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 <optional>
  13
  14 #include "dolphin_export.h"
  15 #include "kitemviews/kitemliststyleoption.h"
  16 #include "kitemviews/kitemlistwidget.h"
  17 #include "kitemviews/kitemmodelbase.h"
  18 #include "kitemviews/kstandarditemlistgroupheader.h"
  19 #include "kitemviews/private/kitemlistviewanimation.h"
  20
  21 #include <QGraphicsWidget>
  22 #include <QSet>
  23
  24 class KItemListController;
  25 class KItemListGroupHeaderCreatorBase;
  26 class KItemListHeader;
  27 class KItemListHeaderWidget;
  28 class KItemListSizeHintResolver;
  29 class KItemListRubberBand;
  30 class KItemListViewAnimation;
  31 class KItemListViewLayouter;
  32 class KItemListWidget;
  33 class KItemListWidgetInformant;
  34 class KItemListWidgetCreatorBase;
  35 class QTimer;
  36 class QPropertyAnimation;
  37 class QVariantAnimation;
  38
  39 /**
  40  * @brief Represents the view of an item-list.
  41  *
  42  * The view is responsible for showing the items of the model within
  43  * a GraphicsItem. Each visible item is represented by a KItemListWidget.
  44  *
  45  * The created view must be applied to the KItemListController with
  46  * KItemListController::setView() or with the constructor of
  47  * KItemListController.
  48  *
  49  * @see KItemListWidget
  50  * @see KItemModelBase
  51  */
  52 class DOLPHIN_EXPORT KItemListView : public QGraphicsWidget
  53 {
  54     Q_OBJECT
  55
  56     Q_PROPERTY(qreal scrollOffset READ scrollOffset WRITE setScrollOffset)
  57     Q_PROPERTY(qreal itemOffset READ itemOffset WRITE setItemOffset)
  58
  59 public:
  60     explicit KItemListView(QGraphicsWidget *parent = nullptr);
  61     ~KItemListView() override;
  62
  63     /**
  64      * Offset of the scrollbar that represents the scroll-orientation
  65      * (see setScrollOrientation()).
  66      */
  67     void setScrollOffset(qreal offset);
  68     qreal scrollOffset() const;
  69
  70     qreal maximumScrollOffset() const;
  71
  72     /**
  73      * Offset related to an item, that does not fit into the available
  74      * size of the listview. If the scroll-orientation is vertical
  75      * the item-offset describes the offset of the horizontal axe, if
  76      * the scroll-orientation is horizontal the item-offset describes
  77      * the offset of the vertical axe.
  78      */
  79     void setItemOffset(qreal scrollOffset);
  80     qreal itemOffset() const;
  81
  82     qreal maximumItemOffset() const;
  83
  84     int maximumVisibleItems() const;
  85
  86     void setVisibleRoles(const QList<QByteArray> &roles);
  87     QList<QByteArray> visibleRoles() const;
  88
  89     /**
  90      * If set to true an automatic scrolling is done as soon as the
  91      * mouse is moved near the borders of the view. Per default
  92      * the automatic scrolling is turned off.
  93      */
  94     void setAutoScroll(bool enabled);
  95     bool autoScroll() const;
  96
  97     /**
  98      * If set to true selection-toggles will be shown when hovering
  99      * an item. Per default the selection-toggles are disabled.
 100      */
 101     void setEnabledSelectionToggles(bool enabled);
 102     bool enabledSelectionToggles() const;
 103
 104     /**
 105      * @return Controller of the item-list. The controller gets
 106      *         initialized by KItemListController::setView() and will
 107      *         result in calling KItemListController::onControllerChanged().
 108      */
 109     KItemListController *controller() const;
 110
 111     /**
 112      * @return Model of the item-list. The model gets
 113      *         initialized by KItemListController::setModel() and will
 114      *         result in calling KItemListController::onModelChanged().
 115      */
 116     KItemModelBase *model() const;
 117
 118     /**
 119      * Sets the creator that creates a widget showing the
 120      * content of one model-item. Usually it is sufficient
 121      * to implement a custom widget X derived from KItemListWidget and
 122      * set the creator by:
 123      * <code>
 124      * itemListView->setWidgetCreator(new KItemListWidgetCreator<X>());
 125      * </code>
 126      * The ownership of the widget creator is transferred to
 127      * the item-list view.
 128      **/
 129     void setWidgetCreator(KItemListWidgetCreatorBase *widgetCreator);
 130     KItemListWidgetCreatorBase *widgetCreator() const;
 131
 132     /**
 133      * Sets the creator that creates a group header. Usually it is sufficient
 134      * to implement a custom header widget X derived from KItemListGroupHeader and
 135      * set the creator by:
 136      * <code>
 137      * itemListView->setGroupHeaderCreator(new KItemListGroupHeaderCreator<X>());
 138      * </code>
 139      * The ownership of the gropup header creator is transferred to
 140      * the item-list view.
 141      **/
 142     void setGroupHeaderCreator(KItemListGroupHeaderCreatorBase *groupHeaderCreator);
 143     KItemListGroupHeaderCreatorBase *groupHeaderCreator() const;
 144
 145     /**
 146      * @return The basic size of all items. The size of an item may be larger than
 147      *         the basic size (see KItemListView::itemRect()).
 148      */
 149     QSizeF itemSize() const;
 150
 151     const KItemListStyleOption &styleOption() const;
 152
 153     void setGeometry(const QRectF &rect) override;
 154
 155     /**
 156      * @return The page step which should be used by the vertical scroll bar.
 157      *         This is the height of the view except for the header widget.
 158      */
 159     qreal verticalPageStep() const;
 160
 161     /**
 162      * @return Index of the item that is below the point \a pos.
 163      *         The position is relative to the upper right of
 164      *         the visible area. Only (at least partly) visible
 165      *         items are considered. std::nullopt is returned if
 166      *         no item is below the position.
 167      */
 168     std::optional<int> itemAt(const QPointF &pos) const;
 169     bool isAboveSelectionToggle(int index, const QPointF &pos) const;
 170     bool isAboveExpansionToggle(int index, const QPointF &pos) const;
 171     bool isAboveText(int index, const QPointF &pos) const;
 172
 173     /**
 174      * @return Index of the first item that is at least partly visible.
 175      *         -1 is returned if the model contains no items.
 176      */
 177     int firstVisibleIndex() const;
 178
 179     /**
 180      * @return Index of the last item that is at least partly visible.
 181      *         -1 is returned if the model contains no items.
 182      */
 183     int lastVisibleIndex() const;
 184
 185     /**
 186      * Calculates the required size for all items in the model.
 187      * It might be larger than KItemListView::itemSize().
 188      * In this case the layout grid will be stretched to assure an
 189      * unclipped item.
 190      *
 191      * @note the logical height (width) is actually the
 192      * width (height) if the scroll orientation is Qt::Vertical!
 193      */
 194     void calculateItemSizeHints(QVector<std::pair<qreal, bool>> &logicalHeightHints, qreal &logicalWidthHint) const;
 195
 196     /**
 197      * If set to true, items having child-items can be expanded to show the child-items as
 198      * part of the view. Per default the expanding of items is disabled. If expanding of
 199      * items is enabled, the methods KItemModelBase::setExpanded(), KItemModelBase::isExpanded(),
 200      * KItemModelBase::isExpandable() and KItemModelBase::expandedParentsCount()
 201      * must be reimplemented. The view-implementation
 202      * has to take care itself how to visually represent the expanded items provided
 203      * by the model.
 204      */
 205     void setSupportsItemExpanding(bool supportsExpanding);
 206     bool supportsItemExpanding() const;
 207
 208     void setHighlightEntireRow(bool highlightEntireRow);
 209     bool highlightEntireRow() const;
 210
 211     void setAlternateBackgrounds(bool alternate);
 212     bool alternateBackgrounds() const;
 213
 214     /**
 215      * @return The rectangle of the item relative to the top/left of
 216      *         the currently visible area (see KItemListView::offset()).
 217      */
 218     QRectF itemRect(int index) const;
 219
 220     /**
 221      * @return The context rectangle of the item relative to the top/left of
 222      *         the currently visible area (see KItemListView::offset()). The
 223      *         context rectangle is defined by the united rectangle of
 224      *         the icon rectangle and the text rectangle (see KItemListWidget::iconRect()
 225      *         and KItemListWidget::textRect()) and is useful as reference for e.g. aligning
 226      *         a tooltip or a context-menu for an item. Note that a context rectangle will
 227      *         only be returned for (at least partly) visible items. An empty rectangle will
 228      *         be returned for fully invisible items.
 229      */
 230     QRectF itemContextRect(int index) const;
 231
 232     /**
 233      * @return Whether or not the name of the file has been elided. At present this will
 234      *         only ever be true when in icons view.
 235      */
 236     bool isElided(int index) const;
 237
 238     /**
 239      * Scrolls to the item with the index \a index so that the item
 240      * will be fully visible.
 241      */
 242     void scrollToItem(int index);
 243
 244     /**
 245      * If several properties of KItemListView are changed synchronously, it is
 246      * recommended to encapsulate the calls between beginTransaction() and endTransaction().
 247      * This prevents unnecessary and expensive layout-calculations.
 248      */
 249     void beginTransaction();
 250
 251     /**
 252      * Counterpart to beginTransaction(). The layout changes will only be animated if
 253      * all property changes between beginTransaction() and endTransaction() support
 254      * animations.
 255      */
 256     void endTransaction();
 257
 258     bool isTransactionActive() const;
 259
 260     /**
 261      * Turns on the header if \p visible is true. Per default the
 262      * header is not visible. Usually the header is turned on when
 263      * showing a classic "table-view" to describe the shown columns.
 264      */
 265     void setHeaderVisible(bool visible);
 266     bool isHeaderVisible() const;
 267
 268     /**
 269      * @return Header of the list. The header is also available if it is not shown
 270      *         (see KItemListView::setHeaderShown()).
 271      */
 272     KItemListHeader *header() const;
 273
 274     /**
 275      * @return Pixmap that is used for a drag operation based on the
 276      *         items given by \a indexes.
 277      */
 278     virtual QPixmap createDragPixmap(const KItemSet &indexes) const;
 279
 280     /**
 281      * Lets the user edit the role \a role for item with the index \a index.
 282      */
 283     void editRole(int index, const QByteArray &role);
 284
 285     void paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget = nullptr) override;
 286
 287 Q_SIGNALS:
 288     void scrollOrientationChanged(Qt::Orientation current, Qt::Orientation previous);
 289     void scrollOffsetChanged(qreal current, qreal previous);
 290     void maximumScrollOffsetChanged(qreal current, qreal previous);
 291     void itemOffsetChanged(qreal current, qreal previous);
 292     void maximumItemOffsetChanged(qreal current, qreal previous);
 293     void scrollTo(qreal newOffset);
 294
 295     /**
 296      * Is emitted if the user has changed the sort order by clicking on a
 297      * header item (see KItemListView::setHeaderShown()). The sort order
 298      * of the model has already been adjusted to
 299      * the current sort order. Note that no signal will be emitted if the
 300      * sort order of the model has been changed without user interaction.
 301      */
 302     void sortOrderChanged(Qt::SortOrder current, Qt::SortOrder previous);
 303
 304     /**
 305      * Is emitted if the user has changed the sort role by clicking on a
 306      * header item (see KItemListView::setHeaderShown()). The sort role
 307      * of the model has already been adjusted to
 308      * the current sort role. Note that no signal will be emitted if the
 309      * sort role of the model has been changed without user interaction.
 310      */
 311     void sortRoleChanged(const QByteArray &current, const QByteArray &previous);
 312
 313     /**
 314      * Is emitted if the user has changed the visible roles by moving a header
 315      * item (see KItemListView::setHeaderShown()). Note that no signal will be
 316      * emitted if the roles have been changed without user interaction by
 317      * KItemListView::setVisibleRoles().
 318      */
 319     void visibleRolesChanged(const QList<QByteArray> &current, const QList<QByteArray> &previous);
 320
 321     void roleEditingCanceled(int index, const QByteArray &role, const QVariant &value);
 322     void roleEditingFinished(int index, const QByteArray &role, const QVariant &value);
 323
 324     /**
 325      * Emitted once scrolling has finished, or immediately if no scrolling was necessary
 326      * to get item in view in scrollToItem.
 327      */
 328     void scrollingStopped();
 329
 330     void columnHovered(int roleIndex);
 331     void columnUnHovered(int roleIndex);
 332
 333 protected:
 334     QVariant itemChange(GraphicsItemChange change, const QVariant &value) override;
 335     void setItemSize(const QSizeF &size);
 336     void setStyleOption(const KItemListStyleOption &option);
 337
 338     /**
 339      * If the scroll-orientation is vertical, the items are ordered
 340      * from top to bottom (= default setting). If the scroll-orientation
 341      * is horizontal, the items are ordered from left to right.
 342      */
 343     void setScrollOrientation(Qt::Orientation orientation);
 344     Qt::Orientation scrollOrientation() const;
 345
 346     /**
 347      * Factory method for creating a default widget-creator. The method will be used
 348      * in case if setWidgetCreator() has not been set by the application.
 349      * @return New instance of the widget-creator that should be used per
 350      *         default.
 351      */
 352     virtual KItemListWidgetCreatorBase *defaultWidgetCreator() const;
 353
 354     /**
 355      * Factory method for creating a default group-header-creator. The method will be used
 356      * in case if setGroupHeaderCreator() has not been set by the application.
 357      * @return New instance of the group-header-creator that should be used per
 358      *         default.
 359      */
 360     virtual KItemListGroupHeaderCreatorBase *defaultGroupHeaderCreator() const;
 361
 362     /**
 363      * Is called when creating a new KItemListWidget instance and allows derived
 364      * classes to do a custom initialization.
 365      */
 366     virtual void initializeItemListWidget(KItemListWidget *item);
 367
 368     /**
 369      * @return True if at least one of the changed roles \p changedRoles might result
 370      *         in the need to update the item-size hint (see KItemListView::itemSizeHint()).
 371      *         Per default true is returned which means on each role-change of existing items
 372      *         the item-size hints are recalculated. For performance reasons it is recommended
 373      *         to return false in case if a role-change will not result in a changed
 374      *         item-size hint.
 375      */
 376     virtual bool itemSizeHintUpdateRequired(const QSet<QByteArray> &changedRoles) const;
 377
 378     virtual void onControllerChanged(KItemListController *current, KItemListController *previous);
 379     virtual void onModelChanged(KItemModelBase *current, KItemModelBase *previous);
 380
 381     virtual void onScrollOrientationChanged(Qt::Orientation current, Qt::Orientation previous);
 382     virtual void onItemSizeChanged(const QSizeF &current, const QSizeF &previous);
 383     virtual void onScrollOffsetChanged(qreal current, qreal previous);
 384     virtual void onVisibleRolesChanged(const QList<QByteArray> &current, const QList<QByteArray> &previous);
 385     virtual void onStyleOptionChanged(const KItemListStyleOption &current, const KItemListStyleOption &previous);
 386     virtual void onHighlightEntireRowChanged(bool highlightEntireRow);
 387     virtual void onSupportsItemExpandingChanged(bool supportsExpanding);
 388
 389     virtual void onTransactionBegin();
 390     virtual void onTransactionEnd();
 391
 392     bool event(QEvent *event) override;
 393     void mousePressEvent(QGraphicsSceneMouseEvent *event) override;
 394     void mouseMoveEvent(QGraphicsSceneMouseEvent *event) override;
 395     void dragEnterEvent(QGraphicsSceneDragDropEvent *event) override;
 396     void dragMoveEvent(QGraphicsSceneDragDropEvent *event) override;
 397     void dragLeaveEvent(QGraphicsSceneDragDropEvent *event) override;
 398     void dropEvent(QGraphicsSceneDragDropEvent *event) override;
 399
 400     QList<KItemListWidget *> visibleItemListWidgets() const;
 401
 402     virtual void updateFont();
 403     virtual void updatePalette();
 404
 405 protected Q_SLOTS:
 406     virtual void slotItemsInserted(const KItemRangeList &itemRanges);
 407     virtual void slotItemsRemoved(const KItemRangeList &itemRanges);
 408     virtual void slotItemsMoved(const KItemRange &itemRange, const QList<int> &movedToIndexes);
 409     virtual void slotItemsChanged(const KItemRangeList &itemRanges, const QSet<QByteArray> &roles);
 410     virtual void slotGroupsChanged();
 411
 412     virtual void slotGroupedSortingChanged(bool current);
 413     virtual void slotSortOrderChanged(Qt::SortOrder current, Qt::SortOrder previous);
 414     virtual void slotSortRoleChanged(const QByteArray &current, const QByteArray &previous);
 415     virtual void slotCurrentChanged(int current, int previous);
 416     virtual void slotSelectionChanged(const KItemSet &current, const KItemSet &previous);
 417
 418 private Q_SLOTS:
 419     void slotAnimationFinished(QGraphicsWidget *widget, KItemListViewAnimation::AnimationType type);
 420
 421     void slotRubberBandPosChanged();
 422     void slotRubberBandActivationChanged(bool active);
 423
 424     /**
 425      * Is invoked if the column-width of one role in the header has
 426      * been changed by the user. The automatic resizing of columns
 427      * will be turned off as soon as this method has been called at
 428      * least once.
 429      */
 430     void slotHeaderColumnWidthChanged(const QByteArray &role, qreal currentWidth, qreal previousWidth);
 431
 432     void slotSidePaddingChanged(qreal width);
 433
 434     /**
 435      * Is invoked if a column has been moved by the user. Applies
 436      * the moved role to the view.
 437      */
 438     void slotHeaderColumnMoved(const QByteArray &role, int currentIndex, int previousIndex);
 439
 440     /**
 441      * Triggers the autoscrolling if autoScroll() is enabled by checking the
 442      * current mouse position. If the mouse position is within the autoscroll
 443      * margins a timer will be started that periodically triggers the autoscrolling.
 444      */
 445     void triggerAutoScrolling();
 446
 447     /**
 448      * Is invoked if the geometry of the parent-widget from a group-header has been
 449      * changed. The x-position and width of the group-header gets adjusted to assure
 450      * that it always spans the whole width even during temporary transitions of the
 451      * parent widget.
 452      */
 453     void slotGeometryOfGroupHeaderParentChanged();
 454
 455     void slotRoleEditingCanceled(int index, const QByteArray &role, const QVariant &value);
 456     void slotRoleEditingFinished(int index, const QByteArray &role, const QVariant &value);
 457
 458 private:
 459     enum LayoutAnimationHint { NoAnimation, Animation };
 460
 461     enum SizeType { LayouterSize, ItemSize };
 462
 463     void setController(KItemListController *controller);
 464     void setModel(KItemModelBase *model);
 465
 466     KItemListRubberBand *rubberBand() const;
 467
 468     void doLayout(LayoutAnimationHint hint, int changedIndex = 0, int changedCount = 0);
 469
 470     /**
 471      * Helper method for doLayout: Returns a list of items that can be reused for the visible
 472      * area. Invisible group headers get recycled. The reusable items are items that are
 473      * invisible. If the animation hint is 'Animation' then items that are currently animated
 474      * won't be reused. Reusing items is faster in comparison to deleting invisible
 475      * items and creating a new instance for visible items.
 476      */
 477     QList<int> recycleInvisibleItems(int firstVisibleIndex, int lastVisibleIndex, LayoutAnimationHint hint);
 478
 479     /**
 480      * Helper method for doLayout: Starts a moving-animation for the widget to the given
 481      * new position. The moving-animation is only started if the new position is within
 482      * the same row or column, otherwise the create-animation is used instead.
 483      * @return True if the moving-animation has been applied.
 484      */
 485     bool moveWidget(KItemListWidget *widget, const QPointF &newPos);
 486
 487     void emitOffsetChanges();
 488
 489     KItemListWidget *createWidget(int index);
 490     void recycleWidget(KItemListWidget *widget);
 491
 492     /**
 493      * Changes the index of the widget to \a index and assures a consistent
 494      * update for m_visibleItems and m_visibleCells. The cell-information
 495      * for the new index will not be updated and be initialized as empty cell.
 496      */
 497     void setWidgetIndex(KItemListWidget *widget, int index);
 498
 499     /**
 500      * Changes the index of the widget to \a index. In opposite to
 501      * setWidgetIndex() the cell-information for the widget gets updated.
 502      * This update gives doLayout() the chance to animate the moving
 503      * of the item visually (see moveWidget()).
 504      */
 505     void moveWidgetToIndex(KItemListWidget *widget, int index);
 506
 507     /**
 508      * Helper method for prepareLayoutForIncreasedItemCount().
 509      */
 510     void setLayouterSize(const QSizeF &size, SizeType sizeType);
 511
 512     /**
 513      * Helper method for createWidget() and setWidgetIndex() to update the properties
 514      * of the itemlist widget.
 515      */
 516     void updateWidgetProperties(KItemListWidget *widget, int index);
 517
 518     /**
 519      * Helper method for updateWidgetPropertes() to create or update
 520      * the itemlist group-header.
 521      */
 522     void updateGroupHeaderForWidget(KItemListWidget *widget);
 523
 524     /**
 525      * Updates the position and size of the group-header that belongs
 526      * to the itemlist widget \a widget. The given widget must represent
 527      * the first item of a group.
 528      */
 529     void updateGroupHeaderLayout(KItemListWidget *widget);
 530
 531     /**
 532      * Recycles the group-header for the widget.
 533      */
 534     void recycleGroupHeaderForWidget(KItemListWidget *widget);
 535
 536     /**
 537      * Helper method for slotGroupedSortingChanged(), slotSortOrderChanged()
 538      * and slotSortRoleChanged(): Iterates through all visible items and updates
 539      * the group-header widgets.
 540      */
 541     void updateVisibleGroupHeaders();
 542
 543     /**
 544      * @return Index for the item in the list returned by KItemModelBase::groups()
 545      *         that represents the group where the item with the index \a index
 546      *         belongs to. -1 is returned if no groups are available.
 547      */
 548     int groupIndexForItem(int index) const;
 549
 550     /**
 551      * Updates the alternate background for all visible items.
 552      * @see updateAlternateBackgroundForWidget()
 553      */
 554     void updateAlternateBackgrounds();
 555
 556     /**
 557      * Updates the alternateBackground-property of the widget dependent
 558      * on the state of useAlternateBackgrounds() and the grouping state.
 559      */
 560     void updateAlternateBackgroundForWidget(KItemListWidget *widget);
 561
 562     /**
 563      * @return True if alternate backgrounds should be used for the items.
 564      *         This is the case if an empty item-size is given and if there
 565      *         is more than one visible role.
 566      */
 567     bool useAlternateBackgrounds() const;
 568
 569     /**
 570      * @param itemRanges Items that must be checked for getting the widths of columns.
 571      * @return           The preferred width of the column of each visible role. The width will
 572      *                   be respected if the width of the item size is <= 0 (see
 573      *                   KItemListView::setItemSize()). Per default an empty hash
 574      *                   is returned.
 575      */
 576     QHash<QByteArray, qreal> preferredColumnWidths(const KItemRangeList &itemRanges) const;
 577
 578     /**
 579      * Applies the column-widths from m_headerWidget to the layout
 580      * of the view.
 581      */
 582     void applyColumnWidthsFromHeader();
 583
 584     /**
 585      * Applies the column-widths from m_headerWidget to \a widget.
 586      */
 587     void updateWidgetColumnWidths(KItemListWidget *widget);
 588
 589     /**
 590      * Updates the preferred column-widths of m_groupHeaderWidget by
 591      * invoking KItemListView::columnWidths().
 592      */
 593     void updatePreferredColumnWidths(const KItemRangeList &itemRanges);
 594
 595     /**
 596      * Convenience method for
 597      * updatePreferredColumnWidths(KItemRangeList() << KItemRange(0, m_model->count()).
 598      */
 599     void updatePreferredColumnWidths();
 600
 601     /**
 602      * Resizes the column-widths of m_headerWidget based on the preferred widths
 603      * and the available view-size.
 604      */
 605     void applyAutomaticColumnWidths();
 606
 607     /**
 608      * @return Sum of the widths of all columns.
 609      */
 610     qreal columnWidthsSum() const;
 611
 612     /**
 613      * @return Boundaries of the header. An empty rectangle is returned
 614      *         if no header is shown.
 615      */
 616     QRectF headerBoundaries() const;
 617
 618     /**
 619      * @return True if the number of columns or rows will be changed when applying
 620      *         the new grid- and item-size. Used to determine whether an animation
 621      *         should be done when applying the new layout.
 622      */
 623     bool changesItemGridLayout(const QSizeF &newGridSize, const QSizeF &newItemSize, const QSizeF &newItemMargin) const;
 624
 625     /**
 626      * @param changedItemCount Number of inserted  or removed items.
 627      * @return                 True if the inserting or removing of items should be animated.
 628      *                         No animation should be done if the number of items is too large
 629      *                         to provide a pleasant animation.
 630      */
 631     bool animateChangedItemCount(int changedItemCount) const;
 632
 633     /**
 634      * @return True if a scrollbar for the given scroll-orientation is required
 635      *         when using a size of \p size for the view. Calling the method is rather
 636      *         expansive as a temporary relayout needs to be done.
 637      */
 638     bool scrollBarRequired(const QSizeF &size) const;
 639
 640     /**
 641      * Shows a drop-indicator between items dependent on the given
 642      * cursor position. The cursor position is relative to the upper left
 643      * edge of the view.
 644      * @return Index of the item where the dropping is done. An index of -1
 645      *         indicates that the item has been dropped after the last item.
 646      */
 647     int showDropIndicator(const QPointF &pos);
 648     void hideDropIndicator();
 649
 650     /**
 651      * Applies the height of the group header to the layouter. The height
 652      * depends on the used scroll orientation.
 653      */
 654     void updateGroupHeaderHeight();
 655
 656     /**
 657      * Updates the siblings-information for all visible items that are inside
 658      * the range of \p firstIndex and \p lastIndex. If firstIndex or lastIndex
 659      * is smaller than 0, the siblings-information for all visible items gets
 660      * updated.
 661      * @see KItemListWidget::setSiblingsInformation()
 662      */
 663     void updateSiblingsInformation(int firstIndex = -1, int lastIndex = -1);
 664
 665     /**
 666      * Helper method for updateExpansionIndicators().
 667      * @return True if the item with the index \a index has a sibling successor
 668      *         (= the item is not the last item of the current hierarchy).
 669      */
 670     bool hasSiblingSuccessor(int index) const;
 671
 672     /**
 673      * Helper method for slotRoleEditingCanceled() and slotRoleEditingFinished().
 674      * Disconnects the two Signals "roleEditingCanceled" and
 675      * "roleEditingFinished"
 676      */
 677     void disconnectRoleEditingSignals(int index);
 678
 679     /**
 680      * Helper function for triggerAutoScrolling().
 681      * @param pos    Logical position of the mouse relative to the range.
 682      * @param range  Range of the visible area.
 683      * @param oldInc Previous increment. Is used to assure that the increment
 684      *               increases only gradually.
 685      * @return Scroll increment that should be added to the offset().
 686      *         As soon as \a pos is inside the autoscroll-margin a
 687      *         value != 0 will be returned.
 688      */
 689     static int calculateAutoScrollingIncrement(int pos, int range, int oldInc);
 690
 691     /**
 692      * Helper functions for changesItemCount().
 693      * @return The number of items that fit into the available size by
 694      *         respecting the size of the item and the margin between the items.
 695      */
 696     static int itemsPerSize(qreal size, qreal itemSize, qreal itemMargin);
 697
 698 private:
 699     bool m_enabledSelectionToggles;
 700     bool m_grouped;
 701     bool m_highlightEntireRow;
 702     bool m_alternateBackgrounds;
 703     bool m_supportsItemExpanding;
 704     bool m_editingRole;
 705     int m_activeTransactions; // Counter for beginTransaction()/endTransaction()
 706     LayoutAnimationHint m_endTransactionAnimationHint;
 707
 708     QSizeF m_itemSize;
 709     KItemListController *m_controller;
 710     KItemModelBase *m_model;
 711     QList<QByteArray> m_visibleRoles;
 712     mutable KItemListWidgetCreatorBase *m_widgetCreator;
 713     mutable KItemListGroupHeaderCreatorBase *m_groupHeaderCreator;
 714     KItemListStyleOption m_styleOption;
 715
 716     QHash<int, KItemListWidget *> m_visibleItems;
 717     QHash<KItemListWidget *, KItemListGroupHeader *> m_visibleGroups;
 718
 719     struct Cell {
 720         Cell()
 721             : column(-1)
 722             , row(-1)
 723         {
 724         }
 725         Cell(int c, int r)
 726             : column(c)
 727             , row(r)
 728         {
 729         }
 730         int column;
 731         int row;
 732     };
 733     QHash<int, Cell> m_visibleCells;
 734
 735     int m_scrollBarExtent;
 736     KItemListViewLayouter *m_layouter;
 737     KItemListViewAnimation *m_animation;
 738
 739     qreal m_oldScrollOffset;
 740     qreal m_oldMaximumScrollOffset;
 741     qreal m_oldItemOffset;
 742     qreal m_oldMaximumItemOffset;
 743
 744     bool m_skipAutoScrollForRubberBand;
 745     KItemListRubberBand *m_rubberBand;
 746     KItemListRubberBand *m_tapAndHoldIndicator;
 747
 748     QPointF m_mousePos;
 749     int m_autoScrollIncrement;
 750     QTimer *m_autoScrollTimer;
 751
 752     KItemListHeader *m_header;
 753     KItemListHeaderWidget *m_headerWidget;
 754
 755     QPropertyAnimation *m_indicatorAnimation;
 756
 757     // When dragging items into the view where the sort-role of the model
 758     // is empty, a visual indicator should be shown during dragging where
 759     // the dropping will happen. This indicator is specified by an index
 760     // of the item. -1 means that no indicator will be shown at all.
 761     // The m_dropIndicator is set by the KItemListController
 762     // by KItemListView::showDropIndicator() and KItemListView::hideDropIndicator().
 763     QRectF m_dropIndicator;
 764
 765     QList<QVariantAnimation *> m_rubberBandAnimations;
 766
 767     KItemListSizeHintResolver *m_sizeHintResolver;
 768
 769     friend class KItemListContainer; // Accesses scrollBarRequired()
 770     friend class KItemListHeader; // Accesses m_headerWidget
 771     friend class KItemListController;
 772     friend class KItemListControllerTest;
 773     friend class KItemListViewAccessible;
 774     friend class KItemListAccessibleCell;
 775 };
 776
 777 /**
 778  * Allows to do a fast logical creation and deletion of QGraphicsWidgets
 779  * by recycling existing QGraphicsWidgets instances. Is used by
 780  * KItemListWidgetCreatorBase and KItemListGroupHeaderCreatorBase.
 781  * @internal
 782  */
 783 class DOLPHIN_EXPORT KItemListCreatorBase
 784 {
 785 public:
 786     virtual ~KItemListCreatorBase();
 787
 788 protected:
 789     void addCreatedWidget(QGraphicsWidget *widget);
 790     void pushRecycleableWidget(QGraphicsWidget *widget);
 791     QGraphicsWidget *popRecycleableWidget();
 792
 793 private:
 794     QSet<QGraphicsWidget *> m_createdWidgets;
 795     QList<QGraphicsWidget *> m_recycleableWidgets;
 796 };
 797
 798 /**
 799  * @brief Base class for creating KItemListWidgets.
 800  *
 801  * It is recommended that applications simply use the KItemListWidgetCreator-template class.
 802  * For a custom implementation the methods create(), itemSizeHint() and preferredColumnWith()
 803  * must be reimplemented. The intention of the widget creator is to prevent repetitive and
 804  * expensive instantiations and deletions of KItemListWidgets by recycling existing widget
 805  * instances.
 806  */
 807 class DOLPHIN_EXPORT KItemListWidgetCreatorBase : public KItemListCreatorBase
 808 {
 809 public:
 810     ~KItemListWidgetCreatorBase() override;
 811
 812     virtual KItemListWidget *create(KItemListView *view) = 0;
 813
 814     virtual void recycle(KItemListWidget *widget);
 815
 816     virtual void calculateItemSizeHints(QVector<std::pair<qreal, bool>> &logicalHeightHints, qreal &logicalWidthHint, const KItemListView *view) const = 0;
 817
 818     virtual qreal preferredRoleColumnWidth(const QByteArray &role, int index, const KItemListView *view) const = 0;
 819 };
 820
 821 /**
 822  * @brief Template class for creating KItemListWidgets.
 823  */
 824 template<class T>
 825 class KItemListWidgetCreator : public KItemListWidgetCreatorBase
 826 {
 827 public:
 828     KItemListWidgetCreator();
 829     ~KItemListWidgetCreator() override;
 830
 831     KItemListWidget *create(KItemListView *view) override;
 832
 833     void calculateItemSizeHints(QVector<std::pair<qreal, bool>> &logicalHeightHints, qreal &logicalWidthHint, const KItemListView *view) const override;
 834
 835     qreal preferredRoleColumnWidth(const QByteArray &role, int index, const KItemListView *view) const override;
 836
 837 private:
 838     KItemListWidgetInformant *m_informant;
 839 };
 840
 841 template<class T>
 842 KItemListWidgetCreator<T>::KItemListWidgetCreator()
 843     : m_informant(T::createInformant())
 844 {
 845 }
 846
 847 template<class T>
 848 KItemListWidgetCreator<T>::~KItemListWidgetCreator()
 849 {
 850     delete m_informant;
 851 }
 852
 853 template<class T>
 854 KItemListWidget *KItemListWidgetCreator<T>::create(KItemListView *view)
 855 {
 856     KItemListWidget *widget = static_cast<KItemListWidget *>(popRecycleableWidget());
 857     if (!widget) {
 858         widget = new T(m_informant, view);
 859         addCreatedWidget(widget);
 860     }
 861     widget->setParentItem(view);
 862     return widget;
 863 }
 864
 865 template<class T>
 866 void KItemListWidgetCreator<T>::calculateItemSizeHints(QVector<std::pair<qreal, bool>> &logicalHeightHints,
 867                                                        qreal &logicalWidthHint,
 868                                                        const KItemListView *view) const
 869 {
 870     return m_informant->calculateItemSizeHints(logicalHeightHints, logicalWidthHint, view);
 871 }
 872
 873 template<class T>
 874 qreal KItemListWidgetCreator<T>::preferredRoleColumnWidth(const QByteArray &role, int index, const KItemListView *view) const
 875 {
 876     return m_informant->preferredRoleColumnWidth(role, index, view);
 877 }
 878
 879 /**
 880  * @brief Base class for creating KItemListGroupHeaders.
 881  *
 882  * It is recommended that applications simply use the KItemListGroupHeaderCreator-template class.
 883  * For a custom implementation the methods create() and recycle() must be reimplemented.
 884  * The intention of the group-header creator is to prevent repetitive and expensive instantiations and
 885  * deletions of KItemListGroupHeaders by recycling existing header instances.
 886  */
 887 class DOLPHIN_EXPORT KItemListGroupHeaderCreatorBase : public KItemListCreatorBase
 888 {
 889 public:
 890     ~KItemListGroupHeaderCreatorBase() override;
 891     virtual KItemListGroupHeader *create(KItemListView *view) = 0;
 892     virtual void recycle(KItemListGroupHeader *header);
 893 };
 894
 895 template<class T>
 896 class KItemListGroupHeaderCreator : public KItemListGroupHeaderCreatorBase
 897 {
 898 public:
 899     ~KItemListGroupHeaderCreator() override;
 900     KItemListGroupHeader *create(KItemListView *view) override;
 901 };
 902
 903 template<class T>
 904 KItemListGroupHeaderCreator<T>::~KItemListGroupHeaderCreator()
 905 {
 906 }
 907
 908 template<class T>
 909 KItemListGroupHeader *KItemListGroupHeaderCreator<T>::create(KItemListView *view)
 910 {
 911     KItemListGroupHeader *widget = static_cast<KItemListGroupHeader *>(popRecycleableWidget());
 912     if (!widget) {
 913         widget = new T(view);
 914         addCreatedWidget(widget);
 915     }
 916     return widget;
 917 }
 918
 919 #endif