaximumScrollOffset = newMaximumScrollOffset;
1404     }
1405
1406     const qreal newItemOffset = m_layouter->itemOffset();
1407     if (m_oldItemOffset != newItemOffset) {
1408         emit itemOffsetChanged(newItemOffset, m_oldItemOffset);
1409         m_oldItemOffset = newItemOffset;
1410     }
1411
1412     const qreal newMaximumItemOffset = m_layouter->maximumItemOffset();
1413     if (m_oldMaximumItemOffset != newMaximumItemOffset) {
1414         emit maximumItemOffsetChanged(newMaximumItemOffset, m_oldMaximumItemOffset);
1415         m_oldMaximumItemOffset = newMaximumItemOffset;
1416     }
1417 }
1418
1419 KItemListWidget* KItemListView::createWidget(int index)
1420 {
1421     KItemListWidget* widget = m_widgetCreator->create(this);
1422     widget->setFlag(QGraphicsItem::ItemStacksBehindParent);
1423
1424     updateWidgetProperties(widget, index);
1425     m_visibleItems.insert(index, widget);
1426
1427     if (m_grouped) {
1428         updateGroupHeaderForWidget(widget);
1429     }
1430
1431     initializeItemListWidget(widget);
1432     return widget;
1433 }
1434
1435 void KItemListView::recycleWidget(KItemListWidget* widget)
1436 {
1437     if (m_grouped) {
1438         recycleGroupHeaderForWidget(widget);
1439     }
1440
1441     m_visibleItems.remove(widget->index());
1442     m_widgetCreator->recycle(widget);
1443 }
1444
1445 void KItemListView::setWidgetIndex(KItemListWidget* widget, int index)
1446 {
1447     const int oldIndex = widget->index();
1448     m_visibleItems.remove(oldIndex);
1449     updateWidgetProperties(widget, index);
1450     m_visibleItems.insert(index, widget);
1451
1452     initializeItemListWidget(widget);
1453 }
1454
1455 void KItemListView::prepareLayoutForIncreasedItemCount(const QSizeF& size, SizeType sizeType)
1456 {
1457     // Calculate the first visible index and last visible index for the current size
1458     const int currentFirst = m_layouter->firstVisibleIndex();
1459     const int currentLast = m_layouter->lastVisibleIndex();
1460
1461     const QSizeF currentSize = (sizeType == LayouterSize) ? m_layouter->size() : m_layouter->itemSize();
1462
1463     // Calculate the first visible index and last visible index for the new size
1464     setLayouterSize(size, sizeType);
1465     const int newFirst = m_layouter->firstVisibleIndex();
1466     const int newLast = m_layouter->lastVisibleIndex();
1467
1468     if ((currentFirst != newFirst) || (currentLast != newLast)) {
1469         // At least one index has been changed. Assure that widgets for all possible
1470         // visible items get created so that a move-animation can be started later.
1471         const int maxVisibleItems = m_layouter->maximumVisibleItems();
1472         int minFirst = qMin(newFirst, currentFirst);
1473         const int maxLast = qMax(newLast, currentLast);
1474
1475         if (maxLast - minFirst + 1 < maxVisibleItems) {
1476             // Increasing the size might result in a smaller KItemListView::offset().
1477             // Decrease the first visible index in a way that at least the maximum
1478             // visible items are shown.
1479             minFirst = qMax(0, maxLast - maxVisibleItems + 1);
1480         }
1481
1482         if (maxLast - minFirst > maxVisibleItems  + maxVisibleItems / 2) {
1483             // The creating of widgets is quite expensive. Assure that never more
1484             // than 50 % of the maximum visible items get created for the animations.
1485             return;
1486         }
1487
1488         setLayouterSize(currentSize, sizeType);
1489         for (int i = minFirst; i <= maxLast; ++i) {
1490             if (!m_visibleItems.contains(i)) {
1491                 KItemListWidget* widget = createWidget(i);
1492                 const QRectF itemRect = m_layouter->itemRect(i);
1493                 widget->setPos(itemRect.topLeft());
1494                 widget->resize(itemRect.size());
1495             }
1496         }
1497         setLayouterSize(size, sizeType);
1498     }
1499 }
1500
1501 void KItemListView::setLayouterSize(const QSizeF& size, SizeType sizeType)
1502 {
1503     switch (sizeType) {
1504     case LayouterSize: m_layouter->setSize(size); break;
1505     case ItemSize: m_layouter->setItemSize(size); break;
1506     default: break;
1507     }
1508 }
1509
1510 void KItemListView::updateWidgetProperties(KItemListWidget* widget, int index)
1511 {
1512     widget->setVisibleRoles(m_visibleRoles);
1513     widget->setVisibleRolesSizes(m_stretchedVisibleRolesSizes);
1514     widget->setStyleOption(m_styleOption);
1515
1516     const KItemListSelectionManager* selectionManager = m_controller->selectionManager();
1517     widget->setCurrent(index == selectionManager->currentItem());
1518     widget->setSelected(selectionManager->isSelected(index));
1519     widget->setHovered(false);
1520     widget->setAlternatingBackgroundColors(false);
1521     widget->setEnabledSelectionToggle(enabledSelectionToggles());
1522     widget->setIndex(index);
1523     widget->setData(m_model->data(index));
1524 }
1525
1526 void KItemListView::updateGroupHeaderForWidget(KItemListWidget* widget)
1527 {
1528     Q_ASSERT(m_grouped);
1529
1530     const int index = widget->index();
1531     if (!m_layouter->isFirstGroupItem(index)) {
1532         // The widget does not represent the first item of a group
1533         // and hence requires no header
1534         recycleGroupHeaderForWidget(widget);
1535         return;
1536     }
1537
1538     const QList<QPair<int, QVariant> > groups = model()->groups();
1539     if (groups.isEmpty()) {
1540         return;
1541     }
1542
1543     KItemListGroupHeader* header = m_visibleGroups.value(widget);
1544     if (!header) {
1545         header = m_groupHeaderCreator->create(this);
1546         header->setParentItem(widget);
1547         m_visibleGroups.insert(widget, header);
1548     }
1549     Q_ASSERT(header->parentItem() == widget);
1550
1551     // Determine the shown data for the header by doing a binary
1552     // search in the groups-list
1553     int min = 0;
1554     int max = groups.count() - 1;
1555     int mid = 0;
1556     do {
1557         mid = (min + max) / 2;
1558         if (index > groups.at(mid).first) {
1559             min = mid + 1;
1560         } else {
1561             max = mid - 1;
1562         }
1563     } while (groups.at(mid).first != index && min <= max);
1564
1565     header->setData(groups.at(mid).second);
1566     header->setRole(model()->sortRole());
1567     header->setStyleOption(m_styleOption);
1568     header->setScrollOrientation(scrollOrientation());
1569
1570     header->show();
1571 }
1572
1573 void KItemListView::updateGroupHeaderLayout(KItemListWidget* widget)
1574 {
1575     KItemListGroupHeader* header = m_visibleGroups.value(widget);
1576     Q_ASSERT(header);
1577
1578     const int index = widget->index();
1579     const QRectF groupHeaderRect = m_layouter->groupHeaderRect(index);
1580     const QRectF itemRect = m_layouter->itemRect(index);
1581
1582     // The group-header is a child of the itemlist widget. Translate the
1583     // group header position to the relative position.
1584     const QPointF groupHeaderPos(groupHeaderRect.x() - itemRect.x(),
1585                                  - groupHeaderRect.height());
1586     header->setPos(groupHeaderPos);
1587     header->resize(groupHeaderRect.size());
1588 }
1589
1590 void KItemListView::recycleGroupHeaderForWidget(KItemListWidget* widget)
1591 {
1592     KItemListGroupHeader* header = m_visibleGroups.value(widget);
1593     if (header) {
1594         header->setParentItem(0);
1595         m_groupHeaderCreator->recycle(header);
1596         m_visibleGroups.remove(widget);
1597     }
1598 }
1599
1600 void KItemListView::updateVisibleGroupHeaders()
1601 {
1602     Q_ASSERT(m_grouped);
1603     m_layouter->markAsDirty();
1604
1605     QHashIterator<int, KItemListWidget*> it(m_visibleItems);
1606     while (it.hasNext()) {
1607         it.next();
1608         updateGroupHeaderForWidget(it.value());
1609     }
1610 }
1611
1612 QHash<QByteArray, qreal> KItemListView::headerRolesWidths() const
1613 {
1614     QHash<QByteArray, qreal> rolesWidths;
1615
1616     QHashIterator<QByteArray, QSizeF> it(m_stretchedVisibleRolesSizes);
1617     while (it.hasNext()) {
1618         it.next();
1619         rolesWidths.insert(it.key(), it.value().width());
1620     }
1621
1622     return rolesWidths;
1623 }
1624
1625 void KItemListView::updateVisibleRolesSizes(const KItemRangeList& itemRanges)
1626 {
1627     if (!m_itemSize.isEmpty() || m_useHeaderWidths) {
1628         return;
1629     }
1630
1631     const int itemCount = m_model->count();
1632     int rangesItemCount = 0;
1633     foreach (const KItemRange& range, itemRanges) {
1634         rangesItemCount += range.count;
1635     }
1636
1637     if (itemCount == rangesItemCount) {
1638         m_visibleRolesSizes = visibleRolesSizes(itemRanges);
1639         if (m_header) {
1640             // Assure the the sizes are not smaller than the minimum defined by the header
1641             // TODO: Currently only implemented for a top-aligned header
1642             const qreal minHeaderRoleWidth = m_header->minimumRoleWidth();
1643             QMutableHashIterator<QByteArray, QSizeF> it (m_visibleRolesSizes);
1644             while (it.hasNext()) {
1645                 it.next();
1646                 const QSizeF& size = it.value();
1647                 if (size.width() < minHeaderRoleWidth) {
1648                     const QSizeF newSize(minHeaderRoleWidth, size.height());
1649                     m_visibleRolesSizes.insert(it.key(), newSize);
1650                 }
1651             }
1652         }
1653     } else {
1654         // Only a sub range of the roles need to be determined.
1655         // The chances are good that the sizes of the sub ranges
1656         // already fit into the available sizes and hence no
1657         // expensive update might be required.
1658         bool updateRequired = false;
1659
1660         const QHash<QByteArray, QSizeF> updatedSizes = visibleRolesSizes(itemRanges);
1661         QHashIterator<QByteArray, QSizeF> it(updatedSizes);
1662         while (it.hasNext()) {
1663             it.next();
1664             const QByteArray& role = it.key();
1665             const QSizeF& updatedSize = it.value();
1666             const QSizeF currentSize = m_visibleRolesSizes.value(role);
1667             if (updatedSize.width() > currentSize.width() || updatedSize.height() > currentSize.height()) {
1668                 m_visibleRolesSizes.insert(role, updatedSize);
1669                 updateRequired = true;
1670             }
1671         }
1672
1673         if (!updateRequired) {
1674             // All the updated sizes are smaller than the current sizes and no change
1675             // of the stretched roles-widths is required
1676             return;
1677         }
1678     }
1679
1680     updateStretchedVisibleRolesSizes();
1681 }
1682
1683 void KItemListView::updateVisibleRolesSizes()
1684 {
1685     if (!m_model) {
1686         return;
1687     }
1688
1689     const int itemCount = m_model->count();
1690     if (itemCount > 0) {
1691         updateVisibleRolesSizes(KItemRangeList() << KItemRange(0, itemCount));
1692     }
1693 }
1694
1695 void KItemListView::updateStretchedVisibleRolesSizes()
1696 {
1697     if (!m_itemSize.isEmpty() || m_useHeaderWidths || m_visibleRoles.isEmpty()) {
1698         return;
1699     }
1700
1701     // Calculate the maximum size of an item by considering the
1702     // visible role sizes and apply them to the layouter. If the
1703     // size does not use the available view-size it the size of the
1704     // first role will get stretched.
1705     m_stretchedVisibleRolesSizes = m_visibleRolesSizes;
1706     const QByteArray role = m_visibleRoles.first();
1707     QSizeF firstRoleSize = m_stretchedVisibleRolesSizes.value(role);
1708
1709     QSizeF dynamicItemSize = m_itemSize;
1710
1711     if (dynamicItemSize.width() <= 0) {
1712         const qreal requiredWidth = visibleRolesSizesWidthSum();
1713         const qreal availableWidth = size().width();
1714         if (requiredWidth < availableWidth) {
1715             // Stretch the first role to use the whole width for the item
1716             firstRoleSize.rwidth() += availableWidth - requiredWidth;
1717             m_stretchedVisibleRolesSizes.insert(role, firstRoleSize);
1718         }
1719         dynamicItemSize.setWidth(qMax(requiredWidth, availableWidth));
1720     }
1721
1722     if (dynamicItemSize.height() <= 0) {
1723         const qreal requiredHeight = visibleRolesSizesHeightSum();
1724         const qreal availableHeight = size().height();
1725         if (requiredHeight < availableHeight) {
1726             // Stretch the first role to use the whole height for the item
1727             firstRoleSize.rheight() += availableHeight - requiredHeight;
1728             m_stretchedVisibleRolesSizes.insert(role, firstRoleSize);
1729         }
1730         dynamicItemSize.setHeight(qMax(requiredHeight, availableHeight));
1731     }
1732
1733     m_layouter->setItemSize(dynamicItemSize);
1734
1735     if (m_header) {
1736         m_header->setVisibleRolesWidths(headerRolesWidths());
1737         m_header->resize(dynamicItemSize.width(), m_header->size().height());
1738     }
1739
1740     // Update the role sizes for all visible widgets
1741     foreach (KItemListWidget* widget, visibleItemListWidgets()) {
1742         widget->setVisibleRolesSizes(m_stretchedVisibleRolesSizes);
1743     }
1744 }
1745
1746 qreal KItemListView::visibleRolesSizesWidthSum() const
1747 {
1748     qreal widthSum = 0;
1749     QHashIterator<QByteArray, QSizeF> it(m_visibleRolesSizes);
1750     while (it.hasNext()) {
1751         it.next();
1752         widthSum += it.value().width();
1753     }
1754     return widthSum;
1755 }
1756
1757 qreal KItemListView::visibleRolesSizesHeightSum() const
1758 {
1759     qreal heightSum = 0;
1760     QHashIterator<QByteArray, QSizeF> it(m_visibleRolesSizes);
1761     while (it.hasNext()) {
1762         it.next();
1763         heightSum += it.value().height();
1764     }
1765     return heightSum;
1766 }
1767
1768 QRectF KItemListView::headerBoundaries() const
1769 {
1770     return m_header ? m_header->geometry() : QRectF();
1771 }
1772
1773 int KItemListView::calculateAutoScrollingIncrement(int pos, int range, int oldInc)
1774 {
1775     int inc = 0;
1776
1777     const int minSpeed = 4;
1778     const int maxSpeed = 128;
1779     const int speedLimiter = 96;
1780     const int autoScrollBorder = 64;
1781
1782     // Limit the increment that is allowed to be added in comparison to 'oldInc'.
1783     // This assures that the autoscrolling speed grows gradually.
1784     const int incLimiter = 1;
1785
1786     if (pos < autoScrollBorder) {
1787         inc = -minSpeed + qAbs(pos - autoScrollBorder) * (pos - autoScrollBorder) / speedLimiter;
1788         inc = qMax(inc, -maxSpeed);
1789         inc = qMax(inc, oldInc - incLimiter);
1790     } else if (pos > range - autoScrollBorder) {
1791         inc = minSpeed + qAbs(pos - range + autoScrollBorder) * (pos - range + autoScrollBorder) / speedLimiter;
1792         inc = qMin(inc, maxSpeed);
1793         inc = qMin(inc, oldInc + incLimiter);
1794     }
1795
1796     return inc;
1797 }
1798
1799
1800
1801 KItemListCreatorBase::~KItemListCreatorBase()
1802 {
1803     qDeleteAll(m_recycleableWidgets);
1804     qDeleteAll(m_createdWidgets);
1805 }
1806
1807 void KItemListCreatorBase::addCreatedWidget(QGraphicsWidget* widget)
1808 {
1809     m_createdWidgets.insert(widget);
1810 }
1811
1812 void KItemListCreatorBase::pushRecycleableWidget(QGraphicsWidget* widget)
1813 {
1814     Q_ASSERT(m_createdWidgets.contains(widget));
1815     m_createdWidgets.remove(widget);
1816
1817     if (m_recycleableWidgets.count() < 100) {
1818         m_recycleableWidgets.append(widget);
1819         widget->setVisible(false);
1820     } else {
1821         delete widget;
1822     }
1823 }
1824
1825 QGraphicsWidget* KItemListCreatorBase::popRecycleableWidget()
1826 {
1827     if (m_recycleableWidgets.isEmpty()) {
1828         return 0;
1829     }
1830
1831     QGraphicsWidget* widget = m_recycleableWidgets.takeLast();
1832     m_createdWidgets.insert(widget);
1833     return widget;
1834 }
1835
1836 KItemListWidgetCreatorBase::~KItemListWidgetCreatorBase()
1837 {
1838 }
1839
1840 void KItemListWidgetCreatorBase::recycle(KItemListWidget* widget)
1841 {
1842     widget->setParentItem(0);
1843     widget->setOpacity(1.0);
1844     pushRecycleableWidget(widget);
1845 }
1846
1847 KItemListGroupHeaderCreatorBase::~KItemListGroupHeaderCreatorBase()
1848 {
1849 }
1850
1851 void KItemListGroupHeaderCreatorBase::recycle(KItemListGroupHeader* header)
1852 {
1853     header->setOpacity(1.0);
1854     pushRecycleableWidget(header);
1855 }
1856
1857 #include "kitemlistview.moc"