src/kitemviews/kitemlistview.h

   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 #ifndef KITEMLISTVIEW_H
  24 #define KITEMLISTVIEW_H
  25
  26 #include <libdolphin_export.h>
  27
  28 #include <kitemviews/kitemlistgroupheader.h>
  29 #include <kitemviews/kitemliststyleoption.h>
  30 #include <kitemviews/kitemlistviewanimation_p.h>
  31 #include <kitemviews/kitemlistwidget.h>
  32 #include <kitemviews/kitemmodelbase.h>
  33 #include <QGraphicsWidget>
  34 #include <QSet>
  35
  36 class KItemListController;
  37 class KItemListGroupHeaderCreatorBase;
  38 class KItemListHeader;
  39 class KItemListSizeHintResolver;
  40 class KItemListRubberBand;
  41 class KItemListViewAnimation;
  42 class KItemListViewLayouter;
  43 class KItemListWidget;
  44 class KItemListWidgetCreatorBase;
  45 class KItemListViewCreatorBase;
  46 class QTimer;
  47
  48 /**
  49  * @brief Represents the view of an item-list.
  50  *
  51  * The view is responsible for showing the items of the model within
  52  * a GraphicsItem. Each visible item is represented by a KItemListWidget.
  53  *
  54  * The created view must be applied to the KItemListController with
  55  * KItemListController::setView(). For showing a custom model it is not
  56  * mandatory to derive from KItemListView, all that is necessary is
  57  * to set a widget-creator that is capable to create KItemListWidgets
  58  * showing the model items. A widget-creator can be set with
  59  * KItemListView::setWidgetCreator().
  60  *
  61  * @see KItemListWidget
  62  * @see KItemModelBase
  63  */
  64 class LIBDOLPHINPRIVATE_EXPORT KItemListView : public QGraphicsWidget
  65 {
  66     Q_OBJECT
  67
  68     Q_PROPERTY(qreal scrollOffset READ scrollOffset WRITE setScrollOffset)
  69     Q_PROPERTY(qreal itemOffset READ itemOffset WRITE setItemOffset)
  70
  71 public:
  72     KItemListView(QGraphicsWidget* parent = 0);
  73     virtual ~KItemListView();
  74
  75     void setScrollOrientation(Qt::Orientation orientation);
  76     Qt::Orientation scrollOrientation() const;
  77
  78     void setItemSize(const QSizeF& size);
  79     QSizeF itemSize() const;
  80
  81     // TODO: add note that offset is not checked against maximumOffset, only against 0.
  82     void setScrollOffset(qreal offset);
  83     qreal scrollOffset() const;
  84
  85     qreal maximumScrollOffset() const;
  86
  87     void setItemOffset(qreal scrollOffset);
  88     qreal itemOffset() const;
  89
  90     qreal maximumItemOffset() const;
  91
  92     void setVisibleRoles(const QList<QByteArray>& roles);
  93     QList<QByteArray> visibleRoles() const;
  94
  95     /**
  96      * If set to true an automatic scrolling is done as soon as the
  97      * mouse is moved near the borders of the view. Per default
  98      * the automatic scrolling is turned off.
  99      */
 100     void setAutoScroll(bool enabled);
 101     bool autoScroll() const;
 102
 103     /**
 104      * If set to true selection-toggles will be shown when hovering
 105      * an item. Per default the selection-toggles are disabled.
 106      */
 107     void setEnabledSelectionToggles(bool enabled);
 108     bool enabledSelectionToggles() const;
 109
 110     /**
 111      * @return Controller of the item-list. The controller gets
 112      *         initialized by KItemListController::setView() and will
 113      *         result in calling KItemListController::onControllerChanged().
 114      */
 115     KItemListController* controller() const;
 116
 117     /**
 118      * @return Model of the item-list. The model gets
 119      *         initialized by KItemListController::setView() and will
 120      *         result in calling KItemListController::onModelChanged().
 121      */
 122     KItemModelBase* model() const;
 123
 124     /**
 125      * Sets the creator that creates a widget showing the
 126      * content of one model-item. Usually it is sufficient
 127      * to implement a custom widget X derived from KItemListWidget and
 128      * set the creator by:
 129      * <code>
 130      * itemListView->setWidgetCreator(new KItemListWidgetCreator<X>());
 131      * </code>
 132      * Note that the ownership of the widget creator is not transferred to
 133      * the item-list view: One instance of a widget creator might get shared
 134      * by several item-list view instances.
 135      **/
 136     void setWidgetCreator(KItemListWidgetCreatorBase* widgetCreator);
 137     KItemListWidgetCreatorBase* widgetCreator() const;
 138
 139     void setGroupHeaderCreator(KItemListGroupHeaderCreatorBase* groupHeaderCreator);
 140     KItemListGroupHeaderCreatorBase* groupHeaderCreator() const;
 141
 142     void setStyleOption(const KItemListStyleOption& option);
 143     const KItemListStyleOption& styleOption() const;
 144
 145     /** @reimp */
 146     virtual void setGeometry(const QRectF& rect);
 147
 148     int itemAt(const QPointF& pos) const;
 149     bool isAboveSelectionToggle(int index, const QPointF& pos) const;
 150     bool isAboveExpansionToggle(int index, const QPointF& pos) const;
 151
 152     int firstVisibleIndex() const;
 153     int lastVisibleIndex() const;
 154
 155     /**
 156      * @return Required size for the item with the index \p index.
 157      *         Per default KItemListView::itemSize() is returned.
 158      *         When reimplementing this method it is recommended to
 159      *         also reimplement KItemListView::itemSizeHintUpdateRequired().
 160      */
 161     virtual QSizeF itemSizeHint(int index) const;
 162
 163     /**
 164      * @param itemRanges Items that must be checked for getting the visible roles sizes.
 165      * @return The size of each visible role in case if KItemListView::itemSize()
 166      *         is empty. This allows to have dynamic but equal role sizes between
 167      *         all items. Per default an empty hash is returned.
 168      */
 169     virtual QHash<QByteArray, QSizeF> visibleRolesSizes(const KItemRangeList& itemRanges) const;
 170
 171     /**
 172      * @return True if the view supports the expanding of items. Per default false
 173      *         is returned. If expanding of items is supported, the methods
 174      *         KItemModelBase::setExpanded(), KItemModelBase::isExpanded() and
 175      *         KItemModelBase::isExpandable() must be reimplemented. The view-implementation
 176      *         has to take care itself how to visually represent the expanded items provided
 177      *         by the model.
 178      */
 179     bool supportsItemExpanding() const;
 180
 181     /**
 182      * @return The rectangle of the item relative to the top/left of
 183      *         the currently visible area (see KItemListView::offset()).
 184      */
 185     QRectF itemRect(int index) const;
 186
 187     /**
 188      * @return The context rectangle of the item relative to the top/left of
 189      *         the currently visible area (see KItemListView::offset()). The
 190      *         context rectangle is defined by by the united rectangle of
 191      *         the icon rectangle and the text rectangle (see KItemListWidget::iconRect()
 192      *         and KItemListWidget::textRect()) and is useful as reference for e.g. aligning
 193      *         a tooltip or a context-menu for an item. Note that a context rectangle will
 194      *         only be returned for (at least partly) visible items. An empty rectangle will
 195      *         be returned for fully invisible items.
 196      */
 197     QRectF itemContextRect(int index) const;
 198
 199     /**
 200      * Scrolls to the item with the index \a index so that the item
 201      * will be fully visible.
 202      */
 203     void scrollToItem(int index);
 204
 205     /**
 206      * If several properties of KItemListView are changed synchronously, it is
 207      * recommended to encapsulate the calls between beginTransaction() and endTransaction().
 208      * This prevents unnecessary and expensive layout-calculations.
 209      */
 210     void beginTransaction();
 211
 212     /**
 213      * Counterpart to beginTransaction(). The layout changes will only be animated if
 214      * all property changes between beginTransaction() and endTransaction() support
 215      * animations.
 216      */
 217     void endTransaction();
 218
 219     bool isTransactionActive() const;
 220
 221     /**
 222      * Turns on the header if \p show is true. Per default the
 223      * header is not shown.
 224      */
 225     void setHeaderShown(bool show);
 226     bool isHeaderShown() const;
 227
 228     /**
 229      * @return Pixmap that is used for a drag operation based on the
 230      *         items given by \a indexes. The default implementation returns
 231      *         a null-pixmap.
 232      */
 233     virtual QPixmap createDragPixmap(const QSet<int>& indexes) const;
 234
 235     /**
 236      * @reimp
 237      */
 238     virtual void paint(QPainter* painter, const QStyleOptionGraphicsItem* option, QWidget* widget = 0);
 239
 240 signals:
 241     void scrollOrientationChanged(Qt::Orientation current, Qt::Orientation previous);
 242     void scrollOffsetChanged(qreal current, qreal previous);
 243     void maximumScrollOffsetChanged(qreal current, qreal previous);
 244     void itemOffsetChanged(qreal current, qreal previous);
 245     void maximumItemOffsetChanged(qreal current, qreal previous);
 246     void scrollTo(qreal newOffset);
 247
 248     /**
 249      * Is emitted if the user has changed the sort order by clicking on a
 250      * header item (see KItemListView::setHeaderShown()). The sort order
 251      * of the model has already been adjusted to
 252      * the current sort order. Note that no signal will be emitted if the
 253      * sort order of the model has been changed without user interaction.
 254      */
 255     void sortOrderChanged(Qt::SortOrder current, Qt::SortOrder previous);
 256
 257     /**
 258      * Is emitted if the user has changed the sort role by clicking on a
 259      * header item (see KItemListView::setHeaderShown()). The sort role
 260      * of the model has already been adjusted to
 261      * the current sort role. Note that no signal will be emitted if the
 262      * sort role of the model has been changed without user interaction.
 263      */
 264     void sortRoleChanged(const QByteArray& current, const QByteArray& previous);
 265
 266 protected:
 267     virtual void initializeItemListWidget(KItemListWidget* item);
 268
 269     /**
 270      * @return True if at least one of the changed roles \p changedRoles might result
 271      *         in the need to update the item-size hint (see KItemListView::itemSizeHint()).
 272      *         Per default true is returned which means on each role-change of existing items
 273      *         the item-size hints are recalculated. For performance reasons it is recommended
 274      *         to return false in case if a role-change will not result in a changed
 275      *         item-size hint.
 276      */
 277     virtual bool itemSizeHintUpdateRequired(const QSet<QByteArray>& changedRoles) const;
 278
 279     virtual void onControllerChanged(KItemListController* current, KItemListController* previous);
 280     virtual void onModelChanged(KItemModelBase* current, KItemModelBase* previous);
 281
 282     virtual void onScrollOrientationChanged(Qt::Orientation current, Qt::Orientation previous);
 283     virtual void onItemSizeChanged(const QSizeF& current, const QSizeF& previous);
 284     virtual void onScrollOffsetChanged(qreal current, qreal previous);
 285     virtual void onVisibleRolesChanged(const QList<QByteArray>& current, const QList<QByteArray>& previous);
 286     virtual void onStyleOptionChanged(const KItemListStyleOption& current, const KItemListStyleOption& previous);
 287
 288     virtual void onTransactionBegin();
 289     virtual void onTransactionEnd();
 290
 291     virtual bool event(QEvent* event);
 292     virtual void mousePressEvent(QGraphicsSceneMouseEvent* event);
 293     virtual void mouseMoveEvent(QGraphicsSceneMouseEvent* event);
 294     virtual void dragEnterEvent(QGraphicsSceneDragDropEvent* event);
 295     virtual void dragMoveEvent(QGraphicsSceneDragDropEvent* event);
 296     virtual void dragLeaveEvent(QGraphicsSceneDragDropEvent* event);
 297     virtual void dropEvent(QGraphicsSceneDragDropEvent* event);
 298
 299     QList<KItemListWidget*> visibleItemListWidgets() const;
 300
 301     /**
 302      * Must be called by the derived class if it supports the expanding
 303      * of items.
 304      * @see supportsItemExpanding()
 305      */
 306     void setSupportsItemExpanding(bool supportsExpanding);
 307
 308 protected slots:
 309     virtual void slotItemsInserted(const KItemRangeList& itemRanges);
 310     virtual void slotItemsRemoved(const KItemRangeList& itemRanges);
 311     virtual void slotItemsMoved(const KItemRange& itemRange, const QList<int>& movedToIndexes);
 312     virtual void slotItemsChanged(const KItemRangeList& itemRanges,
 313                                   const QSet<QByteArray>& roles);
 314
 315     virtual void slotGroupedSortingChanged(bool current);
 316     virtual void slotSortOrderChanged(Qt::SortOrder current, Qt::SortOrder previous);
 317     virtual void slotSortRoleChanged(const QByteArray& current, const QByteArray& previous);
 318     virtual void slotCurrentChanged(int current, int previous);
 319     virtual void slotSelectionChanged(const QSet<int>& current, const QSet<int>& previous);
 320
 321 private slots:
 322     void slotAnimationFinished(QGraphicsWidget* widget,
 323                                KItemListViewAnimation::AnimationType type);
 324     void slotLayoutTimerFinished();
 325
 326     void slotRubberBandPosChanged();
 327     void slotRubberBandActivationChanged(bool active);
 328
 329     /**
 330      * Is invoked if the visible role-width of one role in the header has
 331      * been changed by the user. It is remembered that the user has modified
 332      * the role-width, so that it won't be changed anymore automatically to
 333      * calculate an optimized width.
 334      */
 335     void slotVisibleRoleWidthChanged(const QByteArray& role,
 336                                      qreal currentWidth,
 337                                      qreal previousWidth);
 338
 339     /**
 340      * Triggers the autoscrolling if autoScroll() is enabled by checking the
 341      * current mouse position. If the mouse position is within the autoscroll
 342      * margins a timer will be started that periodically triggers the autoscrolling.
 343      */
 344     void triggerAutoScrolling();
 345
 346     /**
 347      * Is invoked if the geometry of the parent-widget from a group-header has been
 348      * changed. The x-position and width of the group-header gets adjusted to assure
 349      * that it always spans the whole width even during temporary transitions of the
 350      * parent widget.
 351      */
 352     void slotGeometryOfGroupHeaderParentChanged();
 353
 354 private:
 355     enum LayoutAnimationHint
 356     {
 357         NoAnimation,
 358         Animation
 359     };
 360
 361     enum SizeType
 362     {
 363         LayouterSize,
 364         ItemSize
 365     };
 366
 367     void setController(KItemListController* controller);
 368     void setModel(KItemModelBase* model);
 369
 370     KItemListRubberBand* rubberBand() const;
 371
 372     void doLayout(LayoutAnimationHint hint, int changedIndex = 0, int changedCount = 0);
 373
 374     /**
 375      * Helper method for doLayout: Returns a list of items that can be reused for the visible
 376      * area. Invisible group headers get recycled. The reusable items are items that are
 377      * invisible. If the animation hint is 'Animation' then items that are currently animated
 378      * won't be reused. Reusing items is faster in comparison to deleting invisible
 379      * items and creating a new instance for visible items.
 380      */
 381     QList<int> recycleInvisibleItems(int firstVisibleIndex,
 382                                      int lastVisibleIndex,
 383                                      LayoutAnimationHint hint);
 384
 385     /**
 386      * Helper method for doLayout: Starts a moving-animation for the widget to the given
 387      * new position. The moving-animation is only started if the new position is within
 388      * the same row or column, otherwise the create-animation is used instead.
 389      * @return True if the moving-animation has been applied.
 390      */
 391     bool moveWidget(KItemListWidget* widget, const QPointF& newPos);
 392
 393     void emitOffsetChanges();
 394
 395     KItemListWidget* createWidget(int index);
 396     void recycleWidget(KItemListWidget* widget);
 397
 398     /**
 399      * Changes the index of the widget to \a index and assures a consistent
 400      * update for m_visibleItems and m_visibleCells. The cell-information
 401      * for the new index will not be updated and be initialized as empty cell.
 402      */
 403     void setWidgetIndex(KItemListWidget* widget, int index);
 404
 405     /**
 406      * Changes the index of the widget to \a index. In opposite to
 407      * setWidgetIndex() the cell-information for the widget gets updated.
 408      * This update gives doLayout() the chance to animate the moving
 409      * of the item visually (see moveWidget()).
 410      */
 411     void moveWidgetToIndex(KItemListWidget* widget, int index);
 412
 413     /**
 414      * Helper method for prepareLayoutForIncreasedItemCount().
 415      */
 416     void setLayouterSize(const QSizeF& size, SizeType sizeType);
 417
 418     /**
 419      * Helper method for createWidget() and setWidgetIndex() to update the properties
 420      * of the itemlist widget.
 421      */
 422     void updateWidgetProperties(KItemListWidget* widget, int index);
 423
 424     /**
 425      * Helper method for updateWidgetPropertes() to create or update
 426      * the itemlist group-header.
 427      */
 428     void updateGroupHeaderForWidget(KItemListWidget* widget);
 429
 430     /**
 431      * Updates the position and size of the group-header that belongs
 432      * to the itemlist widget \a widget. The given widget must represent
 433      * the first item of a group.
 434      */
 435     void updateGroupHeaderLayout(KItemListWidget* widget);
 436
 437     /**
 438      * Recycles the group-header from the widget.
 439      */
 440     void recycleGroupHeaderForWidget(KItemListWidget* widget);
 441
 442     /**
 443      * Helper method for slotGroupedSortingChanged(), slotSortOrderChanged()
 444      * and slotSortRoleChanged(): Iterates through all visible items and updates
 445      * the group-header widgets.
 446      */
 447     void updateVisibleGroupHeaders();
 448
 449     /**
 450      * @return Index for the item in the list returned by KItemModelBase::groups()
 451      *         that represents the group where the item with the index \a index
 452      *         belongs to. -1 is returned if no groups are available.
 453      */
 454     int groupIndexForItem(int index) const;
 455
 456     /**
 457      * Updates the alternateBackground-property of the widget dependent
 458      * on the state of useAlternateBackgrounds() and the grouping state.
 459      */
 460     void updateAlternateBackgroundForWidget(KItemListWidget* widget);
 461
 462     /**
 463      * @return True if alternate backgrounds should be used for the items.
 464      *         This is the case if an empty item-size is given and if there
 465      *         is more than one visible role.
 466      */
 467     bool useAlternateBackgrounds() const;
 468
 469     /**
 470      * @return The widths of each visible role that is shown in the KItemListHeader.
 471      */
 472     QHash<QByteArray, qreal> headerRolesWidths() const;
 473
 474     /**
 475      * Updates m_visibleRolesSizes by calling KItemListView::visibleRolesSizes().
 476      * Nothing will be done if m_itemRect is not empty or custom header-widths
 477      * are used (see m_useHeaderWidths). Also m_strechedVisibleRolesSizes will be adjusted
 478      * to respect the available view-size.
 479      */
 480     void updateVisibleRolesSizes(const KItemRangeList& itemRanges);
 481
 482     /**
 483      * Convenience method for updateVisibleRoleSizes(KItemRangeList() << KItemRange(0, m_model->count()).
 484      */
 485     void updateVisibleRolesSizes();
 486
 487     /**
 488      * Updates m_stretchedVisibleRolesSizes based on m_visibleRolesSizes and the available
 489      * view-size. Nothing will be done if m_itemRect is not empty or custom header-widths
 490      * are used (see m_useHeaderWidths).
 491      */
 492     void updateStretchedVisibleRolesSizes();
 493
 494     /**
 495      * @return Sum of the widths of all visible roles.
 496      */
 497     qreal visibleRolesSizesWidthSum() const;
 498
 499     /**
 500      * @return Sum of the heights of all visible roles.
 501      */
 502     qreal visibleRolesSizesHeightSum() const;
 503
 504     /**
 505      * @return Boundaries of the header. An empty rectangle is returned
 506      *         if no header is shown.
 507      */
 508     QRectF headerBoundaries() const;
 509
 510     /**
 511      * @return True if the number of columns or rows will be changed when applying
 512      *         the new grid- and item-size. Used to determine whether an animation
 513      *         should be done when applying the new layout.
 514      */
 515     bool changesItemGridLayout(const QSizeF& newGridSize,
 516                                const QSizeF& newItemSize,
 517                                const QSizeF& newItemMargin) const;
 518
 519     /**
 520      * @param changedItemCount Number of inserted  or removed items.
 521      * @return                 True if the inserting or removing of items should be animated.
 522      *                         No animation should be done if the number of items is too large
 523      *                         to provide a pleasant animation.
 524      */
 525     bool animateChangedItemCount(int changedItemCount) const;
 526
 527     /**
 528      * @return True if a scrollbar for the given scroll-orientation is required
 529      *         when using a size of \p size for the view. Calling the method is rather
 530      *         expansive as a temporary relayout needs to be done.
 531      */
 532     bool scrollBarRequired(const QSizeF& size) const;
 533
 534     /**
 535      * Applies the height of the group header to the layouter. The height
 536      * depends on the used scroll orientation.
 537      */
 538     void updateGroupHeaderHeight();
 539
 540     /**
 541      * Updates the siblings-information for all visible items that are inside
 542      * the range of \p firstIndex and \p lastIndex. If firstIndex or lastIndex
 543      * is smaller than 0, the siblings-information for all visible items gets
 544      * updated.
 545      * @see KItemListWidget::setSiblingsInformation()
 546      */
 547     void updateSiblingsInformation(int firstIndex = -1, int lastIndex = -1);
 548
 549     /**
 550      * Helper method for updateExpansionIndicators().
 551      * @return True if the item with the index \a index has a sibling successor
 552      *         (= the item is not the last item of the current hierarchy).
 553      */
 554     bool hasSiblingSuccessor(int index) const;
 555
 556     /**
 557      * Helper function for triggerAutoScrolling().
 558      * @param pos    Logical position of the mouse relative to the range.
 559      * @param range  Range of the visible area.
 560      * @param oldInc Previous increment. Is used to assure that the increment
 561      *               increases only gradually.
 562      * @return Scroll increment that should be added to the offset().
 563      *         As soon as \a pos is inside the autoscroll-margin a
 564      *         value != 0 will be returned.
 565      */
 566     static int calculateAutoScrollingIncrement(int pos, int range, int oldInc);
 567
 568     /**
 569      * Helper functions for changesItemCount().
 570      * @return The number of items that fit into the available size by
 571      *         respecting the size of the item and the margin between the items.
 572      */
 573     static int itemsPerSize(qreal size, qreal itemSize, qreal itemMargin);
 574
 575 private:
 576     bool m_enabledSelectionToggles;
 577     bool m_grouped;
 578     bool m_supportsItemExpanding;
 579     int m_activeTransactions; // Counter for beginTransaction()/endTransaction()
 580     LayoutAnimationHint m_endTransactionAnimationHint;
 581
 582     QSizeF m_itemSize;
 583     KItemListController* m_controller;
 584     KItemModelBase* m_model;
 585     QList<QByteArray> m_visibleRoles;
 586     QHash<QByteArray, QSizeF> m_visibleRolesSizes;
 587     QHash<QByteArray, QSizeF> m_stretchedVisibleRolesSizes;
 588     KItemListWidgetCreatorBase* m_widgetCreator;
 589     KItemListGroupHeaderCreatorBase* m_groupHeaderCreator;
 590     KItemListStyleOption m_styleOption;
 591
 592     QHash<int, KItemListWidget*> m_visibleItems;
 593     QHash<KItemListWidget*, KItemListGroupHeader*> m_visibleGroups;
 594
 595     struct Cell
 596     {
 597         Cell() : column(-1), row(-1) {}
 598         Cell(int c, int r) : column(c), row(r) {}
 599         int column;
 600         int row;
 601     };
 602     QHash<int, Cell> m_visibleCells;
 603
 604     int m_scrollBarExtent;
 605     KItemListSizeHintResolver* m_sizeHintResolver;
 606     KItemListViewLayouter* m_layouter;
 607     KItemListViewAnimation* m_animation;
 608
 609     QTimer* m_layoutTimer; // Triggers an asynchronous doLayout() call.
 610     qreal m_oldScrollOffset;
 611     qreal m_oldMaximumScrollOffset;
 612     qreal m_oldItemOffset;
 613     qreal m_oldMaximumItemOffset;
 614
 615     bool m_skipAutoScrollForRubberBand;
 616     KItemListRubberBand* m_rubberBand;
 617
 618     QPointF m_mousePos;
 619     int m_autoScrollIncrement;
 620     QTimer* m_autoScrollTimer;
 621
 622     KItemListHeader* m_header;
 623     bool m_useHeaderWidths;
 624
 625     friend class KItemListContainer; // Accesses scrollBarRequired()
 626     friend class KItemListController;
 627     friend class KItemListControllerTest;
 628 };
 629
 630 /**
 631  * Allows to do a fast logical creation and deletion of QGraphicsWidgets
 632  * by recycling existing QGraphicsWidgets instances. Is used by
 633  * KItemListWidgetCreatorBase and KItemListGroupHeaderCreatorBase.
 634  * @internal
 635  */
 636 class LIBDOLPHINPRIVATE_EXPORT KItemListCreatorBase
 637 {
 638 public:
 639     virtual ~KItemListCreatorBase();
 640
 641 protected:
 642     void addCreatedWidget(QGraphicsWidget* widget);
 643     void pushRecycleableWidget(QGraphicsWidget* widget);
 644     QGraphicsWidget* popRecycleableWidget();
 645
 646 private:
 647     QSet<QGraphicsWidget*> m_createdWidgets;
 648     QList<QGraphicsWidget*> m_recycleableWidgets;
 649 };
 650
 651 /**
 652  * @brief Base class for creating KItemListWidgets.
 653  *
 654  * It is recommended that applications simply use the KItemListWidgetCreator-template class.
 655  * For a custom implementation the methods create() and recyle() must be reimplemented.
 656  * The intention of the widget creator is to prevent repetitive and expensive instantiations and
 657  * deletions of KItemListWidgets by recycling existing widget instances.
 658  */
 659 class LIBDOLPHINPRIVATE_EXPORT KItemListWidgetCreatorBase : public KItemListCreatorBase
 660 {
 661 public:
 662     virtual ~KItemListWidgetCreatorBase();
 663     virtual KItemListWidget* create(KItemListView* view) = 0;
 664     virtual void recycle(KItemListWidget* widget);
 665 };
 666
 667 template <class T>
 668 class KItemListWidgetCreator : public KItemListWidgetCreatorBase
 669 {
 670 public:
 671     virtual ~KItemListWidgetCreator();
 672     virtual KItemListWidget* create(KItemListView* view);
 673 };
 674
 675 template <class T>
 676 KItemListWidgetCreator<T>::~KItemListWidgetCreator()
 677 {
 678 }
 679
 680 template <class T>
 681 KItemListWidget* KItemListWidgetCreator<T>::create(KItemListView* view)
 682 {
 683     KItemListWidget* widget = static_cast<KItemListWidget*>(popRecycleableWidget());
 684     if (!widget) {
 685         widget = new T(view);
 686         addCreatedWidget(widget);
 687     }
 688     return widget;
 689 }
 690
 691 /**
 692  * @brief Base class for creating KItemListGroupHeaders.
 693  *
 694  * It is recommended that applications simply use the KItemListGroupHeaderCreator-template class.
 695  * For a custom implementation the methods create() and recyle() must be reimplemented.
 696  * The intention of the group-header creator is to prevent repetitive and expensive instantiations and
 697  * deletions of KItemListGroupHeaders by recycling existing header instances.
 698  */
 699 class LIBDOLPHINPRIVATE_EXPORT KItemListGroupHeaderCreatorBase : public KItemListCreatorBase
 700 {
 701 public:
 702     virtual ~KItemListGroupHeaderCreatorBase();
 703     virtual KItemListGroupHeader* create(KItemListView* view) = 0;
 704     virtual void recycle(KItemListGroupHeader* header);
 705 };
 706
 707 template <class T>
 708 class KItemListGroupHeaderCreator : public KItemListGroupHeaderCreatorBase
 709 {
 710 public:
 711     virtual ~KItemListGroupHeaderCreator();
 712     virtual KItemListGroupHeader* create(KItemListView* view);
 713 };
 714
 715 template <class T>
 716 KItemListGroupHeaderCreator<T>::~KItemListGroupHeaderCreator()
 717 {
 718 }
 719
 720 template <class T>
 721 KItemListGroupHeader* KItemListGroupHeaderCreator<T>::create(KItemListView* view)
 722 {
 723     KItemListGroupHeader* widget = static_cast<KItemListGroupHeader*>(popRecycleableWidget());
 724     if (!widget) {
 725         widget = new T(view);
 726         addCreatedWidget(widget);
 727     }
 728     return widget;
 729 }
 730
 731 #endif