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