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_endTransactionAnimationHint(Animation),
  59     m_itemSize(),
  60     m_controller(0),
  61     m_model(0),
  62     m_visibleRoles(),
  63     m_visibleRolesSizes(),
  64     m_stretchedVisibleRolesSizes(),
  65     m_widgetCreator(0),
  66     m_groupHeaderCreator(0),
  67     m_styleOption(),
  68     m_visibleItems(),
  69     m_visibleGroups(),
  70     m_sizeHintResolver(0),
  71     m_layouter(0),
  72     m_animation(0),
  73     m_layoutTimer(0),
  74     m_oldScrollOffset(0),
  75     m_oldMaximumScrollOffset(0),
  76     m_oldItemOffset(0),
  77     m_oldMaximumItemOffset(0),
  78     m_skipAutoScrollForRubberBand(false),
  79     m_rubberBand(0),
  80     m_mousePos(),
  81     m_autoScrollIncrement(0),
  82     m_autoScrollTimer(0),
  83     m_header(0),
  84     m_useHeaderWidths(false)
  85 {
  86     setAcceptHoverEvents(true);
  87
  88     m_sizeHintResolver = new KItemListSizeHintResolver(this);
  89
  90     m_layouter = new KItemListViewLayouter(this);
  91     m_layouter->setSizeHintResolver(m_sizeHintResolver);
  92
  93     m_animation = new KItemListViewAnimation(this);
  94     connect(m_animation, SIGNAL(finished(QGraphicsWidget*,KItemListViewAnimation::AnimationType)),
  95             this, SLOT(slotAnimationFinished(QGraphicsWidget*,KItemListViewAnimation::AnimationType)));
  96
  97     m_layoutTimer = new QTimer(this);
  98     m_layoutTimer->setInterval(300);
  99     m_layoutTimer->setSingleShot(true);
 100     connect(m_layoutTimer, SIGNAL(timeout()), this, SLOT(slotLayoutTimerFinished()));
 101
 102     m_rubberBand = new KItemListRubberBand(this);
 103     connect(m_rubberBand, SIGNAL(activationChanged(bool)), this, SLOT(slotRubberBandActivationChanged(bool)));
 104 }
 105
 106 KItemListView::~KItemListView()
 107 {
 108     delete m_sizeHintResolver;
 109     m_sizeHintResolver = 0;
 110 }
 111
 112 void KItemListView::setScrollOrientation(Qt::Orientation orientation)
 113 {
 114     const Qt::Orientation previousOrientation = m_layouter->scrollOrientation();
 115     if (orientation == previousOrientation) {
 116         return;
 117     }
 118
 119     m_layouter->setScrollOrientation(orientation);
 120     m_animation->setScrollOrientation(orientation);
 121     m_sizeHintResolver->clearCache();
 122
 123     if (m_grouped) {
 124         QMutableHashIterator<KItemListWidget*, KItemListGroupHeader*> it (m_visibleGroups);
 125         while (it.hasNext()) {
 126             it.next();
 127             it.value()->setScrollOrientation(orientation);
 128         }
 129         updateGroupHeaderHeight();
 130
 131     }
 132
 133     doLayout(NoAnimation);
 134
 135     onScrollOrientationChanged(orientation, previousOrientation);
 136     emit scrollOrientationChanged(orientation, previousOrientation);
 137 }
 138
 139 Qt::Orientation KItemListView::scrollOrientation() const
 140 {
 141     return m_layouter->scrollOrientation();
 142 }
 143
 144 void KItemListView::setItemSize(const QSizeF& itemSize)
 145 {
 146     const QSizeF previousSize = m_itemSize;
 147     if (itemSize == previousSize) {
 148         return;
 149     }
 150
 151     // Skip animations when the number of rows or columns
 152     // are changed in the grid layout. Although the animation
 153     // engine can handle this usecase, it looks obtrusive.
 154     const bool animate = !changesItemGridLayout(m_layouter->size(),
 155                                                 itemSize,
 156                                                 m_layouter->itemMargin());
 157
 158     m_itemSize = itemSize;
 159
 160     if (itemSize.isEmpty()) {
 161         updateVisibleRolesSizes();
 162     } else {
 163         m_layouter->setItemSize(itemSize);
 164     }
 165
 166     m_sizeHintResolver->clearCache();
 167     doLayout(animate ? Animation : NoAnimation);
 168     onItemSizeChanged(itemSize, previousSize);
 169 }
 170
 171 QSizeF KItemListView::itemSize() const
 172 {
 173     return m_itemSize;
 174 }
 175
 176 void KItemListView::setScrollOffset(qreal offset)
 177 {
 178     if (offset < 0) {
 179         offset = 0;
 180     }
 181
 182     const qreal previousOffset = m_layouter->scrollOffset();
 183     if (offset == previousOffset) {
 184         return;
 185     }
 186
 187     m_layouter->setScrollOffset(offset);
 188     m_animation->setScrollOffset(offset);
 189
 190     // Don't check whether the m_layoutTimer is active: Changing the
 191     // scroll offset must always trigger a synchronous layout, otherwise
 192     // the smooth-scrolling might get jerky.
 193     doLayout(NoAnimation);
 194     onScrollOffsetChanged(offset, previousOffset);
 195 }
 196
 197 qreal KItemListView::scrollOffset() const
 198 {
 199     return m_layouter->scrollOffset();
 200 }
 201
 202 qreal KItemListView::maximumScrollOffset() const
 203 {
 204     return m_layouter->maximumScrollOffset();
 205 }
 206
 207 void KItemListView::setItemOffset(qreal offset)
 208 {
 209     if (m_layouter->itemOffset() == offset) {
 210         return;
 211     }
 212
 213     m_layouter->setItemOffset(offset);
 214     if (m_header) {
 215         m_header->setPos(-offset, 0);
 216     }
 217
 218     // Don't check whether the m_layoutTimer is active: Changing the
 219     // item offset must always trigger a synchronous layout, otherwise
 220     // the smooth-scrolling might get jerky.
 221     doLayout(NoAnimation);
 222 }
 223
 224 qreal KItemListView::itemOffset() const
 225 {
 226     return m_layouter->itemOffset();
 227 }
 228
 229 qreal KItemListView::maximumItemOffset() const
 230 {
 231     return m_layouter->maximumItemOffset();
 232 }
 233
 234 void KItemListView::setVisibleRoles(const QList<QByteArray>& roles)
 235 {
 236     const QList<QByteArray> previousRoles = m_visibleRoles;
 237     m_visibleRoles = roles;
 238
 239     QHashIterator<int, KItemListWidget*> it(m_visibleItems);
 240     while (it.hasNext()) {
 241         it.next();
 242         KItemListWidget* widget = it.value();
 243         widget->setVisibleRoles(roles);
 244         widget->setVisibleRolesSizes(m_stretchedVisibleRolesSizes);
 245     }
 246
 247     m_sizeHintResolver->clearCache();
 248     m_layouter->markAsDirty();
 249
 250     if (m_header) {
 251         m_header->setVisibleRoles(roles);
 252         m_header->setVisibleRolesWidths(headerRolesWidths());
 253         m_useHeaderWidths = false;
 254     }
 255
 256     updateVisibleRolesSizes();
 257     doLayout(NoAnimation);
 258
 259     onVisibleRolesChanged(roles, previousRoles);
 260 }
 261
 262 QList<QByteArray> KItemListView::visibleRoles() const
 263 {
 264     return m_visibleRoles;
 265 }
 266
 267 void KItemListView::setAutoScroll(bool enabled)
 268 {
 269     if (enabled && !m_autoScrollTimer) {
 270         m_autoScrollTimer = new QTimer(this);
 271         m_autoScrollTimer->setSingleShot(true);
 272         connect(m_autoScrollTimer, SIGNAL(timeout()), this, SLOT(triggerAutoScrolling()));
 273         m_autoScrollTimer->start(InitialAutoScrollDelay);
 274     } else if (!enabled && m_autoScrollTimer) {
 275         delete m_autoScrollTimer;
 276         m_autoScrollTimer = 0;
 277     }
 278
 279 }
 280
 281 bool KItemListView::autoScroll() const
 282 {
 283     return m_autoScrollTimer != 0;
 284 }
 285
 286 void KItemListView::setEnabledSelectionToggles(bool enabled)
 287 {
 288     if (m_enabledSelectionToggles != enabled) {
 289         m_enabledSelectionToggles = enabled;
 290
 291         QHashIterator<int, KItemListWidget*> it(m_visibleItems);
 292         while (it.hasNext()) {
 293             it.next();
 294             it.value()->setEnabledSelectionToggle(enabled);
 295         }
 296     }
 297 }
 298
 299 bool KItemListView::enabledSelectionToggles() const
 300 {
 301     return m_enabledSelectionToggles;
 302 }
 303
 304 KItemListController* KItemListView::controller() const
 305 {
 306     return m_controller;
 307 }
 308
 309 KItemModelBase* KItemListView::model() const
 310 {
 311     return m_model;
 312 }
 313
 314 void KItemListView::setWidgetCreator(KItemListWidgetCreatorBase* widgetCreator)
 315 {
 316     m_widgetCreator = widgetCreator;
 317 }
 318
 319 KItemListWidgetCreatorBase* KItemListView::widgetCreator() const
 320 {
 321     return m_widgetCreator;
 322 }
 323
 324 void KItemListView::setGroupHeaderCreator(KItemListGroupHeaderCreatorBase* groupHeaderCreator)
 325 {
 326     m_groupHeaderCreator = groupHeaderCreator;
 327 }
 328
 329 KItemListGroupHeaderCreatorBase* KItemListView::groupHeaderCreator() const
 330 {
 331     return m_groupHeaderCreator;
 332 }
 333
 334 void KItemListView::setStyleOption(const KItemListStyleOption& option)
 335 {
 336     const KItemListStyleOption previousOption = m_styleOption;
 337     m_styleOption = option;
 338
 339     bool animate = true;
 340     const QSizeF margin(option.horizontalMargin, option.verticalMargin);
 341     if (margin != m_layouter->itemMargin()) {
 342         // Skip animations when the number of rows or columns
 343         // are changed in the grid layout. Although the animation
 344         // engine can handle this usecase, it looks obtrusive.
 345         animate = !changesItemGridLayout(m_layouter->size(),
 346                                          m_layouter->itemSize(),
 347                                          margin);
 348         m_layouter->setItemMargin(margin);
 349     }
 350
 351     if (m_grouped) {
 352         updateGroupHeaderHeight();
 353     }
 354
 355     QHashIterator<int, KItemListWidget*> it(m_visibleItems);
 356     while (it.hasNext()) {
 357         it.next();
 358         it.value()->setStyleOption(option);
 359     }
 360
 361     m_sizeHintResolver->clearCache();
 362     doLayout(animate ? Animation : NoAnimation);
 363
 364     onStyleOptionChanged(option, previousOption);
 365 }
 366
 367 const KItemListStyleOption& KItemListView::styleOption() const
 368 {
 369     return m_styleOption;
 370 }
 371
 372 void KItemListView::setGeometry(const QRectF& rect)
 373 {
 374     QGraphicsWidget::setGeometry(rect);
 375
 376     if (!m_model) {
 377         return;
 378     }
 379
 380     const QSizeF newSize = rect.size();
 381     if (m_itemSize.isEmpty()) {
 382         // The item size is dynamic:
 383         // Changing the geometry does not require to do an expensive
 384         // update of the visible-roles sizes, only the stretched sizes
 385         // need to be adjusted to the new size.
 386         updateStretchedVisibleRolesSizes();
 387
 388         if (m_useHeaderWidths) {
 389             QSizeF dynamicItemSize = m_layouter->itemSize();
 390
 391             if (m_itemSize.width() < 0) {
 392                 const qreal requiredWidth = visibleRolesSizesWidthSum();
 393                 if (newSize.width() > requiredWidth) {
 394                     dynamicItemSize.setWidth(newSize.width());
 395                 }
 396                 const qreal headerWidth = qMax(newSize.width(), requiredWidth);
 397                 m_header->resize(headerWidth, m_header->size().height());
 398             }
 399
 400             if (m_itemSize.height() < 0) {
 401                 const qreal requiredHeight = visibleRolesSizesHeightSum();
 402                 if (newSize.height() > requiredHeight) {
 403                     dynamicItemSize.setHeight(newSize.height());
 404                 }
 405                 // TODO: KItemListHeader is not prepared for vertical alignment
 406             }
 407
 408             m_layouter->setItemSize(dynamicItemSize);
 409         }
 410
 411         // Triggering a synchronous layout is fine from a performance point of view,
 412         // as with dynamic item sizes no moving animation must be done.
 413         m_layouter->setSize(newSize);
 414         doLayout(Animation);
 415     } else {
 416         const bool animate = !changesItemGridLayout(newSize,
 417                                                     m_layouter->itemSize(),
 418                                                     m_layouter->itemMargin());
 419         m_layouter->setSize(newSize);
 420
 421         if (animate) {
 422             // Trigger an asynchronous relayout with m_layoutTimer to prevent
 423             // performance bottlenecks. If the timer is exceeded, an animated layout
 424             // will be triggered.
 425             if (!m_layoutTimer->isActive()) {
 426                 m_layoutTimer->start();
 427             }
 428         } else {
 429             m_layoutTimer->stop();
 430             doLayout(NoAnimation);
 431         }
 432     }
 433 }
 434
 435 int KItemListView::itemAt(const QPointF& pos) const
 436 {
 437     QHashIterator<int, KItemListWidget*> it(m_visibleItems);
 438     while (it.hasNext()) {
 439         it.next();
 440
 441         const KItemListWidget* widget = it.value();
 442         const QPointF mappedPos = widget->mapFromItem(this, pos);
 443         if (widget->contains(mappedPos)) {
 444             return it.key();
 445         }
 446     }
 447
 448     return -1;
 449 }
 450
 451 bool KItemListView::isAboveSelectionToggle(int index, const QPointF& pos) const
 452 {
 453     if (!m_enabledSelectionToggles) {
 454         return false;
 455     }
 456
 457     const KItemListWidget* widget = m_visibleItems.value(index);
 458     if (widget) {
 459         const QRectF selectionToggleRect = widget->selectionToggleRect();
 460         if (!selectionToggleRect.isEmpty()) {
 461             const QPointF mappedPos = widget->mapFromItem(this, pos);
 462             return selectionToggleRect.contains(mappedPos);
 463         }
 464     }
 465     return false;
 466 }
 467
 468 bool KItemListView::isAboveExpansionToggle(int index, const QPointF& pos) const
 469 {
 470     const KItemListWidget* widget = m_visibleItems.value(index);
 471     if (widget) {
 472         const QRectF expansionToggleRect = widget->expansionToggleRect();
 473         if (!expansionToggleRect.isEmpty()) {
 474             const QPointF mappedPos = widget->mapFromItem(this, pos);
 475             return expansionToggleRect.contains(mappedPos);
 476         }
 477     }
 478     return false;
 479 }
 480
 481 int KItemListView::firstVisibleIndex() const
 482 {
 483     return m_layouter->firstVisibleIndex();
 484 }
 485
 486 int KItemListView::lastVisibleIndex() const
 487 {
 488     return m_layouter->lastVisibleIndex();
 489 }
 490
 491 QSizeF KItemListView::itemSizeHint(int index) const
 492 {
 493     Q_UNUSED(index);
 494     return itemSize();
 495 }
 496
 497 QHash<QByteArray, QSizeF> KItemListView::visibleRolesSizes(const KItemRangeList& itemRanges) const
 498 {
 499     Q_UNUSED(itemRanges);
 500     return QHash<QByteArray, QSizeF>();
 501 }
 502
 503 bool KItemListView::supportsItemExpanding() const
 504 {
 505     return false;
 506 }
 507
 508 QRectF KItemListView::itemRect(int index) const
 509 {
 510     return m_layouter->itemRect(index);
 511 }
 512
 513 QRectF KItemListView::itemContextRect(int index) const
 514 {
 515     QRectF contextRect;
 516
 517     const KItemListWidget* widget = m_visibleItems.value(index);
 518     if (widget) {
 519         contextRect = widget->iconRect() | widget->textRect();
 520         contextRect.translate(itemRect(index).topLeft());
 521     }
 522
 523     return contextRect;
 524 }
 525
 526 void KItemListView::scrollToItem(int index)
 527 {
 528     QRectF viewGeometry = geometry();
 529     if (m_header) {
 530         const qreal headerHeight = m_header->size().height();
 531         viewGeometry.adjust(0, headerHeight, 0, 0);
 532     }
 533     const QRectF currentRect = itemRect(index);
 534
 535     if (!viewGeometry.contains(currentRect)) {
 536         qreal newOffset = scrollOffset();
 537         if (scrollOrientation() == Qt::Vertical) {
 538             if (currentRect.top() < viewGeometry.top()) {
 539                 newOffset += currentRect.top() - viewGeometry.top();
 540             } else if (currentRect.bottom() > viewGeometry.bottom()) {
 541                 newOffset += currentRect.bottom() - viewGeometry.bottom();
 542             }
 543         } else {
 544             if (currentRect.left() < viewGeometry.left()) {
 545                 newOffset += currentRect.left() - viewGeometry.left();
 546             } else if (currentRect.right() > viewGeometry.right()) {
 547                 newOffset += currentRect.right() - viewGeometry.right();
 548             }
 549         }
 550
 551         if (newOffset != scrollOffset()) {
 552             emit scrollTo(newOffset);
 553         }
 554     }
 555 }
 556
 557 void KItemListView::beginTransaction()
 558 {
 559     ++m_activeTransactions;
 560     if (m_activeTransactions == 1) {
 561         onTransactionBegin();
 562     }
 563 }
 564
 565 void KItemListView::endTransaction()
 566 {
 567     --m_activeTransactions;
 568     if (m_activeTransactions < 0) {
 569         m_activeTransactions = 0;
 570         kWarning() << "Mismatch between beginTransaction()/endTransaction()";
 571     }
 572
 573     if (m_activeTransactions == 0) {
 574         onTransactionEnd();
 575         doLayout(m_endTransactionAnimationHint);
 576         m_endTransactionAnimationHint = Animation;
 577     }
 578 }
 579
 580 bool KItemListView::isTransactionActive() const
 581 {
 582     return m_activeTransactions > 0;
 583 }
 584
 585 void KItemListView::setHeaderShown(bool show)
 586 {
 587
 588     if (show && !m_header) {
 589         m_header = new KItemListHeader(this);
 590         m_header->setPos(0, 0);
 591         m_header->setModel(m_model);
 592         m_header->setVisibleRoles(m_visibleRoles);
 593         m_header->setVisibleRolesWidths(headerRolesWidths());
 594         m_header->setZValue(1);
 595
 596         connect(m_header, SIGNAL(visibleRoleWidthChanged(QByteArray,qreal,qreal)),
 597                 this, SLOT(slotVisibleRoleWidthChanged(QByteArray,qreal,qreal)));
 598         connect(m_header, SIGNAL(sortOrderChanged(Qt::SortOrder,Qt::SortOrder)),
 599                 this, SIGNAL(sortOrderChanged(Qt::SortOrder,Qt::SortOrder)));
 600         connect(m_header, SIGNAL(sortRoleChanged(QByteArray,QByteArray)),
 601                 this, SIGNAL(sortRoleChanged(QByteArray,QByteArray)));
 602
 603         m_useHeaderWidths = false;
 604
 605         m_layouter->setHeaderHeight(m_header->size().height());
 606     } else if (!show && m_header) {
 607         delete m_header;
 608         m_header = 0;
 609         m_useHeaderWidths = false;
 610         m_layouter->setHeaderHeight(0);
 611     }
 612 }
 613
 614 bool KItemListView::isHeaderShown() const
 615 {
 616     return m_header != 0;
 617 }
 618
 619 QPixmap KItemListView::createDragPixmap(const QSet<int>& indexes) const
 620 {
 621     Q_UNUSED(indexes);
 622     return QPixmap();
 623 }
 624
 625 void KItemListView::paint(QPainter* painter, const QStyleOptionGraphicsItem* option, QWidget* widget)
 626 {
 627     QGraphicsWidget::paint(painter, option, widget);
 628
 629     if (m_rubberBand->isActive()) {
 630         QRectF rubberBandRect = QRectF(m_rubberBand->startPosition(),
 631                                        m_rubberBand->endPosition()).normalized();
 632
 633         const QPointF topLeft = rubberBandRect.topLeft();
 634         if (scrollOrientation() == Qt::Vertical) {
 635             rubberBandRect.moveTo(topLeft.x(), topLeft.y() - scrollOffset());
 636         } else {
 637             rubberBandRect.moveTo(topLeft.x() - scrollOffset(), topLeft.y());
 638         }
 639
 640         QStyleOptionRubberBand opt;
 641         opt.initFrom(widget);
 642         opt.shape = QRubberBand::Rectangle;
 643         opt.opaque = false;
 644         opt.rect = rubberBandRect.toRect();
 645         style()->drawControl(QStyle::CE_RubberBand, &opt, painter);
 646     }
 647 }
 648
 649 void KItemListView::initializeItemListWidget(KItemListWidget* item)
 650 {
 651     Q_UNUSED(item);
 652 }
 653
 654 bool KItemListView::itemSizeHintUpdateRequired(const QSet<QByteArray>& changedRoles) const
 655 {
 656     Q_UNUSED(changedRoles);
 657     return true;
 658 }
 659
 660 void KItemListView::onControllerChanged(KItemListController* current, KItemListController* previous)
 661 {
 662     Q_UNUSED(current);
 663     Q_UNUSED(previous);
 664 }
 665
 666 void KItemListView::onModelChanged(KItemModelBase* current, KItemModelBase* previous)
 667 {
 668     Q_UNUSED(current);
 669     Q_UNUSED(previous);
 670 }
 671
 672 void KItemListView::onScrollOrientationChanged(Qt::Orientation current, Qt::Orientation previous)
 673 {
 674     Q_UNUSED(current);
 675     Q_UNUSED(previous);
 676 }
 677
 678 void KItemListView::onItemSizeChanged(const QSizeF& current, const QSizeF& previous)
 679 {
 680     Q_UNUSED(current);
 681     Q_UNUSED(previous);
 682 }
 683
 684 void KItemListView::onScrollOffsetChanged(qreal current, qreal previous)
 685 {
 686     Q_UNUSED(current);
 687     Q_UNUSED(previous);
 688 }
 689
 690 void KItemListView::onVisibleRolesChanged(const QList<QByteArray>& current, const QList<QByteArray>& previous)
 691 {
 692     Q_UNUSED(current);
 693     Q_UNUSED(previous);
 694 }
 695
 696 void KItemListView::onStyleOptionChanged(const KItemListStyleOption& current, const KItemListStyleOption& previous)
 697 {
 698     Q_UNUSED(current);
 699     Q_UNUSED(previous);
 700 }
 701
 702 void KItemListView::onTransactionBegin()
 703 {
 704 }
 705
 706 void KItemListView::onTransactionEnd()
 707 {
 708 }
 709
 710 bool KItemListView::event(QEvent* event)
 711 {
 712     // Forward all events to the controller and handle them there
 713     if (m_controller && m_controller->processEvent(event, transform())) {
 714         event->accept();
 715         return true;
 716     }
 717     return QGraphicsWidget::event(event);
 718 }
 719
 720 void KItemListView::mousePressEvent(QGraphicsSceneMouseEvent* event)
 721 {
 722     m_mousePos = transform().map(event->pos());
 723     event->accept();
 724 }
 725
 726 void KItemListView::mouseMoveEvent(QGraphicsSceneMouseEvent* event)
 727 {
 728     QGraphicsWidget::mouseMoveEvent(event);
 729
 730     m_mousePos = transform().map(event->pos());
 731     if (m_autoScrollTimer && !m_autoScrollTimer->isActive()) {
 732         m_autoScrollTimer->start(InitialAutoScrollDelay);
 733     }
 734 }
 735
 736 void KItemListView::dragEnterEvent(QGraphicsSceneDragDropEvent* event)
 737 {
 738     event->setAccepted(true);
 739     setAutoScroll(true);
 740 }
 741
 742 void KItemListView::dragMoveEvent(QGraphicsSceneDragDropEvent *event)
 743 {
 744     QGraphicsWidget::dragMoveEvent(event);
 745
 746     m_mousePos = transform().map(event->pos());
 747     if (m_autoScrollTimer && !m_autoScrollTimer->isActive()) {
 748         m_autoScrollTimer->start(InitialAutoScrollDelay);
 749     }
 750 }
 751
 752 void KItemListView::dragLeaveEvent(QGraphicsSceneDragDropEvent *event)
 753 {
 754     QGraphicsWidget::dragLeaveEvent(event);
 755     setAutoScroll(false);
 756 }
 757
 758 void KItemListView::dropEvent(QGraphicsSceneDragDropEvent* event)
 759 {
 760     QGraphicsWidget::dropEvent(event);
 761     setAutoScroll(false);
 762 }
 763
 764 QList<KItemListWidget*> KItemListView::visibleItemListWidgets() const
 765 {
 766     return m_visibleItems.values();
 767 }
 768
 769 void KItemListView::slotItemsInserted(const KItemRangeList& itemRanges)
 770 {
 771     updateVisibleRolesSizes(itemRanges);
 772
 773     const bool hasMultipleRanges = (itemRanges.count() > 1);
 774     if (hasMultipleRanges) {
 775         beginTransaction();
 776     }
 777
 778     int previouslyInsertedCount = 0;
 779     foreach (const KItemRange& range, itemRanges) {
 780         // range.index is related to the model before anything has been inserted.
 781         // As in each loop the current item-range gets inserted the index must
 782         // be increased by the already previously inserted items.
 783         const int index = range.index + previouslyInsertedCount;
 784         const int count = range.count;
 785         if (index < 0 || count <= 0) {
 786             kWarning() << "Invalid item range (index:" << index << ", count:" << count << ")";
 787             continue;
 788         }
 789         previouslyInsertedCount += count;
 790
 791         m_sizeHintResolver->itemsInserted(index, count);
 792
 793         // Determine which visible items must be moved
 794         QList<int> itemsToMove;
 795         QHashIterator<int, KItemListWidget*> it(m_visibleItems);
 796         while (it.hasNext()) {
 797             it.next();
 798             const int visibleItemIndex = it.key();
 799             if (visibleItemIndex >= index) {
 800                 itemsToMove.append(visibleItemIndex);
 801             }
 802         }
 803
 804         // Update the indexes of all KItemListWidget instances that are located
 805         // after the inserted items. It is important to adjust the indexes in the order
 806         // from the highest index to the lowest index to prevent overlaps when setting the new index.
 807         qSort(itemsToMove);
 808         for (int i = itemsToMove.count() - 1; i >= 0; --i) {
 809             KItemListWidget* widget = m_visibleItems.value(itemsToMove[i]);
 810             Q_ASSERT(widget);
 811             setWidgetIndex(widget, widget->index() + count);
 812         }
 813
 814         m_layouter->markAsDirty();
 815         if (m_model->count() == count && m_activeTransactions == 0) {
 816             // Check whether a scrollbar is required to show the inserted items. In this case
 817             // the size of the layouter will be decreased before calling doLayout(): This prevents
 818             // an unnecessary temporary animation due to the geometry change of the inserted scrollbar.
 819             const bool verticalScrollOrientation = (scrollOrientation() == Qt::Vertical);
 820             const bool decreaseLayouterSize = ( verticalScrollOrientation && maximumScrollOffset() > size().height()) ||
 821                                               (!verticalScrollOrientation && maximumScrollOffset() > size().width());
 822             if (decreaseLayouterSize) {
 823                 const int scrollBarExtent = style()->pixelMetric(QStyle::PM_ScrollBarExtent);
 824                 QSizeF layouterSize = m_layouter->size();
 825                 if (verticalScrollOrientation) {
 826                     layouterSize.rwidth() -= scrollBarExtent;
 827                 } else {
 828                     layouterSize.rheight() -= scrollBarExtent;
 829                 }
 830                 m_layouter->setSize(layouterSize);
 831             }
 832         }
 833
 834         if (!hasMultipleRanges) {
 835             doLayout(animateChangedItemCount(count) ? Animation : NoAnimation, index, count);
 836         }
 837     }
 838
 839     if (m_controller) {
 840         m_controller->selectionManager()->itemsInserted(itemRanges);
 841     }
 842
 843     if (hasMultipleRanges) {
 844         endTransaction();
 845     }
 846 }
 847
 848 void KItemListView::slotItemsRemoved(const KItemRangeList& itemRanges)
 849 {
 850     updateVisibleRolesSizes();
 851
 852     const bool hasMultipleRanges = (itemRanges.count() > 1);
 853     if (hasMultipleRanges) {
 854         beginTransaction();
 855     }
 856
 857     for (int i = itemRanges.count() - 1; i >= 0; --i) {
 858         const KItemRange& range = itemRanges.at(i);
 859         const int index = range.index;
 860         const int count = range.count;
 861         if (index < 0 || count <= 0) {
 862             kWarning() << "Invalid item range (index:" << index << ", count:" << count << ")";
 863             continue;
 864         }
 865
 866         m_sizeHintResolver->itemsRemoved(index, count);
 867
 868         const int firstRemovedIndex = index;
 869         const int lastRemovedIndex = index + count - 1;
 870         const int lastIndex = m_model->count() + count - 1;
 871
 872         // Remove all KItemListWidget instances that got deleted
 873         for (int i = firstRemovedIndex; i <= lastRemovedIndex; ++i) {
 874             KItemListWidget* widget = m_visibleItems.value(i);
 875             if (!widget) {
 876                 continue;
 877             }
 878
 879             m_animation->stop(widget);
 880             // Stopping the animation might lead to recycling the widget if
 881             // it is invisible (see slotAnimationFinished()).
 882             // Check again whether it is still visible:
 883             if (!m_visibleItems.contains(i)) {
 884                 continue;
 885             }
 886
 887             if (m_model->count() == 0 || hasMultipleRanges || !animateChangedItemCount(count)) {
 888                 // Remove the widget without animation
 889                 recycleWidget(widget);
 890             } else {
 891                 // Animate the removing of the items. Special case: When removing an item there
 892                 // is no valid model index available anymore. For the
 893                 // remove-animation the item gets removed from m_visibleItems but the widget
 894                 // will stay alive until the animation has been finished and will
 895                 // be recycled (deleted) in KItemListView::slotAnimationFinished().
 896                 m_visibleItems.remove(i);
 897                 widget->setIndex(-1);
 898                 m_animation->start(widget, KItemListViewAnimation::DeleteAnimation);
 899             }
 900         }
 901
 902         // Update the indexes of all KItemListWidget instances that are located
 903         // after the deleted items
 904         for (int i = lastRemovedIndex + 1; i <= lastIndex; ++i) {
 905             KItemListWidget* widget = m_visibleItems.value(i);
 906             if (widget) {
 907                 const int newIndex = i - count;
 908                 setWidgetIndex(widget, newIndex);
 909             }
 910         }
 911
 912         m_layouter->markAsDirty();
 913         if (!hasMultipleRanges) {
 914             // The decrease-layout-size optimization in KItemListView::slotItemsInserted()
 915             // assumes an updated geometry. If items are removed during an active transaction,
 916             // the transaction will be temporary deactivated so that doLayout() triggers a
 917             // geometry update if necessary.
 918             const int activeTransactions = m_activeTransactions;
 919             m_activeTransactions = 0;
 920             doLayout(animateChangedItemCount(count) ? Animation : NoAnimation, index, -count);
 921             m_activeTransactions = activeTransactions;
 922         }
 923     }
 924
 925     if (m_controller) {
 926         m_controller->selectionManager()->itemsRemoved(itemRanges);
 927     }
 928
 929     if (hasMultipleRanges) {
 930         endTransaction();
 931     }
 932 }
 933
 934 void KItemListView::slotItemsMoved(const KItemRange& itemRange, const QList<int>& movedToIndexes)
 935 {
 936     m_sizeHintResolver->itemsMoved(itemRange.index, itemRange.count);
 937     m_layouter->markAsDirty();
 938
 939     if (m_controller) {
 940         m_controller->selectionManager()->itemsMoved(itemRange, movedToIndexes);
 941     }
 942
 943     const int firstVisibleMovedIndex = qMax(firstVisibleIndex(), itemRange.index);
 944     const int lastVisibleMovedIndex = qMin(lastVisibleIndex(), itemRange.index + itemRange.count - 1);
 945
 946     for (int index = firstVisibleMovedIndex; index <= lastVisibleMovedIndex; ++index) {
 947         KItemListWidget* widget = m_visibleItems.value(index);
 948         if (widget) {
 949             updateWidgetProperties(widget, index);
 950             if (m_grouped) {
 951                 updateGroupHeaderForWidget(widget);
 952             }
 953             initializeItemListWidget(widget);
 954         }
 955     }
 956
 957     doLayout(NoAnimation);
 958 }
 959
 960 void KItemListView::slotItemsChanged(const KItemRangeList& itemRanges,
 961                                      const QSet<QByteArray>& roles)
 962 {
 963     const bool updateSizeHints = itemSizeHintUpdateRequired(roles);
 964     if (updateSizeHints) {
 965         updateVisibleRolesSizes(itemRanges);
 966     }
 967
 968     foreach (const KItemRange& itemRange, itemRanges) {
 969         const int index = itemRange.index;
 970         const int count = itemRange.count;
 971
 972         if (updateSizeHints) {
 973             m_sizeHintResolver->itemsChanged(index, count, roles);
 974             m_layouter->markAsDirty();
 975
 976             if (!m_layoutTimer->isActive()) {
 977                 m_layoutTimer->start();
 978             }
 979         }
 980
 981         // Apply the changed roles to the visible item-widgets
 982         const int lastIndex = index + count - 1;
 983         for (int i = index; i <= lastIndex; ++i) {
 984             KItemListWidget* widget = m_visibleItems.value(i);
 985             if (widget) {
 986                 widget->setData(m_model->data(i), roles);
 987             }
 988         }
 989
 990         if (m_grouped && roles.contains(m_model->sortRole())) {
 991             // The sort-role has been changed which might result
 992             // in modified group headers
 993             updateVisibleGroupHeaders();
 994             doLayout(NoAnimation);
 995         }
 996     }
 997 }
 998
 999 void KItemListView::slotGroupedSortingChanged(bool current)
1000 {
1001     m_grouped = current;
1002     m_layouter->markAsDirty();
1003
1004     if (m_grouped) {
1005         updateGroupHeaderHeight();
1006     } else {
1007         // Clear all visible headers
1008         QMutableHashIterator<KItemListWidget*, KItemListGroupHeader*> it (m_visibleGroups);
1009         while (it.hasNext()) {
1010             it.next();
1011             recycleGroupHeaderForWidget(it.key());
1012         }
1013         Q_ASSERT(m_visibleGroups.isEmpty());
1014     }
1015
1016     doLayout(NoAnimation);
1017 }
1018
1019 void KItemListView::slotSortOrderChanged(Qt::SortOrder current, Qt::SortOrder previous)
1020 {
1021     Q_UNUSED(current);
1022     Q_UNUSED(previous);
1023     if (m_grouped) {
1024         updateVisibleGroupHeaders();
1025         doLayout(NoAnimation);
1026     }
1027 }
1028
1029 void KItemListView::slotSortRoleChanged(const QByteArray& current, const QByteArray& previous)
1030 {
1031     Q_UNUSED(current);
1032     Q_UNUSED(previous);
1033     if (m_grouped) {
1034         updateVisibleGroupHeaders();
1035         doLayout(NoAnimation);
1036     }
1037 }
1038
1039 void KItemListView::slotCurrentChanged(int current, int previous)
1040 {
1041     Q_UNUSED(previous);
1042
1043     KItemListWidget* previousWidget = m_visibleItems.value(previous, 0);
1044     if (previousWidget) {
1045         Q_ASSERT(previousWidget->isCurrent());
1046         previousWidget->setCurrent(false);
1047     }
1048
1049     KItemListWidget* currentWidget = m_visibleItems.value(current, 0);
1050     if (currentWidget) {
1051         Q_ASSERT(!currentWidget->isCurrent());
1052         currentWidget->setCurrent(true);
1053     }
1054 }
1055
1056 void KItemListView::slotSelectionChanged(const QSet<int>& current, const QSet<int>& previous)
1057 {
1058     Q_UNUSED(previous);
1059
1060     QHashIterator<int, KItemListWidget*> it(m_visibleItems);
1061     while (it.hasNext()) {
1062         it.next();
1063         const int index = it.key();
1064         KItemListWidget* widget = it.value();
1065         widget->setSelected(current.contains(index));
1066     }
1067 }
1068
1069 void KItemListView::slotAnimationFinished(QGraphicsWidget* widget,
1070                                           KItemListViewAnimation::AnimationType type)
1071 {
1072     KItemListWidget* itemListWidget = qobject_cast<KItemListWidget*>(widget);
1073     Q_ASSERT(itemListWidget);
1074
1075     switch (type) {
1076     case KItemListViewAnimation::DeleteAnimation: {
1077         // As we recycle the widget in this case it is important to assure that no
1078         // other animation has been started. This is a convention in KItemListView and
1079         // not a requirement defined by KItemListViewAnimation.
1080         Q_ASSERT(!m_animation->isStarted(itemListWidget));
1081
1082         // All KItemListWidgets that are animated by the DeleteAnimation are not maintained
1083         // by m_visibleWidgets and must be deleted manually after the animation has
1084         // been finished.
1085         recycleGroupHeaderForWidget(itemListWidget);
1086         m_widgetCreator->recycle(itemListWidget);
1087         break;
1088     }
1089
1090     case KItemListViewAnimation::CreateAnimation:
1091     case KItemListViewAnimation::MovingAnimation:
1092     case KItemListViewAnimation::ResizeAnimation: {
1093         const int index = itemListWidget->index();
1094         const bool invisible = (index < m_layouter->firstVisibleIndex()) ||
1095                                (index > m_layouter->lastVisibleIndex());
1096         if (invisible && !m_animation->isStarted(itemListWidget)) {
1097             recycleWidget(itemListWidget);
1098         }
1099         break;
1100     }
1101
1102     default: break;
1103     }
1104 }
1105
1106 void KItemListView::slotLayoutTimerFinished()
1107 {
1108     m_layouter->setSize(geometry().size());
1109     doLayout(Animation);
1110 }
1111
1112 void KItemListView::slotRubberBandPosChanged()
1113 {
1114     update();
1115 }
1116
1117 void KItemListView::slotRubberBandActivationChanged(bool active)
1118 {
1119     if (active) {
1120         connect(m_rubberBand, SIGNAL(startPositionChanged(QPointF,QPointF)), this, SLOT(slotRubberBandPosChanged()));
1121         connect(m_rubberBand, SIGNAL(endPositionChanged(QPointF,QPointF)), this, SLOT(slotRubberBandPosChanged()));
1122         m_skipAutoScrollForRubberBand = true;
1123     } else {
1124         disconnect(m_rubberBand, SIGNAL(startPositionChanged(QPointF,QPointF)), this, SLOT(slotRubberBandPosChanged()));
1125         disconnect(m_rubberBand, SIGNAL(endPositionChanged(QPointF,QPointF)), this, SLOT(slotRubberBandPosChanged()));
1126         m_skipAutoScrollForRubberBand = false;
1127     }
1128
1129     update();
1130 }
1131
1132 void KItemListView::slotVisibleRoleWidthChanged(const QByteArray& role,
1133                                                 qreal currentWidth,
1134                                                 qreal previousWidth)
1135 {
1136     Q_UNUSED(previousWidth);
1137
1138     m_useHeaderWidths = true;
1139
1140     if (m_visibleRolesSizes.contains(role)) {
1141         QSizeF roleSize = m_visibleRolesSizes.value(role);
1142         roleSize.setWidth(currentWidth);
1143         m_visibleRolesSizes.insert(role, roleSize);
1144         m_stretchedVisibleRolesSizes.insert(role, roleSize);
1145
1146         // Apply the new size to the layouter
1147         QSizeF dynamicItemSize = m_itemSize;
1148         if (dynamicItemSize.width() < 0) {
1149             const qreal requiredWidth = visibleRolesSizesWidthSum();
1150             dynamicItemSize.setWidth(qMax(size().width(), requiredWidth));
1151         }
1152         if (dynamicItemSize.height() < 0) {
1153             const qreal requiredHeight = visibleRolesSizesHeightSum();
1154             dynamicItemSize.setHeight(qMax(size().height(), requiredHeight));
1155         }
1156
1157         m_layouter->setItemSize(dynamicItemSize);
1158
1159         // Update the role sizes for all visible widgets
1160         foreach (KItemListWidget* widget, visibleItemListWidgets()) {
1161             widget->setVisibleRolesSizes(m_stretchedVisibleRolesSizes);
1162         }
1163
1164         doLayout(NoAnimation);
1165     }
1166 }
1167
1168 void KItemListView::triggerAutoScrolling()
1169 {
1170     if (!m_autoScrollTimer) {
1171         return;
1172     }
1173
1174     int pos = 0;
1175     int visibleSize = 0;
1176     if (scrollOrientation() == Qt::Vertical) {
1177         pos = m_mousePos.y();
1178         visibleSize = size().height();
1179     } else {
1180         pos = m_mousePos.x();
1181         visibleSize = size().width();
1182     }
1183
1184     if (m_autoScrollTimer->interval() == InitialAutoScrollDelay) {
1185         m_autoScrollIncrement = 0;
1186     }
1187
1188     m_autoScrollIncrement = calculateAutoScrollingIncrement(pos, visibleSize, m_autoScrollIncrement);
1189     if (m_autoScrollIncrement == 0) {
1190         // The mouse position is not above an autoscroll margin (the autoscroll timer
1191         // will be restarted in mouseMoveEvent())
1192         m_autoScrollTimer->stop();
1193         return;
1194     }
1195
1196     if (m_rubberBand->isActive() && m_skipAutoScrollForRubberBand) {
1197         // If a rubberband selection is ongoing the autoscrolling may only get triggered
1198         // if the direction of the rubberband is similar to the autoscroll direction. This
1199         // prevents that starting to create a rubberband within the autoscroll margins starts
1200         // an autoscrolling.
1201
1202         const qreal minDiff = 4; // Ignore any autoscrolling if the rubberband is very small
1203         const qreal diff = (scrollOrientation() == Qt::Vertical)
1204                            ? m_rubberBand->endPosition().y() - m_rubberBand->startPosition().y()
1205                            : m_rubberBand->endPosition().x() - m_rubberBand->startPosition().x();
1206         if (qAbs(diff) < minDiff || (m_autoScrollIncrement < 0 && diff > 0) || (m_autoScrollIncrement > 0 && diff < 0)) {
1207             // The rubberband direction is different from the scroll direction (e.g. the rubberband has
1208             // been moved up although the autoscroll direction might be down)
1209             m_autoScrollTimer->stop();
1210             return;
1211         }
1212     }
1213
1214     // As soon as the autoscrolling has been triggered at least once despite having an active rubberband,
1215     // the autoscrolling may not get skipped anymore until a new rubberband is created
1216     m_skipAutoScrollForRubberBand = false;
1217
1218     const qreal maxVisibleOffset = qMax(qreal(0), maximumScrollOffset() - visibleSize);
1219     const qreal newScrollOffset = qMin(scrollOffset() + m_autoScrollIncrement, maxVisibleOffset);
1220     setScrollOffset(newScrollOffset);
1221
1222    // Trigger the autoscroll timer which will periodically call
1223    // triggerAutoScrolling()
1224    m_autoScrollTimer->start(RepeatingAutoScrollDelay);
1225 }
1226
1227 void KItemListView::slotGeometryOfGroupHeaderParentChanged()
1228 {
1229     KItemListWidget* widget = qobject_cast<KItemListWidget*>(sender());
1230     Q_ASSERT(widget);
1231     KItemListGroupHeader* groupHeader = m_visibleGroups.value(widget);
1232     Q_ASSERT(groupHeader);
1233     updateGroupHeaderLayout(widget);
1234 }
1235
1236 void KItemListView::setController(KItemListController* controller)
1237 {
1238     if (m_controller != controller) {
1239         KItemListController* previous = m_controller;
1240         if (previous) {
1241             KItemListSelectionManager* selectionManager = previous->selectionManager();
1242             disconnect(selectionManager, SIGNAL(currentChanged(int,int)), this, SLOT(slotCurrentChanged(int,int)));
1243             disconnect(selectionManager, SIGNAL(selectionChanged(QSet<int>,QSet<int>)), this, SLOT(slotSelectionChanged(QSet<int>,QSet<int>)));
1244         }
1245
1246         m_controller = controller;
1247
1248         if (controller) {
1249             KItemListSelectionManager* selectionManager = controller->selectionManager();
1250             connect(selectionManager, SIGNAL(currentChanged(int,int)), this, SLOT(slotCurrentChanged(int,int)));
1251             connect(selectionManager, SIGNAL(selectionChanged(QSet<int>,QSet<int>)), this, SLOT(slotSelectionChanged(QSet<int>,QSet<int>)));
1252         }
1253
1254         onControllerChanged(controller, previous);
1255     }
1256 }
1257
1258 void KItemListView::setModel(KItemModelBase* model)
1259 {
1260     if (m_model == model) {
1261         return;
1262     }
1263
1264     KItemModelBase* previous = m_model;
1265
1266     if (m_model) {
1267         disconnect(m_model, SIGNAL(itemsChanged(KItemRangeList,QSet<QByteArray>)),
1268                    this,    SLOT(slotItemsChanged(KItemRangeList,QSet<QByteArray>)));
1269         disconnect(m_model, SIGNAL(itemsInserted(KItemRangeList)),
1270                    this,    SLOT(slotItemsInserted(KItemRangeList)));
1271         disconnect(m_model, SIGNAL(itemsRemoved(KItemRangeList)),
1272                    this,    SLOT(slotItemsRemoved(KItemRangeList)));
1273         disconnect(m_model, SIGNAL(itemsMoved(KItemRange,QList<int>)),
1274                    this,    SLOT(slotItemsMoved(KItemRange,QList<int>)));
1275         disconnect(m_model, SIGNAL(groupedSortingChanged(bool)),
1276                    this,    SLOT(slotGroupedSortingChanged(bool)));
1277         disconnect(m_model, SIGNAL(sortOrderChanged(Qt::SortOrder,Qt::SortOrder)),
1278                    this,    SLOT(slotSortOrderChanged(Qt::SortOrder,Qt::SortOrder)));
1279         disconnect(m_model, SIGNAL(sortRoleChanged(QByteArray,QByteArray)),
1280                    this,    SLOT(slotSortRoleChanged(QByteArray,QByteArray)));
1281     }
1282
1283     m_model = model;
1284     m_layouter->setModel(model);
1285     m_grouped = model->groupedSorting();
1286
1287     if (m_model) {
1288         connect(m_model, SIGNAL(itemsChanged(KItemRangeList,QSet<QByteArray>)),
1289                 this,    SLOT(slotItemsChanged(KItemRangeList,QSet<QByteArray>)));
1290         connect(m_model, SIGNAL(itemsInserted(KItemRangeList)),
1291                 this,    SLOT(slotItemsInserted(KItemRangeList)));
1292         connect(m_model, SIGNAL(itemsRemoved(KItemRangeList)),
1293                 this,    SLOT(slotItemsRemoved(KItemRangeList)));
1294         connect(m_model, SIGNAL(itemsMoved(KItemRange,QList<int>)),
1295                 this,    SLOT(slotItemsMoved(KItemRange,QList<int>)));
1296         connect(m_model, SIGNAL(groupedSortingChanged(bool)),
1297                 this,    SLOT(slotGroupedSortingChanged(bool)));
1298         connect(m_model, SIGNAL(sortOrderChanged(Qt::SortOrder,Qt::SortOrder)),
1299                 this,    SLOT(slotSortOrderChanged(Qt::SortOrder,Qt::SortOrder)));
1300         connect(m_model, SIGNAL(sortRoleChanged(QByteArray,QByteArray)),
1301                 this,    SLOT(slotSortRoleChanged(QByteArray,QByteArray)));
1302     }
1303
1304     onModelChanged(model, previous);
1305 }
1306
1307 KItemListRubberBand* KItemListView::rubberBand() const
1308 {
1309     return m_rubberBand;
1310 }
1311
1312 void KItemListView::doLayout(LayoutAnimationHint hint, int changedIndex, int changedCount)
1313 {
1314     if (m_layoutTimer->isActive()) {
1315         m_layoutTimer->stop();
1316     }
1317
1318     if (m_activeTransactions > 0) {
1319         if (hint == NoAnimation) {
1320             // As soon as at least one property change should be done without animation,
1321             // the whole transaction will be marked as not animated.
1322             m_endTransactionAnimationHint = NoAnimation;
1323         }
1324         return;
1325     }
1326
1327     if (!m_model || m_model->count() < 0) {
1328         return;
1329     }
1330
1331     int firstVisibleIndex = m_layouter->firstVisibleIndex();
1332     if (firstVisibleIndex < 0) {
1333         emitOffsetChanges();
1334         return;
1335     }
1336
1337     // Do a sanity check of the scroll-offset property: When properties of the itemlist-view have been changed
1338     // it might be possible that the maximum offset got changed too. Assure that the full visible range
1339     // is still shown if the maximum offset got decreased.
1340     const qreal visibleOffsetRange = (scrollOrientation() == Qt::Horizontal) ? size().width() : size().height();
1341     const qreal maxOffsetToShowFullRange = maximumScrollOffset() - visibleOffsetRange;
1342     if (scrollOffset() > maxOffsetToShowFullRange) {
1343         m_layouter->setScrollOffset(qMax(qreal(0), maxOffsetToShowFullRange));
1344         firstVisibleIndex = m_layouter->firstVisibleIndex();
1345     }
1346
1347     const int lastVisibleIndex = m_layouter->lastVisibleIndex();
1348
1349     QList<int> reusableItems = recycleInvisibleItems(firstVisibleIndex, lastVisibleIndex, hint);
1350
1351     // Assure that for each visible item a KItemListWidget is available. KItemListWidget
1352     // instances from invisible items are reused. If no reusable items are
1353     // found then new KItemListWidget instances get created.
1354     const bool animate = (hint == Animation);
1355     for (int i = firstVisibleIndex; i <= lastVisibleIndex; ++i) {
1356         bool applyNewPos = true;
1357         bool wasHidden = false;
1358
1359         const QRectF itemBounds = m_layouter->itemRect(i);
1360         const QPointF newPos = itemBounds.topLeft();
1361         KItemListWidget* widget = m_visibleItems.value(i);
1362         if (!widget) {
1363             wasHidden = true;
1364             if (!reusableItems.isEmpty()) {
1365                 // Reuse a KItemListWidget instance from an invisible item
1366                 const int oldIndex = reusableItems.takeLast();
1367                 widget = m_visibleItems.value(oldIndex);
1368                 setWidgetIndex(widget, i);
1369
1370                 if (m_grouped) {
1371                     updateGroupHeaderForWidget(widget);
1372                 }
1373             } else {
1374                 // No reusable KItemListWidget instance is available, create a new one
1375                 widget = createWidget(i);
1376             }
1377             widget->resize(itemBounds.size());
1378
1379             if (animate && changedCount < 0) {
1380                 // Items have been deleted, move the created item to the
1381                 // imaginary old position. They will get animated to the new position
1382                 // later.
1383                 const QRectF itemRect = m_layouter->itemRect(i - changedCount);
1384                 if (itemRect.isEmpty()) {
1385                     const QPointF invisibleOldPos = (scrollOrientation() == Qt::Vertical)
1386                                                     ? QPointF(0, size().height()) : QPointF(size().width(), 0);
1387                     widget->setPos(invisibleOldPos);
1388                 } else {
1389                     widget->setPos(itemRect.topLeft());
1390                 }
1391                 applyNewPos = false;
1392             }
1393         }
1394
1395         if (animate) {
1396             const bool itemsRemoved = (changedCount < 0);
1397             const bool itemsInserted = (changedCount > 0);
1398             if (itemsRemoved && (i >= changedIndex + changedCount + 1)) {
1399                 // The item is located after the removed items. Animate the moving of the position.
1400                 applyNewPos = !moveWidget(widget, itemBounds);
1401             } else if (itemsInserted && i >= changedIndex) {
1402                 // The item is located after the first inserted item
1403                 if (i <= changedIndex + changedCount - 1) {
1404                     // The item is an inserted item. Animate the appearing of the item.
1405                     // For performance reasons no animation is done when changedCount is equal
1406                     // to all available items.
1407                     if (changedCount < m_model->count()) {
1408                         m_animation->start(widget, KItemListViewAnimation::CreateAnimation);
1409                     }
1410                 } else if (!m_animation->isStarted(widget, KItemListViewAnimation::CreateAnimation)) {
1411                     // The item was already there before, so animate the moving of the position.
1412                     // No moving animation is done if the item is animated by a create animation: This
1413                     // prevents a "move animation mess" when inserting several ranges in parallel.
1414                     applyNewPos = !moveWidget(widget, itemBounds);
1415                 }
1416             } else if (!itemsRemoved && !itemsInserted && !wasHidden) {
1417                 // The size of the view might have been changed. Animate the moving of the position.
1418                 applyNewPos = !moveWidget(widget, itemBounds);
1419             }
1420         } else {
1421             m_animation->stop(widget);
1422         }
1423
1424         if (applyNewPos) {
1425             widget->setPos(newPos);
1426         }
1427
1428         Q_ASSERT(widget->index() == i);
1429         widget->setVisible(true);
1430
1431         if (widget->size() != itemBounds.size()) {
1432             // Resize the widget for the item to the changed size.
1433             if (animate) {
1434                 // If a dynamic item size is used then no animation is done in the direction
1435                 // of the dynamic size.
1436                 if (m_itemSize.width() <= 0) {
1437                     // The width is dynamic, apply the new width without animation.
1438                     widget->resize(itemBounds.width(), widget->size().height());
1439                 } else if (m_itemSize.height() <= 0) {
1440                     // The height is dynamic, apply the new height without animation.
1441                     widget->resize(widget->size().width(), itemBounds.height());
1442                 }
1443                 m_animation->start(widget, KItemListViewAnimation::ResizeAnimation, itemBounds.size());
1444             } else {
1445                 widget->resize(itemBounds.size());
1446             }
1447         }
1448     }
1449
1450     // Delete invisible KItemListWidget instances that have not been reused
1451     foreach (int index, reusableItems) {
1452         recycleWidget(m_visibleItems.value(index));
1453     }
1454
1455     if (m_grouped) {
1456         // Update the layout of all visible group headers
1457         QHashIterator<KItemListWidget*, KItemListGroupHeader*> it(m_visibleGroups);
1458         while (it.hasNext()) {
1459             it.next();
1460             updateGroupHeaderLayout(it.key());
1461         }
1462     }
1463
1464     emitOffsetChanges();
1465 }
1466
1467 QList<int> KItemListView::recycleInvisibleItems(int firstVisibleIndex,
1468                                                 int lastVisibleIndex,
1469                                                 LayoutAnimationHint hint)
1470 {
1471     // Determine all items that are completely invisible and might be
1472     // reused for items that just got (at least partly) visible. If the
1473     // animation hint is set to 'Animation' items that do e.g. an animated
1474     // moving of their position are not marked as invisible: This assures
1475     // that a scrolling inside the view can be done without breaking an animation.
1476
1477     QList<int> items;
1478
1479     QHashIterator<int, KItemListWidget*> it(m_visibleItems);
1480     while (it.hasNext()) {
1481         it.next();
1482
1483         KItemListWidget* widget = it.value();
1484         const int index = widget->index();
1485         const bool invisible = (index < firstVisibleIndex) || (index > lastVisibleIndex);
1486
1487         if (invisible) {
1488             if (m_animation->isStarted(widget)) {
1489                 if (hint == NoAnimation) {
1490                     // Stopping the animation will call KItemListView::slotAnimationFinished()
1491                     // and the widget will be recycled if necessary there.
1492                     m_animation->stop(widget);
1493                 }
1494             } else {
1495                 widget->setVisible(false);
1496                 items.append(index);
1497
1498                 if (m_grouped) {
1499                     recycleGroupHeaderForWidget(widget);
1500                 }
1501             }
1502         }
1503     }
1504
1505     return items;
1506 }
1507
1508 bool KItemListView::moveWidget(KItemListWidget* widget,const QRectF& itemBounds)
1509 {
1510     const QPointF oldPos = widget->pos();
1511     const QPointF newPos = itemBounds.topLeft();
1512     if (oldPos == newPos) {
1513         return false;
1514     }
1515
1516     bool startMovingAnim = m_itemSize.isEmpty() || widget->size() != itemBounds.size();
1517     if (!startMovingAnim) {
1518         // When having a grid the moving-animation should only be started, if it is done within
1519         // one row in the vertical scroll-orientation or one column in the horizontal scroll-orientation.
1520         // Otherwise instead of a moving-animation a create-animation on the new position will be used
1521         // instead. This is done to prevent overlapping (and confusing) moving-animations.
1522         const QSizeF itemMargin = m_layouter->itemMargin();
1523         const qreal xMax = m_itemSize.width() + itemMargin.width();
1524         const qreal yMax = m_itemSize.height() + itemMargin.height();
1525         qreal xDiff = qAbs(oldPos.x() - newPos.x());
1526         qreal yDiff = qAbs(oldPos.y() - newPos.y());
1527         if (scrollOrientation() == Qt::Vertical) {
1528             startMovingAnim = (xDiff > yDiff && yDiff < yMax);
1529         } else {
1530             startMovingAnim = (yDiff > xDiff && xDiff < xMax);
1531         }
1532     }
1533
1534     if (startMovingAnim) {
1535         m_animation->start(widget, KItemListViewAnimation::MovingAnimation, newPos);
1536         return true;
1537     }
1538
1539     m_animation->stop(widget);
1540     m_animation->start(widget, KItemListViewAnimation::CreateAnimation);
1541     return false;
1542 }
1543
1544 void KItemListView::emitOffsetChanges()
1545 {
1546     const qreal newScrollOffset = m_layouter->scrollOffset();
1547     if (m_oldScrollOffset != newScrollOffset) {
1548         emit scrollOffsetChanged(newScrollOffset, m_oldScrollOffset);
1549         m_oldScrollOffset = newScrollOffset;
1550     }
1551
1552     const qreal newMaximumScrollOffset = m_layouter->maximumScrollOffset();
1553     if (m_oldMaximumScrollOffset != newMaximumScrollOffset) {
1554         emit maximumScrollOffsetChanged(newMaximumScrollOffset, m_oldMaximumScrollOffset);
1555         m_oldMaximumScrollOffset = newMaximumScrollOffset;
1556     }
1557
1558     const qreal newItemOffset = m_layouter->itemOffset();
1559     if (m_oldItemOffset != newItemOffset) {
1560         emit itemOffsetChanged(newItemOffset, m_oldItemOffset);
1561         m_oldItemOffset = newItemOffset;
1562     }
1563
1564     const qreal newMaximumItemOffset = m_layouter->maximumItemOffset();
1565     if (m_oldMaximumItemOffset != newMaximumItemOffset) {
1566         emit maximumItemOffsetChanged(newMaximumItemOffset, m_oldMaximumItemOffset);
1567         m_oldMaximumItemOffset = newMaximumItemOffset;
1568     }
1569 }
1570
1571 KItemListWidget* KItemListView::createWidget(int index)
1572 {
1573     KItemListWidget* widget = m_widgetCreator->create(this);
1574     widget->setFlag(QGraphicsItem::ItemStacksBehindParent);
1575
1576     updateWidgetProperties(widget, index);
1577     m_visibleItems.insert(index, widget);
1578
1579     if (m_grouped) {
1580         updateGroupHeaderForWidget(widget);
1581     }
1582
1583     initializeItemListWidget(widget);
1584     return widget;
1585 }
1586
1587 void KItemListView::recycleWidget(KItemListWidget* widget)
1588 {
1589     if (m_grouped) {
1590         recycleGroupHeaderForWidget(widget);
1591     }
1592
1593     m_visibleItems.remove(widget->index());
1594     m_widgetCreator->recycle(widget);
1595 }
1596
1597 void KItemListView::setWidgetIndex(KItemListWidget* widget, int index)
1598 {
1599     const int oldIndex = widget->index();
1600     m_visibleItems.remove(oldIndex);
1601     updateWidgetProperties(widget, index);
1602     m_visibleItems.insert(index, widget);
1603
1604     initializeItemListWidget(widget);
1605 }
1606
1607 void KItemListView::setLayouterSize(const QSizeF& size, SizeType sizeType)
1608 {
1609     switch (sizeType) {
1610     case LayouterSize: m_layouter->setSize(size); break;
1611     case ItemSize: m_layouter->setItemSize(size); break;
1612     default: break;
1613     }
1614 }
1615
1616 void KItemListView::updateWidgetProperties(KItemListWidget* widget, int index)
1617 {
1618     widget->setVisibleRoles(m_visibleRoles);
1619     widget->setVisibleRolesSizes(m_stretchedVisibleRolesSizes);
1620     widget->setStyleOption(m_styleOption);
1621
1622     const KItemListSelectionManager* selectionManager = m_controller->selectionManager();
1623     widget->setCurrent(index == selectionManager->currentItem());
1624     widget->setSelected(selectionManager->isSelected(index));
1625     widget->setHovered(false);
1626     widget->setAlternatingBackgroundColors(false);
1627     widget->setEnabledSelectionToggle(enabledSelectionToggles());
1628     widget->setIndex(index);
1629     widget->setData(m_model->data(index));
1630 }
1631
1632 void KItemListView::updateGroupHeaderForWidget(KItemListWidget* widget)
1633 {
1634     Q_ASSERT(m_grouped);
1635
1636     const int index = widget->index();
1637     if (!m_layouter->isFirstGroupItem(index)) {
1638         // The widget does not represent the first item of a group
1639         // and hence requires no header
1640         recycleGroupHeaderForWidget(widget);
1641         return;
1642     }
1643
1644     const QList<QPair<int, QVariant> > groups = model()->groups();
1645     if (groups.isEmpty()) {
1646         return;
1647     }
1648
1649     KItemListGroupHeader* groupHeader = m_visibleGroups.value(widget);
1650     if (!groupHeader) {
1651         groupHeader = m_groupHeaderCreator->create(this);
1652         groupHeader->setParentItem(widget);
1653         m_visibleGroups.insert(widget, groupHeader);
1654         connect(widget, SIGNAL(geometryChanged()), this, SLOT(slotGeometryOfGroupHeaderParentChanged()));
1655     }
1656     Q_ASSERT(groupHeader->parentItem() == widget);
1657
1658     // Determine the shown data for the header by doing a binary
1659     // search in the groups-list
1660     int min = 0;
1661     int max = groups.count() - 1;
1662     int mid = 0;
1663     do {
1664         mid = (min + max) / 2;
1665         if (index > groups.at(mid).first) {
1666             min = mid + 1;
1667         } else {
1668             max = mid - 1;
1669         }
1670     } while (groups.at(mid).first != index && min <= max);
1671
1672     groupHeader->setData(groups.at(mid).second);
1673     groupHeader->setRole(model()->sortRole());
1674     groupHeader->setStyleOption(m_styleOption);
1675     groupHeader->setScrollOrientation(scrollOrientation());
1676     groupHeader->setItemIndex(index);
1677
1678     groupHeader->show();
1679 }
1680
1681 void KItemListView::updateGroupHeaderLayout(KItemListWidget* widget)
1682 {
1683     KItemListGroupHeader* groupHeader = m_visibleGroups.value(widget);
1684     Q_ASSERT(groupHeader);
1685
1686     const int index = widget->index();
1687     const QRectF groupHeaderRect = m_layouter->groupHeaderRect(index);
1688     const QRectF itemRect = m_layouter->itemRect(index);
1689
1690     // The group-header is a child of the itemlist widget. Translate the
1691     // group header position to the relative position.
1692     if (scrollOrientation() == Qt::Vertical) {
1693         // In the vertical scroll orientation the group header should always span
1694         // the whole width no matter which temporary position the parent widget
1695         // has. In this case the x-position and width will be adjusted manually.
1696         groupHeader->setPos(-widget->x(), -groupHeaderRect.height());
1697         groupHeader->resize(size().width(), groupHeaderRect.size().height());
1698     } else {
1699         groupHeader->setPos(groupHeaderRect.x() - itemRect.x(), -groupHeaderRect.height());
1700         groupHeader->resize(groupHeaderRect.size());
1701     }
1702 }
1703
1704 void KItemListView::recycleGroupHeaderForWidget(KItemListWidget* widget)
1705 {
1706     KItemListGroupHeader* header = m_visibleGroups.value(widget);
1707     if (header) {
1708         header->setParentItem(0);
1709         m_groupHeaderCreator->recycle(header);
1710         m_visibleGroups.remove(widget);
1711         disconnect(widget, SIGNAL(geometryChanged()), this, SLOT(slotGeometryOfGroupHeaderParentChanged()));
1712     }
1713 }
1714
1715 void KItemListView::updateVisibleGroupHeaders()
1716 {
1717     Q_ASSERT(m_grouped);
1718     m_layouter->markAsDirty();
1719
1720     QHashIterator<int, KItemListWidget*> it(m_visibleItems);
1721     while (it.hasNext()) {
1722         it.next();
1723         updateGroupHeaderForWidget(it.value());
1724     }
1725 }
1726
1727 QHash<QByteArray, qreal> KItemListView::headerRolesWidths() const
1728 {
1729     QHash<QByteArray, qreal> rolesWidths;
1730
1731     QHashIterator<QByteArray, QSizeF> it(m_stretchedVisibleRolesSizes);
1732     while (it.hasNext()) {
1733         it.next();
1734         rolesWidths.insert(it.key(), it.value().width());
1735     }
1736
1737     return rolesWidths;
1738 }
1739
1740 void KItemListView::updateVisibleRolesSizes(const KItemRangeList& itemRanges)
1741 {
1742     if (!m_itemSize.isEmpty() || m_useHeaderWidths) {
1743         return;
1744     }
1745
1746     const int itemCount = m_model->count();
1747     int rangesItemCount = 0;
1748     foreach (const KItemRange& range, itemRanges) {
1749         rangesItemCount += range.count;
1750     }
1751
1752     if (itemCount == rangesItemCount) {
1753         m_visibleRolesSizes = visibleRolesSizes(itemRanges);
1754         if (m_header) {
1755             // Assure the the sizes are not smaller than the minimum defined by the header
1756             // TODO: Currently only implemented for a top-aligned header
1757             const qreal minHeaderRoleWidth = m_header->minimumRoleWidth();
1758             QMutableHashIterator<QByteArray, QSizeF> it (m_visibleRolesSizes);
1759             while (it.hasNext()) {
1760                 it.next();
1761                 const QSizeF& size = it.value();
1762                 if (size.width() < minHeaderRoleWidth) {
1763                     const QSizeF newSize(minHeaderRoleWidth, size.height());
1764                     m_visibleRolesSizes.insert(it.key(), newSize);
1765                 }
1766             }
1767         }
1768     } else {
1769         // Only a sub range of the roles need to be determined.
1770         // The chances are good that the sizes of the sub ranges
1771         // already fit into the available sizes and hence no
1772         // expensive update might be required.
1773         bool updateRequired = false;
1774
1775         const QHash<QByteArray, QSizeF> updatedSizes = visibleRolesSizes(itemRanges);
1776         QHashIterator<QByteArray, QSizeF> it(updatedSizes);
1777         while (it.hasNext()) {
1778             it.next();
1779             const QByteArray& role = it.key();
1780             const QSizeF& updatedSize = it.value();
1781             const QSizeF currentSize = m_visibleRolesSizes.value(role);
1782             if (updatedSize.width() > currentSize.width() || updatedSize.height() > currentSize.height()) {
1783                 m_visibleRolesSizes.insert(role, updatedSize);
1784                 updateRequired = true;
1785             }
1786         }
1787
1788         if (!updateRequired) {
1789             // All the updated sizes are smaller than the current sizes and no change
1790             // of the stretched roles-widths is required
1791             return;
1792         }
1793     }
1794
1795     updateStretchedVisibleRolesSizes();
1796 }
1797
1798 void KItemListView::updateVisibleRolesSizes()
1799 {
1800     if (!m_model) {
1801         return;
1802     }
1803
1804     const int itemCount = m_model->count();
1805     if (itemCount > 0) {
1806         updateVisibleRolesSizes(KItemRangeList() << KItemRange(0, itemCount));
1807     }
1808 }
1809
1810 void KItemListView::updateStretchedVisibleRolesSizes()
1811 {
1812     if (!m_itemSize.isEmpty() || m_useHeaderWidths || m_visibleRoles.isEmpty()) {
1813         return;
1814     }
1815
1816     // Calculate the maximum size of an item by considering the
1817     // visible role sizes and apply them to the layouter. If the
1818     // size does not use the available view-size it the size of the
1819     // first role will get stretched.
1820     m_stretchedVisibleRolesSizes = m_visibleRolesSizes;
1821     const QByteArray role = m_visibleRoles.first();
1822     QSizeF firstRoleSize = m_stretchedVisibleRolesSizes.value(role);
1823
1824     QSizeF dynamicItemSize = m_itemSize;
1825
1826     if (dynamicItemSize.width() <= 0) {
1827         const qreal requiredWidth = visibleRolesSizesWidthSum();
1828         const qreal availableWidth = size().width();
1829         if (requiredWidth < availableWidth) {
1830             // Stretch the first role to use the whole width for the item
1831             firstRoleSize.rwidth() += availableWidth - requiredWidth;
1832             m_stretchedVisibleRolesSizes.insert(role, firstRoleSize);
1833         }
1834         dynamicItemSize.setWidth(qMax(requiredWidth, availableWidth));
1835     }
1836
1837     if (dynamicItemSize.height() <= 0) {
1838         const qreal requiredHeight = visibleRolesSizesHeightSum();
1839         const qreal availableHeight = size().height();
1840         if (requiredHeight < availableHeight) {
1841             // Stretch the first role to use the whole height for the item
1842             firstRoleSize.rheight() += availableHeight - requiredHeight;
1843             m_stretchedVisibleRolesSizes.insert(role, firstRoleSize);
1844         }
1845         dynamicItemSize.setHeight(qMax(requiredHeight, availableHeight));
1846     }
1847
1848     m_layouter->setItemSize(dynamicItemSize);
1849
1850     if (m_header) {
1851         m_header->setVisibleRolesWidths(headerRolesWidths());
1852         m_header->resize(dynamicItemSize.width(), m_header->size().height());
1853     }
1854
1855     // Update the role sizes for all visible widgets
1856     foreach (KItemListWidget* widget, visibleItemListWidgets()) {
1857         widget->setVisibleRolesSizes(m_stretchedVisibleRolesSizes);
1858     }
1859 }
1860
1861 qreal KItemListView::visibleRolesSizesWidthSum() const
1862 {
1863     qreal widthSum = 0;
1864     QHashIterator<QByteArray, QSizeF> it(m_visibleRolesSizes);
1865     while (it.hasNext()) {
1866         it.next();
1867         widthSum += it.value().width();
1868     }
1869     return widthSum;
1870 }
1871
1872 qreal KItemListView::visibleRolesSizesHeightSum() const
1873 {
1874     qreal heightSum = 0;
1875     QHashIterator<QByteArray, QSizeF> it(m_visibleRolesSizes);
1876     while (it.hasNext()) {
1877         it.next();
1878         heightSum += it.value().height();
1879     }
1880     return heightSum;
1881 }
1882
1883 QRectF KItemListView::headerBoundaries() const
1884 {
1885     return m_header ? m_header->geometry() : QRectF();
1886 }
1887
1888 bool KItemListView::changesItemGridLayout(const QSizeF& newGridSize,
1889                                           const QSizeF& newItemSize,
1890                                           const QSizeF& newItemMargin) const
1891 {
1892     if (newItemSize.isEmpty() || newGridSize.isEmpty()) {
1893         return false;
1894     }
1895
1896     if (m_layouter->scrollOrientation() == Qt::Vertical) {
1897         const qreal itemWidth = m_layouter->itemSize().width();
1898         if (itemWidth > 0) {
1899             const int newColumnCount = itemsPerSize(newGridSize.width(),
1900                                                     newItemSize.width(),
1901                                                     newItemMargin.width());
1902             if (m_model->count() > newColumnCount) {
1903                 const int oldColumnCount = itemsPerSize(m_layouter->size().width(),
1904                                                         itemWidth,
1905                                                         m_layouter->itemMargin().width());
1906                 return oldColumnCount != newColumnCount;
1907             }
1908         }
1909     } else {
1910         const qreal itemHeight = m_layouter->itemSize().height();
1911         if (itemHeight > 0) {
1912             const int newRowCount = itemsPerSize(newGridSize.height(),
1913                                                  newItemSize.height(),
1914                                                  newItemMargin.height());
1915             if (m_model->count() > newRowCount) {
1916                 const int oldRowCount = itemsPerSize(m_layouter->size().height(),
1917                                                      itemHeight,
1918                                                      m_layouter->itemMargin().height());
1919                 return oldRowCount != newRowCount;
1920             }
1921         }
1922     }
1923
1924     return false;
1925 }
1926
1927 bool KItemListView::animateChangedItemCount(int changedItemCount) const
1928 {
1929     if (m_layouter->size().isEmpty() || m_layouter->itemSize().isEmpty()) {
1930         return false;
1931     }
1932
1933     const int maximum = (scrollOrientation() == Qt::Vertical)
1934                         ? m_layouter->size().width()  / m_layouter->itemSize().width()
1935                         : m_layouter->size().height() / m_layouter->itemSize().height();
1936     // Only animate if up to 2/3 of a row or column are inserted or removed
1937     return changedItemCount <= maximum * 2 / 3;
1938 }
1939
1940
1941 bool KItemListView::scrollBarRequired(const QSizeF& size) const
1942 {
1943     const QSizeF oldSize = m_layouter->size();
1944
1945     m_layouter->setSize(size);
1946     const qreal maxOffset = m_layouter->maximumScrollOffset();
1947     m_layouter->setSize(oldSize);
1948
1949     return m_layouter->scrollOrientation() == Qt::Vertical ? maxOffset > size.height()
1950                                                            : maxOffset > size.width();
1951 }
1952
1953 void KItemListView::updateGroupHeaderHeight()
1954 {
1955     const qreal groupHeaderHeight = m_styleOption.fontMetrics.height() + m_styleOption.padding * 2;
1956
1957     qreal groupHeaderMargin = 0;
1958     if (scrollOrientation() == Qt::Horizontal) {
1959         groupHeaderMargin = m_styleOption.horizontalMargin;
1960     } else if (m_itemSize.isEmpty()){
1961         groupHeaderMargin = groupHeaderHeight / 2;
1962     } else {
1963         groupHeaderMargin = m_styleOption.verticalMargin * 2;
1964     }
1965     m_layouter->setGroupHeaderHeight(groupHeaderHeight);
1966     m_layouter->setGroupHeaderMargin(groupHeaderMargin);
1967
1968     updateVisibleGroupHeaders();
1969 }
1970
1971 int KItemListView::calculateAutoScrollingIncrement(int pos, int range, int oldInc)
1972 {
1973     int inc = 0;
1974
1975     const int minSpeed = 4;
1976     const int maxSpeed = 128;
1977     const int speedLimiter = 96;
1978     const int autoScrollBorder = 64;
1979
1980     // Limit the increment that is allowed to be added in comparison to 'oldInc'.
1981     // This assures that the autoscrolling speed grows gradually.
1982     const int incLimiter = 1;
1983
1984     if (pos < autoScrollBorder) {
1985         inc = -minSpeed + qAbs(pos - autoScrollBorder) * (pos - autoScrollBorder) / speedLimiter;
1986         inc = qMax(inc, -maxSpeed);
1987         inc = qMax(inc, oldInc - incLimiter);
1988     } else if (pos > range - autoScrollBorder) {
1989         inc = minSpeed + qAbs(pos - range + autoScrollBorder) * (pos - range + autoScrollBorder) / speedLimiter;
1990         inc = qMin(inc, maxSpeed);
1991         inc = qMin(inc, oldInc + incLimiter);
1992     }
1993
1994     return inc;
1995 }
1996
1997 int KItemListView::itemsPerSize(qreal size, qreal itemSize, qreal itemMargin)
1998 {
1999     const qreal availableSize = size - itemMargin;
2000     const int count = availableSize / (itemSize + itemMargin);
2001     return count;
2002 }
2003
2004
2005
2006 KItemListCreatorBase::~KItemListCreatorBase()
2007 {
2008     qDeleteAll(m_recycleableWidgets);
2009     qDeleteAll(m_createdWidgets);
2010 }
2011
2012 void KItemListCreatorBase::addCreatedWidget(QGraphicsWidget* widget)
2013 {
2014     m_createdWidgets.insert(widget);
2015 }
2016
2017 void KItemListCreatorBase::pushRecycleableWidget(QGraphicsWidget* widget)
2018 {
2019     Q_ASSERT(m_createdWidgets.contains(widget));
2020     m_createdWidgets.remove(widget);
2021
2022     if (m_recycleableWidgets.count() < 100) {
2023         m_recycleableWidgets.append(widget);
2024         widget->setVisible(false);
2025     } else {
2026         delete widget;
2027     }
2028 }
2029
2030 QGraphicsWidget* KItemListCreatorBase::popRecycleableWidget()
2031 {
2032     if (m_recycleableWidgets.isEmpty()) {
2033         return 0;
2034     }
2035
2036     QGraphicsWidget* widget = m_recycleableWidgets.takeLast();
2037     m_createdWidgets.insert(widget);
2038     return widget;
2039 }
2040
2041 KItemListWidgetCreatorBase::~KItemListWidgetCreatorBase()
2042 {
2043 }
2044
2045 void KItemListWidgetCreatorBase::recycle(KItemListWidget* widget)
2046 {
2047     widget->setParentItem(0);
2048     widget->setOpacity(1.0);
2049     pushRecycleableWidget(widget);
2050 }
2051
2052 KItemListGroupHeaderCreatorBase::~KItemListGroupHeaderCreatorBase()
2053 {
2054 }
2055
2056 void KItemListGroupHeaderCreatorBase::recycle(KItemListGroupHeader* header)
2057 {
2058     header->setOpacity(1.0);
2059     pushRecycleableWidget(header);
2060 }
2061
2062 #include "kitemlistview.moc"