src/kitemviews/kitemlistview.h

   1 /*
   2  * SPDX-FileCopyrightText: 2011 Peter Penz <peter.penz19@gmail.com>
   3  *
   4  * Based on the Itemviews NG project from Trolltech Labs
   5  *
   6  * SPDX-License-Identifier: GPL-2.0-or-later
   7  */
   8
   9 #ifndef KITEMLISTVIEW_H
  10 #define KITEMLISTVIEW_H
  11
  12 #include "dolphin_export.h"
  13 #include "kitemviews/kitemliststyleoption.h"
  14 #include "kitemviews/kitemlistwidget.h"
  15 #include "kitemviews/kitemmodelbase.h"
  16 #include "kitemviews/kstandarditemlistgroupheader.h"
  17 #include "kitemviews/private/kitemlistviewanimation.h"
  18
  19 #include <QGraphicsWidget>
  20 #include <QSet>
  21
  22 class KItemListController;
  23 class KItemListGroupHeaderCreatorBase;
  24 class KItemListHeader;
  25 class KItemListHeaderWidget;
  26 class KItemListSizeHintResolver;
  27 class KItemListRubberBand;
  28 class KItemListViewAnimation;
  29 class KItemListViewLayouter;
  30 class KItemListWidget;
  31 class KItemListWidgetInformant;
  32 class KItemListWidgetCreatorBase;
  33 class QTimer;
  34 class QPropertyAnimation;
  35 class QVariantAnimation;
  36
  37 /**
  38  * @brief Represents the view of an item-list.
  39  *
  40  * The view is responsible for showing the items of the model within
  41  * a GraphicsItem. Each visible item is represented by a KItemListWidget.
  42  *
  43  * The created view must be applied to the KItemListController with
  44  * KItemListController::setView() or with the constructor of
  45  * KItemListController.
  46  *
  47  * @see KItemListWidget
  48  * @see KItemModelBase
  49  */
  50 class DOLPHIN_EXPORT KItemListView : public QGraphicsWidget
  51 {
  52     Q_OBJECT
  53
  54     Q_PROPERTY(qreal scrollOffset READ scrollOffset WRITE setScrollOffset)
  55     Q_PROPERTY(qreal itemOffset READ itemOffset WRITE setItemOffset)
  56
  57 public:
  58     explicit KItemListView(QGraphicsWidget* parent = nullptr);
  59     ~KItemListView() override;
  60
  61     /**
  62      * Offset of the scrollbar that represents the scroll-orientation
  63      * (see setScrollOrientation()).
  64      */
  65     void setScrollOffset(qreal offset);
  66     qreal scrollOffset() const;
  67
  68     qreal maximumScrollOffset() const;
  69
  70     /**
  71      * Offset related to an item, that does not fit into the available
  72      * size of the listview. If the scroll-orientation is vertical
  73      * the item-offset describes the offset of the horizontal axe, if
  74      * the scroll-orientation is horizontal the item-offset describes
  75      * the offset of the vertical axe.
  76      */
  77     void setItemOffset(qreal scrollOffset);
  78     qreal itemOffset() const;
  79
  80     qreal maximumItemOffset() const;
  81
  82     int maximumVisibleItems() const;
  83
  84     void setVisibleRoles(const QList<QByteArray>& roles);
  85     QList<QByteArray> visibleRoles() const;
  86
  87     /**
  88      * If set to true an automatic scrolling is done as soon as the
  89      * mouse is moved near the borders of the view. Per default
  90      * the automatic scrolling is turned off.
  91      */
  92     void setAutoScroll(bool enabled);
  93     bool autoScroll() const;
  94
  95     /**
  96      * If set to true selection-toggles will be shown when hovering
  97      * an item. Per default the selection-toggles are disabled.
  98      */
  99     void setEnabledSelectionToggles(bool enabled);
 100     bool enabledSelectionToggles() const;
 101
 102     /**
 103      * @return Controller of the item-list. The controller gets
 104      *         initialized by KItemListController::setView() and will
 105      *         result in calling KItemListController::onControllerChanged().
 106      */
 107     KItemListController* controller() const;
 108
 109     /**
 110      * @return Model of the item-list. The model gets
 111      *         initialized by KItemListController::setModel() and will
 112      *         result in calling KItemListController::onModelChanged().
 113      */
 114     KItemModelBase* model() const;
 115
 116     /**
 117      * Sets the creator that creates a widget showing the
 118      * content of one model-item. Usually it is sufficient
 119      * to implement a custom widget X derived from KItemListWidget and
 120      * set the creator by:
 121      * <code>
 122      * itemListView->setWidgetCreator(new KItemListWidgetCreator<X>());
 123      * </code>
 124      * The ownership of the widget creator is transferred to
 125      * the item-list view.
 126      **/
 127     void setWidgetCreator(KItemListWidgetCreatorBase* widgetCreator);
 128     KItemListWidgetCreatorBase* widgetCreator() const;
 129
 130     /**
 131      * Sets the creator that creates a group header. Usually it is sufficient
 132      * to implement a custom header widget X derived from KItemListGroupHeader and
 133      * set the creator by:
 134      * <code>
 135      * itemListView->setGroupHeaderCreator(new KItemListGroupHeaderCreator<X>());
 136      * </code>
 137      * The ownership of the gropup header creator is transferred to
 138      * the item-list view.
 139      **/
 140     void setGroupHeaderCreator(KItemListGroupHeaderCreatorBase* groupHeaderCreator);
 141     KItemListGroupHeaderCreatorBase* groupHeaderCreator() const;
 142
 143     /**
 144      * @return The basic size of all items. The size of an item may be larger than
 145      *         the basic size (see KItemListView::itemRect()).
 146      */
 147     QSizeF itemSize() const;
 148
 149     const KItemListStyleOption& styleOption() const;
 150
 151     void setGeometry(const QRectF& rect) override;
 152
 153     /**
 154      * @return The page step which should be used by the vertical scroll bar.
 155      *         This is the height of the view except for the header widget.
 156      */
 157     qreal verticalPageStep() const;
 158
 159     /**
 160      * @return Index of the item that is below the point \a pos.
 161      *         The position is relative to the upper right of
 162      *         the visible area. Only (at least partly) visible
 163      *         items are considered. -1 is returned if no item is
 164      *         below the position.
 165      */
 166     int itemAt(const QPointF& pos) const;
 167     bool isAboveSelectionToggle(int index, const QPointF& pos) const;
 168     bool isAboveExpansionToggle(int index, const QPointF& pos) const;
 169     bool isAboveText(int index, const QPointF& pos) const;
 170
 171     /**
 172      * @return Index of the first item that is at least partly visible.
 173      *         -1 is returned if the model contains no items.
 174      */
 175     int firstVisibleIndex() const;
 176
 177     /**
 178      * @return Index of the last item that is at least partly visible.
 179      *         -1 is returned if the model contains no items.
 180      */
 181     int lastVisibleIndex() const;
 182
 183     /**
 184      * Calculates the required size for all items in the model.
 185      * It might be larger than KItemListView::itemSize().
 186      * In this case the layout grid will be stretched to assure an
 187      * unclipped item.
 188      *
 189      * @note the logical height (width) is actually the
 190      * width (height) if the scroll orientation is Qt::Vertical!
 191      */
 192     void calculateItemSizeHints(QVector<qreal>& logicalHeightHints, qreal& logicalWidthHint) const;
 193
 194     /**
 195      * If set to true, items having child-items can be expanded to show the child-items as
 196      * part of the view. Per default the expanding of items is disabled. If expanding of
 197      * items is enabled, the methods KItemModelBase::setExpanded(), KItemModelBase::isExpanded(),
 198      * KItemModelBase::isExpandable() and KItemModelBase::expandedParentsCount()
 199      * must be reimplemented. The view-implementation
 200      * has to take care itself how to visually represent the expanded items provided
 201      * by the model.
 202      */
 203     void setSupportsItemExpanding(bool supportsExpanding);
 204     bool supportsItemExpanding() const;
 205
 206     /**
 207      * @return The rectangle of the item relative to the top/left of
 208      *         the currently visible area (see KItemListView::offset()).
 209      */
 210     QRectF itemRect(int index) const;
 211
 212     /**
 213      * @return The context rectangle of the item relative to the top/left of
 214      *         the currently visible area (see KItemListView::offset()). The
 215      *         context rectangle is defined by the united rectangle of
 216      *         the icon rectangle and the text rectangle (see KItemListWidget::iconRect()
 217      *         and KItemListWidget::textRect()) and is useful as reference for e.g. aligning
 218      *         a tooltip or a context-menu for an item. Note that a context rectangle will
 219      *         only be returned for (at least partly) visible items. An empty rectangle will
 220      *         be returned for fully invisible items.
 221      */
 222     QRectF itemContextRect(int index) const;
 223
 224     /**
 225      * Scrolls to the item with the index \a index so that the item
 226      * will be fully visible.
 227      */
 228     void scrollToItem(int index);
 229
 230     /**
 231      * If several properties of KItemListView are changed synchronously, it is
 232      * recommended to encapsulate the calls between beginTransaction() and endTransaction().
 233      * This prevents unnecessary and expensive layout-calculations.
 234      */
 235     void beginTransaction();
 236
 237     /**
 238      * Counterpart to beginTransaction(). The layout changes will only be animated if
 239      * all property changes between beginTransaction() and endTransaction() support
 240      * animations.
 241      */
 242     void endTransaction();
 243
 244     bool isTransactionActive() const;
 245
 246     /**
 247      * Turns on the header if \p visible is true. Per default the
 248      * header is not visible. Usually the header is turned on when
 249      * showing a classic "table-view" to describe the shown columns.
 250      */
 251     void setHeaderVisible(bool visible);
 252     bool isHeaderVisible() const;
 253
 254     /**
 255      * @return Header of the list. The header is also available if it is not shown
 256      *         (see KItemListView::setHeaderShown()).
 257      */
 258     KItemListHeader* header() const;
 259
 260     /**
 261      * @return Pixmap that is used for a drag operation based on the
 262      *         items given by \a indexes.
 263      */
 264     virtual QPixmap createDragPixmap(const KItemSet& indexes) const;
 265
 266     /**
 267      * Lets the user edit the role \a role for item with the index \a index.
 268      */
 269     void editRole(int index, const QByteArray& role);
 270
 271     void paint(QPainter* painter, const QStyleOptionGraphicsItem* option, QWidget* widget = nullptr) override;
 272
 273 Q_SIGNALS:
 274     void scrollOrientationChanged(Qt::Orientation current, Qt::Orientation previous);
 275     void scrollOffsetChanged(qreal current, qreal previous);
 276     void maximumScrollOffsetChanged(qreal current, qreal previous);
 277     void itemOffsetChanged(qreal current, qreal previous);
 278     void maximumItemOffsetChanged(qreal current, qreal previous);
 279     void scrollTo(qreal newOffset);
 280
 281     /**
 282      * Is emitted if the user has changed the sort order by clicking on a
 283      * header item (see KItemListView::setHeaderShown()). The sort order
 284      * of the model has already been adjusted to
 285      * the current sort order. Note that no signal will be emitted if the
 286      * sort order of the model has been changed without user interaction.
 287      */
 288     void sortOrderChanged(Qt::SortOrder current, Qt::SortOrder previous);
 289
 290     /**
 291      * Is emitted if the user has changed the sort role by clicking on a
 292      * header item (see KItemListView::setHeaderShown()). The sort role
 293      * of the model has already been adjusted to
 294      * the current sort role. Note that no signal will be emitted if the
 295      * sort role of the model has been changed without user interaction.
 296      */
 297     void sortRoleChanged(const QByteArray& current, const QByteArray& previous);
 298
 299     /**
 300      * Is emitted if the user has changed the visible roles by moving a header
 301      * item (see KItemListView::setHeaderShown()). Note that no signal will be
 302      * emitted if the roles have been changed without user interaction by
 303      * KItemListView::setVisibleRoles().
 304      */
 305     void visibleRolesChanged(const QList<QByteArray>& current, const QList<QByteArray>& previous);
 306
 307     void roleEditingCanceled(int index, const QByteArray& role, const QVariant& value);
 308     void roleEditingFinished(int index, const QByteArray& role, const QVariant& value);
 309
 310     /**
 311      * Emitted once scrolling has finished, or immediately if no scrolling was necessary
 312      * to get item in view in scrollToItem.
 313      */
 314     void scrollingStopped();
 315
 316 protected:
 317     QVariant itemChange(GraphicsItemChange change, const QVariant &value) override;
 318     void setItemSize(const QSizeF& size);
 319     void setStyleOption(const KItemListStyleOption& option);
 320
 321     /**
 322      * If the scroll-orientation is vertical, the items are ordered
 323      * from top to bottom (= default setting). If the scroll-orientation
 324      * is horizontal, the items are ordered from left to right.
 325      */
 326     void setScrollOrientation(Qt::Orientation orientation);
 327     Qt::Orientation scrollOrientation() const;
 328
 329     /**
 330      * Factory method for creating a default widget-creator. The method will be used
 331      * in case if setWidgetCreator() has not been set by the application.
 332      * @return New instance of the widget-creator that should be used per
 333      *         default.
 334      */
 335     virtual KItemListWidgetCreatorBase* defaultWidgetCreator() const;
 336
 337     /**
 338      * Factory method for creating a default group-header-creator. The method will be used
 339      * in case if setGroupHeaderCreator() has not been set by the application.
 340      * @return New instance of the group-header-creator that should be used per
 341      *         default.
 342      */
 343     virtual KItemListGroupHeaderCreatorBase* defaultGroupHeaderCreator() const;
 344
 345     /**
 346      * Is called when creating a new KItemListWidget instance and allows derived
 347      * classes to do a custom initialization.
 348      */
 349     virtual void initializeItemListWidget(KItemListWidget* item);
 350
 351     /**
 352      * @return True if at least one of the changed roles \p changedRoles might result
 353      *         in the need to update the item-size hint (see KItemListView::itemSizeHint()).
 354      *         Per default true is returned which means on each role-change of existing items
 355      *         the item-size hints are recalculated. For performance reasons it is recommended
 356      *         to return false in case if a role-change will not result in a changed
 357      *         item-size hint.
 358      */
 359     virtual bool itemSizeHintUpdateRequired(const QSet<QByteArray>& changedRoles) const;
 360
 361     virtual void onControllerChanged(KItemListController* current, KItemListController* previous);
 362     virtual void onModelChanged(KItemModelBase* current, KItemModelBase* previous);
 363
 364     virtual void onScrollOrientationChanged(Qt::Orientation current, Qt::Orientation previous);
 365     virtual void onItemSizeChanged(const QSizeF& current, const QSizeF& previous);
 366     virtual void onScrollOffsetChanged(qreal current, qreal previous);
 367     virtual void onVisibleRolesChanged(const QList<QByteArray>& current, const QList<QByteArray>& previous);
 368     virtual void onStyleOptionChanged(const KItemListStyleOption& current, const KItemListStyleOption& previous);
 369     virtual void onSupportsItemExpandingChanged(bool supportsExpanding);
 370
 371     virtual void onTransactionBegin();
 372     virtual void onTransactionEnd();
 373
 374     bool event(QEvent* event) override;
 375     void mousePressEvent(QGraphicsSceneMouseEvent* event) override;
 376     void mouseMoveEvent(QGraphicsSceneMouseEvent* event) override;
 377     void dragEnterEvent(QGraphicsSceneDragDropEvent* event) override;
 378     void dragMoveEvent(QGraphicsSceneDragDropEvent* event) override;
 379     void dragLeaveEvent(QGraphicsSceneDragDropEvent* event) override;
 380     void dropEvent(QGraphicsSceneDragDropEvent* event) override;
 381
 382     QList<KItemListWidget*> visibleItemListWidgets() const;
 383
 384     virtual void updateFont();
 385     virtual void updatePalette();
 386
 387 protected Q_SLOTS:
 388     virtual void slotItemsInserted(const KItemRangeList& itemRanges);
 389     virtual void slotItemsRemoved(const KItemRangeList& itemRanges);
 390     virtual void slotItemsMoved(const KItemRange& itemRange, const QList<int>& movedToIndexes);
 391     virtual void slotItemsChanged(const KItemRangeList& itemRanges,
 392                                   const QSet<QByteArray>& roles);
 393     virtual void slotGroupsChanged();
 394
 395     virtual void slotGroupedSortingChanged(bool current);
 396     virtual void slotSortOrderChanged(Qt::SortOrder current, Qt::SortOrder previous);
 397     virtual void slotSortRoleChanged(const QByteArray& current, const QByteArray& previous);
 398     virtual void slotCurrentChanged(int current, int previous);
 399     virtual void slotSelectionChanged(const KItemSet& current, const KItemSet& previous);
 400
 401 private Q_SLOTS:
 402     void slotAnimationFinished(QGraphicsWidget* widget,
 403                                KItemListViewAnimation::AnimationType type);
 404     void slotLayoutTimerFinished();
 405
 406     void slotRubberBandPosChanged();
 407     void slotRubberBandActivationChanged(bool active);
 408
 409     /**
 410      * Is invoked if the column-width of one role in the header has
 411      * been changed by the user. The automatic resizing of columns
 412      * will be turned off as soon as this method has been called at
 413      * least once.
 414      */
 415     void slotHeaderColumnWidthChanged(const QByteArray& role,
 416                                       qreal currentWidth,
 417                                       qreal previousWidth);
 418
 419     /**
 420      * Is invoked if a column has been moved by the user. Applies
 421      * the moved role to the view.
 422      */
 423     void slotHeaderColumnMoved(const QByteArray& role,
 424                                int currentIndex,
 425                                int previousIndex);
 426
 427     /**
 428      * Triggers the autoscrolling if autoScroll() is enabled by checking the
 429      * current mouse position. If the mouse position is within the autoscroll
 430      * margins a timer will be started that periodically triggers the autoscrolling.
 431      */
 432     void triggerAutoScrolling();
 433
 434     /**
 435      * Is invoked if the geometry of the parent-widget from a group-header has been
 436      * changed. The x-position and width of the group-header gets adjusted to assure
 437      * that it always spans the whole width even during temporary transitions of the
 438      * parent widget.
 439      */
 440     void slotGeometryOfGroupHeaderParentChanged();
 441
 442     void slotRoleEditingCanceled(int index, const QByteArray& role, const QVariant& value);
 443     void slotRoleEditingFinished(int index, const QByteArray& role, const QVariant& value);
 444
 445 private:
 446     enum LayoutAnimationHint
 447     {
 448         NoAnimation,
 449         Animation
 450     };
 451
 452     enum SizeType
 453     {
 454         LayouterSize,
 455         ItemSize
 456     };
 457
 458     void setController(KItemListController* controller);
 459     void setModel(KItemModelBase* model);
 460
 461     KItemListRubberBand* rubberBand() const;
 462
 463     void doLayout(LayoutAnimationHint hint, int changedIndex = 0, int changedCount = 0);
 464
 465     /**
 466      * Helper method for doLayout: Returns a list of items that can be reused for the visible
 467      * area. Invisible group headers get recycled. The reusable items are items that are
 468      * invisible. If the animation hint is 'Animation' then items that are currently animated
 469      * won't be reused. Reusing items is faster in comparison to deleting invisible
 470      * items and creating a new instance for visible items.
 471      */
 472     QList<int> recycleInvisibleItems(int firstVisibleIndex,
 473                                      int lastVisibleIndex,
 474                                      LayoutAnimationHint hint);
 475
 476     /**
 477      * Helper method for doLayout: Starts a moving-animation for the widget to the given
 478      * new position. The moving-animation is only started if the new position is within
 479      * the same row or column, otherwise the create-animation is used instead.
 480      * @return True if the moving-animation has been applied.
 481      */
 482     bool moveWidget(KItemListWidget* widget, const QPointF& newPos);
 483
 484     void emitOffsetChanges();
 485
 486     KItemListWidget* createWidget(int index);
 487     void recycleWidget(KItemListWidget* widget);
 488
 489     /**
 490      * Changes the index of the widget to \a index and assures a consistent
 491      * update for m_visibleItems and m_visibleCells. The cell-information
 492      * for the new index will not be updated and be initialized as empty cell.
 493      */
 494     void setWidgetIndex(KItemListWidget* widget, int index);
 495
 496     /**
 497      * Changes the index of the widget to \a index. In opposite to
 498      * setWidgetIndex() the cell-information for the widget gets updated.
 499      * This update gives doLayout() the chance to animate the moving
 500      * of the item visually (see moveWidget()).
 501      */
 502     void moveWidgetToIndex(KItemListWidget* widget, int index);
 503
 504     /**
 505      * Helper method for prepareLayoutForIncreasedItemCount().
 506      */
 507     void setLayouterSize(const QSizeF& size, SizeType sizeType);
 508
 509     /**
 510      * Helper method for createWidget() and setWidgetIndex() to update the properties
 511      * of the itemlist widget.
 512      */
 513     void updateWidgetProperties(KItemListWidget* widget, int index);
 514
 515     /**
 516      * Helper method for updateWidgetPropertes() to create or update
 517      * the itemlist group-header.
 518      */
 519     void updateGroupHeaderForWidget(KItemListWidget* widget);
 520
 521     /**
 522      * Updates the position and size of the group-header that belongs
 523      * to the itemlist widget \a widget. The given widget must represent
 524      * the first item of a group.
 525      */
 526     void updateGroupHeaderLayout(KItemListWidget* widget);
 527
 528     /**
 529      * Recycles the group-header for the widget.
 530      */
 531     void recycleGroupHeaderForWidget(KItemListWidget* widget);
 532
 533     /**
 534      * Helper method for slotGroupedSortingChanged(), slotSortOrderChanged()
 535      * and slotSortRoleChanged(): Iterates through all visible items and updates
 536      * the group-header widgets.
 537      */
 538     void updateVisibleGroupHeaders();
 539
 540     /**
 541      * @return Index for the item in the list returned by KItemModelBase::groups()
 542      *         that represents the group where the item with the index \a index
 543      *         belongs to. -1 is returned if no groups are available.
 544      */
 545     int groupIndexForItem(int index) const;
 546
 547     /**
 548      * Updates the alternate background for all visible items.
 549      * @see updateAlternateBackgroundForWidget()
 550      */
 551     void updateAlternateBackgrounds();
 552
 553     /**
 554      * Updates the alternateBackground-property of the widget dependent
 555      * on the state of useAlternateBackgrounds() and the grouping state.
 556      */
 557     void updateAlternateBackgroundForWidget(KItemListWidget* widget);
 558
 559     /**
 560      * @return True if alternate backgrounds should be used for the items.
 561      *         This is the case if an empty item-size is given and if there
 562      *         is more than one visible role.
 563      */
 564     bool useAlternateBackgrounds() const;
 565
 566     /**
 567      * @param itemRanges Items that must be checked for getting the widths of columns.
 568      * @return           The preferred width of the column of each visible role. The width will
 569      *                   be respected if the width of the item size is <= 0 (see
 570      *                   KItemListView::setItemSize()). Per default an empty hash
 571      *                   is returned.
 572      */
 573     QHash<QByteArray, qreal> preferredColumnWidths(const KItemRangeList& itemRanges) const;
 574
 575     /**
 576      * Applies the column-widths from m_headerWidget to the layout
 577      * of the view.
 578      */
 579     void applyColumnWidthsFromHeader();
 580
 581     /**
 582      * Applies the column-widths from m_headerWidget to \a widget.
 583      */
 584     void updateWidgetColumnWidths(KItemListWidget* widget);
 585
 586     /**
 587      * Updates the preferred column-widths of m_groupHeaderWidget by
 588      * invoking KItemListView::columnWidths().
 589      */
 590     void updatePreferredColumnWidths(const KItemRangeList& itemRanges);
 591
 592     /**
 593      * Convenience method for
 594      * updatePreferredColumnWidths(KItemRangeList() << KItemRange(0, m_model->count()).
 595      */
 596     void updatePreferredColumnWidths();
 597
 598     /**
 599      * Resizes the column-widths of m_headerWidget based on the preferred widths
 600      * and the available view-size.
 601      */
 602     void applyAutomaticColumnWidths();
 603
 604     /**
 605      * @return Sum of the widths of all columns.
 606      */
 607     qreal columnWidthsSum() const;
 608
 609     /**
 610      * @return Boundaries of the header. An empty rectangle is returned
 611      *         if no header is shown.
 612      */
 613     QRectF headerBoundaries() const;
 614
 615     /**
 616      * @return True if the number of columns or rows will be changed when applying
 617      *         the new grid- and item-size. Used to determine whether an animation
 618      *         should be done when applying the new layout.
 619      */
 620     bool changesItemGridLayout(const QSizeF& newGridSize,
 621                                const QSizeF& newItemSize,
 622                                const QSizeF& newItemMargin) const;
 623
 624     /**
 625      * @param changedItemCount Number of inserted  or removed items.
 626      * @return                 True if the inserting or removing of items should be animated.
 627      *                         No animation should be done if the number of items is too large
 628      *                         to provide a pleasant animation.
 629      */
 630     bool animateChangedItemCount(int changedItemCount) const;
 631
 632     /**
 633      * @return True if a scrollbar for the given scroll-orientation is required
 634      *         when using a size of \p size for the view. Calling the method is rather
 635      *         expansive as a temporary relayout needs to be done.
 636      */
 637     bool scrollBarRequired(const QSizeF& size) const;
 638
 639     /**
 640      * Shows a drop-indicator between items dependent on the given
 641      * cursor position. The cursor position is relative to the upper left
 642      * edge of the view.
 643      * @return Index of the item where the dropping is done. An index of -1
 644      *         indicates that the item has been dropped after the last item.
 645      */
 646     int showDropIndicator(const QPointF& pos);
 647     void hideDropIndicator();
 648
 649     /**
 650      * Applies the height of the group header to the layouter. The height
 651      * depends on the used scroll orientation.
 652      */
 653     void updateGroupHeaderHeight();
 654
 655     /**
 656      * Updates the siblings-information for all visible items that are inside
 657      * the range of \p firstIndex and \p lastIndex. If firstIndex or lastIndex
 658      * is smaller than 0, the siblings-information for all visible items gets
 659      * updated.
 660      * @see KItemListWidget::setSiblingsInformation()
 661      */
 662     void updateSiblingsInformation(int firstIndex = -1, int lastIndex = -1);
 663
 664     /**
 665      * Helper method for updateExpansionIndicators().
 666      * @return True if the item with the index \a index has a sibling successor
 667      *         (= the item is not the last item of the current hierarchy).
 668      */
 669     bool hasSiblingSuccessor(int index) const;
 670
 671     /**
 672      * Helper method for slotRoleEditingCanceled() and slotRoleEditingFinished().
 673      * Disconnects the two Signals "roleEditingCanceled" and
 674      * "roleEditingFinished"
 675      */
 676     void disconnectRoleEditingSignals(int index);
 677
 678     /**
 679      * Helper function for triggerAutoScrolling().
 680      * @param pos    Logical position of the mouse relative to the range.
 681      * @param range  Range of the visible area.
 682      * @param oldInc Previous increment. Is used to assure that the increment
 683      *               increases only gradually.
 684      * @return Scroll increment that should be added to the offset().
 685      *         As soon as \a pos is inside the autoscroll-margin a
 686      *         value != 0 will be returned.
 687      */
 688     static int calculateAutoScrollingIncrement(int pos, int range, int oldInc);
 689
 690     /**
 691      * Helper functions for changesItemCount().
 692      * @return The number of items that fit into the available size by
 693      *         respecting the size of the item and the margin between the items.
 694      */
 695     static int itemsPerSize(qreal size, qreal itemSize, qreal itemMargin);
 696
 697 private:
 698     bool m_enabledSelectionToggles;
 699     bool m_grouped;
 700     bool m_supportsItemExpanding;
 701     bool m_editingRole;
 702     int m_activeTransactions; // Counter for beginTransaction()/endTransaction()
 703     LayoutAnimationHint m_endTransactionAnimationHint;
 704
 705     QSizeF m_itemSize;
 706     KItemListController* m_controller;
 707     KItemModelBase* m_model;
 708     QList<QByteArray> m_visibleRoles;
 709     mutable KItemListWidgetCreatorBase* m_widgetCreator;
 710     mutable KItemListGroupHeaderCreatorBase* m_groupHeaderCreator;
 711     KItemListStyleOption m_styleOption;
 712
 713     QHash<int, KItemListWidget*> m_visibleItems;
 714     QHash<KItemListWidget*, KItemListGroupHeader*> m_visibleGroups;
 715
 716     struct Cell
 717     {
 718         Cell() : column(-1), row(-1) {}
 719         Cell(int c, int r) : column(c), row(r) {}
 720         int column;
 721         int row;
 722     };
 723     QHash<int, Cell> m_visibleCells;
 724
 725     int m_scrollBarExtent;
 726     KItemListSizeHintResolver* m_sizeHintResolver;
 727     KItemListViewLayouter* m_layouter;
 728     KItemListViewAnimation* m_animation;
 729
 730     QTimer* m_layoutTimer; // Triggers an asynchronous doLayout() call.
 731     qreal m_oldScrollOffset;
 732     qreal m_oldMaximumScrollOffset;
 733     qreal m_oldItemOffset;
 734     qreal m_oldMaximumItemOffset;
 735
 736     bool m_skipAutoScrollForRubberBand;
 737     KItemListRubberBand* m_rubberBand;
 738     KItemListRubberBand* m_tapAndHoldIndicator;
 739
 740     QPointF m_mousePos;
 741     int m_autoScrollIncrement;
 742     QTimer* m_autoScrollTimer;
 743
 744     KItemListHeader* m_header;
 745     KItemListHeaderWidget* m_headerWidget;
 746
 747     QPropertyAnimation* m_indicatorAnimation;
 748
 749     // When dragging items into the view where the sort-role of the model
 750     // is empty, a visual indicator should be shown during dragging where
 751     // the dropping will happen. This indicator is specified by an index
 752     // of the item. -1 means that no indicator will be shown at all.
 753     // The m_dropIndicator is set by the KItemListController
 754     // by KItemListView::showDropIndicator() and KItemListView::hideDropIndicator().
 755     QRectF m_dropIndicator;
 756
 757     QList<QVariantAnimation*> m_rubberBandAnimations;
 758
 759     friend class KItemListContainer; // Accesses scrollBarRequired()
 760     friend class KItemListHeader;    // Accesses m_headerWidget
 761     friend class KItemListController;
 762     friend class KItemListControllerTest;
 763     friend class KItemListViewAccessible;
 764     friend class KItemListAccessibleCell;
 765 };
 766
 767 /**
 768  * Allows to do a fast logical creation and deletion of QGraphicsWidgets
 769  * by recycling existing QGraphicsWidgets instances. Is used by
 770  * KItemListWidgetCreatorBase and KItemListGroupHeaderCreatorBase.
 771  * @internal
 772  */
 773 class DOLPHIN_EXPORT KItemListCreatorBase
 774 {
 775 public:
 776     virtual ~KItemListCreatorBase();
 777
 778 protected:
 779     void addCreatedWidget(QGraphicsWidget* widget);
 780     void pushRecycleableWidget(QGraphicsWidget* widget);
 781     QGraphicsWidget* popRecycleableWidget();
 782
 783 private:
 784     QSet<QGraphicsWidget*> m_createdWidgets;
 785     QList<QGraphicsWidget*> m_recycleableWidgets;
 786 };
 787
 788 /**
 789  * @brief Base class for creating KItemListWidgets.
 790  *
 791  * It is recommended that applications simply use the KItemListWidgetCreator-template class.
 792  * For a custom implementation the methods create(), itemSizeHint() and preferredColumnWith()
 793  * must be reimplemented. The intention of the widget creator is to prevent repetitive and
 794  * expensive instantiations and deletions of KItemListWidgets by recycling existing widget
 795  * instances.
 796  */
 797 class DOLPHIN_EXPORT KItemListWidgetCreatorBase : public KItemListCreatorBase
 798 {
 799 public:
 800     ~KItemListWidgetCreatorBase() override;
 801
 802     virtual KItemListWidget* create(KItemListView* view) = 0;
 803
 804     virtual void recycle(KItemListWidget* widget);
 805
 806     virtual void calculateItemSizeHints(QVector<qreal>& logicalHeightHints, qreal& logicalWidthHint, const KItemListView* view) const = 0;
 807
 808     virtual qreal preferredRoleColumnWidth(const QByteArray& role,
 809                                            int index,
 810                                            const KItemListView* view) const = 0;
 811 };
 812
 813 /**
 814  * @brief Template class for creating KItemListWidgets.
 815  */
 816 template <class T>
 817 class KItemListWidgetCreator : public KItemListWidgetCreatorBase
 818 {
 819 public:
 820     KItemListWidgetCreator();
 821     ~KItemListWidgetCreator() override;
 822
 823     KItemListWidget* create(KItemListView* view) override;
 824
 825     void calculateItemSizeHints(QVector<qreal>& logicalHeightHints, qreal& logicalWidthHint, const KItemListView* view) const override;
 826
 827     qreal preferredRoleColumnWidth(const QByteArray& role,
 828                                            int index,
 829                                            const KItemListView* view) const override;
 830 private:
 831     KItemListWidgetInformant* m_informant;
 832 };
 833
 834 template <class T>
 835 KItemListWidgetCreator<T>::KItemListWidgetCreator() :
 836     m_informant(T::createInformant())
 837 {
 838 }
 839
 840 template <class T>
 841 KItemListWidgetCreator<T>::~KItemListWidgetCreator()
 842 {
 843     delete m_informant;
 844 }
 845
 846 template <class T>
 847 KItemListWidget* KItemListWidgetCreator<T>::create(KItemListView* view)
 848 {
 849     KItemListWidget* widget = static_cast<KItemListWidget*>(popRecycleableWidget());
 850     if (!widget) {
 851         widget = new T(m_informant, view);
 852         addCreatedWidget(widget);
 853     }
 854     widget->setParentItem(view);
 855     return widget;
 856 }
 857
 858 template<class T>
 859 void KItemListWidgetCreator<T>::calculateItemSizeHints(QVector<qreal>& logicalHeightHints, qreal& logicalWidthHint, const KItemListView* view) const
 860 {
 861     return m_informant->calculateItemSizeHints(logicalHeightHints, logicalWidthHint, view);
 862 }
 863
 864 template<class T>
 865 qreal KItemListWidgetCreator<T>::preferredRoleColumnWidth(const QByteArray& role,
 866                                                           int index,
 867                                                           const KItemListView* view) const
 868 {
 869     return m_informant->preferredRoleColumnWidth(role, index, view);
 870 }
 871
 872 /**
 873  * @brief Base class for creating KItemListGroupHeaders.
 874  *
 875  * It is recommended that applications simply use the KItemListGroupHeaderCreator-template class.
 876  * For a custom implementation the methods create() and recycle() must be reimplemented.
 877  * The intention of the group-header creator is to prevent repetitive and expensive instantiations and
 878  * deletions of KItemListGroupHeaders by recycling existing header instances.
 879  */
 880 class DOLPHIN_EXPORT KItemListGroupHeaderCreatorBase : public KItemListCreatorBase
 881 {
 882 public:
 883     ~KItemListGroupHeaderCreatorBase() override;
 884     virtual KItemListGroupHeader* create(KItemListView* view) = 0;
 885     virtual void recycle(KItemListGroupHeader* header);
 886 };
 887
 888 template <class T>
 889 class KItemListGroupHeaderCreator : public KItemListGroupHeaderCreatorBase
 890 {
 891 public:
 892     ~KItemListGroupHeaderCreator() override;
 893     KItemListGroupHeader* create(KItemListView* view) override;
 894 };
 895
 896 template <class T>
 897 KItemListGroupHeaderCreator<T>::~KItemListGroupHeaderCreator()
 898 {
 899 }
 900
 901 template <class T>
 902 KItemListGroupHeader* KItemListGroupHeaderCreator<T>::create(KItemListView* view)
 903 {
 904     KItemListGroupHeader* widget = static_cast<KItemListGroupHeader*>(popRecycleableWidget());
 905     if (!widget) {
 906         widget = new T(view);
 907         addCreatedWidget(widget);
 908     }
 909     return widget;
 910 }
 911
 912 #endif