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);
 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);
 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
 185     // Don't check whether the m_layoutTimer is active: Changing the
 186     // scroll offset must always trigger a synchronous layout, otherwise
 187     // the smooth-scrolling might get jerky.
 188     doLayout(NoAnimation);
 189     onScrollOffsetChanged(offset, previousOffset);
 190 }
 191
 192 qreal KItemListView::scrollOffset() const
 193 {
 194     return m_layouter->scrollOffset();
 195 }
 196
 197 qreal KItemListView::maximumScrollOffset() const
 198 {
 199     return m_layouter->maximumScrollOffset();
 200 }
 201
 202 void KItemListView::setItemOffset(qreal offset)
 203 {
 204     m_layouter->setItemOffset(offset);
 205     if (m_header) {
 206         m_header->setPos(-offset, 0);
 207     }
 208     if (!m_layoutTimer->isActive()) {
 209         doLayout(NoAnimation);
 210     }
 211 }
 212
 213 qreal KItemListView::itemOffset() const
 214 {
 215     return m_layouter->itemOffset();
 216 }
 217
 218 qreal KItemListView::maximumItemOffset() const
 219 {
 220     return m_layouter->maximumItemOffset();
 221 }
 222
 223 void KItemListView::setVisibleRoles(const QList<QByteArray>& roles)
 224 {
 225     const QList<QByteArray> previousRoles = m_visibleRoles;
 226     m_visibleRoles = roles;
 227
 228     QHashIterator<int, KItemListWidget*> it(m_visibleItems);
 229     while (it.hasNext()) {
 230         it.next();
 231         KItemListWidget* widget = it.value();
 232         widget->setVisibleRoles(roles);
 233         widget->setVisibleRolesSizes(m_stretchedVisibleRolesSizes);
 234     }
 235
 236     m_sizeHintResolver->clearCache();
 237     m_layouter->markAsDirty();
 238
 239     if (m_header) {
 240         m_header->setVisibleRoles(roles);
 241         m_header->setVisibleRolesWidths(headerRolesWidths());
 242         m_useHeaderWidths = false;
 243     }
 244
 245     updateVisibleRolesSizes();
 246     doLayout(Animation);
 247
 248     onVisibleRolesChanged(roles, previousRoles);
 249 }
 250
 251 QList<QByteArray> KItemListView::visibleRoles() const
 252 {
 253     return m_visibleRoles;
 254 }
 255
 256 void KItemListView::setAutoScroll(bool enabled)
 257 {
 258     if (enabled && !m_autoScrollTimer) {
 259         m_autoScrollTimer = new QTimer(this);
 260         m_autoScrollTimer->setSingleShot(false);
 261         connect(m_autoScrollTimer, SIGNAL(timeout()), this, SLOT(triggerAutoScrolling()));
 262         m_autoScrollTimer->start(InitialAutoScrollDelay);
 263     } else if (!enabled && m_autoScrollTimer) {
 264         delete m_autoScrollTimer;
 265         m_autoScrollTimer = 0;
 266     }
 267
 268 }
 269
 270 bool KItemListView::autoScroll() const
 271 {
 272     return m_autoScrollTimer != 0;
 273 }
 274
 275 void KItemListView::setEnabledSelectionToggles(bool enabled)
 276 {
 277     if (m_enabledSelectionToggles != enabled) {
 278         m_enabledSelectionToggles = enabled;
 279
 280         QHashIterator<int, KItemListWidget*> it(m_visibleItems);
 281         while (it.hasNext()) {
 282             it.next();
 283             it.value()->setEnabledSelectionToggle(enabled);
 284         }
 285     }
 286 }
 287
 288 bool KItemListView::enabledSelectionToggles() const
 289 {
 290     return m_enabledSelectionToggles;
 291 }
 292
 293 KItemListController* KItemListView::controller() const
 294 {
 295     return m_controller;
 296 }
 297
 298 KItemModelBase* KItemListView::model() const
 299 {
 300     return m_model;
 301 }
 302
 303 void KItemListView::setWidgetCreator(KItemListWidgetCreatorBase* widgetCreator)
 304 {
 305     m_widgetCreator = widgetCreator;
 306 }
 307
 308 KItemListWidgetCreatorBase* KItemListView::widgetCreator() const
 309 {
 310     return m_widgetCreator;
 311 }
 312
 313 void KItemListView::setGroupHeaderCreator(KItemListGroupHeaderCreatorBase* groupHeaderCreator)
 314 {
 315     m_groupHeaderCreator = groupHeaderCreator;
 316 }
 317
 318 KItemListGroupHeaderCreatorBase* KItemListView::groupHeaderCreator() const
 319 {
 320     return m_groupHeaderCreator;
 321 }
 322
 323 void KItemListView::setStyleOption(const KItemListStyleOption& option)
 324 {
 325     const KItemListStyleOption previousOption = m_styleOption;
 326     m_styleOption = option;
 327
 328     QHashIterator<int, KItemListWidget*> it(m_visibleItems);
 329     while (it.hasNext()) {
 330         it.next();
 331         it.value()->setStyleOption(option);
 332     }
 333
 334     m_sizeHintResolver->clearCache();
 335     doLayout(Animation);
 336     onStyleOptionChanged(option, previousOption);
 337 }
 338
 339 const KItemListStyleOption& KItemListView::styleOption() const
 340 {
 341     return m_styleOption;
 342 }
 343
 344 void KItemListView::setGeometry(const QRectF& rect)
 345 {
 346     QGraphicsWidget::setGeometry(rect);
 347
 348     if (!m_model) {
 349         return;
 350     }
 351
 352     if (m_model->count() > 0) {
 353         prepareLayoutForIncreasedItemCount(rect.size(), LayouterSize);
 354     } else {
 355         m_layouter->setSize(rect.size());
 356     }
 357
 358     if (!m_layoutTimer->isActive()) {
 359         m_layoutTimer->start();
 360     }
 361
 362     // Changing the geometry does not require to do an expensive
 363     // update of the visible-roles sizes, only the stretched sizes
 364     // need to be adjusted to the new size.
 365     updateStretchedVisibleRolesSizes();
 366 }
 367
 368 int KItemListView::itemAt(const QPointF& pos) const
 369 {
 370     QHashIterator<int, KItemListWidget*> it(m_visibleItems);
 371     while (it.hasNext()) {
 372         it.next();
 373
 374         const KItemListWidget* widget = it.value();
 375         const QPointF mappedPos = widget->mapFromItem(this, pos);
 376         if (widget->contains(mappedPos)) {
 377             return it.key();
 378         }
 379     }
 380
 381     return -1;
 382 }
 383
 384 bool KItemListView::isAboveSelectionToggle(int index, const QPointF& pos) const
 385 {
 386     const KItemListWidget* widget = m_visibleItems.value(index);
 387     if (widget) {
 388         const QRectF selectionToggleRect = widget->selectionToggleRect();
 389         if (!selectionToggleRect.isEmpty()) {
 390             const QPointF mappedPos = widget->mapFromItem(this, pos);
 391             return selectionToggleRect.contains(mappedPos);
 392         }
 393     }
 394     return false;
 395 }
 396
 397 bool KItemListView::isAboveExpansionToggle(int index, const QPointF& pos) const
 398 {
 399     const KItemListWidget* widget = m_visibleItems.value(index);
 400     if (widget) {
 401         const QRectF expansionToggleRect = widget->expansionToggleRect();
 402         if (!expansionToggleRect.isEmpty()) {
 403             const QPointF mappedPos = widget->mapFromItem(this, pos);
 404             return expansionToggleRect.contains(mappedPos);
 405         }
 406     }
 407     return false;
 408 }
 409
 410 int KItemListView::firstVisibleIndex() const
 411 {
 412     return m_layouter->firstVisibleIndex();
 413 }
 414
 415 int KItemListView::lastVisibleIndex() const
 416 {
 417     return m_layouter->lastVisibleIndex();
 418 }
 419
 420 QSizeF KItemListView::itemSizeHint(int index) const
 421 {
 422     Q_UNUSED(index);
 423     return itemSize();
 424 }
 425
 426 QHash<QByteArray, QSizeF> KItemListView::visibleRolesSizes(const KItemRangeList& itemRanges) const
 427 {
 428     Q_UNUSED(itemRanges);
 429     return QHash<QByteArray, QSizeF>();
 430 }
 431
 432 bool KItemListView::supportsItemExpanding() const
 433 {
 434     return false;
 435 }
 436
 437 QRectF KItemListView::itemRect(int index) const
 438 {
 439     return m_layouter->itemRect(index);
 440 }
 441
 442 QRectF KItemListView::itemContextRect(int index) const
 443 {
 444     QRectF contextRect;
 445
 446     const KItemListWidget* widget = m_visibleItems.value(index);
 447     if (widget) {
 448         contextRect = widget->iconRect() | widget->textRect();
 449         contextRect.translate(itemRect(index).topLeft());
 450     }
 451
 452     return contextRect;
 453 }
 454
 455 void KItemListView::scrollToItem(int index)
 456 {
 457     QRectF viewGeometry = geometry();
 458     if (m_header) {
 459         const qreal headerHeight = m_header->size().height();
 460         viewGeometry.adjust(0, headerHeight, 0, 0);
 461     }
 462     const QRectF currentRect = itemRect(index);
 463
 464     if (!viewGeometry.contains(currentRect)) {
 465         qreal newOffset = scrollOffset();
 466         if (currentRect.top() < viewGeometry.top()) {
 467             Q_ASSERT(scrollOrientation() == Qt::Vertical);
 468             newOffset += currentRect.top() - viewGeometry.top();
 469         } else if ((currentRect.bottom() > viewGeometry.bottom())) {
 470             Q_ASSERT(scrollOrientation() == Qt::Vertical);
 471             newOffset += currentRect.bottom() - viewGeometry.bottom();
 472         } else if (currentRect.left() < viewGeometry.left()) {
 473             if (scrollOrientation() == Qt::Horizontal) {
 474                 newOffset += currentRect.left() - viewGeometry.left();
 475             }
 476         } else if ((currentRect.right() > viewGeometry.right())) {
 477             if (scrollOrientation() == Qt::Horizontal) {
 478                 newOffset += currentRect.right() - viewGeometry.right();
 479             }
 480         }
 481
 482         if (newOffset != scrollOffset()) {
 483             emit scrollTo(newOffset);
 484         }
 485     }
 486 }
 487
 488 int KItemListView::itemsPerOffset() const
 489 {
 490     return m_layouter->itemsPerOffset();
 491 }
 492
 493 void KItemListView::beginTransaction()
 494 {
 495     ++m_activeTransactions;
 496     if (m_activeTransactions == 1) {
 497         onTransactionBegin();
 498     }
 499 }
 500
 501 void KItemListView::endTransaction()
 502 {
 503     --m_activeTransactions;
 504     if (m_activeTransactions < 0) {
 505         m_activeTransactions = 0;
 506         kWarning() << "Mismatch between beginTransaction()/endTransaction()";
 507     }
 508
 509     if (m_activeTransactions == 0) {
 510         onTransactionEnd();
 511         doLayout(Animation);
 512     }
 513 }
 514
 515 bool KItemListView::isTransactionActive() const
 516 {
 517     return m_activeTransactions > 0;
 518 }
 519
 520
 521 void KItemListView::setHeaderShown(bool show)
 522 {
 523
 524     if (show && !m_header) {
 525         m_header = new KItemListHeader(this);
 526         m_header->setPos(0, 0);
 527         m_header->setModel(m_model);
 528         m_header->setVisibleRoles(m_visibleRoles);
 529         m_header->setVisibleRolesWidths(headerRolesWidths());
 530         m_header->setZValue(1);
 531
 532         connect(m_header, SIGNAL(visibleRoleWidthChanged(QByteArray,qreal,qreal)),
 533                 this, SLOT(slotVisibleRoleWidthChanged(QByteArray,qreal,qreal)));
 534         connect(m_header, SIGNAL(sortOrderChanged(Qt::SortOrder,Qt::SortOrder)),
 535                 this, SIGNAL(sortOrderChanged(Qt::SortOrder,Qt::SortOrder)));
 536         connect(m_header, SIGNAL(sortRoleChanged(QByteArray,QByteArray)),
 537                 this, SIGNAL(sortRoleChanged(QByteArray,QByteArray)));
 538
 539         m_useHeaderWidths = false;
 540
 541         m_layouter->setHeaderHeight(m_header->size().height());
 542     } else if (!show && m_header) {
 543         delete m_header;
 544         m_header = 0;
 545         m_useHeaderWidths = false;
 546         m_layouter->setHeaderHeight(0);
 547     }
 548 }
 549
 550 bool KItemListView::isHeaderShown() const
 551 {
 552     return m_header != 0;
 553 }
 554
 555 QPixmap KItemListView::createDragPixmap(const QSet<int>& indexes) const
 556 {
 557     Q_UNUSED(indexes);
 558     return QPixmap();
 559 }
 560
 561 void KItemListView::paint(QPainter* painter, const QStyleOptionGraphicsItem* option, QWidget* widget)
 562 {
 563     QGraphicsWidget::paint(painter, option, widget);
 564
 565     if (m_rubberBand->isActive()) {
 566         QRectF rubberBandRect = QRectF(m_rubberBand->startPosition(),
 567                                        m_rubberBand->endPosition()).normalized();
 568
 569         const QPointF topLeft = rubberBandRect.topLeft();
 570         if (scrollOrientation() == Qt::Vertical) {
 571             rubberBandRect.moveTo(topLeft.x(), topLeft.y() - scrollOffset());
 572         } else {
 573             rubberBandRect.moveTo(topLeft.x() - scrollOffset(), topLeft.y());
 574         }
 575
 576         QStyleOptionRubberBand opt;
 577         opt.initFrom(widget);
 578         opt.shape = QRubberBand::Rectangle;
 579         opt.opaque = false;
 580         opt.rect = rubberBandRect.toRect();
 581         style()->drawControl(QStyle::CE_RubberBand, &opt, painter);
 582     }
 583 }
 584
 585 void KItemListView::initializeItemListWidget(KItemListWidget* item)
 586 {
 587     Q_UNUSED(item);
 588 }
 589
 590 bool KItemListView::itemSizeHintUpdateRequired(const QSet<QByteArray>& changedRoles) const
 591 {
 592     Q_UNUSED(changedRoles);
 593     return true;
 594 }
 595
 596 void KItemListView::onControllerChanged(KItemListController* current, KItemListController* previous)
 597 {
 598     Q_UNUSED(current);
 599     Q_UNUSED(previous);
 600 }
 601
 602 void KItemListView::onModelChanged(KItemModelBase* current, KItemModelBase* previous)
 603 {
 604     Q_UNUSED(current);
 605     Q_UNUSED(previous);
 606 }
 607
 608 void KItemListView::onScrollOrientationChanged(Qt::Orientation current, Qt::Orientation previous)
 609 {
 610     Q_UNUSED(current);
 611     Q_UNUSED(previous);
 612 }
 613
 614 void KItemListView::onItemSizeChanged(const QSizeF& current, const QSizeF& previous)
 615 {
 616     Q_UNUSED(current);
 617     Q_UNUSED(previous);
 618 }
 619
 620 void KItemListView::onScrollOffsetChanged(qreal current, qreal previous)
 621 {
 622     Q_UNUSED(current);
 623     Q_UNUSED(previous);
 624 }
 625
 626 void KItemListView::onVisibleRolesChanged(const QList<QByteArray>& current, const QList<QByteArray>& previous)
 627 {
 628     Q_UNUSED(current);
 629     Q_UNUSED(previous);
 630 }
 631
 632 void KItemListView::onStyleOptionChanged(const KItemListStyleOption& current, const KItemListStyleOption& previous)
 633 {
 634     Q_UNUSED(current);
 635     Q_UNUSED(previous);
 636 }
 637
 638 void KItemListView::onTransactionBegin()
 639 {
 640 }
 641
 642 void KItemListView::onTransactionEnd()
 643 {
 644 }
 645
 646 bool KItemListView::event(QEvent* event)
 647 {
 648     // Forward all events to the controller and handle them there
 649     if (m_controller && m_controller->processEvent(event, transform())) {
 650         event->accept();
 651         return true;
 652     }
 653     return QGraphicsWidget::event(event);
 654 }
 655
 656 void KItemListView::mousePressEvent(QGraphicsSceneMouseEvent* event)
 657 {
 658     m_mousePos = transform().map(event->pos());
 659     event->accept();
 660 }
 661
 662 void KItemListView::mouseMoveEvent(QGraphicsSceneMouseEvent* event)
 663 {
 664     QGraphicsWidget::mouseMoveEvent(event);
 665
 666     m_mousePos = transform().map(event->pos());
 667     if (m_autoScrollTimer && !m_autoScrollTimer->isActive()) {
 668         m_autoScrollTimer->start(InitialAutoScrollDelay);
 669     }
 670 }
 671
 672 void KItemListView::dragEnterEvent(QGraphicsSceneDragDropEvent* event)
 673 {
 674     event->setAccepted(true);
 675     setAutoScroll(true);
 676 }
 677
 678 void KItemListView::dragMoveEvent(QGraphicsSceneDragDropEvent *event)
 679 {
 680     QGraphicsWidget::dragMoveEvent(event);
 681
 682     m_mousePos = transform().map(event->pos());
 683     if (m_autoScrollTimer && !m_autoScrollTimer->isActive()) {
 684         m_autoScrollTimer->start(InitialAutoScrollDelay);
 685     }
 686 }
 687
 688 void KItemListView::dragLeaveEvent(QGraphicsSceneDragDropEvent *event)
 689 {
 690     QGraphicsWidget::dragLeaveEvent(event);
 691     setAutoScroll(false);
 692 }
 693
 694 void KItemListView::dropEvent(QGraphicsSceneDragDropEvent* event)
 695 {
 696     QGraphicsWidget::dropEvent(event);
 697     setAutoScroll(false);
 698 }
 699
 700 QList<KItemListWidget*> KItemListView::visibleItemListWidgets() const
 701 {
 702     return m_visibleItems.values();
 703 }
 704
 705 void KItemListView::resizeEvent(QGraphicsSceneResizeEvent* event)
 706 {
 707     QGraphicsWidget::resizeEvent(event);
 708     if (m_itemSize.isEmpty() && m_useHeaderWidths) {
 709         QSizeF dynamicItemSize = m_layouter->itemSize();
 710         const QSizeF newSize = event->newSize();
 711
 712         if (m_itemSize.width() < 0) {
 713             const qreal requiredWidth = visibleRolesSizesWidthSum();
 714             if (newSize.width() > requiredWidth) {
 715                 dynamicItemSize.setWidth(newSize.width());
 716             }
 717             const qreal headerWidth = qMax(newSize.width(), requiredWidth);
 718             m_header->resize(headerWidth, m_header->size().height());
 719         }
 720
 721         if (m_itemSize.height() < 0) {
 722             const qreal requiredHeight = visibleRolesSizesHeightSum();
 723             if (newSize.height() > requiredHeight) {
 724                 dynamicItemSize.setHeight(newSize.height());
 725             }
 726             // TODO: KItemListHeader is not prepared for vertical alignment
 727         }
 728
 729         m_layouter->setItemSize(dynamicItemSize);
 730     }
 731 }
 732
 733 void KItemListView::slotItemsInserted(const KItemRangeList& itemRanges)
 734 {
 735     updateVisibleRolesSizes(itemRanges);
 736
 737     const bool hasMultipleRanges = (itemRanges.count() > 1);
 738     if (hasMultipleRanges) {
 739         beginTransaction();
 740     }
 741
 742     int previouslyInsertedCount = 0;
 743     foreach (const KItemRange& range, itemRanges) {
 744         // range.index is related to the model before anything has been inserted.
 745         // As in each loop the current item-range gets inserted the index must
 746         // be increased by the already previously inserted items.
 747         const int index = range.index + previouslyInsertedCount;
 748         const int count = range.count;
 749         if (index < 0 || count <= 0) {
 750             kWarning() << "Invalid item range (index:" << index << ", count:" << count << ")";
 751             continue;
 752         }
 753         previouslyInsertedCount += count;
 754
 755         m_sizeHintResolver->itemsInserted(index, count);
 756
 757         // Determine which visible items must be moved
 758         QList<int> itemsToMove;
 759         QHashIterator<int, KItemListWidget*> it(m_visibleItems);
 760         while (it.hasNext()) {
 761             it.next();
 762             const int visibleItemIndex = it.key();
 763             if (visibleItemIndex >= index) {
 764                 itemsToMove.append(visibleItemIndex);
 765             }
 766         }
 767
 768         // Update the indexes of all KItemListWidget instances that are located
 769         // after the inserted items. It is important to adjust the indexes in the order
 770         // from the highest index to the lowest index to prevent overlaps when setting the new index.
 771         qSort(itemsToMove);
 772         for (int i = itemsToMove.count() - 1; i >= 0; --i) {
 773             KItemListWidget* widget = m_visibleItems.value(itemsToMove[i]);
 774             Q_ASSERT(widget);
 775             setWidgetIndex(widget, widget->index() + count);
 776         }
 777
 778         m_layouter->markAsDirty();
 779         if (m_model->count() == count && maximumScrollOffset() > size().height()) {
 780             const int scrollBarExtent = style()->pixelMetric(QStyle::PM_ScrollBarExtent);
 781             QSizeF layouterSize = m_layouter->size();
 782             if (scrollOrientation() == Qt::Vertical) {
 783                 layouterSize.rwidth() -= scrollBarExtent;
 784             } else {
 785                 layouterSize.rheight() -= scrollBarExtent;
 786             }
 787             m_layouter->setSize(layouterSize);
 788         }
 789
 790         if (!hasMultipleRanges) {
 791             doLayout(Animation, index, count);
 792         }
 793     }
 794
 795     if (m_controller) {
 796         m_controller->selectionManager()->itemsInserted(itemRanges);
 797     }
 798
 799     if (hasMultipleRanges) {
 800         endTransaction();
 801     }
 802 }
 803
 804 void KItemListView::slotItemsRemoved(const KItemRangeList& itemRanges)
 805 {
 806     updateVisibleRolesSizes();
 807
 808     const bool hasMultipleRanges = (itemRanges.count() > 1);
 809     if (hasMultipleRanges) {
 810         beginTransaction();
 811     }
 812
 813     for (int i = itemRanges.count() - 1; i >= 0; --i) {
 814         const KItemRange& range = itemRanges.at(i);
 815         const int index = range.index;
 816         const int count = range.count;
 817         if (index < 0 || count <= 0) {
 818             kWarning() << "Invalid item range (index:" << index << ", count:" << count << ")";
 819             continue;
 820         }
 821
 822         m_sizeHintResolver->itemsRemoved(index, count);
 823
 824         const int firstRemovedIndex = index;
 825         const int lastRemovedIndex = index + count - 1;
 826         const int lastIndex = m_model->count() + count - 1;
 827
 828         // Remove all KItemListWidget instances that got deleted
 829         for (int i = firstRemovedIndex; i <= lastRemovedIndex; ++i) {
 830             KItemListWidget* widget = m_visibleItems.value(i);
 831             if (!widget) {
 832                 continue;
 833             }
 834
 835             m_animation->stop(widget);
 836             // Stopping the animation might lead to recycling the widget if
 837             // it is invisible (see slotAnimationFinished()).
 838             // Check again whether it is still visible:
 839             if (!m_visibleItems.contains(i)) {
 840                 continue;
 841             }
 842
 843             if (m_model->count() == 0) {
 844                 // For performance reasons no animation is done when all items have
 845                 // been removed.
 846                 recycleWidget(widget);
 847             } else {
 848                 // Animate the removing of the items. Special case: When removing an item there
 849                 // is no valid model index available anymore. For the
 850                 // remove-animation the item gets removed from m_visibleItems but the widget
 851                 // will stay alive until the animation has been finished and will
 852                 // be recycled (deleted) in KItemListView::slotAnimationFinished().
 853                 m_visibleItems.remove(i);
 854                 widget->setIndex(-1);
 855                 m_animation->start(widget, KItemListViewAnimation::DeleteAnimation);
 856             }
 857         }
 858
 859         // Update the indexes of all KItemListWidget instances that are located
 860         // after the deleted items
 861         for (int i = lastRemovedIndex + 1; i <= lastIndex; ++i) {
 862             KItemListWidget* widget = m_visibleItems.value(i);
 863             if (widget) {
 864                 const int newIndex = i - count;
 865                 setWidgetIndex(widget, newIndex);
 866             }
 867         }
 868
 869         m_layouter->markAsDirty();
 870         if (!hasMultipleRanges) {
 871             doLayout(Animation, index, -count);
 872         }
 873     }
 874
 875     if (m_controller) {
 876         m_controller->selectionManager()->itemsRemoved(itemRanges);
 877     }
 878
 879     if (hasMultipleRanges) {
 880         endTransaction();
 881     }
 882 }
 883
 884 void KItemListView::slotItemsMoved(const KItemRange& itemRange, const QList<int>& movedToIndexes)
 885 {
 886     m_sizeHintResolver->itemsMoved(itemRange.index, itemRange.count);
 887     m_layouter->markAsDirty();
 888
 889     if (m_controller) {
 890         m_controller->selectionManager()->itemsMoved(itemRange, movedToIndexes);
 891     }
 892
 893     const int firstVisibleMovedIndex = qMax(firstVisibleIndex(), itemRange.index);
 894     const int lastVisibleMovedIndex = qMin(lastVisibleIndex(), itemRange.index + itemRange.count - 1);
 895
 896     for (int index = firstVisibleMovedIndex; index <= lastVisibleMovedIndex; ++index) {
 897         KItemListWidget* widget = m_visibleItems.value(index);
 898         if (widget) {
 899             updateWidgetProperties(widget, index);
 900             if (m_grouped) {
 901                 updateGroupHeaderForWidget(widget);
 902             }
 903             initializeItemListWidget(widget);
 904         }
 905     }
 906
 907     doLayout(NoAnimation);
 908 }
 909
 910 void KItemListView::slotItemsChanged(const KItemRangeList& itemRanges,
 911                                      const QSet<QByteArray>& roles)
 912 {
 913     const bool updateSizeHints = itemSizeHintUpdateRequired(roles);
 914     if (updateSizeHints) {
 915         updateVisibleRolesSizes(itemRanges);
 916     }
 917
 918     foreach (const KItemRange& itemRange, itemRanges) {
 919         const int index = itemRange.index;
 920         const int count = itemRange.count;
 921
 922         if (updateSizeHints) {
 923             m_sizeHintResolver->itemsChanged(index, count, roles);
 924             m_layouter->markAsDirty();
 925
 926             if (!m_layoutTimer->isActive()) {
 927                 m_layoutTimer->start();
 928             }
 929         }
 930
 931         // Apply the changed roles to the visible item-widgets
 932         const int lastIndex = index + count - 1;
 933         for (int i = index; i <= lastIndex; ++i) {
 934             KItemListWidget* widget = m_visibleItems.value(i);
 935             if (widget) {
 936                 widget->setData(m_model->data(i), roles);
 937             }
 938         }
 939
 940         if (m_grouped && roles.contains(m_model->sortRole())) {
 941             // The sort-role has been changed which might result
 942             // in modified group headers
 943             updateVisibleGroupHeaders();
 944             doLayout(NoAnimation);
 945         }
 946     }
 947 }
 948
 949 void KItemListView::slotGroupedSortingChanged(bool current)
 950 {
 951     m_grouped = current;
 952     m_layouter->markAsDirty();
 953
 954     if (m_grouped) {
 955         // Apply the height of the header to the layouter
 956         const qreal groupHeaderHeight = m_styleOption.fontMetrics.height() +
 957                                         m_styleOption.margin * 2;
 958         m_layouter->setGroupHeaderHeight(groupHeaderHeight);
 959
 960         updateVisibleGroupHeaders();
 961     } else {
 962         // Clear all visible headers
 963         QMutableHashIterator<KItemListWidget*, KItemListGroupHeader*> it (m_visibleGroups);
 964         while (it.hasNext()) {
 965             it.next();
 966             recycleGroupHeaderForWidget(it.key());
 967         }
 968         Q_ASSERT(m_visibleGroups.isEmpty());
 969     }
 970
 971     doLayout(Animation);
 972 }
 973
 974 void KItemListView::slotSortOrderChanged(Qt::SortOrder current, Qt::SortOrder previous)
 975 {
 976     Q_UNUSED(current);
 977     Q_UNUSED(previous);
 978     if (m_grouped) {
 979         updateVisibleGroupHeaders();
 980         doLayout(Animation);
 981     }
 982 }
 983
 984 void KItemListView::slotSortRoleChanged(const QByteArray& current, const QByteArray& previous)
 985 {
 986     Q_UNUSED(current);
 987     Q_UNUSED(previous);
 988     if (m_grouped) {
 989         updateVisibleGroupHeaders();
 990         doLayout(Animation);
 991     }
 992 }
 993
 994 void KItemListView::slotCurrentChanged(int current, int previous)
 995 {
 996     Q_UNUSED(previous);
 997
 998     KItemListWidget* previousWidget = m_visibleItems.value(previous, 0);
 999     if (previousWidget) {
1000         Q_ASSERT(previousWidget->isCurrent());
1001         previousWidget->setCurrent(false);
1002     }
1003
1004     KItemListWidget* currentWidget = m_visibleItems.value(current, 0);
1005     if (currentWidget) {
1006         Q_ASSERT(!currentWidget->isCurrent());
1007         currentWidget->setCurrent(true);
1008     }
1009 }
1010
1011 void KItemListView::slotSelectionChanged(const QSet<int>& current, const QSet<int>& previous)
1012 {
1013     Q_UNUSED(previous);
1014
1015     QHashIterator<int, KItemListWidget*> it(m_visibleItems);
1016     while (it.hasNext()) {
1017         it.next();
1018         const int index = it.key();
1019         KItemListWidget* widget = it.value();
1020         widget->setSelected(current.contains(index));
1021     }
1022 }
1023
1024 void KItemListView::slotAnimationFinished(QGraphicsWidget* widget,
1025                                           KItemListViewAnimation::AnimationType type)
1026 {
1027     KItemListWidget* itemListWidget = qobject_cast<KItemListWidget*>(widget);
1028     Q_ASSERT(itemListWidget);
1029
1030     switch (type) {
1031     case KItemListViewAnimation::DeleteAnimation: {
1032         // As we recycle the widget in this case it is important to assure that no
1033         // other animation has been started. This is a convention in KItemListView and
1034         // not a requirement defined by KItemListViewAnimation.
1035         Q_ASSERT(!m_animation->isStarted(itemListWidget));
1036
1037         // All KItemListWidgets that are animated by the DeleteAnimation are not maintained
1038         // by m_visibleWidgets and must be deleted manually after the animation has
1039         // been finished.
1040         recycleGroupHeaderForWidget(itemListWidget);
1041         m_widgetCreator->recycle(itemListWidget);
1042         break;
1043     }
1044
1045     case KItemListViewAnimation::CreateAnimation:
1046     case KItemListViewAnimation::MovingAnimation:
1047     case KItemListViewAnimation::ResizeAnimation: {
1048         const int index = itemListWidget->index();
1049         const bool invisible = (index < m_layouter->firstVisibleIndex()) ||
1050                                (index > m_layouter->lastVisibleIndex());
1051         if (invisible && !m_animation->isStarted(itemListWidget)) {
1052             recycleWidget(itemListWidget);
1053         }
1054         break;
1055     }
1056
1057     default: break;
1058     }
1059 }
1060
1061 void KItemListView::slotLayoutTimerFinished()
1062 {
1063     m_layouter->setSize(geometry().size());
1064     doLayout(Animation);
1065 }
1066
1067 void KItemListView::slotRubberBandPosChanged()
1068 {
1069     update();
1070 }
1071
1072 void KItemListView::slotRubberBandActivationChanged(bool active)
1073 {
1074     if (active) {
1075         connect(m_rubberBand, SIGNAL(startPositionChanged(QPointF,QPointF)), this, SLOT(slotRubberBandPosChanged()));
1076         connect(m_rubberBand, SIGNAL(endPositionChanged(QPointF,QPointF)), this, SLOT(slotRubberBandPosChanged()));
1077         m_skipAutoScrollForRubberBand = true;
1078     } else {
1079         disconnect(m_rubberBand, SIGNAL(startPositionChanged(QPointF,QPointF)), this, SLOT(slotRubberBandPosChanged()));
1080         disconnect(m_rubberBand, SIGNAL(endPositionChanged(QPointF,QPointF)), this, SLOT(slotRubberBandPosChanged()));
1081         m_skipAutoScrollForRubberBand = false;
1082     }
1083
1084     update();
1085 }
1086
1087 void KItemListView::slotVisibleRoleWidthChanged(const QByteArray& role,
1088                                                 qreal currentWidth,
1089                                                 qreal previousWidth)
1090 {
1091     Q_UNUSED(previousWidth);
1092
1093     m_useHeaderWidths = true;
1094
1095     if (m_visibleRolesSizes.contains(role)) {
1096         QSizeF roleSize = m_visibleRolesSizes.value(role);
1097         roleSize.setWidth(currentWidth);
1098         m_visibleRolesSizes.insert(role, roleSize);
1099         m_stretchedVisibleRolesSizes.insert(role, roleSize);
1100
1101         // Apply the new size to the layouter
1102         QSizeF dynamicItemSize = m_itemSize;
1103         if (dynamicItemSize.width() < 0) {
1104             const qreal requiredWidth = visibleRolesSizesWidthSum();
1105             dynamicItemSize.setWidth(qMax(size().width(), requiredWidth));
1106         }
1107         if (dynamicItemSize.height() < 0) {
1108             const qreal requiredHeight = visibleRolesSizesHeightSum();
1109             dynamicItemSize.setHeight(qMax(size().height(), requiredHeight));
1110         }
1111
1112         m_layouter->setItemSize(dynamicItemSize);
1113
1114         // Update the role sizes for all visible widgets
1115         foreach (KItemListWidget* widget, visibleItemListWidgets()) {
1116             widget->setVisibleRolesSizes(m_stretchedVisibleRolesSizes);
1117         }
1118
1119         doLayout(Animation);
1120     }
1121 }
1122
1123 void KItemListView::triggerAutoScrolling()
1124 {
1125     if (!m_autoScrollTimer) {
1126         return;
1127     }
1128
1129     int pos = 0;
1130     int visibleSize = 0;
1131     if (scrollOrientation() == Qt::Vertical) {
1132         pos = m_mousePos.y();
1133         visibleSize = size().height();
1134     } else {
1135         pos = m_mousePos.x();
1136         visibleSize = size().width();
1137     }
1138
1139     if (m_autoScrollTimer->interval() == InitialAutoScrollDelay) {
1140         m_autoScrollIncrement = 0;
1141     }
1142
1143     m_autoScrollIncrement = calculateAutoScrollingIncrement(pos, visibleSize, m_autoScrollIncrement);
1144     if (m_autoScrollIncrement == 0) {
1145         // The mouse position is not above an autoscroll margin (the autoscroll timer
1146         // will be restarted in mouseMoveEvent())
1147         m_autoScrollTimer->stop();
1148         return;
1149     }
1150
1151     if (m_rubberBand->isActive() && m_skipAutoScrollForRubberBand) {
1152         // If a rubberband selection is ongoing the autoscrolling may only get triggered
1153         // if the direction of the rubberband is similar to the autoscroll direction. This
1154         // prevents that starting to create a rubberband within the autoscroll margins starts
1155         // an autoscrolling.
1156
1157         const qreal minDiff = 4; // Ignore any autoscrolling if the rubberband is very small
1158         const qreal diff = (scrollOrientation() == Qt::Vertical)
1159                            ? m_rubberBand->endPosition().y() - m_rubberBand->startPosition().y()
1160                            : m_rubberBand->endPosition().x() - m_rubberBand->startPosition().x();
1161         if (qAbs(diff) < minDiff || (m_autoScrollIncrement < 0 && diff > 0) || (m_autoScrollIncrement > 0 && diff < 0)) {
1162             // The rubberband direction is different from the scroll direction (e.g. the rubberband has
1163             // been moved up although the autoscroll direction might be down)
1164             m_autoScrollTimer->stop();
1165             return;
1166         }
1167     }
1168
1169     // As soon as the autoscrolling has been triggered at least once despite having an active rubberband,
1170     // the autoscrolling may not get skipped anymore until a new rubberband is created
1171     m_skipAutoScrollForRubberBand = false;
1172
1173     setScrollOffset(scrollOffset() + m_autoScrollIncrement);
1174
1175    // Trigger the autoscroll timer which will periodically call
1176    // triggerAutoScrolling()
1177    m_autoScrollTimer->start(RepeatingAutoScrollDelay);
1178 }
1179
1180 void KItemListView::setController(KItemListController* controller)
1181 {
1182     if (m_controller != controller) {
1183         KItemListController* previous = m_controller;
1184         if (previous) {
1185             KItemListSelectionManager* selectionManager = previous->selectionManager();
1186             disconnect(selectionManager, SIGNAL(currentChanged(int,int)), this, SLOT(slotCurrentChanged(int,int)));
1187             disconnect(selectionManager, SIGNAL(selectionChanged(QSet<int>,QSet<int>)), this, SLOT(slotSelectionChanged(QSet<int>,QSet<int>)));
1188         }
1189
1190         m_controller = controller;
1191
1192         if (controller) {
1193             KItemListSelectionManager* selectionManager = controller->selectionManager();
1194             connect(selectionManager, SIGNAL(currentChanged(int,int)), this, SLOT(slotCurrentChanged(int,int)));
1195             connect(selectionManager, SIGNAL(selectionChanged(QSet<int>,QSet<int>)), this, SLOT(slotSelectionChanged(QSet<int>,QSet<int>)));
1196         }
1197
1198         onControllerChanged(controller, previous);
1199     }
1200 }
1201
1202 void KItemListView::setModel(KItemModelBase* model)
1203 {
1204     if (m_model == model) {
1205         return;
1206     }
1207
1208     KItemModelBase* previous = m_model;
1209
1210     if (m_model) {
1211         disconnect(m_model, SIGNAL(itemsChanged(KItemRangeList,QSet<QByteArray>)),
1212                    this,    SLOT(slotItemsChanged(KItemRangeList,QSet<QByteArray>)));
1213         disconnect(m_model, SIGNAL(itemsInserted(KItemRangeList)),
1214                    this,    SLOT(slotItemsInserted(KItemRangeList)));
1215         disconnect(m_model, SIGNAL(itemsRemoved(KItemRangeList)),
1216                    this,    SLOT(slotItemsRemoved(KItemRangeList)));
1217         disconnect(m_model, SIGNAL(itemsMoved(KItemRange,QList<int>)),
1218                    this,    SLOT(slotItemsMoved(KItemRange,QList<int>)));
1219         disconnect(m_model, SIGNAL(groupedSortingChanged(bool)),
1220                    this,    SLOT(slotGroupedSortingChanged(bool)));
1221         disconnect(m_model, SIGNAL(sortOrderChanged(Qt::SortOrder,Qt::SortOrder)),
1222                    this,    SLOT(slotSortOrderChanged(Qt::SortOrder,Qt::SortOrder)));
1223         disconnect(m_model, SIGNAL(sortRoleChanged(QByteArray,QByteArray)),
1224                    this,    SLOT(slotSortRoleChanged(QByteArray,QByteArray)));
1225     }
1226
1227     m_model = model;
1228     m_layouter->setModel(model);
1229     m_grouped = model->groupedSorting();
1230
1231     if (m_model) {
1232         connect(m_model, SIGNAL(itemsChanged(KItemRangeList,QSet<QByteArray>)),
1233                 this,    SLOT(slotItemsChanged(KItemRangeList,QSet<QByteArray>)));
1234         connect(m_model, SIGNAL(itemsInserted(KItemRangeList)),
1235                 this,    SLOT(slotItemsInserted(KItemRangeList)));
1236         connect(m_model, SIGNAL(itemsRemoved(KItemRangeList)),
1237                 this,    SLOT(slotItemsRemoved(KItemRangeList)));
1238         connect(m_model, SIGNAL(itemsMoved(KItemRange,QList<int>)),
1239                 this,    SLOT(slotItemsMoved(KItemRange,QList<int>)));
1240         connect(m_model, SIGNAL(groupedSortingChanged(bool)),
1241                 this,    SLOT(slotGroupedSortingChanged(bool)));
1242         connect(m_model, SIGNAL(sortOrderChanged(Qt::SortOrder,Qt::SortOrder)),
1243                 this,    SLOT(slotSortOrderChanged(Qt::SortOrder,Qt::SortOrder)));
1244         connect(m_model, SIGNAL(sortRoleChanged(QByteArray,QByteArray)),
1245                 this,    SLOT(slotSortRoleChanged(QByteArray,QByteArray)));
1246     }
1247
1248     onModelChanged(model, previous);
1249 }
1250
1251 KItemListRubberBand* KItemListView::rubberBand() const
1252 {
1253     return m_rubberBand;
1254 }
1255
1256 void KItemListView::doLayout(LayoutAnimationHint hint, int changedIndex, int changedCount)
1257 {
1258     if (m_layoutTimer->isActive()) {
1259         m_layoutTimer->stop();
1260     }
1261
1262     if (!m_model || m_model->count() < 0 || m_activeTransactions > 0) {
1263         return;
1264     }
1265
1266     const int firstVisibleIndex = m_layouter->firstVisibleIndex();
1267     const int lastVisibleIndex = m_layouter->lastVisibleIndex();
1268     if (firstVisibleIndex < 0) {
1269         emitOffsetChanges();
1270         return;
1271     }
1272
1273     // Do a sanity check of the scroll-offset property: When properties of the itemlist-view have been changed
1274     // it might be possible that the maximum offset got changed too. Assure that the full visible range
1275     // is still shown if the maximum offset got decreased.
1276     const qreal visibleOffsetRange = (scrollOrientation() == Qt::Horizontal) ? size().width() : size().height();
1277     const qreal maxOffsetToShowFullRange = maximumScrollOffset() - visibleOffsetRange;
1278     if (scrollOffset() > maxOffsetToShowFullRange) {
1279         m_layouter->setScrollOffset(qMax(qreal(0), maxOffsetToShowFullRange));
1280     }
1281
1282     // Determine all items that are completely invisible and might be
1283     // reused for items that just got (at least partly) visible.
1284     // Items that do e.g. an animated moving of their position are not
1285     // marked as invisible: This assures that a scrolling inside the view
1286     // can be done without breaking an animation.
1287     QList<int> reusableItems;
1288     QHashIterator<int, KItemListWidget*> it(m_visibleItems);
1289     while (it.hasNext()) {
1290         it.next();
1291         KItemListWidget* widget = it.value();
1292         const int index = widget->index();
1293         const bool invisible = (index < firstVisibleIndex) || (index > lastVisibleIndex);
1294         if (invisible && !m_animation->isStarted(widget)) {
1295             widget->setVisible(false);
1296             reusableItems.append(index);
1297
1298             if (m_grouped) {
1299                 recycleGroupHeaderForWidget(widget);
1300             }
1301         }
1302     }
1303
1304     // Assure that for each visible item a KItemListWidget is available. KItemListWidget
1305     // instances from invisible items are reused. If no reusable items are
1306     // found then new KItemListWidget instances get created.
1307     const bool animate = (hint == Animation);
1308     for (int i = firstVisibleIndex; i <= lastVisibleIndex; ++i) {
1309         bool applyNewPos = true;
1310         bool wasHidden = false;
1311
1312         const QRectF itemBounds = m_layouter->itemRect(i);
1313         const QPointF newPos = itemBounds.topLeft();
1314         KItemListWidget* widget = m_visibleItems.value(i);
1315         if (!widget) {
1316             wasHidden = true;
1317             if (!reusableItems.isEmpty()) {
1318                 // Reuse a KItemListWidget instance from an invisible item
1319                 const int oldIndex = reusableItems.takeLast();
1320                 widget = m_visibleItems.value(oldIndex);
1321                 setWidgetIndex(widget, i);
1322
1323                 if (m_grouped) {
1324                     updateGroupHeaderForWidget(widget);
1325                 }
1326             } else {
1327                 // No reusable KItemListWidget instance is available, create a new one
1328                 widget = createWidget(i);
1329             }
1330             widget->resize(itemBounds.size());
1331
1332             if (animate && changedCount < 0) {
1333                 // Items have been deleted, move the created item to the
1334                 // imaginary old position. They will get animated to the new position
1335                 // later.
1336                 const QRectF itemRect = m_layouter->itemRect(i - changedCount);
1337                 if (itemRect.isEmpty()) {
1338                     const QPointF invisibleOldPos = (scrollOrientation() == Qt::Vertical)
1339                                                     ? QPointF(0, size().height()) : QPointF(size().width(), 0);
1340                     widget->setPos(invisibleOldPos);
1341                 } else {
1342                     widget->setPos(itemRect.topLeft());
1343                 }
1344                 applyNewPos = false;
1345             }
1346         } else if (m_animation->isStarted(widget, KItemListViewAnimation::MovingAnimation)) {
1347             applyNewPos = false;
1348         }
1349
1350         if (animate) {
1351             const bool itemsRemoved = (changedCount < 0);
1352             const bool itemsInserted = (changedCount > 0);
1353             if (itemsRemoved && (i >= changedIndex + changedCount + 1)) {
1354                 // The item is located after the removed items. Animate the moving of the position.
1355                 m_animation->start(widget, KItemListViewAnimation::MovingAnimation, newPos);
1356                 applyNewPos = false;
1357             } else if (itemsInserted && i >= changedIndex) {
1358                 // The item is located after the first inserted item
1359                 if (i <= changedIndex + changedCount - 1) {
1360                     // The item is an inserted item. Animate the appearing of the item.
1361                     // For performance reasons no animation is done when changedCount is equal
1362                     // to all available items.
1363                     if (changedCount < m_model->count()) {
1364                         m_animation->start(widget, KItemListViewAnimation::CreateAnimation);
1365                     }
1366                 } else if (!m_animation->isStarted(widget, KItemListViewAnimation::CreateAnimation)) {
1367                     // The item was already there before, so animate the moving of the position.
1368                     // No moving animation is done if the item is animated by a create animation: This
1369                     // prevents a "move animation mess" when inserting several ranges in parallel.
1370                     m_animation->start(widget, KItemListViewAnimation::MovingAnimation, newPos);
1371                     applyNewPos = false;
1372                 }
1373             } else if (!itemsRemoved && !itemsInserted && !wasHidden) {
1374                 // The size of the view might have been changed. Animate the moving of the position.
1375                 m_animation->start(widget, KItemListViewAnimation::MovingAnimation, newPos);
1376                 applyNewPos = false;
1377             }
1378         }
1379
1380         if (applyNewPos) {
1381             widget->setPos(newPos);
1382         }
1383
1384         Q_ASSERT(widget->index() == i);
1385         widget->setVisible(true);
1386
1387         if (widget->size() != itemBounds.size()) {
1388             if (animate) {
1389                 m_animation->start(widget, KItemListViewAnimation::ResizeAnimation, itemBounds.size());
1390             } else {
1391                 widget->resize(itemBounds.size());
1392             }
1393         }
1394     }
1395
1396     // Delete invisible KItemListWidget instances that have not been reused
1397     foreach (int index, reusableItems) {
1398         recycleWidget(m_visibleItems.value(index));
1399     }
1400
1401     if (m_grouped) {
1402         // Update the layout of all visible group headers
1403         QHashIterator<KItemListWidget*, KItemListGroupHeader*> it(m_visibleGroups);
1404         while (it.hasNext()) {
1405             it.next();
1406             updateGroupHeaderLayout(it.key());
1407         }
1408     }
1409
1410     emitOffsetChanges();
1411 }
1412
1413 void KItemListView::emitOffsetChanges()
1414 {
1415     const qreal newScrollOffset = m_layouter->scrollOffset();
1416     if (m_oldScrollOffset != newScrollOffset) {
1417         emit scrollOffsetChanged(newScrollOffset, m_oldScrollOffset);
1418         m_oldScrollOffset = newScrollOffset;
1419     }
1420
1421     const qreal newMaximumScrollOffset = m_layouter->maximumScrollOffset();
1422     if (m_oldMaximumScrollOffset != newMaximumScrollOffset) {
1423         emit maximumScrollOffsetChanged(newMaximumScrollOffset, m_oldMaximumScrollOffset);
1424         m_oldMaximumScrollOffset = newMaximumScrollOffset;
1425     }
1426
1427     const qreal newItemOffset = m_layouter->itemOffset();
1428     if (m_oldItemOffset != newItemOffset) {
1429         emit itemOffsetChanged(newItemOffset, m_oldItemOffset);
1430         m_oldItemOffset = newItemOffset;
1431     }
1432
1433     const qreal newMaximumItemOffset = m_layouter->maximumItemOffset();
1434     if (m_oldMaximumItemOffset != newMaximumItemOffset) {
1435         emit maximumItemOffsetChanged(newMaximumItemOffset, m_oldMaximumItemOffset);
1436         m_oldMaximumItemOffset = newMaximumItemOffset;
1437     }
1438 }
1439
1440 KItemListWidget* KItemListView::createWidget(int index)
1441 {
1442     KItemListWidget* widget = m_widgetCreator->create(this);
1443     widget->setFlag(QGraphicsItem::ItemStacksBehindParent);
1444
1445     updateWidgetProperties(widget, index);
1446     m_visibleItems.insert(index, widget);
1447
1448     if (m_grouped) {
1449         updateGroupHeaderForWidget(widget);
1450     }
1451
1452     initializeItemListWidget(widget);
1453     return widget;
1454 }
1455
1456 void KItemListView::recycleWidget(KItemListWidget* widget)
1457 {
1458     if (m_grouped) {
1459         recycleGroupHeaderForWidget(widget);
1460     }
1461
1462     m_visibleItems.remove(widget->index());
1463     m_widgetCreator->recycle(widget);
1464 }
1465
1466 void KItemListView::setWidgetIndex(KItemListWidget* widget, int index)
1467 {
1468     const int oldIndex = widget->index();
1469     m_visibleItems.remove(oldIndex);
1470     updateWidgetProperties(widget, index);
1471     m_visibleItems.insert(index, widget);
1472
1473     initializeItemListWidget(widget);
1474 }
1475
1476 void KItemListView::prepareLayoutForIncreasedItemCount(const QSizeF& size, SizeType sizeType)
1477 {
1478     // Calculate the first visible index and last visible index for the current size
1479     const int currentFirst = m_layouter->firstVisibleIndex();
1480     const int currentLast = m_layouter->lastVisibleIndex();
1481
1482     const QSizeF currentSize = (sizeType == LayouterSize) ? m_layouter->size() : m_layouter->itemSize();
1483
1484     // Calculate the first visible index and last visible index for the new size
1485     setLayouterSize(size, sizeType);
1486     const int newFirst = m_layouter->firstVisibleIndex();
1487     const int newLast = m_layouter->lastVisibleIndex();
1488
1489     if ((currentFirst != newFirst) || (currentLast != newLast)) {
1490         // At least one index has been changed. Assure that widgets for all possible
1491         // visible items get created so that a move-animation can be started later.
1492         const int maxVisibleItems = m_layouter->maximumVisibleItems();
1493         int minFirst = qMin(newFirst, currentFirst);
1494         const int maxLast = qMax(newLast, currentLast);
1495
1496         if (maxLast - minFirst + 1 < maxVisibleItems) {
1497             // Increasing the size might result in a smaller KItemListView::offset().
1498             // Decrease the first visible index in a way that at least the maximum
1499             // visible items are shown.
1500             minFirst = qMax(0, maxLast - maxVisibleItems + 1);
1501         }
1502
1503         if (maxLast - minFirst > maxVisibleItems  + maxVisibleItems / 2) {
1504             // The creating of widgets is quite expensive. Assure that never more
1505             // than 50 % of the maximum visible items get created for the animations.
1506             return;
1507         }
1508
1509         setLayouterSize(currentSize, sizeType);
1510         for (int i = minFirst; i <= maxLast; ++i) {
1511             if (!m_visibleItems.contains(i)) {
1512                 KItemListWidget* widget = createWidget(i);
1513                 const QRectF itemRect = m_layouter->itemRect(i);
1514                 widget->setPos(itemRect.topLeft());
1515                 widget->resize(itemRect.size());
1516             }
1517         }
1518         setLayouterSize(size, sizeType);
1519     }
1520 }
1521
1522 void KItemListView::setLayouterSize(const QSizeF& size, SizeType sizeType)
1523 {
1524     switch (sizeType) {
1525     case LayouterSize: m_layouter->setSize(size); break;
1526     case ItemSize: m_layouter->setItemSize(size); break;
1527     default: break;
1528     }
1529 }
1530
1531 void KItemListView::updateWidgetProperties(KItemListWidget* widget, int index)
1532 {
1533     widget->setVisibleRoles(m_visibleRoles);
1534     widget->setVisibleRolesSizes(m_stretchedVisibleRolesSizes);
1535     widget->setStyleOption(m_styleOption);
1536
1537     const KItemListSelectionManager* selectionManager = m_controller->selectionManager();
1538     widget->setCurrent(index == selectionManager->currentItem());
1539     widget->setSelected(selectionManager->isSelected(index));
1540     widget->setHovered(false);
1541     widget->setAlternatingBackgroundColors(false);
1542     widget->setEnabledSelectionToggle(enabledSelectionToggles());
1543     widget->setIndex(index);
1544     widget->setData(m_model->data(index));
1545 }
1546
1547 void KItemListView::updateGroupHeaderForWidget(KItemListWidget* widget)
1548 {
1549     Q_ASSERT(m_grouped);
1550
1551     const int index = widget->index();
1552     if (!m_layouter->isFirstGroupItem(index)) {
1553         // The widget does not represent the first item of a group
1554         // and hence requires no header
1555         recycleGroupHeaderForWidget(widget);
1556         return;
1557     }
1558
1559     const QList<QPair<int, QVariant> > groups = model()->groups();
1560     if (groups.isEmpty()) {
1561         return;
1562     }
1563
1564     KItemListGroupHeader* header = m_visibleGroups.value(widget);
1565     if (!header) {
1566         header = m_groupHeaderCreator->create(this);
1567         header->setParentItem(widget);
1568         m_visibleGroups.insert(widget, header);
1569     }
1570     Q_ASSERT(header->parentItem() == widget);
1571
1572     // Determine the shown data for the header by doing a binary
1573     // search in the groups-list
1574     int min = 0;
1575     int max = groups.count() - 1;
1576     int mid = 0;
1577     do {
1578         mid = (min + max) / 2;
1579         if (index > groups.at(mid).first) {
1580             min = mid + 1;
1581         } else {
1582             max = mid - 1;
1583         }
1584     } while (groups.at(mid).first != index && min <= max);
1585
1586     header->setData(groups.at(mid).second);
1587     header->setRole(model()->sortRole());
1588     header->setStyleOption(m_styleOption);
1589     header->setScrollOrientation(scrollOrientation());
1590
1591     header->show();
1592 }
1593
1594 void KItemListView::updateGroupHeaderLayout(KItemListWidget* widget)
1595 {
1596     KItemListGroupHeader* header = m_visibleGroups.value(widget);
1597     Q_ASSERT(header);
1598
1599     const int index = widget->index();
1600     const QRectF groupHeaderRect = m_layouter->groupHeaderRect(index);
1601     const QRectF itemRect = m_layouter->itemRect(index);
1602
1603     // The group-header is a child of the itemlist widget. Translate the
1604     // group header position to the relative position.
1605     const QPointF groupHeaderPos(groupHeaderRect.x() - itemRect.x(),
1606                                  - groupHeaderRect.height());
1607     header->setPos(groupHeaderPos);
1608     header->resize(groupHeaderRect.size());
1609 }
1610
1611 void KItemListView::recycleGroupHeaderForWidget(KItemListWidget* widget)
1612 {
1613     KItemListGroupHeader* header = m_visibleGroups.value(widget);
1614     if (header) {
1615         header->setParentItem(0);
1616         m_groupHeaderCreator->recycle(header);
1617         m_visibleGroups.remove(widget);
1618     }
1619 }
1620
1621 void KItemListView::updateVisibleGroupHeaders()
1622 {
1623     Q_ASSERT(m_grouped);
1624     m_layouter->markAsDirty();
1625
1626     QHashIterator<int, KItemListWidget*> it(m_visibleItems);
1627     while (it.hasNext()) {
1628         it.next();
1629         updateGroupHeaderForWidget(it.value());
1630     }
1631 }
1632
1633 QHash<QByteArray, qreal> KItemListView::headerRolesWidths() const
1634 {
1635     QHash<QByteArray, qreal> rolesWidths;
1636
1637     QHashIterator<QByteArray, QSizeF> it(m_stretchedVisibleRolesSizes);
1638     while (it.hasNext()) {
1639         it.next();
1640         rolesWidths.insert(it.key(), it.value().width());
1641     }
1642
1643     return rolesWidths;
1644 }
1645
1646 void KItemListView::updateVisibleRolesSizes(const KItemRangeList& itemRanges)
1647 {
1648     if (!m_itemSize.isEmpty() || m_useHeaderWidths) {
1649         return;
1650     }
1651
1652     const int itemCount = m_model->count();
1653     int rangesItemCount = 0;
1654     foreach (const KItemRange& range, itemRanges) {
1655         rangesItemCount += range.count;
1656     }
1657
1658     if (itemCount == rangesItemCount) {
1659         m_visibleRolesSizes = visibleRolesSizes(itemRanges);
1660         if (m_header) {
1661             // Assure the the sizes are not smaller than the minimum defined by the header
1662             // TODO: Currently only implemented for a top-aligned header
1663             const qreal minHeaderRoleWidth = m_header->minimumRoleWidth();
1664             QMutableHashIterator<QByteArray, QSizeF> it (m_visibleRolesSizes);
1665             while (it.hasNext()) {
1666                 it.next();
1667                 const QSizeF& size = it.value();
1668                 if (size.width() < minHeaderRoleWidth) {
1669                     const QSizeF newSize(minHeaderRoleWidth, size.height());
1670                     m_visibleRolesSizes.insert(it.key(), newSize);
1671                 }
1672             }
1673         }
1674     } else {
1675         // Only a sub range of the roles need to be determined.
1676         // The chances are good that the sizes of the sub ranges
1677         // already fit into the available sizes and hence no
1678         // expensive update might be required.
1679         bool updateRequired = false;
1680
1681         const QHash<QByteArray, QSizeF> updatedSizes = visibleRolesSizes(itemRanges);
1682         QHashIterator<QByteArray, QSizeF> it(updatedSizes);
1683         while (it.hasNext()) {
1684             it.next();
1685             const QByteArray& role = it.key();
1686             const QSizeF& updatedSize = it.value();
1687             const QSizeF currentSize = m_visibleRolesSizes.value(role);
1688             if (updatedSize.width() > currentSize.width() || updatedSize.height() > currentSize.height()) {
1689                 m_visibleRolesSizes.insert(role, updatedSize);
1690                 updateRequired = true;
1691             }
1692         }
1693
1694         if (!updateRequired) {
1695             // All the updated sizes are smaller than the current sizes and no change
1696             // of the stretched roles-widths is required
1697             return;
1698         }
1699     }
1700
1701     updateStretchedVisibleRolesSizes();
1702 }
1703
1704 void KItemListView::updateVisibleRolesSizes()
1705 {
1706     if (!m_model) {
1707         return;
1708     }
1709
1710     const int itemCount = m_model->count();
1711     if (itemCount > 0) {
1712         updateVisibleRolesSizes(KItemRangeList() << KItemRange(0, itemCount));
1713     }
1714 }
1715
1716 void KItemListView::updateStretchedVisibleRolesSizes()
1717 {
1718     if (!m_itemSize.isEmpty() || m_useHeaderWidths || m_visibleRoles.isEmpty()) {
1719         return;
1720     }
1721
1722     // Calculate the maximum size of an item by considering the
1723     // visible role sizes and apply them to the layouter. If the
1724     // size does not use the available view-size it the size of the
1725     // first role will get stretched.
1726     m_stretchedVisibleRolesSizes = m_visibleRolesSizes;
1727     const QByteArray role = m_visibleRoles.first();
1728     QSizeF firstRoleSize = m_stretchedVisibleRolesSizes.value(role);
1729
1730     QSizeF dynamicItemSize = m_itemSize;
1731
1732     if (dynamicItemSize.width() <= 0) {
1733         const qreal requiredWidth = visibleRolesSizesWidthSum();
1734         const qreal availableWidth = size().width();
1735         if (requiredWidth < availableWidth) {
1736             // Stretch the first role to use the whole width for the item
1737             firstRoleSize.rwidth() += availableWidth - requiredWidth;
1738             m_stretchedVisibleRolesSizes.insert(role, firstRoleSize);
1739         }
1740         dynamicItemSize.setWidth(qMax(requiredWidth, availableWidth));
1741     }
1742
1743     if (dynamicItemSize.height() <= 0) {
1744         const qreal requiredHeight = visibleRolesSizesHeightSum();
1745         const qreal availableHeight = size().height();
1746         if (requiredHeight < availableHeight) {
1747             // Stretch the first role to use the whole height for the item
1748             firstRoleSize.rheight() += availableHeight - requiredHeight;
1749             m_stretchedVisibleRolesSizes.insert(role, firstRoleSize);
1750         }
1751         dynamicItemSize.setHeight(qMax(requiredHeight, availableHeight));
1752     }
1753
1754     m_layouter->setItemSize(dynamicItemSize);
1755
1756     if (m_header) {
1757         m_header->setVisibleRolesWidths(headerRolesWidths());
1758         m_header->resize(dynamicItemSize.width(), m_header->size().height());
1759     }
1760
1761     // Update the role sizes for all visible widgets
1762     foreach (KItemListWidget* widget, visibleItemListWidgets()) {
1763         widget->setVisibleRolesSizes(m_stretchedVisibleRolesSizes);
1764     }
1765 }
1766
1767 qreal KItemListView::visibleRolesSizesWidthSum() const
1768 {
1769     qreal widthSum = 0;
1770     QHashIterator<QByteArray, QSizeF> it(m_visibleRolesSizes);
1771     while (it.hasNext()) {
1772         it.next();
1773         widthSum += it.value().width();
1774     }
1775     return widthSum;
1776 }
1777
1778 qreal KItemListView::visibleRolesSizesHeightSum() const
1779 {
1780     qreal heightSum = 0;
1781     QHashIterator<QByteArray, QSizeF> it(m_visibleRolesSizes);
1782     while (it.hasNext()) {
1783         it.next();
1784         heightSum += it.value().height();
1785     }
1786     return heightSum;
1787 }
1788
1789 QRectF KItemListView::headerBoundaries() const
1790 {
1791     return m_header ? m_header->geometry() : QRectF();
1792 }
1793
1794 int KItemListView::calculateAutoScrollingIncrement(int pos, int range, int oldInc)
1795 {
1796     int inc = 0;
1797
1798     const int minSpeed = 4;
1799     const int maxSpeed = 128;
1800     const int speedLimiter = 96;
1801     const int autoScrollBorder = 64;
1802
1803     // Limit the increment that is allowed to be added in comparison to 'oldInc'.
1804     // This assures that the autoscrolling speed grows gradually.
1805     const int incLimiter = 1;
1806
1807     if (pos < autoScrollBorder) {
1808         inc = -minSpeed + qAbs(pos - autoScrollBorder) * (pos - autoScrollBorder) / speedLimiter;
1809         inc = qMax(inc, -maxSpeed);
1810         inc = qMax(inc, oldInc - incLimiter);
1811     } else if (pos > range - autoScrollBorder) {
1812         inc = minSpeed + qAbs(pos - range + autoScrollBorder) * (pos - range + autoScrollBorder) / speedLimiter;
1813         inc = qMin(inc, maxSpeed);
1814         inc = qMin(inc, oldInc + incLimiter);
1815     }
1816
1817     return inc;
1818 }
1819
1820
1821
1822 KItemListCreatorBase::~KItemListCreatorBase()
1823 {
1824     qDeleteAll(m_recycleableWidgets);
1825     qDeleteAll(m_createdWidgets);
1826 }
1827
1828 void KItemListCreatorBase::addCreatedWidget(QGraphicsWidget* widget)
1829 {
1830     m_createdWidgets.insert(widget);
1831 }
1832
1833 void KItemListCreatorBase::pushRecycleableWidget(QGraphicsWidget* widget)
1834 {
1835     Q_ASSERT(m_createdWidgets.contains(widget));
1836     m_createdWidgets.remove(widget);
1837
1838     if (m_recycleableWidgets.count() < 100) {
1839         m_recycleableWidgets.append(widget);
1840         widget->setVisible(false);
1841     } else {
1842         delete widget;
1843     }
1844 }
1845
1846 QGraphicsWidget* KItemListCreatorBase::popRecycleableWidget()
1847 {
1848     if (m_recycleableWidgets.isEmpty()) {
1849         return 0;
1850     }
1851
1852     QGraphicsWidget* widget = m_recycleableWidgets.takeLast();
1853     m_createdWidgets.insert(widget);
1854     return widget;
1855 }
1856
1857 KItemListWidgetCreatorBase::~KItemListWidgetCreatorBase()
1858 {
1859 }
1860
1861 void KItemListWidgetCreatorBase::recycle(KItemListWidget* widget)
1862 {
1863     widget->setParentItem(0);
1864     widget->setOpacity(1.0);
1865     pushRecycleableWidget(widget);
1866 }
1867
1868 KItemListGroupHeaderCreatorBase::~KItemListGroupHeaderCreatorBase()
1869 {
1870 }
1871
1872 void KItemListGroupHeaderCreatorBase::recycle(KItemListGroupHeader* header)
1873 {
1874     header->setOpacity(1.0);
1875     pushRecycleableWidget(header);
1876 }
1877
1878 #include "kitemlistview.moc"