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     virtual 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      * @return The number of items that can be shown in parallel for one offset.
 207      *         Assuming the scrolldirection is vertical then a value of 4 means
 208      *         that 4 columns for items are available. Assuming the scrolldirection
 209      *         is horizontal then a value of 4 means that 4 lines for items are
 210      *         available.
 211      */
 212     int itemsPerOffset() const;
 213
 214     void beginTransaction();
 215     void endTransaction();
 216     bool isTransactionActive() const;
 217
 218     /**
 219      * Turns on the header if \p show is true. Per default the
 220      * header is not shown.
 221      */
 222     void setHeaderShown(bool show);
 223     bool isHeaderShown() const;
 224
 225     /**
 226      * @return Pixmap that is used for a drag operation based on the
 227      *         items given by \a indexes. The default implementation returns
 228      *         a null-pixmap.
 229      */
 230     virtual QPixmap createDragPixmap(const QSet<int>& indexes) const;
 231
 232     /**
 233      * @reimp
 234      */
 235     virtual void paint(QPainter* painter, const QStyleOptionGraphicsItem* option, QWidget* widget = 0);
 236
 237 signals:
 238     void scrollOrientationChanged(Qt::Orientation current, Qt::Orientation previous);
 239     void scrollOffsetChanged(qreal current, qreal previous);
 240     void maximumScrollOffsetChanged(qreal current, qreal previous);
 241     void itemOffsetChanged(qreal current, qreal previous);
 242     void maximumItemOffsetChanged(qreal current, qreal previous);
 243     void scrollTo(qreal newOffset);
 244
 245     /**
 246      * Is emitted if the user has changed the sort order by clicking on a
 247      * header item (see KItemListView::setHeaderShown()). The sort order
 248      * of the model has already been adjusted to
 249      * the current sort order. Note that no signal will be emitted if the
 250      * sort order of the model has been changed without user interaction.
 251      */
 252     void sortOrderChanged(Qt::SortOrder current, Qt::SortOrder previous);
 253
 254     /**
 255      * Is emitted if the user has changed the sort role by clicking on a
 256      * header item (see KItemListView::setHeaderShown()). The sort role
 257      * of the model has already been adjusted to
 258      * the current sort role. Note that no signal will be emitted if the
 259      * sort role of the model has been changed without user interaction.
 260      */
 261     void sortRoleChanged(const QByteArray& current, const QByteArray& previous);
 262
 263 protected:
 264     virtual void initializeItemListWidget(KItemListWidget* item);
 265
 266     /**
 267      * @return True if at least one of the changed roles \p changedRoles might result
 268      *         in the need to update the item-size hint (see KItemListView::itemSizeHint()).
 269      *         Per default true is returned which means on each role-change of existing items
 270      *         the item-size hints are recalculated. For performance reasons it is recommended
 271      *         to return false in case if a role-change will not result in a changed
 272      *         item-size hint.
 273      */
 274     virtual bool itemSizeHintUpdateRequired(const QSet<QByteArray>& changedRoles) const;
 275
 276     virtual void onControllerChanged(KItemListController* current, KItemListController* previous);
 277     virtual void onModelChanged(KItemModelBase* current, KItemModelBase* previous);
 278
 279     virtual void onScrollOrientationChanged(Qt::Orientation current, Qt::Orientation previous);
 280     virtual void onItemSizeChanged(const QSizeF& current, const QSizeF& previous);
 281     virtual void onScrollOffsetChanged(qreal current, qreal previous);
 282     virtual void onVisibleRolesChanged(const QList<QByteArray>& current, const QList<QByteArray>& previous);
 283     virtual void onStyleOptionChanged(const KItemListStyleOption& current, const KItemListStyleOption& previous);
 284
 285     virtual void onTransactionBegin();
 286     virtual void onTransactionEnd();
 287
 288     virtual bool event(QEvent* event);
 289     virtual void mousePressEvent(QGraphicsSceneMouseEvent* event);
 290     virtual void mouseMoveEvent(QGraphicsSceneMouseEvent* event);
 291     virtual void dragEnterEvent(QGraphicsSceneDragDropEvent* event);
 292     virtual void dragMoveEvent(QGraphicsSceneDragDropEvent* event);
 293     virtual void dragLeaveEvent(QGraphicsSceneDragDropEvent* event);
 294     virtual void dropEvent(QGraphicsSceneDragDropEvent* event);
 295
 296     QList<KItemListWidget*> visibleItemListWidgets() const;
 297
 298     /** @reimp */
 299     virtual void resizeEvent(QGraphicsSceneResizeEvent* event);
 300
 301 protected slots:
 302     virtual void slotItemsInserted(const KItemRangeList& itemRanges);
 303     virtual void slotItemsRemoved(const KItemRangeList& itemRanges);
 304     virtual void slotItemsMoved(const KItemRange& itemRange, const QList<int>& movedToIndexes);
 305     virtual void slotItemsChanged(const KItemRangeList& itemRanges,
 306                                   const QSet<QByteArray>& roles);
 307
 308     virtual void slotGroupedSortingChanged(bool current);
 309     virtual void slotSortOrderChanged(Qt::SortOrder current, Qt::SortOrder previous);
 310     virtual void slotSortRoleChanged(const QByteArray& current, const QByteArray& previous);
 311     virtual void slotCurrentChanged(int current, int previous);
 312     virtual void slotSelectionChanged(const QSet<int>& current, const QSet<int>& previous);
 313
 314 private slots:
 315     void slotAnimationFinished(QGraphicsWidget* widget,
 316                                KItemListViewAnimation::AnimationType type);
 317     void slotLayoutTimerFinished();
 318
 319     void slotRubberBandPosChanged();
 320     void slotRubberBandActivationChanged(bool active);
 321
 322     /**
 323      * Is invoked if the visible role-width of one role in the header has
 324      * been changed by the user. It is remembered that the user has modified
 325      * the role-width, so that it won't be changed anymore automatically to
 326      * calculate an optimized width.
 327      */
 328     void slotVisibleRoleWidthChanged(const QByteArray& role,
 329                                      qreal currentWidth,
 330                                      qreal previousWidth);
 331
 332     /**
 333      * Triggers the autoscrolling if autoScroll() is enabled by checking the
 334      * current mouse position. If the mouse position is within the autoscroll
 335      * margins a timer will be started that periodically triggers the autoscrolling.
 336      */
 337     void triggerAutoScrolling();
 338
 339 private:
 340     enum LayoutAnimationHint
 341     {
 342         NoAnimation,
 343         Animation
 344     };
 345
 346     enum SizeType
 347     {
 348         LayouterSize,
 349         ItemSize
 350     };
 351
 352     void setController(KItemListController* controller);
 353     void setModel(KItemModelBase* model);
 354
 355     KItemListRubberBand* rubberBand() const;
 356
 357     void doLayout(LayoutAnimationHint hint, int changedIndex = 0, int changedCount = 0);
 358
 359     void emitOffsetChanges();
 360
 361     KItemListWidget* createWidget(int index);
 362     void recycleWidget(KItemListWidget* widget);
 363     void setWidgetIndex(KItemListWidget* widget, int index);
 364
 365     /**
 366      * Helper method for setGeometry() and setItemSize(): Calling both methods might result
 367      * in a changed number of visible items. To assure that currently invisible items can
 368      * get animated from the old position to the new position prepareLayoutForIncreasedItemCount()
 369      * takes care to create all item widgets that are visible with the old or the new size.
 370      * @param size     Size of the layouter or the item dependent on \p sizeType.
 371      * @param sizeType LayouterSize: KItemListLayouter::setSize() is used.
 372      *                 ItemSize: KItemListLayouter::setItemSize() is used.
 373      */
 374     void prepareLayoutForIncreasedItemCount(const QSizeF& size, SizeType sizeType);
 375
 376     /**
 377      * Helper method for prepareLayoutForIncreasedItemCount().
 378      */
 379     void setLayouterSize(const QSizeF& size, SizeType sizeType);
 380
 381     /**
 382      * Helper method for createWidget() and setWidgetIndex() to update the properties
 383      * of the itemlist widget.
 384      */
 385     void updateWidgetProperties(KItemListWidget* widget, int index);
 386
 387     /**
 388      * Helper method for createWidget() and setWidgetIndex() to create or update
 389      * the itemlist group-header.
 390      */
 391     void updateGroupHeaderForWidget(KItemListWidget* widget);
 392
 393     /**
 394      * Updates the position and size of the group-header that belongs
 395      * to the itemlist widget \a widget. The given widget must represent
 396      * the first item of a group.
 397      */
 398     void updateGroupHeaderLayout(KItemListWidget* widget);
 399
 400     /**
 401      * Recycles the group-header from the widget.
 402      */
 403     void recycleGroupHeaderForWidget(KItemListWidget* widget);
 404
 405     /**
 406      * Helper method for slotGroupedSortingChanged(), slotSortOrderChanged()
 407      * and slotSortRoleChanged(): Iterates through all visible items and updates
 408      * the group-header widgets.
 409      */
 410     void updateVisibleGroupHeaders();
 411
 412     /**
 413      * @return The widths of each visible role that is shown in the KItemListHeader.
 414      */
 415     QHash<QByteArray, qreal> headerRolesWidths() const;
 416
 417     /**
 418      * Updates m_visibleRolesSizes by calling KItemListView::visibleRolesSizes().
 419      * Nothing will be done if m_itemRect is not empty or custom header-widths
 420      * are used (see m_useHeaderWidths). Also m_strechedVisibleRolesSizes will be adjusted
 421      * to respect the available view-size.
 422      */
 423     void updateVisibleRolesSizes(const KItemRangeList& itemRanges);
 424
 425     /**
 426      * Convenience method for updateVisibleRoleSizes(KItemRangeList() << KItemRange(0, m_model->count()).
 427      */
 428     void updateVisibleRolesSizes();
 429
 430     /**
 431      * Updates m_stretchedVisibleRolesSizes based on m_visibleRolesSizes and the available
 432      * view-size. Nothing will be done if m_itemRect is not empty or custom header-widths
 433      * are used (see m_useHeaderWidths).
 434      */
 435     void updateStretchedVisibleRolesSizes();
 436
 437     /**
 438      * @return Sum of the widths of all visible roles.
 439      */
 440     qreal visibleRolesSizesWidthSum() const;
 441
 442     /**
 443      * @return Sum of the heights of all visible roles.
 444      */
 445     qreal visibleRolesSizesHeightSum() const;
 446
 447     /**
 448      * @return Boundaries of the header. An empty rectangle is returned
 449      *         if no header is shown.
 450      */
 451     QRectF headerBoundaries() const;
 452
 453     /**
 454      * Helper function for triggerAutoScrolling().
 455      * @param pos    Logical position of the mouse relative to the range.
 456      * @param range  Range of the visible area.
 457      * @param oldInc Previous increment. Is used to assure that the increment
 458      *               increases only gradually.
 459      * @return Scroll increment that should be added to the offset().
 460      *         As soon as \a pos is inside the autoscroll-margin a
 461      *         value != 0 will be returned.
 462      */
 463     static int calculateAutoScrollingIncrement(int pos, int range, int oldInc);
 464
 465 private:
 466     bool m_enabledSelectionToggles;
 467     bool m_grouped;
 468     int m_activeTransactions; // Counter for beginTransaction()/endTransaction()
 469
 470     QSizeF m_itemSize;
 471     KItemListController* m_controller;
 472     KItemModelBase* m_model;
 473     QList<QByteArray> m_visibleRoles;
 474     QHash<QByteArray, QSizeF> m_visibleRolesSizes;
 475     QHash<QByteArray, QSizeF> m_stretchedVisibleRolesSizes;
 476     KItemListWidgetCreatorBase* m_widgetCreator;
 477     KItemListGroupHeaderCreatorBase* m_groupHeaderCreator;
 478     KItemListStyleOption m_styleOption;
 479
 480     QHash<int, KItemListWidget*> m_visibleItems;
 481     QHash<KItemListWidget*, KItemListGroupHeader*> m_visibleGroups;
 482
 483     int m_scrollBarExtent;
 484     KItemListSizeHintResolver* m_sizeHintResolver;
 485     KItemListViewLayouter* m_layouter;
 486     KItemListViewAnimation* m_animation;
 487
 488     QTimer* m_layoutTimer; // Triggers an asynchronous doLayout() call.
 489     qreal m_oldScrollOffset;
 490     qreal m_oldMaximumScrollOffset;
 491     qreal m_oldItemOffset;
 492     qreal m_oldMaximumItemOffset;
 493
 494     bool m_skipAutoScrollForRubberBand;
 495     KItemListRubberBand* m_rubberBand;
 496
 497     QPointF m_mousePos;
 498     int m_autoScrollIncrement;
 499     QTimer* m_autoScrollTimer;
 500
 501     KItemListHeader* m_header;
 502     bool m_useHeaderWidths;
 503
 504     friend class KItemListController;
 505 };
 506
 507 /**
 508  * Allows to do a fast logical creation and deletion of QGraphicsWidgets
 509  * by recycling existing QGraphicsWidgets instances. Is used by
 510  * KItemListWidgetCreatorBase and KItemListGroupHeaderCreatorBase.
 511  * @internal
 512  */
 513 class LIBDOLPHINPRIVATE_EXPORT KItemListCreatorBase
 514 {
 515 public:
 516     virtual ~KItemListCreatorBase();
 517
 518 protected:
 519     void addCreatedWidget(QGraphicsWidget* widget);
 520     void pushRecycleableWidget(QGraphicsWidget* widget);
 521     QGraphicsWidget* popRecycleableWidget();
 522
 523 private:
 524     QSet<QGraphicsWidget*> m_createdWidgets;
 525     QList<QGraphicsWidget*> m_recycleableWidgets;
 526 };
 527
 528 /**
 529  * @brief Base class for creating KItemListWidgets.
 530  *
 531  * It is recommended that applications simply use the KItemListWidgetCreator-template class.
 532  * For a custom implementation the methods create() and recyle() must be reimplemented.
 533  * The intention of the widget creator is to prevent repetitive and expensive instantiations and
 534  * deletions of KItemListWidgets by recycling existing widget instances.
 535  */
 536 class LIBDOLPHINPRIVATE_EXPORT KItemListWidgetCreatorBase : public KItemListCreatorBase
 537 {
 538 public:
 539     virtual ~KItemListWidgetCreatorBase();
 540     virtual KItemListWidget* create(KItemListView* view) = 0;
 541     virtual void recycle(KItemListWidget* widget);
 542 };
 543
 544 template <class T>
 545 class KItemListWidgetCreator : public KItemListWidgetCreatorBase
 546 {
 547 public:
 548     virtual ~KItemListWidgetCreator();
 549     virtual KItemListWidget* create(KItemListView* view);
 550 };
 551
 552 template <class T>
 553 KItemListWidgetCreator<T>::~KItemListWidgetCreator()
 554 {
 555 }
 556
 557 template <class T>
 558 KItemListWidget* KItemListWidgetCreator<T>::create(KItemListView* view)
 559 {
 560     KItemListWidget* widget = static_cast<KItemListWidget*>(popRecycleableWidget());
 561     if (!widget) {
 562         widget = new T(view);
 563         addCreatedWidget(widget);
 564     }
 565     return widget;
 566 }
 567
 568 /**
 569  * @brief Base class for creating KItemListGroupHeaders.
 570  *
 571  * It is recommended that applications simply use the KItemListGroupHeaderCreator-template class.
 572  * For a custom implementation the methods create() and recyle() must be reimplemented.
 573  * The intention of the group-header creator is to prevent repetitive and expensive instantiations and
 574  * deletions of KItemListGroupHeaders by recycling existing header instances.
 575  */
 576 class LIBDOLPHINPRIVATE_EXPORT KItemListGroupHeaderCreatorBase : public KItemListCreatorBase
 577 {
 578 public:
 579     virtual ~KItemListGroupHeaderCreatorBase();
 580     virtual KItemListGroupHeader* create(KItemListView* view) = 0;
 581     virtual void recycle(KItemListGroupHeader* header);
 582 };
 583
 584 template <class T>
 585 class KItemListGroupHeaderCreator : public KItemListGroupHeaderCreatorBase
 586 {
 587 public:
 588     virtual ~KItemListGroupHeaderCreator();
 589     virtual KItemListGroupHeader* create(KItemListView* view);
 590 };
 591
 592 template <class T>
 593 KItemListGroupHeaderCreator<T>::~KItemListGroupHeaderCreator()
 594 {
 595 }
 596
 597 template <class T>
 598 KItemListGroupHeader* KItemListGroupHeaderCreator<T>::create(KItemListView* view)
 599 {
 600     KItemListGroupHeader* widget = static_cast<KItemListGroupHeader*>(popRecycleableWidget());
 601     if (!widget) {
 602         widget = new T(view);
 603         addCreatedWidget(widget);
 604     }
 605     return widget;
 606 }
 607
 608 #endif