src/kitemviews/kitemlistview.cpp

   1 /***************************************************************************
   2  *   Copyright (C) 2011 by Peter Penz <peter.penz19@gmail.com>             *
   3  *                                                                         *
   4  *   Based on the Itemviews NG project from Trolltech Labs:                *
   5  *   http://qt.gitorious.org/qt-labs/itemviews-ng                          *
   6  *                                                                         *
   7  *   This program is free software; you can redistribute it and/or modify  *
   8  *   it under the terms of the GNU General Public License as published by  *
   9  *   the Free Software Foundation; either version 2 of the License, or     *
  10  *   (at your option) any later version.                                   *
  11  *                                                                         *
  12  *   This program is distributed in the hope that it will be useful,       *
  13  *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
  14  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
  15  *   GNU General Public License for more details.                          *
  16  *                                                                         *
  17  *   You should have received a copy of the GNU General Public License     *
  18  *   along with this program; if not, write to the                         *
  19  *   Free Software Foundation, Inc.,                                       *
  20  *   51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA            *
  21  ***************************************************************************/
  22
  23 #include "kitemlistview.h"
  24
  25 #include "kitemlistcontroller.h"
  26 #include "kitemlistheader_p.h"
  27 #include "kitemlistrubberband_p.h"
  28 #include "kitemlistselectionmanager.h"
  29 #include "kitemlistsizehintresolver_p.h"
  30 #include "kitemlistviewlayouter_p.h"
  31 #include "kitemlistviewanimation_p.h"
  32 #include "kitemlistwidget.h"
  33
  34 #include <KDebug>
  35
  36 #include <QCursor>
  37 #include <QGraphicsSceneMouseEvent>
  38 #include <QPainter>
  39 #include <QPropertyAnimation>
  40 #include <QStyle>
  41 #include <QStyleOptionRubberBand>
  42 #include <QTimer>
  43
  44 namespace {
  45     // Time in ms until reaching the autoscroll margin triggers
  46     // an initial autoscrolling
  47     const int InitialAutoScrollDelay = 700;
  48
  49     // Delay in ms for triggering the next autoscroll
  50     const int RepeatingAutoScrollDelay = 1000 / 60;
  51 }
  52
  53 KItemListView::KItemListView(QGraphicsWidget* parent) :
  54     QGraphicsWidget(parent),
  55     m_enabledSelectionToggles(false),
  56     m_grouped(false),
  57     m_activeTransactions(0),
  58     m_itemSize(),
  59     m_controller(0),
  60     m_model(0),
  61     m_visibleRoles(),
  62     m_visibleRolesSizes(),
  63     m_stretchedVisibleRolesSizes(),
  64     m_widgetCreator(0),
  65     m_groupHeaderCreator(0),
  66     m_styleOption(),
  67     m_visibleItems(),
  68     m_visibleGroups(),
  69     m_sizeHintResolver(0),
  70     m_layouter(0),
  71     m_animation(0),
  72     m_layoutTimer(0),
  73     m_oldScrollOffset(0),
  74     m_oldMaximumScrollOffset(0),
  75     m_oldItemOffset(0),
  76     m_oldMaximumItemOffset(0),
  77     m_skipAutoScrollForRubberBand(false),
  78     m_rubberBand(0),
  79     m_mousePos(),
  80     m_autoScrollIncrement(0),
  81     m_autoScrollTimer(0),
  82     m_header(0),
  83     m_useHeaderWidths(false)
  84 {
  85     setAcceptHoverEvents(true);
  86
  87     m_sizeHintResolver = new KItemListSizeHintResolver(this);
  88
  89     m_layouter = new KItemListViewLayouter(this);
  90     m_layouter->setSizeHintResolver(m_sizeHintResolver);
  91
  92     m_animation = new KItemListViewAnimation(this);
  93     connect(m_animation, SIGNAL(finished(QGraphicsWidget*,KItemListViewAnimation::AnimationType)),
  94             this, SLOT(slotAnimationFinished(QGraphicsWidget*,KItemListViewAnimation::AnimationType)));
  95
  96     m_layoutTimer = new QTimer(this);
  97     m_layoutTimer->setInterval(300);
  98     m_layoutTimer->setSingleShot(true);
  99     connect(m_layoutTimer, SIGNAL(timeout()), this, SLOT(slotLayoutTimerFinished()));
 100
 101     m_rubberBand = new KItemListRubberBand(this);
 102     connect(m_rubberBand, SIGNAL(activationChanged(bool)), this, SLOT(slotRubberBandActivationChanged(bool)));
 103 }
 104
 105 KItemListView::~KItemListView()
 106 {
 107     delete m_sizeHintResolver;
 108     m_sizeHintResolver = 0;
 109 }
 110
 111 void KItemListView::setScrollOrientation(Qt::Orientation orientation)
 112 {
 113     const Qt::Orientation previousOrientation = m_layouter->scrollOrientation();
 114     if (orientation == previousOrientation) {
 115         return;
 116     }
 117
 118     m_layouter->setScrollOrientation(orientation);
 119     m_animation->setScrollOrientation(orientation);
 120     m_sizeHintResolver->clearCache();
 121
 122     if (m_grouped) {
 123         QMutableHashIterator<KItemListWidget*, KItemListGroupHeader*> it (m_visibleGroups);
 124         while (it.hasNext()) {
 125             it.next();
 126             it.value()->setScrollOrientation(orientation);
 127         }
 128     }
 129
 130     doLayout(Animation);
 131
 132     onScrollOrientationChanged(orientation, previousOrientation);
 133     emit scrollOrientationChanged(orientation, previousOrientation);
 134 }
 135
 136 Qt::Orientation KItemListView::scrollOrientation() const
 137 {
 138     return m_layouter->scrollOrientation();
 139 }
 140
 141 void KItemListView::setItemSize(const QSizeF& itemSize)
 142 {
 143     const QSizeF previousSize = m_itemSize;
 144     if (itemSize == previousSize) {
 145         return;
 146     }
 147
 148     m_itemSize = itemSize;
 149
 150     const bool emptySize = itemSize.isEmpty();
 151     if (emptySize) {
 152         updateVisibleRolesSizes();
 153     } else {
 154         if (itemSize.width() < previousSize.width() || itemSize.height() < previousSize.height()) {
 155             prepareLayoutForIncreasedItemCount(itemSize, ItemSize);
 156         } else {
 157             m_layouter->setItemSize(itemSize);
 158         }
 159     }
 160
 161     m_sizeHintResolver->clearCache();
 162     doLayout(Animation);
 163     onItemSizeChanged(itemSize, previousSize);
 164 }
 165
 166 QSizeF KItemListView::itemSize() const
 167 {
 168     return m_itemSize;
 169 }
 170
 171 void KItemListView::setScrollOffset(qreal offset)
 172 {
 173     if (offset < 0) {
 174         offset = 0;
 175     }
 176
 177     const qreal previousOffset = m_layouter->scrollOffset();
 178     if (offset == previousOffset) {
 179         return;
 180     }
 181
 182     m_layouter->setScrollOffset(offset);
 183     m_animation->setScrollOffset(offset);
 184
 185     // Don't check whether the m_layoutTimer is active: Changing the
 186     // scroll offset must always trigger a synchronous layout, otherwise
 187     // the smooth-scrolling might get jerky.
 188     doLayout(NoAnimation);
 189     onScrollOffsetChanged(offset, previousOffset);
 190 }
 191
 192 qreal KItemListView::scrollOffset() const
 193 {
 194     return m_layouter->scrollOffset();
 195 }
 196
 197 qreal KItemListView::maximumScrollOffset() const
 198 {
 199     return m_layouter->maximumScrollOffset();
 200 }
 201
 202 void KItemListView::setItemOffset(qreal offset)
 203 {
 204     if (m_layouter->itemOffset() == offset) {
 205         return;
 206     }
 207
 208     m_layouter->setItemOffset(offset);
 209     if (m_header) {
 210         m_header->setPos(-offset, 0);
 211     }
 212
 213     // Don't check whether the m_layoutTimer is active: Changing the
 214     // item offset must always trigger a synchronous layout, otherwise
 215     // the smooth-scrolling might get jerky.
 216     doLayout(NoAnimation);
 217 }
 218
 219 qreal KItemListView::itemOffset() const
 220 {
 221     return m_layouter->itemOffset();
 222 }
 223
 224 qreal KItemListView::maximumItemOffset() const
 225 {
 226     return m_layouter->maximumItemOffset();
 227 }
 228
 229 void KItemListView::setVisibleRoles(const QList<QByteArray>& roles)
 230 {
 231     const QList<QByteArray> previousRoles = m_visibleRoles;
 232     m_visibleRoles = roles;
 233
 234     QHashIterator<int, KItemListWidget*> it(m_visibleItems);
 235     while (it.hasNext()) {
 236         it.next();
 237         KItemListWidget* widget = it.value();
 238         widget->setVisibleRoles(roles);
 239         widget->setVisibleRolesSizes(m_stretchedVisibleRolesSizes);
 240     }
 241
 242     m_sizeHintResolver->clearCache();
 243     m_layouter->markAsDirty();
 244
 245     if (m_header) {
 246         m_header->setVisibleRoles(roles);
 247         m_header->setVisibleRolesWidths(headerRolesWidths());
 248         m_useHeaderWidths = false;
 249     }
 250
 251     updateVisibleRolesSizes();
 252     doLayout(Animation);
 253
 254     onVisibleRolesChanged(roles, previousRoles);
 255 }
 256
 257 QList<QByteArray> KItemListView::visibleRoles() const
 258 {
 259     return m_visibleRoles;
 260 }
 261
 262 void KItemListView::setAutoScroll(bool enabled)
 263 {
 264     if (enabled && !m_autoScrollTimer) {
 265         m_autoScrollTimer = new QTimer(this);
 266         m_autoScrollTimer->setSingleShot(false);
 267         connect(m_autoScrollTimer, SIGNAL(timeout()), this, SLOT(triggerAutoScrolling()));
 268         m_autoScrollTimer->start(InitialAutoScrollDelay);
 269     } else if (!enabled && m_autoScrollTimer) {
 270         delete m_autoScrollTimer;
 271         m_autoScrollTimer = 0;
 272     }
 273
 274 }
 275
 276 bool KItemListView::autoScroll() const
 277 {
 278     return m_autoScrollTimer != 0;
 279 }
 280
 281 void KItemListView::setEnabledSelectionToggles(bool enabled)
 282 {
 283     if (m_enabledSelectionToggles != enabled) {
 284         m_enabledSelectionToggles = enabled;
 285
 286         QHashIterator<int, KItemListWidget*> it(m_visibleItems);
 287         while (it.hasNext()) {
 288             it.next();
 289             it.value()->setEnabledSelectionToggle(enabled);
 290         }
 291     }
 292 }
 293
 294 bool KItemListView::enabledSelectionToggles() const
 295 {
 296     return m_enabledSelectionToggles;
 297 }
 298
 299 KItemListController* KItemListView::controller() const
 300 {
 301     return m_controller;
 302 }
 303
 304 KItemModelBase* KItemListView::model() const
 305 {
 306     return m_model;
 307 }
 308
 309 void KItemListView::setWidgetCreator(KItemListWidgetCreatorBase* widgetCreator)
 310 {
 311     m_widgetCreator = widgetCreator;
 312 }
 313
 314 KItemListWidgetCreatorBase* KItemListView::widgetCreator() const
 315 {
 316     return m_widgetCreator;
 317 }
 318
 319 void KItemListView::setGroupHeaderCreator(KItemListGroupHeaderCreatorBase* groupHeaderCreator)
 320 {
 321     m_groupHeaderCreator = groupHeaderCreator;
 322 }
 323
 324 KItemListGroupHeaderCreatorBase* KItemListView::groupHeaderCreator() const
 325 {
 326     return m_groupHeaderCreator;
 327 }
 328
 329 void KItemListView::setStyleOption(const KItemListStyleOption& option)
 330 {
 331     const KItemListStyleOption previousOption = m_styleOption;
 332     m_styleOption = option;
 333
 334     QHashIterator<int, KItemListWidget*> it(m_visibleItems);
 335     while (it.hasNext()) {
 336         it.next();
 337         it.value()->setStyleOption(option);
 338     }
 339
 340     m_sizeHintResolver->clearCache();
 341     doLayout(Animation);
 342     onStyleOptionChanged(option, previousOption);
 343 }
 344
 345 const KItemListStyleOption& KItemListView::styleOption() const
 346 {
 347     return m_styleOption;
 348 }
 349
 350 void KItemListView::setGeometry(const QRectF& rect)
 351 {
 352     QGraphicsWidget::setGeometry(rect);
 353
 354     if (!m_model) {
 355         return;
 356     }
 357
 358     const QSizeF newSize = rect.size();
 359     if (m_itemSize.isEmpty()) {
 360         // The item size is dynamic:
 361         // Changing the geometry does not require to do an expensive
 362         // update of the visible-roles sizes, only the stretched sizes
 363         // need to be adjusted to the new size.
 364         updateStretchedVisibleRolesSizes();
 365
 366         if (m_useHeaderWidths) {
 367             QSizeF dynamicItemSize = m_layouter->itemSize();
 368
 369             if (m_itemSize.width() < 0) {
 370                 const qreal requiredWidth = visibleRolesSizesWidthSum();
 371                 if (newSize.width() > requiredWidth) {
 372                     dynamicItemSize.setWidth(newSize.width());
 373                 }
 374                 const qreal headerWidth = qMax(newSize.width(), requiredWidth);
 375                 m_header->resize(headerWidth, m_header->size().height());
 376             }
 377
 378             if (m_itemSize.height() < 0) {
 379                 const qreal requiredHeight = visibleRolesSizesHeightSum();
 380                 if (newSize.height() > requiredHeight) {
 381                     dynamicItemSize.setHeight(newSize.height());
 382                 }
 383                 // TODO: KItemListHeader is not prepared for vertical alignment
 384             }
 385
 386             m_layouter->setItemSize(dynamicItemSize);
 387         }
 388
 389         // Triggering a synchronous layout is fine from a performance point of view,
 390         // as with dynamic item sizes no moving animation must be done.
 391         m_layouter->setSize(newSize);
 392         doLayout(Animation);
 393     } else {
 394         // The item size is not dynamic and most probably the geometry change results
 395         // in animated position changes of the items. Trigger an asynchronous relayout
 396         // with m_layoutTimer to prevent performance bottlenecks.
 397         if (m_model->count() > 0) {
 398             prepareLayoutForIncreasedItemCount(newSize, LayouterSize);
 399         } else {
 400             m_layouter->setSize(newSize);
 401         }
 402
 403         if (!m_layoutTimer->isActive()) {
 404           m_layoutTimer->start();
 405         }
 406     }
 407 }
 408
 409 int KItemListView::itemAt(const QPointF& pos) const
 410 {
 411     QHashIterator<int, KItemListWidget*> it(m_visibleItems);
 412     while (it.hasNext()) {
 413         it.next();
 414
 415         const KItemListWidget* widget = it.value();
 416         const QPointF mappedPos = widget->mapFromItem(this, pos);
 417         if (widget->contains(mappedPos)) {
 418             return it.key();
 419         }
 420     }
 421
 422     return -1;
 423 }
 424
 425 bool KItemListView::isAboveSelectionToggle(int index, const QPointF& pos) const
 426 {
 427     if (!m_enabledSelectionToggles) {
 428         return false;
 429     }
 430
 431     const KItemListWidget* widget = m_visibleItems.value(index);
 432     if (widget) {
 433         const QRectF selectionToggleRect = widget->selectionToggleRect();
 434         if (!selectionToggleRect.isEmpty()) {
 435             const QPointF mappedPos = widget->mapFromItem(this, pos);
 436             return selectionToggleRect.contains(mappedPos);
 437         }
 438     }
 439     return false;
 440 }
 441
 442 bool KItemListView::isAboveExpansionToggle(int index, const QPointF& pos) const
 443 {
 444     const KItemListWidget* widget = m_visibleItems.value(index);
 445     if (widget) {
 446         const QRectF expansionToggleRect = widget->expansionToggleRect();
 447         if (!expansionToggleRect.isEmpty()) {
 448             const QPointF mappedPos = widget->mapFromItem(this, pos);
 449             return expansionToggleRect.contains(mappedPos);
 450         }
 451     }
 452     return false;
 453 }
 454
 455 int KItemListView::firstVisibleIndex() const
 456 {
 457     return m_layouter->firstVisibleIndex();
 458 }
 459
 460 int KItemListView::lastVisibleIndex() const
 461 {
 462     return m_layouter->lastVisibleIndex();
 463 }
 464
 465 QSizeF KItemListView::itemSizeHint(int index) const
 466 {
 467     Q_UNUSED(index);
 468     return itemSize();
 469 }
 470
 471 QHash<QByteArray, QSizeF> KItemListView::visibleRolesSizes(const KItemRangeList& itemRanges) const
 472 {
 473     Q_UNUSED(itemRanges);
 474     return QHash<QByteArray, QSizeF>();
 475 }
 476
 477 bool KItemListView::supportsItemExpanding() const
 478 {
 479     return false;
 480 }
 481
 482 QRectF KItemListView::itemRect(int index) const
 483 {
 484     return m_layouter->itemRect(index);
 485 }
 486
 487 QRectF KItemListView::itemContextRect(int index) const
 488 {
 489     QRectF contextRect;
 490
 491     const KItemListWidget* widget = m_visibleItems.value(index);
 492     if (widget) {
 493         contextRect = widget->iconRect() | widget->textRect();
 494         contextRect.translate(itemRect(index).topLeft());
 495     }
 496
 497     return contextRect;
 498 }
 499
 500 void KItemListView::scrollToItem(int index)
 501 {
 502     QRectF viewGeometry = geometry();
 503     if (m_header) {
 504         const qreal headerHeight = m_header->size().height();
 505         viewGeometry.adjust(0, headerHeight, 0, 0);
 506     }
 507     const QRectF currentRect = itemRect(index);
 508
 509     if (!viewGeometry.contains(currentRect)) {
 510         qreal newOffset = scrollOffset();
 511         if (currentRect.top() < viewGeometry.top()) {
 512             Q_ASSERT(scrollOrientation() == Qt::Vertical);
 513             newOffset += currentRect.top() - viewGeometry.top();
 514         } else if ((currentRect.bottom() > viewGeometry.bottom())) {
 515             Q_ASSERT(scrollOrientation() == Qt::Vertical);
 516             newOffset += currentRect.bottom() - viewGeometry.bottom();
 517         } else if (currentRect.left() < viewGeometry.left()) {
 518             if (scrollOrientation() == Qt::Horizontal) {
 519                 newOffset += currentRect.left() - viewGeometry.left();
 520             }
 521         } else if ((currentRect.right() > viewGeometry.right())) {
 522             if (scrollOrientation() == Qt::Horizontal) {
 523                 newOffset += currentRect.right() - viewGeometry.right();
 524             }
 525         }
 526
 527         if (newOffset != scrollOffset()) {
 528             emit scrollTo(newOffset);
 529         }
 530     }
 531 }
 532
 533 void KItemListView::beginTransaction()
 534 {
 535     ++m_activeTransactions;
 536     if (m_activeTransactions == 1) {
 537         onTransactionBegin();
 538     }
 539 }
 540
 541 void KItemListView::endTransaction()
 542 {
 543     --m_activeTransactions;
 544     if (m_activeTransactions < 0) {
 545         m_activeTransactions = 0;
 546         kWarning() << "Mismatch between beginTransaction()/endTransaction()";
 547     }
 548
 549     if (m_activeTransactions == 0) {
 550         onTransactionEnd();
 551         doLayout(Animation);
 552     }
 553 }
 554
 555 bool KItemListView::isTransactionActive() const
 556 {
 557     return m_activeTransactions > 0;
 558 }
 559
 560
 561 void KItemListView::setHeaderShown(bool show)
 562 {
 563
 564     if (show && !m_header) {
 565         m_header = new KItemListHeader(this);
 566         m_header->setPos(0, 0);
 567         m_header->setModel(m_model);
 568         m_header->setVisibleRoles(m_visibleRoles);
 569         m_header->setVisibleRolesWidths(headerRolesWidths());
 570         m_header->setZValue(1);
 571
 572         connect(m_header, SIGNAL(visibleRoleWidthChanged(QByteArray,qreal,qreal)),
 573                 this, SLOT(slotVisibleRoleWidthChanged(QByteArray,qreal,qreal)));
 574         connect(m_header, SIGNAL(sortOrderChanged(Qt::SortOrder,Qt::SortOrder)),
 575                 this, SIGNAL(sortOrderChanged(Qt::SortOrder,Qt::SortOrder)));
 576         connect(m_header, SIGNAL(sortRoleChanged(QByteArray,QByteArray)),
 577                 this, SIGNAL(sortRoleChanged(QByteArray,QByteArray)));
 578
 579         m_useHeaderWidths = false;
 580
 581         m_layouter->setHeaderHeight(m_header->size().height());
 582     } else if (!show && m_header) {
 583         delete m_header;
 584         m_header = 0;
 585         m_useHeaderWidths = false;
 586         m_layouter->setHeaderHeight(0);
 587     }
 588 }
 589
 590 bool KItemListView::isHeaderShown() const
 591 {
 592     return m_header != 0;
 593 }
 594
 595 QPixmap KItemListView::createDragPixmap(const QSet<int>& indexes) const
 596 {
 597     Q_UNUSED(indexes);
 598     return QPixmap();
 599 }
 600
 601 void KItemListView::paint(QPainter* painter, const QStyleOptionGraphicsItem* option, QWidget* widget)
 602 {
 603     QGraphicsWidget::paint(painter, option, widget);
 604
 605     if (m_rubberBand->isActive()) {
 606         QRectF rubberBandRect = QRectF(m_rubberBand->startPosition(),
 607                                        m_rubberBand->endPosition()).normalized();
 608
 609         const QPointF topLeft = rubberBandRect.topLeft();
 610         if (scrollOrientation() == Qt::Vertical) {
 611             rubberBandRect.moveTo(topLeft.x(), topLeft.y() - scrollOffset());
 612         } else {
 613             rubberBandRect.moveTo(topLeft.x() - scrollOffset(), topLeft.y());
 614         }
 615
 616         QStyleOptionRubberBand opt;
 617         opt.initFrom(widget);
 618         opt.shape = QRubberBand::Rectangle;
 619         opt.opaque = false;
 620         opt.rect = rubberBandRect.toRect();
 621         style()->drawControl(QStyle::CE_RubberBand, &opt, painter);
 622     }
 623 }
 624
 625 void KItemListView::initializeItemListWidget(KItemListWidget* item)
 626 {
 627     Q_UNUSED(item);
 628 }
 629
 630 bool KItemListView::itemSizeHintUpdateRequired(const QSet<QByteArray>& changedRoles) const
 631 {
 632     Q_UNUSED(changedRoles);
 633     return true;
 634 }
 635
 636 void KItemListView::onControllerChanged(KItemListController* current, KItemListController* previous)
 637 {
 638     Q_UNUSED(current);
 639     Q_UNUSED(previous);
 640 }
 641
 642 void KItemListView::onModelChanged(KItemModelBase* current, KItemModelBase* previous)
 643 {
 644     Q_UNUSED(current);
 645     Q_UNUSED(previous);
 646 }
 647
 648 void KItemListView::onScrollOrientationChanged(Qt::Orientation current, Qt::Orientation previous)
 649 {
 650     Q_UNUSED(current);
 651     Q_UNUSED(previous);
 652 }
 653
 654 void KItemListView::onItemSizeChanged(const QSizeF& current, const QSizeF& previous)
 655 {
 656     Q_UNUSED(current);
 657     Q_UNUSED(previous);
 658 }
 659
 660 void KItemListView::onScrollOffsetChanged(qreal current, qreal previous)
 661 {
 662     Q_UNUSED(current);
 663     Q_UNUSED(previous);
 664 }
 665
 666 void KItemListView::onVisibleRolesChanged(const QList<QByteArray>& current, const QList<QByteArray>& previous)
 667 {
 668     Q_UNUSED(current);
 669     Q_UNUSED(previous);
 670 }
 671
 672 void KItemListView::onStyleOptionChanged(const KItemListStyleOption& current, const KItemListStyleOption& previous)
 673 {
 674     Q_UNUSED(current);
 675     Q_UNUSED(previous);
 676 }
 677
 678 void KItemListView::onTransactionBegin()
 679 {
 680 }
 681
 682 void KItemListView::onTransactionEnd()
 683 {
 684 }
 685
 686 bool KItemListView::event(QEvent* event)
 687 {
 688     // Forward all events to the controller and handle them there
 689     if (m_controller && m_controller->processEvent(event, transform())) {
 690         event->accept();
 691         return true;
 692     }
 693     return QGraphicsWidget::event(event);
 694 }
 695
 696 void KItemListView::mousePressEvent(QGraphicsSceneMouseEvent* event)
 697 {
 698     m_mousePos = transform().map(event->pos());
 699     event->accept();
 700 }
 701
 702 void KItemListView::mouseMoveEvent(QGraphicsSceneMouseEvent* event)
 703 {
 704     QGraphicsWidget::mouseMoveEvent(event);
 705
 706     m_mousePos = transform().map(event->pos());
 707     if (m_autoScrollTimer && !m_autoScrollTimer->isActive()) {
 708         m_autoScrollTimer->start(InitialAutoScrollDelay);
 709     }
 710 }
 711
 712 void KItemListView::dragEnterEvent(QGraphicsSceneDragDropEvent* event)
 713 {
 714     event->setAccepted(true);
 715     setAutoScroll(true);
 716 }
 717
 718 void KItemListView::dragMoveEvent(QGraphicsSceneDragDropEvent *event)
 719 {
 720     QGraphicsWidget::dragMoveEvent(event);
 721
 722     m_mousePos = transform().map(event->pos());
 723     if (m_autoScrollTimer && !m_autoScrollTimer->isActive()) {
 724         m_autoScrollTimer->start(InitialAutoScrollDelay);
 725     }
 726 }
 727
 728 void KItemListView::dragLeaveEvent(QGraphicsSceneDragDropEvent *event)
 729 {
 730     QGraphicsWidget::dragLeaveEvent(event);
 731     setAutoScroll(false);
 732 }
 733
 734 void KItemListView::dropEvent(QGraphicsSceneDragDropEvent* event)
 735 {
 736     QGraphicsWidget::dropEvent(event);
 737     setAutoScroll(false);
 738 }
 739
 740 QList<KItemListWidget*> KItemListView::visibleItemListWidgets() const
 741 {
 742     return m_visibleItems.values();
 743 }
 744
 745 void KItemListView::slotItemsInserted(const KItemRangeList& itemRanges)
 746 {
 747     updateVisibleRolesSizes(itemRanges);
 748
 749     const bool hasMultipleRanges = (itemRanges.count() > 1);
 750     if (hasMultipleRanges) {
 751         beginTransaction();
 752     }
 753
 754     int previouslyInsertedCount = 0;
 755     foreach (const KItemRange& range, itemRanges) {
 756         // range.index is related to the model before anything has been inserted.
 757         // As in each loop the current item-range gets inserted the index must
 758         // be increased by the already previously inserted items.
 759         const int index = range.index + previouslyInsertedCount;
 760         const int count = range.count;
 761         if (index < 0 || count <= 0) {
 762             kWarning() << "Invalid item range (index:" << index << ", count:" << count << ")";
 763             continue;
 764         }
 765         previouslyInsertedCount += count;
 766
 767         m_sizeHintResolver->itemsInserted(index, count);
 768
 769         // Determine which visible items must be moved
 770         QList<int> itemsToMove;
 771         QHashIterator<int, KItemListWidget*> it(m_visibleItems);
 772         while (it.hasNext()) {
 773             it.next();
 774             const int visibleItemIndex = it.key();
 775             if (visibleItemIndex >= index) {
 776                 itemsToMove.append(visibleItemIndex);
 777             }
 778         }
 779
 780         // Update the indexes of all KItemListWidget instances that are located
 781         // after the inserted items. It is important to adjust the indexes in the order
 782         // from the highest index to the lowest index to prevent overlaps when setting the new index.
 783         qSort(itemsToMove);
 784         for (int i = itemsToMove.count() - 1; i >= 0; --i) {
 785             KItemListWidget* widget = m_visibleItems.value(itemsToMove[i]);
 786             Q_ASSERT(widget);
 787             setWidgetIndex(widget, widget->index() + count);
 788         }
 789
 790         m_layouter->markAsDirty();
 791         if (m_model->count() == count && maximumScrollOffset() > size().height()) {
 792             const int scrollBarExtent = style()->pixelMetric(QStyle::PM_ScrollBarExtent);
 793             QSizeF layouterSize = m_layouter->size();
 794             if (scrollOrientation() == Qt::Vertical) {
 795                 layouterSize.rwidth() -= scrollBarExtent;
 796             } else {
 797                 layouterSize.rheight() -= scrollBarExtent;
 798             }
 799             m_layouter->setSize(layouterSize);
 800         }
 801
 802         if (!hasMultipleRanges) {
 803             doLayout(Animation, index, count);
 804         }
 805     }
 806
 807     if (m_controller) {
 808         m_controller->selectionManager()->itemsInserted(itemRanges);
 809     }
 810
 811     if (hasMultipleRanges) {
 812         endTransaction();
 813     }
 814 }
 815
 816 void KItemListView::slotItemsRemoved(const KItemRangeList& itemRanges)
 817 {
 818     updateVisibleRolesSizes();
 819
 820     const bool hasMultipleRanges = (itemRanges.count() > 1);
 821     if (hasMultipleRanges) {
 822         beginTransaction();
 823     }
 824
 825     for (int i = itemRanges.count() - 1; i >= 0; --i) {
 826         const KItemRange& range = itemRanges.at(i);
 827         const int index = range.index;
 828         const int count = range.count;
 829         if (index < 0 || count <= 0) {
 830             kWarning() << "Invalid item range (index:" << index << ", count:" << count << ")";
 831             continue;
 832         }
 833
 834         m_sizeHintResolver->itemsRemoved(index, count);
 835
 836         const int firstRemovedIndex = index;
 837         const int lastRemovedIndex = index + count - 1;
 838         const int lastIndex = m_model->count() + count - 1;
 839
 840         // Remove all KItemListWidget instances that got deleted
 841         for (int i = firstRemovedIndex; i <= lastRemovedIndex; ++i) {
 842             KItemListWidget* widget = m_visibleItems.value(i);
 843             if (!widget) {
 844                 continue;
 845             }
 846
 847             m_animation->stop(widget);
 848             // Stopping the animation might lead to recycling the widget if
 849             // it is invisible (see slotAnimationFinished()).
 850             // Check again whether it is still visible:
 851             if (!m_visibleItems.contains(i)) {
 852                 continue;
 853             }
 854
 855             if (m_model->count() == 0) {
 856                 // For performance reasons no animation is done when all items have
 857                 // been removed.
 858                 recycleWidget(widget);
 859             } else {
 860                 // Animate the removing of the items. Special case: When removing an item there
 861                 // is no valid model index available anymore. For the
 862                 // remove-animation the item gets removed from m_visibleItems but the widget
 863                 // will stay alive until the animation has been finished and will
 864                 // be recycled (deleted) in KItemListView::slotAnimationFinished().
 865                 m_visibleItems.remove(i);
 866                 widget->setIndex(-1);
 867                 m_animation->start(widget, KItemListViewAnimation::DeleteAnimation);
 868             }
 869         }
 870
 871         // Update the indexes of all KItemListWidget instances that are located
 872         // after the deleted items
 873         for (int i = lastRemovedIndex + 1; i <= lastIndex; ++i) {
 874             KItemListWidget* widget = m_visibleItems.value(i);
 875             if (widget) {
 876                 const int newIndex = i - count;
 877                 setWidgetIndex(widget, newIndex);
 878             }
 879         }
 880
 881         m_layouter->markAsDirty();
 882         if (!hasMultipleRanges) {
 883             doLayout(Animation, index, -count);
 884         }
 885     }
 886
 887     if (m_controller) {
 888         m_controller->selectionManager()->itemsRemoved(itemRanges);
 889     }
 890
 891     if (hasMultipleRanges) {
 892         endTransaction();
 893     }
 894 }
 895
 896 void KItemListView::slotItemsMoved(const KItemRange& itemRange, const QList<int>& movedToIndexes)
 897 {
 898     m_sizeHintResolver->itemsMoved(itemRange.index, itemRange.count);
 899     m_layouter->markAsDirty();
 900
 901     if (m_controller) {
 902         m_controller->selectionManager()->itemsMoved(itemRange, movedToIndexes);
 903     }
 904
 905     const int firstVisibleMovedIndex = qMax(firstVisibleIndex(), itemRange.index);
 906     const int lastVisibleMovedIndex = qMin(lastVisibleIndex(), itemRange.index + itemRange.count - 1);
 907
 908     for (int index = firstVisibleMovedIndex; index <= lastVisibleMovedIndex; ++index) {
 909         KItemListWidget* widget = m_visibleItems.value(index);
 910         if (widget) {
 911             updateWidgetProperties(widget, index);
 912             if (m_grouped) {
 913                 updateGroupHeaderForWidget(widget);
 914             }
 915             initializeItemListWidget(widget);
 916         }
 917     }
 918
 919     doLayout(NoAnimation);
 920 }
 921
 922 void KItemListView::slotItemsChanged(const KItemRangeList& itemRanges,
 923                                      const QSet<QByteArray>& roles)
 924 {
 925     const bool updateSizeHints = itemSizeHintUpdateRequired(roles);
 926     if (updateSizeHints) {
 927         updateVisibleRolesSizes(itemRanges);
 928     }
 929
 930     foreach (const KItemRange& itemRange, itemRanges) {
 931         const int index = itemRange.index;
 932         const int count = itemRange.count;
 933
 934         if (updateSizeHints) {
 935             m_sizeHintResolver->itemsChanged(index, count, roles);
 936             m_layouter->markAsDirty();
 937
 938             if (!m_layoutTimer->isActive()) {
 939                 m_layoutTimer->start();
 940             }
 941         }
 942
 943         // Apply the changed roles to the visible item-widgets
 944         const int lastIndex = index + count - 1;
 945         for (int i = index; i <= lastIndex; ++i) {
 946             KItemListWidget* widget = m_visibleItems.value(i);
 947             if (widget) {
 948                 widget->setData(m_model->data(i), roles);
 949             }
 950         }
 951
 952         if (m_grouped && roles.contains(m_model->sortRole())) {
 953             // The sort-role has been changed which might result
 954             // in modified group headers
 955             updateVisibleGroupHeaders();
 956             doLayout(NoAnimation);
 957         }
 958     }
 959 }
 960
 961 void KItemListView::slotGroupedSortingChanged(bool current)
 962 {
 963     m_grouped = current;
 964     m_layouter->markAsDirty();
 965
 966     if (m_grouped) {
 967         // Apply the height of the header to the layouter
 968         const qreal groupHeaderHeight = m_styleOption.fontMetrics.height() +
 969                                         m_styleOption.margin * 2;
 970         m_layouter->setGroupHeaderHeight(groupHeaderHeight);
 971
 972         updateVisibleGroupHeaders();
 973     } else {
 974         // Clear all visible headers
 975         QMutableHashIterator<KItemListWidget*, KItemListGroupHeader*> it (m_visibleGroups);
 976         while (it.hasNext()) {
 977             it.next();
 978             recycleGroupHeaderForWidget(it.key());
 979         }
 980         Q_ASSERT(m_visibleGroups.isEmpty());
 981     }
 982
 983     doLayout(Animation);
 984 }
 985
 986 void KItemListView::slotSortOrderChanged(Qt::SortOrder current, Qt::SortOrder previous)
 987 {
 988     Q_UNUSED(current);
 989     Q_UNUSED(previous);
 990     if (m_grouped) {
 991         updateVisibleGroupHeaders();
 992         doLayout(Animation);
 993     }
 994 }
 995
 996 void KItemListView::slotSortRoleChanged(const QByteArray& current, const QByteArray& previous)
 997 {
 998     Q_UNUSED(current);
 999     Q_UNUSED(previous);
1000     if (m_grouped) {
1001         updateVisibleGroupHeaders();
1002         doLayout(Animation);
1003     }
1004 }
1005
1006 void KItemListView::slotCurrentChanged(int current, int previous)
1007 {
1008     Q_UNUSED(previous);
1009
1010     KItemListWidget* previousWidget = m_visibleItems.value(previous, 0);
1011     if (previousWidget) {
1012         Q_ASSERT(previousWidget->isCurrent());
1013         previousWidget->setCurrent(false);
1014     }
1015
1016     KItemListWidget* currentWidget = m_visibleItems.value(current, 0);
1017     if (currentWidget) {
1018         Q_ASSERT(!currentWidget->isCurrent());
1019         currentWidget->setCurrent(true);
1020     }
1021 }
1022
1023 void KItemListView::slotSelectionChanged(const QSet<int>& current, const QSet<int>& previous)
1024 {
1025     Q_UNUSED(previous);
1026
1027     QHashIterator<int, KItemListWidget*> it(m_visibleItems);
1028     while (it.hasNext()) {
1029         it.next();
1030         const int index = it.key();
1031         KItemListWidget* widget = it.value();
1032         widget->setSelected(current.contains(index));
1033     }
1034 }
1035
1036 void KItemListView::slotAnimationFinished(QGraphicsWidget* widget,
1037                                           KItemListViewAnimation::AnimationType type)
1038 {
1039     KItemListWidget* itemListWidget = qobject_cast<KItemListWidget*>(widget);
1040     Q_ASSERT(itemListWidget);
1041
1042     switch (type) {
1043     case KItemListViewAnimation::DeleteAnimation: {
1044         // As we recycle the widget in this case it is important to assure that no
1045         // other animation has been started. This is a convention in KItemListView and
1046         // not a requirement defined by KItemListViewAnimation.
1047         Q_ASSERT(!m_animation->isStarted(itemListWidget));
1048
1049         // All KItemListWidgets that are animated by the DeleteAnimation are not maintained
1050         // by m_visibleWidgets and must be deleted manually after the animation has
1051         // been finished.
1052         recycleGroupHeaderForWidget(itemListWidget);
1053         m_widgetCreator->recycle(itemListWidget);
1054         break;
1055     }
1056
1057     case KItemListViewAnimation::CreateAnimation:
1058     case KItemListViewAnimation::MovingAnimation:
1059     case KItemListViewAnimation::ResizeAnimation: {
1060         const int index = itemListWidget->index();
1061         const bool invisible = (index < m_layouter->firstVisibleIndex()) ||
1062                                (index > m_layouter->lastVisibleIndex());
1063         if (invisible && !m_animation->isStarted(itemListWidget)) {
1064             recycleWidget(itemListWidget);
1065         }
1066         break;
1067     }
1068
1069     default: break;
1070     }
1071 }
1072
1073 void KItemListView::slotLayoutTimerFinished()
1074 {
1075     m_layouter->setSize(geometry().size());
1076     doLayout(Animation);
1077 }
1078
1079 void KItemListView::slotRubberBandPosChanged()
1080 {
1081     update();
1082 }
1083
1084 void KItemListView::slotRubberBandActivationChanged(bool active)
1085 {
1086     if (active) {
1087         connect(m_rubberBand, SIGNAL(startPositionChanged(QPointF,QPointF)), this, SLOT(slotRubberBandPosChanged()));
1088         connect(m_rubberBand, SIGNAL(endPositionChanged(QPointF,QPointF)), this, SLOT(slotRubberBandPosChanged()));
1089         m_skipAutoScrollForRubberBand = true;
1090     } else {
1091         disconnect(m_rubberBand, SIGNAL(startPositionChanged(QPointF,QPointF)), this, SLOT(slotRubberBandPosChanged()));
1092         disconnect(m_rubberBand, SIGNAL(endPositionChanged(QPointF,QPointF)), this, SLOT(slotRubberBandPosChanged()));
1093         m_skipAutoScrollForRubberBand = false;
1094     }
1095
1096     update();
1097 }
1098
1099 void KItemListView::slotVisibleRoleWidthChanged(const QByteArray& role,
1100                                                 qreal currentWidth,
1101                                                 qreal previousWidth)
1102 {
1103     Q_UNUSED(previousWidth);
1104
1105     m_useHeaderWidths = true;
1106
1107     if (m_visibleRolesSizes.contains(role)) {
1108         QSizeF roleSize = m_visibleRolesSizes.value(role);
1109         roleSize.setWidth(currentWidth);
1110         m_visibleRolesSizes.insert(role, roleSize);
1111         m_stretchedVisibleRolesSizes.insert(role, roleSize);
1112
1113         // Apply the new size to the layouter
1114         QSizeF dynamicItemSize = m_itemSize;
1115         if (dynamicItemSize.width() < 0) {
1116             const qreal requiredWidth = visibleRolesSizesWidthSum();
1117             dynamicItemSize.setWidth(qMax(size().width(), requiredWidth));
1118         }
1119         if (dynamicItemSize.height() < 0) {
1120             const qreal requiredHeight = visibleRolesSizesHeightSum();
1121             dynamicItemSize.setHeight(qMax(size().height(), requiredHeight));
1122         }
1123
1124         m_layouter->setItemSize(dynamicItemSize);
1125
1126         // Update the role sizes for all visible widgets
1127         foreach (KItemListWidget* widget, visibleItemListWidgets()) {
1128             widget->setVisibleRolesSizes(m_stretchedVisibleRolesSizes);
1129         }
1130
1131         doLayout(Animation);
1132     }
1133 }
1134
1135 void KItemListView::triggerAutoScrolling()
1136 {
1137     if (!m_autoScrollTimer) {
1138         return;
1139     }
1140
1141     int pos = 0;
1142     int visibleSize = 0;
1143     if (scrollOrientation() == Qt::Vertical) {
1144         pos = m_mousePos.y();
1145         visibleSize = size().height();
1146     } else {
1147         pos = m_mousePos.x();
1148         visibleSize = size().width();
1149     }
1150
1151     if (m_autoScrollTimer->interval() == InitialAutoScrollDelay) {
1152         m_autoScrollIncrement = 0;
1153     }
1154
1155     m_autoScrollIncrement = calculateAutoScrollingIncrement(pos, visibleSize, m_autoScrollIncrement);
1156     if (m_autoScrollIncrement == 0) {
1157         // The mouse position is not above an autoscroll margin (the autoscroll timer
1158         // will be restarted in mouseMoveEvent())
1159         m_autoScrollTimer->stop();
1160         return;
1161     }
1162
1163     if (m_rubberBand->isActive() && m_skipAutoScrollForRubberBand) {
1164         // If a rubberband selection is ongoing the autoscrolling may only get triggered
1165         // if the direction of the rubberband is similar to the autoscroll direction. This
1166         // prevents that starting to create a rubberband within the autoscroll margins starts
1167         // an autoscrolling.
1168
1169         const qreal minDiff = 4; // Ignore any autoscrolling if the rubberband is very small
1170         const qreal diff = (scrollOrientation() == Qt::Vertical)
1171                            ? m_rubberBand->endPosition().y() - m_rubberBand->startPosition().y()
1172                            : m_rubberBand->endPosition().x() - m_rubberBand->startPosition().x();
1173         if (qAbs(diff) < minDiff || (m_autoScrollIncrement < 0 && diff > 0) || (m_autoScrollIncrement > 0 && diff < 0)) {
1174             // The rubberband direction is different from the scroll direction (e.g. the rubberband has
1175             // been moved up although the autoscroll direction might be down)
1176             m_autoScrollTimer->stop();
1177             return;
1178         }
1179     }
1180
1181     // As soon as the autoscrolling has been triggered at least once despite having an active rubberband,
1182     // the autoscrolling may not get skipped anymore until a new rubberband is created
1183     m_skipAutoScrollForRubberBand = false;
1184
1185     const qreal maxVisibleOffset = qMax(qreal(0), maximumScrollOffset() - visibleSize);
1186     const qreal newScrollOffset = qMin(scrollOffset() + m_autoScrollIncrement, maxVisibleOffset);
1187     setScrollOffset(newScrollOffset);
1188
1189    // Trigger the autoscroll timer which will periodically call
1190    // triggerAutoScrolling()
1191    m_autoScrollTimer->start(RepeatingAutoScrollDelay);
1192 }
1193
1194 void KItemListView::setController(KItemListController* controller)
1195 {
1196     if (m_controller != controller) {
1197         KItemListController* previous = m_controller;
1198         if (previous) {
1199             KItemListSelectionManager* selectionManager = previous->selectionManager();
1200             disconnect(selectionManager, SIGNAL(currentChanged(int,int)), this, SLOT(slotCurrentChanged(int,int)));
1201             disconnect(selectionManager, SIGNAL(selectionChanged(QSet<int>,QSet<int>)), this, SLOT(slotSelectionChanged(QSet<int>,QSet<int>)));
1202         }
1203
1204         m_controller = controller;
1205
1206         if (controller) {
1207             KItemListSelectionManager* selectionManager = controller->selectionManager();
1208             connect(selectionManager, SIGNAL(currentChanged(int,int)), this, SLOT(slotCurrentChanged(int,int)));
1209             connect(selectionManager, SIGNAL(selectionChanged(QSet<int>,QSet<int>)), this, SLOT(slotSelectionChanged(QSet<int>,QSet<int>)));
1210         }
1211
1212         onControllerChanged(controller, previous);
1213     }
1214 }
1215
1216 void KItemListView::setModel(KItemModelBase* model)
1217 {
1218     if (m_model == model) {
1219         return;
1220     }
1221
1222     KItemModelBase* previous = m_model;
1223
1224     if (m_model) {
1225         disconnect(m_model, SIGNAL(itemsChanged(KItemRangeList,QSet<QByteArray>)),
1226                    this,    SLOT(slotItemsChanged(KItemRangeList,QSet<QByteArray>)));
1227         disconnect(m_model, SIGNAL(itemsInserted(KItemRangeList)),
1228                    this,    SLOT(slotItemsInserted(KItemRangeList)));
1229         disconnect(m_model, SIGNAL(itemsRemoved(KItemRangeList)),
1230                    this,    SLOT(slotItemsRemoved(KItemRangeList)));
1231         disconnect(m_model, SIGNAL(itemsMoved(KItemRange,QList<int>)),
1232                    this,    SLOT(slotItemsMoved(KItemRange,QList<int>)));
1233         disconnect(m_model, SIGNAL(groupedSortingChanged(bool)),
1234                    this,    SLOT(slotGroupedSortingChanged(bool)));
1235         disconnect(m_model, SIGNAL(sortOrderChanged(Qt::SortOrder,Qt::SortOrder)),
1236                    this,    SLOT(slotSortOrderChanged(Qt::SortOrder,Qt::SortOrder)));
1237         disconnect(m_model, SIGNAL(sortRoleChanged(QByteArray,QByteArray)),
1238                    this,    SLOT(slotSortRoleChanged(QByteArray,QByteArray)));
1239     }
1240
1241     m_model = model;
1242     m_layouter->setModel(model);
1243     m_grouped = model->groupedSorting();
1244
1245     if (m_model) {
1246         connect(m_model, SIGNAL(itemsChanged(KItemRangeList,QSet<QByteArray>)),
1247                 this,    SLOT(slotItemsChanged(KItemRangeList,QSet<QByteArray>)));
1248         connect(m_model, SIGNAL(itemsInserted(KItemRangeList)),
1249                 this,    SLOT(slotItemsInserted(KItemRangeList)));
1250         connect(m_model, SIGNAL(itemsRemoved(KItemRangeList)),
1251                 this,    SLOT(slotItemsRemoved(KItemRangeList)));
1252         connect(m_model, SIGNAL(itemsMoved(KItemRange,QList<int>)),
1253                 this,    SLOT(slotItemsMoved(KItemRange,QList<int>)));
1254         connect(m_model, SIGNAL(groupedSortingChanged(bool)),
1255                 this,    SLOT(slotGroupedSortingChanged(bool)));
1256         connect(m_model, SIGNAL(sortOrderChanged(Qt::SortOrder,Qt::SortOrder)),
1257                 this,    SLOT(slotSortOrderChanged(Qt::SortOrder,Qt::SortOrder)));
1258         connect(m_model, SIGNAL(sortRoleChanged(QByteArray,QByteArray)),
1259                 this,    SLOT(slotSortRoleChanged(QByteArray,QByteArray)));
1260     }
1261
1262     onModelChanged(model, previous);
1263 }
1264
1265 KItemListRubberBand* KItemListView::rubberBand() const
1266 {
1267     return m_rubberBand;
1268 }
1269
1270 void KItemListView::doLayout(LayoutAnimationHint hint, int changedIndex, int changedCount)
1271 {
1272     if (m_layoutTimer->isActive()) {
1273         m_layoutTimer->stop();
1274     }
1275
1276     if (!m_model || m_model->count() < 0 || m_activeTransactions > 0) {
1277         return;
1278     }
1279
1280     const int firstVisibleIndex = m_layouter->firstVisibleIndex();
1281     const int lastVisibleIndex = m_layouter->lastVisibleIndex();
1282     if (firstVisibleIndex < 0) {
1283         emitOffsetChanges();
1284         return;
1285     }
1286
1287     // Do a sanity check of the scroll-offset property: When properties of the itemlist-view have been changed
1288     // it might be possible that the maximum offset got changed too. Assure that the full visible range
1289     // is still shown if the maximum offset got decreased.
1290     const qreal visibleOffsetRange = (scrollOrientation() == Qt::Horizontal) ? size().width() : size().height();
1291     const qreal maxOffsetToShowFullRange = maximumScrollOffset() - visibleOffsetRange;
1292     if (scrollOffset() > maxOffsetToShowFullRange) {
1293         m_layouter->setScrollOffset(qMax(qreal(0), maxOffsetToShowFullRange));
1294     }
1295
1296     // Determine all items that are completely invisible and might be
1297     // reused for items that just got (at least partly) visible.
1298     // Items that do e.g. an animated moving of their position are not
1299     // marked as invisible: This assures that a scrolling inside the view
1300     // can be done without breaking an animation.
1301     QList<int> reusableItems;
1302     QHashIterator<int, KItemListWidget*> it(m_visibleItems);
1303     while (it.hasNext()) {
1304         it.next();
1305         KItemListWidget* widget = it.value();
1306         const int index = widget->index();
1307         const bool invisible = (index < firstVisibleIndex) || (index > lastVisibleIndex);
1308         if (invisible && !m_animation->isStarted(widget)) {
1309             widget->setVisible(false);
1310             reusableItems.append(index);
1311
1312             if (m_grouped) {
1313                 recycleGroupHeaderForWidget(widget);
1314             }
1315         }
1316     }
1317
1318     // Assure that for each visible item a KItemListWidget is available. KItemListWidget
1319     // instances from invisible items are reused. If no reusable items are
1320     // found then new KItemListWidget instances get created.
1321     const bool animate = (hint == Animation);
1322     for (int i = firstVisibleIndex; i <= lastVisibleIndex; ++i) {
1323         bool applyNewPos = true;
1324         bool wasHidden = false;
1325
1326         const QRectF itemBounds = m_layouter->itemRect(i);
1327         const QPointF newPos = itemBounds.topLeft();
1328         KItemListWidget* widget = m_visibleItems.value(i);
1329         if (!widget) {
1330             wasHidden = true;
1331             if (!reusableItems.isEmpty()) {
1332                 // Reuse a KItemListWidget instance from an invisible item
1333                 const int oldIndex = reusableItems.takeLast();
1334                 widget = m_visibleItems.value(oldIndex);
1335                 setWidgetIndex(widget, i);
1336
1337                 if (m_grouped) {
1338                     updateGroupHeaderForWidget(widget);
1339                 }
1340             } else {
1341                 // No reusable KItemListWidget instance is available, create a new one
1342                 widget = createWidget(i);
1343             }
1344             widget->resize(itemBounds.size());
1345
1346             if (animate && changedCount < 0) {
1347                 // Items have been deleted, move the created item to the
1348                 // imaginary old position. They will get animated to the new position
1349                 // later.
1350                 const QRectF itemRect = m_layouter->itemRect(i - changedCount);
1351                 if (itemRect.isEmpty()) {
1352                     const QPointF invisibleOldPos = (scrollOrientation() == Qt::Vertical)
1353                                                     ? QPointF(0, size().height()) : QPointF(size().width(), 0);
1354                     widget->setPos(invisibleOldPos);
1355                 } else {
1356                     widget->setPos(itemRect.topLeft());
1357                 }
1358                 applyNewPos = false;
1359             }
1360         } else if (m_animation->isStarted(widget, KItemListViewAnimation::MovingAnimation)) {
1361             applyNewPos = false;
1362         }
1363
1364         if (animate) {
1365             const bool itemsRemoved = (changedCount < 0);
1366             const bool itemsInserted = (changedCount > 0);
1367             if (itemsRemoved && (i >= changedIndex + changedCount + 1)) {
1368                 // The item is located after the removed items. Animate the moving of the position.
1369                 m_animation->start(widget, KItemListViewAnimation::MovingAnimation, newPos);
1370                 applyNewPos = false;
1371             } else if (itemsInserted && i >= changedIndex) {
1372                 // The item is located after the first inserted item
1373                 if (i <= changedIndex + changedCount - 1) {
1374                     // The item is an inserted item. Animate the appearing of the item.
1375                     // For performance reasons no animation is done when changedCount is equal
1376                     // to all available items.
1377                     if (changedCount < m_model->count()) {
1378                         m_animation->start(widget, KItemListViewAnimation::CreateAnimation);
1379                     }
1380                 } else if (!m_animation->isStarted(widget, KItemListViewAnimation::CreateAnimation)) {
1381                     // The item was already there before, so animate the moving of the position.
1382                     // No moving animation is done if the item is animated by a create animation: This
1383                     // prevents a "move animation mess" when inserting several ranges in parallel.
1384                     m_animation->start(widget, KItemListViewAnimation::MovingAnimation, newPos);
1385                     applyNewPos = false;
1386                 }
1387             } else if (!itemsRemoved && !itemsInserted && !wasHidden) {
1388                 // The size of the view might have been changed. Animate the moving of the position.
1389                 m_animation->start(widget, KItemListViewAnimation::MovingAnimation, newPos);
1390                 applyNewPos = false;
1391             }
1392         }
1393
1394         if (applyNewPos) {
1395             widget->setPos(newPos);
1396         }
1397
1398         Q_ASSERT(widget->index() == i);
1399         widget->setVisible(true);
1400
1401         if (widget->size() != itemBounds.size()) {
1402             // Resize the widget for the item to the changed size.
1403             if (animate) {
1404                 // If a dynamic item size is used then no animation is done in the direction
1405                 // of the dynamic size.
1406                 if (m_itemSize.width() <= 0) {
1407                     // The width is dynamic, apply the new width without animation.
1408                     widget->resize(itemBounds.width(), widget->size().height());
1409                 } else if (m_itemSize.height() <= 0) {
1410                     // The height is dynamic, apply the new height without animation.
1411                     widget->resize(widget->size().width(), itemBounds.height());
1412                 }
1413                 m_animation->start(widget, KItemListViewAnimation::ResizeAnimation, itemBounds.size());
1414             } else {
1415                 widget->resize(itemBounds.size());
1416             }
1417         }
1418     }
1419
1420     // Delete invisible KItemListWidget instances that have not been reused
1421     foreach (int index, reusableItems) {
1422         recycleWidget(m_visibleItems.value(index));
1423     }
1424
1425     if (m_grouped) {
1426         // Update the layout of all visible group headers
1427         QHashIterator<KItemListWidget*, KItemListGroupHeader*> it(m_visibleGroups);
1428         while (it.hasNext()) {
1429             it.next();
1430             updateGroupHeaderLayout(it.key());
1431         }
1432     }
1433
1434     emitOffsetChanges();
1435 }
1436
1437 void KItemListView::emitOffsetChanges()
1438 {
1439     const qreal newScrollOffset = m_layouter->scrollOffset();
1440     if (m_oldScrollOffset != newScrollOffset) {
1441         emit scrollOffsetChanged(newScrollOffset, m_oldScrollOffset);
1442         m_oldScrollOffset = newScrollOffset;
1443     }
1444
1445     const qreal newMaximumScrollOffset = m_layouter->maximumScrollOffset();
1446     if (m_oldMaximumScrollOffset != newMaximumScrollOffset) {
1447         emit maximumScrollOffsetChanged(newMaximumScrollOffset, m_oldMaximumScrollOffset);
1448         m_oldMaximumScrollOffset = newMaximumScrollOffset;
1449     }
1450
1451     const qreal newItemOffset = m_layouter->itemOffset();
1452     if (m_oldItemOffset != newItemOffset) {
1453         emit itemOffsetChanged(newItemOffset, m_oldItemOffset);
1454         m_oldItemOffset = newItemOffset;
1455     }
1456
1457     const qreal newMaximumItemOffset = m_layouter->maximumItemOffset();
1458     if (m_oldMaximumItemOffset != newMaximumItemOffset) {
1459         emit maximumItemOffsetChanged(newMaximumItemOffset, m_oldMaximumItemOffset);
1460         m_oldMaximumItemOffset = newMaximumItemOffset;
1461     }
1462 }
1463
1464 KItemListWidget* KItemListView::createWidget(int index)
1465 {
1466     KItemListWidget* widget = m_widgetCreator->create(this);
1467     widget->setFlag(QGraphicsItem::ItemStacksBehindParent);
1468
1469     updateWidgetProperties(widget, index);
1470     m_visibleItems.insert(index, widget);
1471
1472     if (m_grouped) {
1473         updateGroupHeaderForWidget(widget);
1474     }
1475
1476     initializeItemListWidget(widget);
1477     return widget;
1478 }
1479
1480 void KItemListView::recycleWidget(KItemListWidget* widget)
1481 {
1482     if (m_grouped) {
1483         recycleGroupHeaderForWidget(widget);
1484     }
1485
1486     m_visibleItems.remove(widget->index());
1487     m_widgetCreator->recycle(widget);
1488 }
1489
1490 void KItemListView::setWidgetIndex(KItemListWidget* widget, int index)
1491 {
1492     const int oldIndex = widget->index();
1493     m_visibleItems.remove(oldIndex);
1494     updateWidgetProperties(widget, index);
1495     m_visibleItems.insert(index, widget);
1496
1497     initializeItemListWidget(widget);
1498 }
1499
1500 void KItemListView::prepareLayoutForIncreasedItemCount(const QSizeF& size, SizeType sizeType)
1501 {
1502     // Calculate the first visible index and last visible index for the current size
1503     const int currentFirst = m_layouter->firstVisibleIndex();
1504     const int currentLast = m_layouter->lastVisibleIndex();
1505
1506     const QSizeF currentSize = (sizeType == LayouterSize) ? m_layouter->size() : m_layouter->itemSize();
1507
1508     // Calculate the first visible index and last visible index for the new size
1509     setLayouterSize(size, sizeType);
1510     const int newFirst = m_layouter->firstVisibleIndex();
1511     const int newLast = m_layouter->lastVisibleIndex();
1512
1513     if ((currentFirst != newFirst) || (currentLast != newLast)) {
1514         // At least one index has been changed. Assure that widgets for all possible
1515         // visible items get created so that a move-animation can be started later.
1516         const int maxVisibleItems = m_layouter->maximumVisibleItems();
1517         int minFirst = qMin(newFirst, currentFirst);
1518         const int maxLast = qMax(newLast, currentLast);
1519
1520         if (maxLast - minFirst + 1 < maxVisibleItems) {
1521             // Increasing the size might result in a smaller KItemListView::offset().
1522             // Decrease the first visible index in a way that at least the maximum
1523             // visible items are shown.
1524             minFirst = qMax(0, maxLast - maxVisibleItems + 1);
1525         }
1526
1527         if (maxLast - minFirst > maxVisibleItems  + maxVisibleItems / 2) {
1528             // The creating of widgets is quite expensive. Assure that never more
1529             // than 50 % of the maximum visible items get created for the animations.
1530             return;
1531         }
1532
1533         setLayouterSize(currentSize, sizeType);
1534         for (int i = minFirst; i <= maxLast; ++i) {
1535             if (!m_visibleItems.contains(i)) {
1536                 KItemListWidget* widget = createWidget(i);
1537                 const QRectF itemRect = m_layouter->itemRect(i);
1538                 widget->setPos(itemRect.topLeft());
1539                 widget->resize(itemRect.size());
1540             }
1541         }
1542         setLayouterSize(size, sizeType);
1543     }
1544 }
1545
1546 void KItemListView::setLayouterSize(const QSizeF& size, SizeType sizeType)
1547 {
1548     switch (sizeType) {
1549     case LayouterSize: m_layouter->setSize(size); break;
1550     case ItemSize: m_layouter->setItemSize(size); break;
1551     default: break;
1552     }
1553 }
1554
1555 void KItemListView::updateWidgetProperties(KItemListWidget* widget, int index)
1556 {
1557     widget->setVisibleRoles(m_visibleRoles);
1558     widget->setVisibleRolesSizes(m_stretchedVisibleRolesSizes);
1559     widget->setStyleOption(m_styleOption);
1560
1561     const KItemListSelectionManager* selectionManager = m_controller->selectionManager();
1562     widget->setCurrent(index == selectionManager->currentItem());
1563     widget->setSelected(selectionManager->isSelected(index));
1564     widget->setHovered(false);
1565     widget->setAlternatingBackgroundColors(false);
1566     widget->setEnabledSelectionToggle(enabledSelectionToggles());
1567     widget->setIndex(index);
1568     widget->setData(m_model->data(index));
1569 }
1570
1571 void KItemListView::updateGroupHeaderForWidget(KItemListWidget* widget)
1572 {
1573     Q_ASSERT(m_grouped);
1574
1575     const int index = widget->index();
1576     if (!m_layouter->isFirstGroupItem(index)) {
1577         // The widget does not represent the first item of a group
1578         // and hence requires no header
1579         recycleGroupHeaderForWidget(widget);
1580         return;
1581     }
1582
1583     const QList<QPair<int, QVariant> > groups = model()->groups();
1584     if (groups.isEmpty()) {
1585         return;
1586     }
1587
1588     KItemListGroupHeader* header = m_visibleGroups.value(widget);
1589     if (!header) {
1590         header = m_groupHeaderCreator->create(this);
1591         header->setParentItem(widget);
1592         m_visibleGroups.insert(widget, header);
1593     }
1594     Q_ASSERT(header->parentItem() == widget);
1595
1596     // Determine the shown data for the header by doing a binary
1597     // search in the groups-list
1598     int min = 0;
1599     int max = groups.count() - 1;
1600     int mid = 0;
1601     do {
1602         mid = (min + max) / 2;
1603         if (index > groups.at(mid).first) {
1604             min = mid + 1;
1605         } else {
1606             max = mid - 1;
1607         }
1608     } while (groups.at(mid).first != index && min <= max);
1609
1610     header->setData(groups.at(mid).second);
1611     header->setRole(model()->sortRole());
1612     header->setStyleOption(m_styleOption);
1613     header->setScrollOrientation(scrollOrientation());
1614
1615     header->show();
1616 }
1617
1618 void KItemListView::updateGroupHeaderLayout(KItemListWidget* widget)
1619 {
1620     KItemListGroupHeader* header = m_visibleGroups.value(widget);
1621     Q_ASSERT(header);
1622
1623     const int index = widget->index();
1624     const QRectF groupHeaderRect = m_layouter->groupHeaderRect(index);
1625     const QRectF itemRect = m_layouter->itemRect(index);
1626
1627     // The group-header is a child of the itemlist widget. Translate the
1628     // group header position to the relative position.
1629     const QPointF groupHeaderPos(groupHeaderRect.x() - itemRect.x(),
1630                                  - groupHeaderRect.height());
1631     header->setPos(groupHeaderPos);
1632     header->resize(groupHeaderRect.size());
1633 }
1634
1635 void KItemListView::recycleGroupHeaderForWidget(KItemListWidget* widget)
1636 {
1637     KItemListGroupHeader* header = m_visibleGroups.value(widget);
1638     if (header) {
1639         header->setParentItem(0);
1640         m_groupHeaderCreator->recycle(header);
1641         m_visibleGroups.remove(widget);
1642     }
1643 }
1644
1645 void KItemListView::updateVisibleGroupHeaders()
1646 {
1647     Q_ASSERT(m_grouped);
1648     m_layouter->markAsDirty();
1649
1650     QHashIterator<int, KItemListWidget*> it(m_visibleItems);
1651     while (it.hasNext()) {
1652         it.next();
1653         updateGroupHeaderForWidget(it.value());
1654     }
1655 }
1656
1657 QHash<QByteArray, qreal> KItemListView::headerRolesWidths() const
1658 {
1659     QHash<QByteArray, qreal> rolesWidths;
1660
1661     QHashIterator<QByteArray, QSizeF> it(m_stretchedVisibleRolesSizes);
1662     while (it.hasNext()) {
1663         it.next();
1664         rolesWidths.insert(it.key(), it.value().width());
1665     }
1666
1667     return rolesWidths;
1668 }
1669
1670 void KItemListView::updateVisibleRolesSizes(const KItemRangeList& itemRanges)
1671 {
1672     if (!m_itemSize.isEmpty() || m_useHeaderWidths) {
1673         return;
1674     }
1675
1676     const int itemCount = m_model->count();
1677     int rangesItemCount = 0;
1678     foreach (const KItemRange& range, itemRanges) {
1679         rangesItemCount += range.count;
1680     }
1681
1682     if (itemCount == rangesItemCount) {
1683         m_visibleRolesSizes = visibleRolesSizes(itemRanges);
1684         if (m_header) {
1685             // Assure the the sizes are not smaller than the minimum defined by the header
1686             // TODO: Currently only implemented for a top-aligned header
1687             const qreal minHeaderRoleWidth = m_header->minimumRoleWidth();
1688             QMutableHashIterator<QByteArray, QSizeF> it (m_visibleRolesSizes);
1689             while (it.hasNext()) {
1690                 it.next();
1691                 const QSizeF& size = it.value();
1692                 if (size.width() < minHeaderRoleWidth) {
1693                     const QSizeF newSize(minHeaderRoleWidth, size.height());
1694                     m_visibleRolesSizes.insert(it.key(), newSize);
1695                 }
1696             }
1697         }
1698     } else {
1699         // Only a sub range of the roles need to be determined.
1700         // The chances are good that the sizes of the sub ranges
1701         // already fit into the available sizes and hence no
1702         // expensive update might be required.
1703         bool updateRequired = false;
1704
1705         const QHash<QByteArray, QSizeF> updatedSizes = visibleRolesSizes(itemRanges);
1706         QHashIterator<QByteArray, QSizeF> it(updatedSizes);
1707         while (it.hasNext()) {
1708             it.next();
1709             const QByteArray& role = it.key();
1710             const QSizeF& updatedSize = it.value();
1711             const QSizeF currentSize = m_visibleRolesSizes.value(role);
1712             if (updatedSize.width() > currentSize.width() || updatedSize.height() > currentSize.height()) {
1713                 m_visibleRolesSizes.insert(role, updatedSize);
1714                 updateRequired = true;
1715             }
1716         }
1717
1718         if (!updateRequired) {
1719             // All the updated sizes are smaller than the current sizes and no change
1720             // of the stretched roles-widths is required
1721             return;
1722         }
1723     }
1724
1725     updateStretchedVisibleRolesSizes();
1726 }
1727
1728 void KItemListView::updateVisibleRolesSizes()
1729 {
1730     if (!m_model) {
1731         return;
1732     }
1733
1734     const int itemCount = m_model->count();
1735     if (itemCount > 0) {
1736         updateVisibleRolesSizes(KItemRangeList() << KItemRange(0, itemCount));
1737     }
1738 }
1739
1740 void KItemListView::updateStretchedVisibleRolesSizes()
1741 {
1742     if (!m_itemSize.isEmpty() || m_useHeaderWidths || m_visibleRoles.isEmpty()) {
1743         return;
1744     }
1745
1746     // Calculate the maximum size of an item by considering the
1747     // visible role sizes and apply them to the layouter. If the
1748     // size does not use the available view-size it the size of the
1749     // first role will get stretched.
1750     m_stretchedVisibleRolesSizes = m_visibleRolesSizes;
1751     const QByteArray role = m_visibleRoles.first();
1752     QSizeF firstRoleSize = m_stretchedVisibleRolesSizes.value(role);
1753
1754     QSizeF dynamicItemSize = m_itemSize;
1755
1756     if (dynamicItemSize.width() <= 0) {
1757         const qreal requiredWidth = visibleRolesSizesWidthSum();
1758         const qreal availableWidth = size().width();
1759         if (requiredWidth < availableWidth) {
1760             // Stretch the first role to use the whole width for the item
1761             firstRoleSize.rwidth() += availableWidth - requiredWidth;
1762             m_stretchedVisibleRolesSizes.insert(role, firstRoleSize);
1763         }
1764         dynamicItemSize.setWidth(qMax(requiredWidth, availableWidth));
1765     }
1766
1767     if (dynamicItemSize.height() <= 0) {
1768         const qreal requiredHeight = visibleRolesSizesHeightSum();
1769         const qreal availableHeight = size().height();
1770         if (requiredHeight < availableHeight) {
1771             // Stretch the first role to use the whole height for the item
1772             firstRoleSize.rheight() += availableHeight - requiredHeight;
1773             m_stretchedVisibleRolesSizes.insert(role, firstRoleSize);
1774         }
1775         dynamicItemSize.setHeight(qMax(requiredHeight, availableHeight));
1776     }
1777
1778     m_layouter->setItemSize(dynamicItemSize);
1779
1780     if (m_header) {
1781         m_header->setVisibleRolesWidths(headerRolesWidths());
1782         m_header->resize(dynamicItemSize.width(), m_header->size().height());
1783     }
1784
1785     // Update the role sizes for all visible widgets
1786     foreach (KItemListWidget* widget, visibleItemListWidgets()) {
1787         widget->setVisibleRolesSizes(m_stretchedVisibleRolesSizes);
1788     }
1789 }
1790
1791 qreal KItemListView::visibleRolesSizesWidthSum() const
1792 {
1793     qreal widthSum = 0;
1794     QHashIterator<QByteArray, QSizeF> it(m_visibleRolesSizes);
1795     while (it.hasNext()) {
1796         it.next();
1797         widthSum += it.value().width();
1798     }
1799     return widthSum;
1800 }
1801
1802 qreal KItemListView::visibleRolesSizesHeightSum() const
1803 {
1804     qreal heightSum = 0;
1805     QHashIterator<QByteArray, QSizeF> it(m_visibleRolesSizes);
1806     while (it.hasNext()) {
1807         it.next();
1808         heightSum += it.value().height();
1809     }
1810     return heightSum;
1811 }
1812
1813 QRectF KItemListView::headerBoundaries() const
1814 {
1815     return m_header ? m_header->geometry() : QRectF();
1816 }
1817
1818 int KItemListView::calculateAutoScrollingIncrement(int pos, int range, int oldInc)
1819 {
1820     int inc = 0;
1821
1822     const int minSpeed = 4;
1823     const int maxSpeed = 128;
1824     const int speedLimiter = 96;
1825     const int autoScrollBorder = 64;
1826
1827     // Limit the increment that is allowed to be added in comparison to 'oldInc'.
1828     // This assures that the autoscrolling speed grows gradually.
1829     const int incLimiter = 1;
1830
1831     if (pos < autoScrollBorder) {
1832         inc = -minSpeed + qAbs(pos - autoScrollBorder) * (pos - autoScrollBorder) / speedLimiter;
1833         inc = qMax(inc, -maxSpeed);
1834         inc = qMax(inc, oldInc - incLimiter);
1835     } else if (pos > range - autoScrollBorder) {
1836         inc = minSpeed + qAbs(pos - range + autoScrollBorder) * (pos - range + autoScrollBorder) / speedLimiter;
1837         inc = qMin(inc, maxSpeed);
1838         inc = qMin(inc, oldInc + incLimiter);
1839     }
1840
1841     return inc;
1842 }
1843
1844
1845
1846 KItemListCreatorBase::~KItemListCreatorBase()
1847 {
1848     qDeleteAll(m_recycleableWidgets);
1849     qDeleteAll(m_createdWidgets);
1850 }
1851
1852 void KItemListCreatorBase::addCreatedWidget(QGraphicsWidget* widget)
1853 {
1854     m_createdWidgets.insert(widget);
1855 }
1856
1857 void KItemListCreatorBase::pushRecycleableWidget(QGraphicsWidget* widget)
1858 {
1859     Q_ASSERT(m_createdWidgets.contains(widget));
1860     m_createdWidgets.remove(widget);
1861
1862     if (m_recycleableWidgets.count() < 100) {
1863         m_recycleableWidgets.append(widget);
1864         widget->setVisible(false);
1865     } else {
1866         delete widget;
1867     }
1868 }
1869
1870 QGraphicsWidget* KItemListCreatorBase::popRecycleableWidget()
1871 {
1872     if (m_recycleableWidgets.isEmpty()) {
1873         return 0;
1874     }
1875
1876     QGraphicsWidget* widget = m_recycleableWidgets.takeLast();
1877     m_createdWidgets.insert(widget);
1878     return widget;
1879 }
1880
1881 KItemListWidgetCreatorBase::~KItemListWidgetCreatorBase()
1882 {
1883 }
1884
1885 void KItemListWidgetCreatorBase::recycle(KItemListWidget* widget)
1886 {
1887     widget->setParentItem(0);
1888     widget->setOpacity(1.0);
1889     pushRecycleableWidget(widget);
1890 }
1891
1892 KItemListGroupHeaderCreatorBase::~KItemListGroupHeaderCreatorBase()
1893 {
1894 }
1895
1896 void KItemListGroupHeaderCreatorBase::recycle(KItemListGroupHeader* header)
1897 {
1898     header->setOpacity(1.0);
1899     pushRecycleableWidget(header);
1900 }
1901
1902 #include "kitemlistview.moc"