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 KItemListContainer;
  25 class KItemListContainerAccessible;
  26 class KItemListController;
  27 class KItemListGroupHeaderCreatorBase;
  28 class KItemListHeader;
  29 class KItemListHeaderWidget;
  30 class KItemListSizeHintResolver;
  31 class KItemListRubberBand;
  32 class KItemListViewAnimation;
  33 class KItemListViewLayouter;
  34 class KItemListWidget;
  35 class KItemListWidgetInformant;
  36 class KItemListWidgetCreatorBase;
  37 class QTimer;
  38 class QPropertyAnimation;
  39 class QVariantAnimation;
  40
  41 /**
  42  * @brief Represents the view of an item-list.
  43  *
  44  * The view is responsible for showing the items of the model within
  45  * a GraphicsItem. Each visible item is represented by a KItemListWidget.
  46  *
  47  * The created view must be applied to the KItemListController with
  48  * KItemListController::setView() or with the constructor of
  49  * KItemListController.
  50  *
  51  * @see KItemListWidget
  52  * @see KItemModelBase
  53  */
  54 class DOLPHIN_EXPORT KItemListView : public QGraphicsWidget
  55 {
  56     Q_OBJECT
  57
  58     Q_PROPERTY(qreal scrollOffset READ scrollOffset WRITE setScrollOffset NOTIFY scrollOffsetChanged)
  59     Q_PROPERTY(qreal itemOffset READ itemOffset WRITE setItemOffset NOTIFY itemOffsetChanged)
  60
  61 public:
  62     explicit KItemListView(QGraphicsWidget *parent = nullptr);
  63     ~KItemListView() override;
  64
  65     /**
  66      * Offset of the scrollbar that represents the scroll-orientation
  67      * (see setScrollOrientation()).
  68      */
  69     void setScrollOffset(qreal offset);
  70     qreal scrollOffset() const;
  71
  72     qreal maximumScrollOffset() const;
  73
  74     /**
  75      * Offset related to an item, that does not fit into the available
  76      * size of the listview. If the scroll-orientation is vertical
  77      * the item-offset describes the offset of the horizontal axe, if
  78      * the scroll-orientation is horizontal the item-offset describes
  79      * the offset of the vertical axe.
  80      */
  81     void setItemOffset(qreal scrollOffset);
  82     qreal itemOffset() const;
  83
  84     qreal maximumItemOffset() const;
  85
  86     int maximumVisibleItems() const;
  87
  88     void setVisibleRoles(const QList<QByteArray> &roles);
  89     QList<QByteArray> visibleRoles() const;
  90
  91     /**
  92      * If set to true an automatic scrolling is done as soon as the
  93      * mouse is moved near the borders of the view. Per default
  94      * the automatic scrolling is turned off.
  95      */
  96     void setAutoScroll(bool enabled);
  97     bool autoScroll() const;
  98
  99     /**
 100      * If set to true selection-toggles will be shown when hovering
 101      * an item. Per default the selection-toggles are disabled.
 102      */
 103     void setEnabledSelectionToggles(bool enabled);
 104     bool enabledSelectionToggles() const;
 105
 106     /**
 107      * @return Controller of the item-list. The controller gets
 108      *         initialized by KItemListController::setView() and will
 109      *         result in calling KItemListController::onControllerChanged().
 110      */
 111     KItemListController *controller() const;
 112
 113     /**
 114      * @return Model of the item-list. The model gets
 115      *         initialized by KItemListController::setModel() and will
 116      *         result in calling KItemListController::onModelChanged().
 117      */
 118     KItemModelBase *model() const;
 119
 120     /**
 121      * Sets the creator that creates a widget showing the
 122      * content of one model-item. Usually it is sufficient
 123      * to implement a custom widget X derived from KItemListWidget and
 124      * set the creator by:
 125      * <code>
 126      * itemListView->setWidgetCreator(new KItemListWidgetCreator<X>());
 127      * </code>
 128      * The ownership of the widget creator is transferred to
 129      * the item-list view.
 130      **/
 131     void setWidgetCreator(KItemListWidgetCreatorBase *widgetCreator);
 132     KItemListWidgetCreatorBase *widgetCreator() const;
 133
 134     /**
 135      * Sets the creator that creates a group header. Usually it is sufficient
 136      * to implement a custom header widget X derived from KItemListGroupHeader and
 137      * set the creator by:
 138      * <code>
 139      * itemListView->setGroupHeaderCreator(new KItemListGroupHeaderCreator<X>());
 140      * </code>
 141      * The ownership of the gropup header creator is transferred to
 142      * the item-list view.
 143      **/
 144     void setGroupHeaderCreator(KItemListGroupHeaderCreatorBase *groupHeaderCreator);
 145     KItemListGroupHeaderCreatorBase *groupHeaderCreator() const;
 146
 147 #ifndef QT_NO_ACCESSIBILITY
 148     /**
 149      * Uses \a parent to create an accessible object for \a parent. That accessible object will
 150      * then be used as the accessible parent of the accessible object for this KItemListView.
 151      * Make sure \a parent is the container which contains this specific KItemListView.
 152      * This method must be called once before the accessible interface is queried for this class.
 153      */
 154     void setAccessibleParentsObject(KItemListContainer *accessibleParentsObject);
 155     /** The parent of the QAccessibilityInterface of this class. */
 156     KItemListContainerAccessible *accessibleParent();
 157 #endif
 158
 159     /**
 160      * @return The basic size of all items. The size of an item may be larger than
 161      *         the basic size (see KItemListView::itemRect()).
 162      */
 163     QSizeF itemSize() const;
 164
 165     const KItemListStyleOption &styleOption() const;
 166
 167     void setGeometry(const QRectF &rect) override;
 168
 169     /**
 170      * @return The page step which should be used by the vertical scroll bar.
 171      *         This is the height of the view except for the header widget.
 172      */
 173     qreal verticalPageStep() const;
 174
 175     /**
 176      * @return Index of the item that is below the point \a pos.
 177      *         The position is relative to the upper right of
 178      *         the visible area. Only (at least partly) visible
 179      *         items are considered. std::nullopt is returned if
 180      *         no item is below the position.
 181      */
 182     std::optional<int> itemAt(const QPointF &pos) const;
 183     bool isAboveSelectionToggle(int index, const QPointF &pos) const;
 184     bool isAboveExpansionToggle(int index, const QPointF &pos) const;
 185     bool isAboveText(int index, const QPointF &pos) const;
 186
 187     /**
 188      * @return Index of the first item that is at least partly visible.
 189      *         -1 is returned if the model contains no items.
 190      */
 191     int firstVisibleIndex() const;
 192
 193     /**
 194      * @return Index of the last item that is at least partly visible.
 195      *         -1 is returned if the model contains no items.
 196      */
 197     int lastVisibleIndex() const;
 198
 199     /**
 200      * Calculates the required size for all items in the model.
 201      * It might be larger than KItemListView::itemSize().
 202      * In this case the layout grid will be stretched to assure an
 203      * unclipped item.
 204      *
 205      * @note the logical height (width) is actually the
 206      * width (height) if the scroll orientation is Qt::Vertical!
 207      */
 208     void calculateItemSizeHints(QVector<std::pair<qreal, bool>> &logicalHeightHints, qreal &logicalWidthHint) const;
 209
 210     /**
 211      * If set to true, items having child-items can be expanded to show the child-items as
 212      * part of the view. Per default the expanding of items is disabled. If expanding of
 213      * items is enabled, the methods KItemModelBase::setExpanded(), KItemModelBase::isExpanded(),
 214      * KItemModelBase::isExpandable() and KItemModelBase::expandedParentsCount()
 215      * must be reimplemented. The view-implementation
 216      * has to take care itself how to visually represent the expanded items provided
 217      * by the model.
 218      */
 219     void setSupportsItemExpanding(bool supportsExpanding);
 220     bool supportsItemExpanding() const;
 221
 222     void setHighlightEntireRow(bool highlightEntireRow);
 223     bool highlightEntireRow() const;
 224
 225     void setAlternateBackgrounds(bool alternate);
 226     bool alternateBackgrounds() const;
 227
 228     /**
 229      * @return The rectangle of the item relative to the top/left of
 230      *         the currently visible area (see KItemListView::offset()).
 231      */
 232     QRectF itemRect(int index) const;
 233
 234     /**
 235      * @return The context rectangle of the item relative to the top/left of
 236      *         the currently visible area (see KItemListView::offset()). The
 237      *         context rectangle is defined by the united rectangle of
 238      *         the icon rectangle and the text rectangle (see KItemListWidget::iconRect()
 239      *         and KItemListWidget::textRect()) and is useful as reference for e.g. aligning
 240      *         a tooltip or a context-menu for an item. Note that a context rectangle will
 241      *         only be returned for (at least partly) visible items. An empty rectangle will
 242      *         be returned for fully invisible items.
 243      */
 244     QRectF itemContextRect(int index) const;
 245
 246     /**
 247      * @return Whether or not the name of the file has been elided. At present this will
 248      *         only ever be true when in icons view.
 249      */
 250     bool isElided(int index) const;
 251
 252     /**
 253      * Scrolls to the item with the index \a index so that the item
 254      * will be fully visible.
 255      */
 256     void scrollToItem(int index);
 257
 258     /**
 259      * If several properties of KItemListView are changed synchronously, it is
 260      * recommended to encapsulate the calls between beginTransaction() and endTransaction().
 261      * This prevents unnecessary and expensive layout-calculations.
 262      */
 263     void beginTransaction();
 264
 265     /**
 266      * Counterpart to beginTransaction(). The layout changes will only be animated if
 267      * all property changes between beginTransaction() and endTransaction() support
 268      * animations.
 269      */
 270     void endTransaction();
 271
 272     bool isTransactionActive() const;
 273
 274     /**
 275      * Turns on the header if \p visible is true. Per default the
 276      * header is not visible. Usually the header is turned on when
 277      * showing a classic "table-view" to describe the shown columns.
 278      */
 279     void setHeaderVisible(bool visible);
 280     bool isHeaderVisible() const;
 281
 282     /**
 283      * @return Header of the list. The header is also available if it is not shown
 284      *         (see KItemListView::setHeaderShown()).
 285      */
 286     KItemListHeader *header() const;
 287
 288     /**
 289      * @return Pixmap that is used for a drag operation based on the
 290      *         items given by \a indexes.
 291      */
 292     virtual QPixmap createDragPixmap(const KItemSet &indexes) const;
 293
 294     /**
 295      * Lets the user edit the role \a role for item with the index \a index.
 296      */
 297     void editRole(int index, const QByteArray &role);
 298
 299     void paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget = nullptr) override;
 300
 301 Q_SIGNALS:
 302     void scrollOrientationChanged(Qt::Orientation current, Qt::Orientation previous);
 303     void scrollOffsetChanged(qreal current, qreal previous);
 304     void maximumScrollOffsetChanged(qreal current, qreal previous);
 305     void itemOffsetChanged(qreal current, qreal previous);
 306     void maximumItemOffsetChanged(qreal current, qreal previous);
 307     void scrollTo(qreal newOffset);
 308
 309     /**
 310      * Is emitted if the user has changed the sort order by clicking on a
 311      * header item (see KItemListView::setHeaderShown()). The sort order
 312      * of the model has already been adjusted to
 313      * the current sort order. Note that no signal will be emitted if the
 314      * sort order of the model has been changed without user interaction.
 315      */
 316     void sortOrderChanged(Qt::SortOrder current, Qt::SortOrder previous);
 317
 318     /**
 319      * Is emitted if the user has changed the sort role by clicking on a
 320      * header item (see KItemListView::setHeaderShown()). The sort role
 321      * of the model has already been adjusted to
 322      * the current sort role. Note that no signal will be emitted if the
 323      * sort role of the model has been changed without user interaction.
 324      */
 325     void sortRoleChanged(const QByteArray &current, const QByteArray &previous);
 326
 327     /**
 328      * Is emitted if the user has changed the visible roles by moving a header
 329      * item (see KItemListView::setHeaderShown()). Note that no signal will be
 330      * emitted if the roles have been changed without user interaction by
 331      * KItemListView::setVisibleRoles().
 332      */
 333     void visibleRolesChanged(const QList<QByteArray> &current, const QList<QByteArray> &previous);
 334
 335     void roleEditingCanceled(int index, const QByteArray &role, const QVariant &value);
 336     void roleEditingFinished(int index, const QByteArray &role, const QVariant &value);
 337
 338     /**
 339      * Emitted once scrolling has finished, or immediately if no scrolling was necessary
 340      * to get item in view in scrollToItem.
 341      */
 342     void scrollingStopped();
 343
 344     void columnHovered(int roleIndex);
 345     void columnUnHovered(int roleIndex);
 346
 347 protected:
 348     QVariant itemChange(GraphicsItemChange change, const QVariant &value) override;
 349     void setItemSize(const QSizeF &size);
 350     void setStyleOption(const KItemListStyleOption &option);
 351
 352     /**
 353      * If the scroll-orientation is vertical, the items are ordered
 354      * from top to bottom (= default setting). If the scroll-orientation
 355      * is horizontal, the items are ordered from left to right.
 356      */
 357     void setScrollOrientation(Qt::Orientation orientation);
 358     Qt::Orientation scrollOrientation() const;
 359
 360     /**
 361      * Factory method for creating a default widget-creator. The method will be used
 362      * in case if setWidgetCreator() has not been set by the application.
 363      * @return New instance of the widget-creator that should be used per
 364      *         default.
 365      */
 366     virtual KItemListWidgetCreatorBase *defaultWidgetCreator() const;
 367
 368     /**
 369      * Factory method for creating a default group-header-creator. The method will be used
 370      * in case if setGroupHeaderCreator() has not been set by the application.
 371      * @return New instance of the group-header-creator that should be used per
 372      *         default.
 373      */
 374     virtual KItemListGroupHeaderCreatorBase *defaultGroupHeaderCreator() const;
 375
 376     /**
 377      * Is called when creating a new KItemListWidget instance and allows derived
 378      * classes to do a custom initialization.
 379      */
 380     virtual void initializeItemListWidget(KItemListWidget *item);
 381
 382     /**
 383      * @return True if at least one of the changed roles \p changedRoles might result
 384      *         in the need to update the item-size hint (see KItemListView::itemSizeHint()).
 385      *         Per default true is returned which means on each role-change of existing items
 386      *         the item-size hints are recalculated. For performance reasons it is recommended
 387      *         to return false in case if a role-change will not result in a changed
 388      *         item-size hint.
 389      */
 390     virtual bool itemSizeHintUpdateRequired(const QSet<QByteArray> &changedRoles) const;
 391
 392     virtual void onControllerChanged(KItemListController *current, KItemListController *previous);
 393     virtual void onModelChanged(KItemModelBase *current, KItemModelBase *previous);
 394
 395     virtual void onScrollOrientationChanged(Qt::Orientation current, Qt::Orientation previous);
 396     virtual void onItemSizeChanged(const QSizeF &current, const QSizeF &previous);
 397     virtual void onScrollOffsetChanged(qreal current, qreal previous);
 398     virtual void onVisibleRolesChanged(const QList<QByteArray> &current, const QList<QByteArray> &previous);
 399     virtual void onStyleOptionChanged(const KItemListStyleOption &current, const KItemListStyleOption &previous);
 400     virtual void onHighlightEntireRowChanged(bool highlightEntireRow);
 401     virtual void onSupportsItemExpandingChanged(bool supportsExpanding);
 402
 403     virtual void onTransactionBegin();
 404     virtual void onTransactionEnd();
 405
 406     bool event(QEvent *event) override;
 407     void mousePressEvent(QGraphicsSceneMouseEvent *event) override;
 408     void mouseMoveEvent(QGraphicsSceneMouseEvent *event) override;
 409     void dragEnterEvent(QGraphicsSceneDragDropEvent *event) override;
 410     void dragMoveEvent(QGraphicsSceneDragDropEvent *event) override;
 411     void dragLeaveEvent(QGraphicsSceneDragDropEvent *event) override;
 412     void dropEvent(QGraphicsSceneDragDropEvent *event) override;
 413
 414     QList<KItemListWidget *> visibleItemListWidgets() const;
 415
 416     virtual void updateFont();
 417     virtual void updatePalette();
 418
 419 protected Q_SLOTS:
 420     virtual void slotItemsInserted(const KItemRangeList &itemRanges);
 421     virtual void slotItemsRemoved(const KItemRangeList &itemRanges);
 422     virtual void slotItemsMoved(const KItemRange &itemRange, const QList<int> &movedToIndexes);
 423     virtual void slotItemsChanged(const KItemRangeList &itemRanges, const QSet<QByteArray> &roles);
 424     virtual void slotGroupsChanged();
 425
 426     virtual void slotGroupedSortingChanged(bool current);
 427     virtual void slotSortOrderChanged(Qt::SortOrder current, Qt::SortOrder previous);
 428     virtual void slotSortRoleChanged(const QByteArray &current, const QByteArray &previous);
 429     virtual void slotCurrentChanged(int current, int previous);
 430     virtual void slotSelectionChanged(const KItemSet &current, const KItemSet &previous);
 431
 432 private Q_SLOTS:
 433     void slotAnimationFinished(QGraphicsWidget *widget, KItemListViewAnimation::AnimationType type);
 434
 435     void slotRubberBandPosChanged();
 436     void slotRubberBandActivationChanged(bool active);
 437
 438     /**
 439      * Is invoked if the column-width of one role in the header has
 440      * been changed by the user. The automatic resizing of columns
 441      * will be turned off as soon as this method has been called at
 442      * least once.
 443      */
 444     void slotHeaderColumnWidthChanged(const QByteArray &role, qreal currentWidth, qreal previousWidth);
 445
 446     void slotSidePaddingChanged(qreal width);
 447
 448     /**
 449      * Is invoked if a column has been moved by the user. Applies
 450      * the moved role to the view.
 451      */
 452     void slotHeaderColumnMoved(const QByteArray &role, int currentIndex, int previousIndex);
 453
 454     /**
 455      * Triggers the autoscrolling if autoScroll() is enabled by checking the
 456      * current mouse position. If the mouse position is within the autoscroll
 457      * margins a timer will be started that periodically triggers the autoscrolling.
 458      */
 459     void triggerAutoScrolling();
 460
 461     /**
 462      * Is invoked if the geometry of the parent-widget from a group-header has been
 463      * changed. The x-position and width of the group-header gets adjusted to assure
 464      * that it always spans the whole width even during temporary transitions of the
 465      * parent widget.
 466      */
 467     void slotGeometryOfGroupHeaderParentChanged();
 468
 469     void slotRoleEditingCanceled(int index, const QByteArray &role, const QVariant &value);
 470     void slotRoleEditingFinished(int index, const QByteArray &role, const QVariant &value);
 471
 472 private:
 473     enum LayoutAnimationHint { NoAnimation, Animation };
 474
 475     enum SizeType { LayouterSize, ItemSize };
 476
 477     void setController(KItemListController *controller);
 478     void setModel(KItemModelBase *model);
 479
 480     KItemListRubberBand *rubberBand() const;
 481
 482     void doLayout(LayoutAnimationHint hint, int changedIndex = 0, int changedCount = 0);
 483
 484     /**
 485      * Helper method for doLayout: Returns a list of items that can be reused for the visible
 486      * area. Invisible group headers get recycled. The reusable items are items that are
 487      * invisible. If the animation hint is 'Animation' then items that are currently animated
 488      * won't be reused. Reusing items is faster in comparison to deleting invisible
 489      * items and creating a new instance for visible items.
 490      */
 491     QList<int> recycleInvisibleItems(int firstVisibleIndex, int lastVisibleIndex, LayoutAnimationHint hint);
 492
 493     /**
 494      * Helper method for doLayout: Starts a moving-animation for the widget to the given
 495      * new position. The moving-animation is only started if the new position is within
 496      * the same row or column, otherwise the create-animation is used instead.
 497      * @return True if the moving-animation has been applied.
 498      */
 499     bool moveWidget(KItemListWidget *widget, const QPointF &newPos);
 500
 501     void emitOffsetChanges();
 502
 503     KItemListWidget *createWidget(int index);
 504     void recycleWidget(KItemListWidget *widget);
 505
 506     /**
 507      * Changes the index of the widget to \a index and assures a consistent
 508      * update for m_visibleItems and m_visibleCells. The cell-information
 509      * for the new index will not be updated and be initialized as empty cell.
 510      */
 511     void setWidgetIndex(KItemListWidget *widget, int index);
 512
 513     /**
 514      * Changes the index of the widget to \a index. In opposite to
 515      * setWidgetIndex() the cell-information for the widget gets updated.
 516      * This update gives doLayout() the chance to animate the moving
 517      * of the item visually (see moveWidget()).
 518      */
 519     void moveWidgetToIndex(KItemListWidget *widget, int index);
 520
 521     /**
 522      * Helper method for prepareLayoutForIncreasedItemCount().
 523      */
 524     void setLayouterSize(const QSizeF &size, SizeType sizeType);
 525
 526     /**
 527      * Helper method for createWidget() and setWidgetIndex() to update the properties
 528      * of the itemlist widget.
 529      */
 530     void updateWidgetProperties(KItemListWidget *widget, int index);
 531
 532     /**
 533      * Helper method for updateWidgetPropertes() to create or update
 534      * the itemlist group-header.
 535      */
 536     void updateGroupHeaderForWidget(KItemListWidget *widget);
 537
 538     /**
 539      * Updates the position and size of the group-header that belongs
 540      * to the itemlist widget \a widget. The given widget must represent
 541      * the first item of a group.
 542      */
 543     void updateGroupHeaderLayout(KItemListWidget *widget);
 544
 545     /**
 546      * Recycles the group-header for the widget.
 547      */
 548     void recycleGroupHeaderForWidget(KItemListWidget *widget);
 549
 550     /**
 551      * Helper method for slotGroupedSortingChanged(), slotSortOrderChanged()
 552      * and slotSortRoleChanged(): Iterates through all visible items and updates
 553      * the group-header widgets.
 554      */
 555     void updateVisibleGroupHeaders();
 556
 557     /**
 558      * @return Index for the item in the list returned by KItemModelBase::groups()
 559      *         that represents the group where the item with the index \a index
 560      *         belongs to. -1 is returned if no groups are available.
 561      */
 562     int groupIndexForItem(int index) const;
 563
 564     /**
 565      * Updates the alternate background for all visible items.
 566      * @see updateAlternateBackgroundForWidget()
 567      */
 568     void updateAlternateBackgrounds();
 569
 570     /**
 571      * Updates the alternateBackground-property of the widget dependent
 572      * on the state of useAlternateBackgrounds() and the grouping state.
 573      */
 574     void updateAlternateBackgroundForWidget(KItemListWidget *widget);
 575
 576     /**
 577      * @return True if alternate backgrounds should be used for the items.
 578      *         This is the case if an empty item-size is given and if there
 579      *         is more than one visible role.
 580      */
 581     bool useAlternateBackgrounds() const;
 582
 583     /**
 584      * @param itemRanges Items that must be checked for getting the widths of columns.
 585      * @return           The preferred width of the column of each visible role. The width will
 586      *                   be respected if the width of the item size is <= 0 (see
 587      *                   KItemListView::setItemSize()). Per default an empty hash
 588      *                   is returned.
 589      */
 590     QHash<QByteArray, qreal> preferredColumnWidths(const KItemRangeList &itemRanges) const;
 591
 592     /**
 593      * Applies the column-widths from m_headerWidget to the layout
 594      * of the view.
 595      */
 596     void applyColumnWidthsFromHeader();
 597
 598     /**
 599      * Applies the column-widths from m_headerWidget to \a widget.
 600      */
 601     void updateWidgetColumnWidths(KItemListWidget *widget);
 602
 603     /**
 604      * Updates the preferred column-widths of m_groupHeaderWidget by
 605      * invoking KItemListView::columnWidths().
 606      */
 607     void updatePreferredColumnWidths(const KItemRangeList &itemRanges);
 608
 609     /**
 610      * Convenience method for
 611      * updatePreferredColumnWidths(KItemRangeList() << KItemRange(0, m_model->count()).
 612      */
 613     void updatePreferredColumnWidths();
 614
 615     /**
 616      * Resizes the column-widths of m_headerWidget based on the preferred widths
 617      * and the available view-size.
 618      */
 619     void applyAutomaticColumnWidths();
 620
 621     /**
 622      * @return Sum of the widths of all columns.
 623      */
 624     qreal columnWidthsSum() const;
 625
 626     /**
 627      * @return Boundaries of the header. An empty rectangle is returned
 628      *         if no header is shown.
 629      */
 630     QRectF headerBoundaries() const;
 631
 632     /**
 633      * @return True if the number of columns or rows will be changed when applying
 634      *         the new grid- and item-size. Used to determine whether an animation
 635      *         should be done when applying the new layout.
 636      */
 637     bool changesItemGridLayout(const QSizeF &newGridSize, const QSizeF &newItemSize, const QSizeF &newItemMargin) const;
 638
 639     /**
 640      * @param changedItemCount Number of inserted  or removed items.
 641      * @return                 True if the inserting or removing of items should be animated.
 642      *                         No animation should be done if the number of items is too large
 643      *                         to provide a pleasant animation.
 644      */
 645     bool animateChangedItemCount(int changedItemCount) const;
 646
 647     /**
 648      * @return True if a scrollbar for the given scroll-orientation is required
 649      *         when using a size of \p size for the view. Calling the method is rather
 650      *         expansive as a temporary relayout needs to be done.
 651      */
 652     bool scrollBarRequired(const QSizeF &size) const;
 653
 654     /**
 655      * Shows a drop-indicator between items dependent on the given
 656      * cursor position. The cursor position is relative to the upper left
 657      * edge of the view.
 658      * @return Index of the item where the dropping is done. An index of -1
 659      *         indicates that the item has been dropped after the last item.
 660      */
 661     int showDropIndicator(const QPointF &pos);
 662     void hideDropIndicator();
 663
 664     /**
 665      * Applies the height of the group header to the layouter. The height
 666      * depends on the used scroll orientation.
 667      */
 668     void updateGroupHeaderHeight();
 669
 670     /**
 671      * Updates the siblings-information for all visible items that are inside
 672      * the range of \p firstIndex and \p lastIndex. If firstIndex or lastIndex
 673      * is smaller than 0, the siblings-information for all visible items gets
 674      * updated.
 675      * @see KItemListWidget::setSiblingsInformation()
 676      */
 677     void updateSiblingsInformation(int firstIndex = -1, int lastIndex = -1);
 678
 679     /**
 680      * Helper method for updateExpansionIndicators().
 681      * @return True if the item with the index \a index has a sibling successor
 682      *         (= the item is not the last item of the current hierarchy).
 683      */
 684     bool hasSiblingSuccessor(int index) const;
 685
 686     /**
 687      * Helper method for slotRoleEditingCanceled() and slotRoleEditingFinished().
 688      * Disconnects the two Signals "roleEditingCanceled" and
 689      * "roleEditingFinished"
 690      */
 691     void disconnectRoleEditingSignals(int index);
 692
 693     /**
 694      * Helper function for triggerAutoScrolling().
 695      * @param pos    Logical position of the mouse relative to the range.
 696      * @param range  Range of the visible area.
 697      * @param oldInc Previous increment. Is used to assure that the increment
 698      *               increases only gradually.
 699      * @return Scroll increment that should be added to the offset().
 700      *         As soon as \a pos is inside the autoscroll-margin a
 701      *         value != 0 will be returned.
 702      */
 703     static int calculateAutoScrollingIncrement(int pos, int range, int oldInc);
 704
 705     /**
 706      * Helper functions for changesItemCount().
 707      * @return The number of items that fit into the available size by
 708      *         respecting the size of the item and the margin between the items.
 709      */
 710     static int itemsPerSize(qreal size, qreal itemSize, qreal itemMargin);
 711
 712 private:
 713     bool m_enabledSelectionToggles;
 714     bool m_grouped;
 715     bool m_highlightEntireRow;
 716     bool m_alternateBackgrounds;
 717     bool m_supportsItemExpanding;
 718     bool m_editingRole;
 719     int m_activeTransactions; // Counter for beginTransaction()/endTransaction()
 720     LayoutAnimationHint m_endTransactionAnimationHint;
 721
 722     QSizeF m_itemSize;
 723     KItemListController *m_controller;
 724     KItemModelBase *m_model;
 725     QList<QByteArray> m_visibleRoles;
 726     mutable KItemListWidgetCreatorBase *m_widgetCreator;
 727     mutable KItemListGroupHeaderCreatorBase *m_groupHeaderCreator;
 728 #ifndef QT_NO_ACCESSIBILITY
 729     /** The object that will be the parent of this classes QAccessibleInterface. */
 730     KItemListContainerAccessible *m_accessibleParent = nullptr;
 731 #endif
 732     KItemListStyleOption m_styleOption;
 733
 734     QHash<int, KItemListWidget *> m_visibleItems;
 735     QHash<KItemListWidget *, KItemListGroupHeader *> m_visibleGroups;
 736
 737     struct Cell {
 738         Cell()
 739             : column(-1)
 740             , row(-1)
 741         {
 742         }
 743         Cell(int c, int r)
 744             : column(c)
 745             , row(r)
 746         {
 747         }
 748         int column;
 749         int row;
 750     };
 751     QHash<int, Cell> m_visibleCells;
 752
 753     int m_scrollBarExtent;
 754     KItemListViewLayouter *m_layouter;
 755     KItemListViewAnimation *m_animation;
 756
 757     qreal m_oldScrollOffset;
 758     qreal m_oldMaximumScrollOffset;
 759     qreal m_oldItemOffset;
 760     qreal m_oldMaximumItemOffset;
 761
 762     bool m_skipAutoScrollForRubberBand;
 763     KItemListRubberBand *m_rubberBand;
 764     KItemListRubberBand *m_tapAndHoldIndicator;
 765
 766     QPointF m_mousePos;
 767     int m_autoScrollIncrement;
 768     QTimer *m_autoScrollTimer;
 769
 770     KItemListHeader *m_header;
 771     KItemListHeaderWidget *m_headerWidget;
 772
 773     QPropertyAnimation *m_indicatorAnimation;
 774
 775     // When dragging items into the view where the sort-role of the model
 776     // is empty, a visual indicator should be shown during dragging where
 777     // the dropping will happen. This indicator is specified by an index
 778     // of the item. -1 means that no indicator will be shown at all.
 779     // The m_dropIndicator is set by the KItemListController
 780     // by KItemListView::showDropIndicator() and KItemListView::hideDropIndicator().
 781     QRectF m_dropIndicator;
 782
 783     QList<QVariantAnimation *> m_rubberBandAnimations;
 784
 785     KItemListSizeHintResolver *m_sizeHintResolver;
 786
 787     friend class KItemListContainer; // Accesses scrollBarRequired()
 788     friend class KItemListHeader; // Accesses m_headerWidget
 789     friend class KItemListController;
 790     friend class KItemListControllerTest;
 791     friend class KItemListViewAccessible;
 792     friend class KItemListAccessibleCell;
 793 };
 794
 795 /**
 796  * Allows to do a fast logical creation and deletion of QGraphicsWidgets
 797  * by recycling existing QGraphicsWidgets instances. Is used by
 798  * KItemListWidgetCreatorBase and KItemListGroupHeaderCreatorBase.
 799  * @internal
 800  */
 801 class DOLPHIN_EXPORT KItemListCreatorBase
 802 {
 803 public:
 804     virtual ~KItemListCreatorBase();
 805
 806 protected:
 807     void addCreatedWidget(QGraphicsWidget *widget);
 808     void pushRecycleableWidget(QGraphicsWidget *widget);
 809     QGraphicsWidget *popRecycleableWidget();
 810
 811 private:
 812     QSet<QGraphicsWidget *> m_createdWidgets;
 813     QList<QGraphicsWidget *> m_recycleableWidgets;
 814 };
 815
 816 /**
 817  * @brief Base class for creating KItemListWidgets.
 818  *
 819  * It is recommended that applications simply use the KItemListWidgetCreator-template class.
 820  * For a custom implementation the methods create(), itemSizeHint() and preferredColumnWith()
 821  * must be reimplemented. The intention of the widget creator is to prevent repetitive and
 822  * expensive instantiations and deletions of KItemListWidgets by recycling existing widget
 823  * instances.
 824  */
 825 class DOLPHIN_EXPORT KItemListWidgetCreatorBase : public KItemListCreatorBase
 826 {
 827 public:
 828     ~KItemListWidgetCreatorBase() override;
 829
 830     virtual KItemListWidget *create(KItemListView *view) = 0;
 831
 832     virtual void recycle(KItemListWidget *widget);
 833
 834     virtual void calculateItemSizeHints(QVector<std::pair<qreal, bool>> &logicalHeightHints, qreal &logicalWidthHint, const KItemListView *view) const = 0;
 835
 836     virtual qreal preferredRoleColumnWidth(const QByteArray &role, int index, const KItemListView *view) const = 0;
 837 };
 838
 839 /**
 840  * @brief Template class for creating KItemListWidgets.
 841  */
 842 template<class T>
 843 class KItemListWidgetCreator : public KItemListWidgetCreatorBase
 844 {
 845 public:
 846     KItemListWidgetCreator();
 847     ~KItemListWidgetCreator() override;
 848
 849     KItemListWidget *create(KItemListView *view) override;
 850
 851     void calculateItemSizeHints(QVector<std::pair<qreal, bool>> &logicalHeightHints, qreal &logicalWidthHint, const KItemListView *view) const override;
 852
 853     qreal preferredRoleColumnWidth(const QByteArray &role, int index, const KItemListView *view) const override;
 854
 855 private:
 856     KItemListWidgetInformant *m_informant;
 857 };
 858
 859 template<class T>
 860 KItemListWidgetCreator<T>::KItemListWidgetCreator()
 861     : m_informant(T::createInformant())
 862 {
 863 }
 864
 865 template<class T>
 866 KItemListWidgetCreator<T>::~KItemListWidgetCreator()
 867 {
 868     delete m_informant;
 869 }
 870
 871 template<class T>
 872 KItemListWidget *KItemListWidgetCreator<T>::create(KItemListView *view)
 873 {
 874     KItemListWidget *widget = static_cast<KItemListWidget *>(popRecycleableWidget());
 875     if (!widget) {
 876         widget = new T(m_informant, view);
 877         addCreatedWidget(widget);
 878     }
 879     widget->setParentItem(view);
 880     return widget;
 881 }
 882
 883 template<class T>
 884 void KItemListWidgetCreator<T>::calculateItemSizeHints(QVector<std::pair<qreal, bool>> &logicalHeightHints,
 885                                                        qreal &logicalWidthHint,
 886                                                        const KItemListView *view) const
 887 {
 888     return m_informant->calculateItemSizeHints(logicalHeightHints, logicalWidthHint, view);
 889 }
 890
 891 template<class T>
 892 qreal KItemListWidgetCreator<T>::preferredRoleColumnWidth(const QByteArray &role, int index, const KItemListView *view) const
 893 {
 894     return m_informant->preferredRoleColumnWidth(role, index, view);
 895 }
 896
 897 /**
 898  * @brief Base class for creating KItemListGroupHeaders.
 899  *
 900  * It is recommended that applications simply use the KItemListGroupHeaderCreator-template class.
 901  * For a custom implementation the methods create() and recycle() must be reimplemented.
 902  * The intention of the group-header creator is to prevent repetitive and expensive instantiations and
 903  * deletions of KItemListGroupHeaders by recycling existing header instances.
 904  */
 905 class DOLPHIN_EXPORT KItemListGroupHeaderCreatorBase : public KItemListCreatorBase
 906 {
 907 public:
 908     ~KItemListGroupHeaderCreatorBase() override;
 909     virtual KItemListGroupHeader *create(KItemListView *view) = 0;
 910     virtual void recycle(KItemListGroupHeader *header);
 911 };
 912
 913 template<class T>
 914 class KItemListGroupHeaderCreator : public KItemListGroupHeaderCreatorBase
 915 {
 916 public:
 917     ~KItemListGroupHeaderCreator() override;
 918     KItemListGroupHeader *create(KItemListView *view) override;
 919 };
 920
 921 template<class T>
 922 KItemListGroupHeaderCreator<T>::~KItemListGroupHeaderCreator()
 923 {
 924 }
 925
 926 template<class T>
 927 KItemListGroupHeader *KItemListGroupHeaderCreator<T>::create(KItemListView *view)
 928 {
 929     KItemListGroupHeader *widget = static_cast<KItemListGroupHeader *>(popRecycleableWidget());
 930     if (!widget) {
 931         widget = new T(view);
 932         addCreatedWidget(widget);
 933     }
 934     return widget;
 935 }
 936
 937 #endif