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