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     /** The position in the view to which an item should be scrolled to. */
  63     enum ViewItemPosition { Beginning, Middle, End, Nearest };
  64
  65     explicit KItemListView(QGraphicsWidget *parent = nullptr);
  66     ~KItemListView() override;
  67
  68     /**
  69      * Offset of the scrollbar that represents the scroll-orientation
  70      * (see setScrollOrientation()).
  71      */
  72     void setScrollOffset(qreal offset);
  73     qreal scrollOffset() const;
  74
  75     qreal maximumScrollOffset() const;
  76
  77     /**
  78      * Offset related to an item, that does not fit into the available
  79      * size of the listview. If the scroll-orientation is vertical
  80      * the item-offset describes the offset of the horizontal axe, if
  81      * the scroll-orientation is horizontal the item-offset describes
  82      * the offset of the vertical axe.
  83      */
  84     void setItemOffset(qreal scrollOffset);
  85     qreal itemOffset() const;
  86
  87     qreal maximumItemOffset() const;
  88
  89     int maximumVisibleItems() const;
  90
  91     void setVisibleRoles(const QList<QByteArray> &roles);
  92     QList<QByteArray> visibleRoles() const;
  93
  94     /**
  95      * If set to true an automatic scrolling is done as soon as the
  96      * mouse is moved near the borders of the view. Per default
  97      * the automatic scrolling is turned off.
  98      */
  99     void setAutoScroll(bool enabled);
 100     bool autoScroll() const;
 101
 102     /**
 103      * If set to true selection-toggles will be shown when hovering
 104      * an item. Per default the selection-toggles are disabled.
 105      */
 106     void setEnabledSelectionToggles(bool enabled);
 107     bool enabledSelectionToggles() const;
 108
 109     /**
 110      * @return Controller of the item-list. The controller gets
 111      *         initialized by KItemListController::setView() and will
 112      *         result in calling KItemListController::onControllerChanged().
 113      */
 114     KItemListController *controller() const;
 115
 116     /**
 117      * @return Model of the item-list. The model gets
 118      *         initialized by KItemListController::setModel() and will
 119      *         result in calling KItemListController::onModelChanged().
 120      */
 121     KItemModelBase *model() const;
 122
 123     /**
 124      * Sets the creator that creates a widget showing the
 125      * content of one model-item. Usually it is sufficient
 126      * to implement a custom widget X derived from KItemListWidget and
 127      * set the creator by:
 128      * <code>
 129      * itemListView->setWidgetCreator(new KItemListWidgetCreator<X>());
 130      * </code>
 131      * The ownership of the widget creator is transferred to
 132      * the item-list view.
 133      **/
 134     void setWidgetCreator(KItemListWidgetCreatorBase *widgetCreator);
 135     KItemListWidgetCreatorBase *widgetCreator() const;
 136
 137     /**
 138      * Sets the creator that creates a group header. Usually it is sufficient
 139      * to implement a custom header widget X derived from KItemListGroupHeader and
 140      * set the creator by:
 141      * <code>
 142      * itemListView->setGroupHeaderCreator(new KItemListGroupHeaderCreator<X>());
 143      * </code>
 144      * The ownership of the gropup header creator is transferred to
 145      * the item-list view.
 146      **/
 147     void setGroupHeaderCreator(KItemListGroupHeaderCreatorBase *groupHeaderCreator);
 148     KItemListGroupHeaderCreatorBase *groupHeaderCreator() const;
 149
 150 #ifndef QT_NO_ACCESSIBILITY
 151     /**
 152      * Uses \a parent to create an accessible object for \a parent. That accessible object will
 153      * then be used as the accessible parent of the accessible object for this KItemListView.
 154      * Make sure \a parent is the container which contains this specific KItemListView.
 155      * This method must be called once before the accessible interface is queried for this class.
 156      */
 157     void setAccessibleParentsObject(KItemListContainer *accessibleParentsObject);
 158     /** The parent of the QAccessibilityInterface of this class. */
 159     KItemListContainerAccessible *accessibleParent();
 160 #endif
 161
 162     /**
 163      * @return The basic size of all items. The size of an item may be larger than
 164      *         the basic size (see KItemListView::itemRect()).
 165      */
 166     QSizeF itemSize() const;
 167
 168     const KItemListStyleOption &styleOption() const;
 169
 170     void setGeometry(const QRectF &rect) override;
 171
 172     /**
 173      * @return The page step which should be used by the vertical scroll bar.
 174      *         This is the height of the view except for the header widget.
 175      */
 176     qreal verticalPageStep() const;
 177
 178     /**
 179      * @return Index of the item that is below the point \a pos.
 180      *         The position is relative to the upper right of
 181      *         the visible area. Only (at least partly) visible
 182      *         items are considered. std::nullopt is returned if
 183      *         no item is below the position.
 184      */
 185     std::optional<int> itemAt(const QPointF &pos) const;
 186     bool isAboveSelectionToggle(int index, const QPointF &pos) const;
 187     bool isAboveExpansionToggle(int index, const QPointF &pos) const;
 188     bool isAboveText(int index, const QPointF &pos) const;
 189
 190     /**
 191      * @return Index of the first item that is at least partly visible.
 192      *         -1 is returned if the model contains no items.
 193      */
 194     int firstVisibleIndex() const;
 195
 196     /**
 197      * @return Index of the last item that is at least partly visible.
 198      *         -1 is returned if the model contains no items.
 199      */
 200     int lastVisibleIndex() const;
 201
 202     /**
 203      * Calculates the required size for all items in the model.
 204      * It might be larger than KItemListView::itemSize().
 205      * In this case the layout grid will be stretched to assure an
 206      * unclipped item.
 207      *
 208      * @note the logical height (width) is actually the
 209      * width (height) if the scroll orientation is Qt::Vertical!
 210      */
 211     void calculateItemSizeHints(QVector<std::pair<qreal, bool>> &logicalHeightHints, qreal &logicalWidthHint) const;
 212
 213     /**
 214      * If set to true, items having child-items can be expanded to show the child-items as
 215      * part of the view. Per default the expanding of items is disabled. If expanding of
 216      * items is enabled, the methods KItemModelBase::setExpanded(), KItemModelBase::isExpanded(),
 217      * KItemModelBase::isExpandable() and KItemModelBase::expandedParentsCount()
 218      * must be reimplemented. The view-implementation
 219      * has to take care itself how to visually represent the expanded items provided
 220      * by the model.
 221      */
 222     void setSupportsItemExpanding(bool supportsExpanding);
 223     bool supportsItemExpanding() const;
 224
 225     void setHighlightEntireRow(bool highlightEntireRow);
 226     bool highlightEntireRow() const;
 227
 228     void setAlternateBackgrounds(bool alternate);
 229     bool alternateBackgrounds() const;
 230
 231     /**
 232      * @return The rectangle of the item relative to the top/left of
 233      *         the currently visible area (see KItemListView::offset()).
 234      */
 235     QRectF itemRect(int index) const;
 236
 237     /**
 238      * @return The context rectangle of the item relative to the top/left of
 239      *         the currently visible area (see KItemListView::offset()). The
 240      *         context rectangle is defined by the united rectangle of
 241      *         the icon rectangle and the text rectangle (see KItemListWidget::iconRect()
 242      *         and KItemListWidget::textRect()) and is useful as reference for e.g. aligning
 243      *         a tooltip or a context-menu for an item. Note that a context rectangle will
 244      *         only be returned for (at least partly) visible items. An empty rectangle will
 245      *         be returned for fully invisible items.
 246      */
 247     QRectF itemContextRect(int index) const;
 248
 249     /**
 250      * @return Whether or not the name of the file has been elided. At present this will
 251      *         only ever be true when in icons view.
 252      */
 253     bool isElided(int index) const;
 254
 255     /**
 256      * Scrolls to the item with the index \a index so that the item
 257      * will be fully visible. The item is positioned within the view
 258      * as specified by \a viewItemPosition.
 259      */
 260     void scrollToItem(int index, ViewItemPosition viewItemPosition = ViewItemPosition::Nearest);
 261
 262     /**
 263      * If several properties of KItemListView are changed synchronously, it is
 264      * recommended to encapsulate the calls between beginTransaction() and endTransaction().
 265      * This prevents unnecessary and expensive layout-calculations.
 266      */
 267     void beginTransaction();
 268
 269     /**
 270      * Counterpart to beginTransaction(). The layout changes will only be animated if
 271      * all property changes between beginTransaction() and endTransaction() support
 272      * animations.
 273      */
 274     void endTransaction();
 275
 276     bool isTransactionActive() const;
 277
 278     /**
 279      * Turns on the header if \p visible is true. Per default the
 280      * header is not visible. Usually the header is turned on when
 281      * showing a classic "table-view" to describe the shown columns.
 282      */
 283     void setHeaderVisible(bool visible);
 284     bool isHeaderVisible() const;
 285
 286     /**
 287      * @return Header of the list. The header is also available if it is not shown
 288      *         (see KItemListView::setHeaderShown()).
 289      */
 290     KItemListHeader *header() const;
 291
 292     /**
 293      * @return Pixmap that is used for a drag operation based on the
 294      *         items given by \a indexes.
 295      */
 296     virtual QPixmap createDragPixmap(const KItemSet &indexes) const;
 297
 298     /**
 299      * Lets the user edit the role \a role for item with the index \a index.
 300      */
 301     void editRole(int index, const QByteArray &role);
 302
 303     void paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget = nullptr) override;
 304
 305 Q_SIGNALS:
 306     void scrollOrientationChanged(Qt::Orientation current, Qt::Orientation previous);
 307     void scrollOffsetChanged(qreal current, qreal previous);
 308     void maximumScrollOffsetChanged(qreal current, qreal previous);
 309     void itemOffsetChanged(qreal current, qreal previous);
 310     void maximumItemOffsetChanged(qreal current, qreal previous);
 311     void scrollTo(qreal newOffset);
 312
 313     /**
 314      * Is emitted if the user has changed the sort order by clicking on a
 315      * header item (see KItemListView::setHeaderShown()). The sort order
 316      * of the model has already been adjusted to
 317      * the current sort order. Note that no signal will be emitted if the
 318      * sort order of the model has been changed without user interaction.
 319      */
 320     void sortOrderChanged(Qt::SortOrder current, Qt::SortOrder previous);
 321
 322     /**
 323      * Is emitted if the user has changed the sort role by clicking on a
 324      * header item (see KItemListView::setHeaderShown()). The sort role
 325      * of the model has already been adjusted to
 326      * the current sort role. Note that no signal will be emitted if the
 327      * sort role of the model has been changed without user interaction.
 328      */
 329     void sortRoleChanged(const QByteArray &current, const QByteArray &previous);
 330
 331     /**
 332      * Is emitted if the user has changed the visible roles by moving a header
 333      * item (see KItemListView::setHeaderShown()). Note that no signal will be
 334      * emitted if the roles have been changed without user interaction by
 335      * KItemListView::setVisibleRoles().
 336      */
 337     void visibleRolesChanged(const QList<QByteArray> &current, const QList<QByteArray> &previous);
 338
 339     void roleEditingCanceled(int index, const QByteArray &role, const QVariant &value);
 340     void roleEditingFinished(int index, const QByteArray &role, const QVariant &value);
 341
 342     /**
 343      * Emitted once scrolling has finished, or immediately if no scrolling was necessary
 344      * to get item in view in scrollToItem.
 345      */
 346     void scrollingStopped();
 347
 348     void columnHovered(int roleIndex);
 349     void columnUnHovered(int roleIndex);
 350
 351 protected:
 352     QVariant itemChange(GraphicsItemChange change, const QVariant &value) override;
 353     void setItemSize(const QSizeF &size);
 354     void setStyleOption(const KItemListStyleOption &option);
 355
 356     /**
 357      * If the scroll-orientation is vertical, the items are ordered
 358      * from top to bottom (= default setting). If the scroll-orientation
 359      * is horizontal, the items are ordered from left to right.
 360      */
 361     void setScrollOrientation(Qt::Orientation orientation);
 362     Qt::Orientation scrollOrientation() const;
 363
 364     /**
 365      * Factory method for creating a default widget-creator. The method will be used
 366      * in case if setWidgetCreator() has not been set by the application.
 367      * @return New instance of the widget-creator that should be used per
 368      *         default.
 369      */
 370     virtual KItemListWidgetCreatorBase *defaultWidgetCreator() const;
 371
 372     /**
 373      * Factory method for creating a default group-header-creator. The method will be used
 374      * in case if setGroupHeaderCreator() has not been set by the application.
 375      * @return New instance of the group-header-creator that should be used per
 376      *         default.
 377      */
 378     virtual KItemListGroupHeaderCreatorBase *defaultGroupHeaderCreator() const;
 379
 380     /**
 381      * Is called when creating a new KItemListWidget instance and allows derived
 382      * classes to do a custom initialization.
 383      */
 384     virtual void initializeItemListWidget(KItemListWidget *item);
 385
 386     /**
 387      * @return True if at least one of the changed roles \p changedRoles might result
 388      *         in the need to update the item-size hint (see KItemListView::itemSizeHint()).
 389      *         Per default true is returned which means on each role-change of existing items
 390      *         the item-size hints are recalculated. For performance reasons it is recommended
 391      *         to return false in case if a role-change will not result in a changed
 392      *         item-size hint.
 393      */
 394     virtual bool itemSizeHintUpdateRequired(const QSet<QByteArray> &changedRoles) const;
 395
 396     virtual void onControllerChanged(KItemListController *current, KItemListController *previous);
 397     virtual void onModelChanged(KItemModelBase *current, KItemModelBase *previous);
 398
 399     virtual void onScrollOrientationChanged(Qt::Orientation current, Qt::Orientation previous);
 400     virtual void onItemSizeChanged(const QSizeF &current, const QSizeF &previous);
 401     virtual void onScrollOffsetChanged(qreal current, qreal previous);
 402     virtual void onVisibleRolesChanged(const QList<QByteArray> &current, const QList<QByteArray> &previous);
 403     virtual void onStyleOptionChanged(const KItemListStyleOption &current, const KItemListStyleOption &previous);
 404     virtual void onHighlightEntireRowChanged(bool highlightEntireRow);
 405     virtual void onSupportsItemExpandingChanged(bool supportsExpanding);
 406
 407     virtual void onTransactionBegin();
 408     virtual void onTransactionEnd();
 409
 410     bool event(QEvent *event) override;
 411     void mousePressEvent(QGraphicsSceneMouseEvent *event) override;
 412     void mouseMoveEvent(QGraphicsSceneMouseEvent *event) override;
 413     void dragEnterEvent(QGraphicsSceneDragDropEvent *event) override;
 414     void dragMoveEvent(QGraphicsSceneDragDropEvent *event) override;
 415     void dragLeaveEvent(QGraphicsSceneDragDropEvent *event) override;
 416     void dropEvent(QGraphicsSceneDragDropEvent *event) override;
 417
 418     QList<KItemListWidget *> visibleItemListWidgets() const;
 419
 420     virtual void updateFont();
 421     virtual void updatePalette();
 422
 423 protected Q_SLOTS:
 424     virtual void slotItemsInserted(const KItemRangeList &itemRanges);
 425     virtual void slotItemsRemoved(const KItemRangeList &itemRanges);
 426     virtual void slotItemsMoved(const KItemRange &itemRange, const QList<int> &movedToIndexes);
 427     virtual void slotItemsChanged(const KItemRangeList &itemRanges, const QSet<QByteArray> &roles);
 428     virtual void slotGroupsChanged();
 429
 430     virtual void slotGroupedSortingChanged(bool current);
 431     virtual void slotSortOrderChanged(Qt::SortOrder current, Qt::SortOrder previous);
 432     virtual void slotSortRoleChanged(const QByteArray &current, const QByteArray &previous);
 433     virtual void slotGroupOrderChanged(Qt::SortOrder current, Qt::SortOrder previous);
 434     virtual void slotGroupRoleChanged(const QByteArray &current, const QByteArray &previous);
 435     virtual void slotCurrentChanged(int current, int previous);
 436     virtual void slotSelectionChanged(const KItemSet &current, const KItemSet &previous);
 437
 438 private Q_SLOTS:
 439     void slotAnimationFinished(QGraphicsWidget *widget, KItemListViewAnimation::AnimationType type);
 440
 441     void slotRubberBandPosChanged();
 442     void slotRubberBandActivationChanged(bool active);
 443
 444     /**
 445      * Is invoked if the column-width of one role in the header has
 446      * been changed by the user. The automatic resizing of columns
 447      * will be turned off as soon as this method has been called at
 448      * least once.
 449      */
 450     void slotHeaderColumnWidthChanged(const QByteArray &role, qreal currentWidth, qreal previousWidth);
 451
 452     void slotSidePaddingChanged(qreal width);
 453
 454     /**
 455      * Is invoked if a column has been moved by the user. Applies
 456      * the moved role to the view.
 457      */
 458     void slotHeaderColumnMoved(const QByteArray &role, int currentIndex, int previousIndex);
 459
 460     /**
 461      * Triggers the autoscrolling if autoScroll() is enabled by checking the
 462      * current mouse position. If the mouse position is within the autoscroll
 463      * margins a timer will be started that periodically triggers the autoscrolling.
 464      */
 465     void triggerAutoScrolling();
 466
 467     /**
 468      * Is invoked if the geometry of the parent-widget from a group-header has been
 469      * changed. The x-position and width of the group-header gets adjusted to assure
 470      * that it always spans the whole width even during temporary transitions of the
 471      * parent widget.
 472      */
 473     void slotGeometryOfGroupHeaderParentChanged();
 474
 475     void slotRoleEditingCanceled(int index, const QByteArray &role, const QVariant &value);
 476     void slotRoleEditingFinished(int index, const QByteArray &role, const QVariant &value);
 477
 478 private:
 479     enum LayoutAnimationHint { NoAnimation, Animation };
 480
 481     enum SizeType { LayouterSize, ItemSize };
 482
 483     void setController(KItemListController *controller);
 484     void setModel(KItemModelBase *model);
 485
 486     KItemListRubberBand *rubberBand() const;
 487
 488     void doLayout(LayoutAnimationHint hint, int changedIndex = 0, int changedCount = 0);
 489
 490     /**
 491      * Helper method for doLayout: Returns a list of items that can be reused for the visible
 492      * area. Invisible group headers get recycled. The reusable items are items that are
 493      * invisible. If the animation hint is 'Animation' then items that are currently animated
 494      * won't be reused. Reusing items is faster in comparison to deleting invisible
 495      * items and creating a new instance for visible items.
 496      */
 497     QList<int> recycleInvisibleItems(int firstVisibleIndex, int lastVisibleIndex, LayoutAnimationHint hint);
 498
 499     /**
 500      * Helper method for doLayout: Starts a moving-animation for the widget to the given
 501      * new position. The moving-animation is only started if the new position is within
 502      * the same row or column, otherwise the create-animation is used instead.
 503      * @return True if the moving-animation has been applied.
 504      */
 505     bool moveWidget(KItemListWidget *widget, const QPointF &newPos);
 506
 507     void emitOffsetChanges();
 508
 509     KItemListWidget *createWidget(int index);
 510     void recycleWidget(KItemListWidget *widget);
 511
 512     /**
 513      * Changes the index of the widget to \a index and assures a consistent
 514      * update for m_visibleItems and m_visibleCells. The cell-information
 515      * for the new index will not be updated and be initialized as empty cell.
 516      */
 517     void setWidgetIndex(KItemListWidget *widget, int index);
 518
 519     /**
 520      * Changes the index of the widget to \a index. In opposite to
 521      * setWidgetIndex() the cell-information for the widget gets updated.
 522      * This update gives doLayout() the chance to animate the moving
 523      * of the item visually (see moveWidget()).
 524      */
 525     void moveWidgetToIndex(KItemListWidget *widget, int index);
 526
 527     /**
 528      * Helper method for prepareLayoutForIncreasedItemCount().
 529      */
 530     void setLayouterSize(const QSizeF &size, SizeType sizeType);
 531
 532     /**
 533      * Helper method for createWidget() and setWidgetIndex() to update the properties
 534      * of the itemlist widget.
 535      */
 536     void updateWidgetProperties(KItemListWidget *widget, int index);
 537
 538     /**
 539      * Helper method for updateWidgetPropertes() to create or update
 540      * the itemlist group-header.
 541      */
 542     void updateGroupHeaderForWidget(KItemListWidget *widget);
 543
 544     /**
 545      * Updates the position and size of the group-header that belongs
 546      * to the itemlist widget \a widget. The given widget must represent
 547      * the first item of a group.
 548      */
 549     void updateGroupHeaderLayout(KItemListWidget *widget);
 550
 551     /**
 552      * Recycles the group-header for the widget.
 553      */
 554     void recycleGroupHeaderForWidget(KItemListWidget *widget);
 555
 556     /**
 557      * Helper method for slotGroupedSortingChanged(), slotSortOrderChanged(),
 558      * slotSortRoleChanged(), slotGroupOrderChanged() and slotGroupRoleChanged():
 559      * Iterates through all visible items and updates
 560      * the group-header widgets.
 561      */
 562     void updateVisibleGroupHeaders();
 563
 564     /**
 565      * @return Index for the item in the list returned by KItemModelBase::groups()
 566      *         that represents the group where the item with the index \a index
 567      *         belongs to. -1 is returned if no groups are available.
 568      */
 569     int groupIndexForItem(int index) const;
 570
 571     /**
 572      * Updates the alternate background for all visible items.
 573      * @see updateAlternateBackgroundForWidget()
 574      */
 575     void updateAlternateBackgrounds();
 576
 577     /**
 578      * Updates the alternateBackground-property of the widget dependent
 579      * on the state of useAlternateBackgrounds() and the grouping state.
 580      */
 581     void updateAlternateBackgroundForWidget(KItemListWidget *widget);
 582
 583     /**
 584      * @return True if alternate backgrounds should be used for the items.
 585      *         This is the case if an empty item-size is given and if there
 586      *         is more than one visible role.
 587      */
 588     bool useAlternateBackgrounds() const;
 589
 590     /**
 591      * @param itemRanges Items that must be checked for getting the widths of columns.
 592      * @return           The preferred width of the column of each visible role. The width will
 593      *                   be respected if the width of the item size is <= 0 (see
 594      *                   KItemListView::setItemSize()). Per default an empty hash
 595      *                   is returned.
 596      */
 597     QHash<QByteArray, qreal> preferredColumnWidths(const KItemRangeList &itemRanges) const;
 598
 599     /**
 600      * Applies the column-widths from m_headerWidget to the layout
 601      * of the view.
 602      */
 603     void applyColumnWidthsFromHeader();
 604
 605     /**
 606      * Applies the column-widths from m_headerWidget to \a widget.
 607      */
 608     void updateWidgetColumnWidths(KItemListWidget *widget);
 609
 610     /**
 611      * Updates the preferred column-widths of m_groupHeaderWidget by
 612      * invoking KItemListView::columnWidths().
 613      */
 614     void updatePreferredColumnWidths(const KItemRangeList &itemRanges);
 615
 616     /**
 617      * Convenience method for
 618      * updatePreferredColumnWidths(KItemRangeList() << KItemRange(0, m_model->count()).
 619      */
 620     void updatePreferredColumnWidths();
 621
 622     /**
 623      * Resizes the column-widths of m_headerWidget based on the preferred widths
 624      * and the available view-size.
 625      */
 626     void applyAutomaticColumnWidths();
 627
 628     /**
 629      * @return Sum of the widths of all columns.
 630      */
 631     qreal columnWidthsSum() const;
 632
 633     /**
 634      * @return Boundaries of the header. An empty rectangle is returned
 635      *         if no header is shown.
 636      */
 637     QRectF headerBoundaries() const;
 638
 639     /**
 640      * @return True if the number of columns or rows will be changed when applying
 641      *         the new grid- and item-size. Used to determine whether an animation
 642      *         should be done when applying the new layout.
 643      */
 644     bool changesItemGridLayout(const QSizeF &newGridSize, const QSizeF &newItemSize, const QSizeF &newItemMargin) const;
 645
 646     /**
 647      * @param changedItemCount Number of inserted  or removed items.
 648      * @return                 True if the inserting or removing of items should be animated.
 649      *                         No animation should be done if the number of items is too large
 650      *                         to provide a pleasant animation.
 651      */
 652     bool animateChangedItemCount(int changedItemCount) const;
 653
 654     /**
 655      * @return True if a scrollbar for the given scroll-orientation is required
 656      *         when using a size of \p size for the view. Calling the method is rather
 657      *         expansive as a temporary relayout needs to be done.
 658      */
 659     bool scrollBarRequired(const QSizeF &size) const;
 660
 661     /**
 662      * Shows a drop-indicator between items dependent on the given
 663      * cursor position. The cursor position is relative to the upper left
 664      * edge of the view.
 665      * @return Index of the item where the dropping is done. An index of -1
 666      *         indicates that the item has been dropped after the last item.
 667      */
 668     int showDropIndicator(const QPointF &pos);
 669     void hideDropIndicator();
 670
 671     /**
 672      * Applies the height of the group header to the layouter. The height
 673      * depends on the used scroll orientation.
 674      */
 675     void updateGroupHeaderHeight();
 676
 677     /**
 678      * Updates the siblings-information for all visible items that are inside
 679      * the range of \p firstIndex and \p lastIndex. If firstIndex or lastIndex
 680      * is smaller than 0, the siblings-information for all visible items gets
 681      * updated.
 682      * @see KItemListWidget::setSiblingsInformation()
 683      */
 684     void updateSiblingsInformation(int firstIndex = -1, int lastIndex = -1);
 685
 686     /**
 687      * Helper method for updateExpansionIndicators().
 688      * @return True if the item with the index \a index has a sibling successor
 689      *         (= the item is not the last item of the current hierarchy).
 690      */
 691     bool hasSiblingSuccessor(int index) const;
 692
 693     /**
 694      * Helper method for slotRoleEditingCanceled() and slotRoleEditingFinished().
 695      * Disconnects the two Signals "roleEditingCanceled" and
 696      * "roleEditingFinished"
 697      */
 698     void disconnectRoleEditingSignals(int index);
 699
 700     /**
 701      * Helper function for triggerAutoScrolling().
 702      * @param pos    Logical position of the mouse relative to the range.
 703      * @param range  Range of the visible area.
 704      * @param oldInc Previous increment. Is used to assure that the increment
 705      *               increases only gradually.
 706      * @return Scroll increment that should be added to the offset().
 707      *         As soon as \a pos is inside the autoscroll-margin a
 708      *         value != 0 will be returned.
 709      */
 710     static int calculateAutoScrollingIncrement(int pos, int range, int oldInc);
 711
 712     /**
 713      * Helper functions for changesItemCount().
 714      * @return The number of items that fit into the available size by
 715      *         respecting the size of the item and the margin between the items.
 716      */
 717     static int itemsPerSize(qreal size, qreal itemSize, qreal itemMargin);
 718
 719 private:
 720     bool m_enabledSelectionToggles;
 721     bool m_grouped;
 722     bool m_highlightEntireRow;
 723     bool m_alternateBackgrounds;
 724     bool m_supportsItemExpanding;
 725     bool m_editingRole;
 726     int m_activeTransactions; // Counter for beginTransaction()/endTransaction()
 727     LayoutAnimationHint m_endTransactionAnimationHint;
 728
 729     QSizeF m_itemSize;
 730     KItemListController *m_controller;
 731     KItemModelBase *m_model;
 732     QList<QByteArray> m_visibleRoles;
 733     mutable KItemListWidgetCreatorBase *m_widgetCreator;
 734     mutable KItemListGroupHeaderCreatorBase *m_groupHeaderCreator;
 735 #ifndef QT_NO_ACCESSIBILITY
 736     /** The object that will be the parent of this classes QAccessibleInterface. */
 737     KItemListContainerAccessible *m_accessibleParent = nullptr;
 738 #endif
 739     KItemListStyleOption m_styleOption;
 740
 741     QHash<int, KItemListWidget *> m_visibleItems;
 742     QHash<KItemListWidget *, KItemListGroupHeader *> m_visibleGroups;
 743
 744     struct Cell {
 745         Cell()
 746             : column(-1)
 747             , row(-1)
 748         {
 749         }
 750         Cell(int c, int r)
 751             : column(c)
 752             , row(r)
 753         {
 754         }
 755         int column;
 756         int row;
 757     };
 758     QHash<int, Cell> m_visibleCells;
 759
 760     int m_scrollBarExtent;
 761     KItemListViewLayouter *m_layouter;
 762     KItemListViewAnimation *m_animation;
 763
 764     qreal m_oldScrollOffset;
 765     qreal m_oldMaximumScrollOffset;
 766     qreal m_oldItemOffset;
 767     qreal m_oldMaximumItemOffset;
 768
 769     bool m_skipAutoScrollForRubberBand;
 770     KItemListRubberBand *m_rubberBand;
 771     KItemListRubberBand *m_tapAndHoldIndicator;
 772
 773     QPointF m_mousePos;
 774     int m_autoScrollIncrement;
 775     QTimer *m_autoScrollTimer;
 776
 777     KItemListHeader *m_header;
 778     KItemListHeaderWidget *m_headerWidget;
 779
 780     QPropertyAnimation *m_indicatorAnimation;
 781
 782     // When dragging items into the view where the sort-role of the model
 783     // is empty, a visual indicator should be shown during dragging where
 784     // the dropping will happen. This indicator is specified by an index
 785     // of the item. -1 means that no indicator will be shown at all.
 786     // The m_dropIndicator is set by the KItemListController
 787     // by KItemListView::showDropIndicator() and KItemListView::hideDropIndicator().
 788     QRectF m_dropIndicator;
 789
 790     QList<QVariantAnimation *> m_rubberBandAnimations;
 791
 792     KItemListSizeHintResolver *m_sizeHintResolver;
 793
 794     friend class KItemListContainer; // Accesses scrollBarRequired()
 795     friend class KItemListHeader; // Accesses m_headerWidget
 796     friend class KItemListController;
 797     friend class KItemListControllerTest;
 798     friend class KItemListViewAccessible;
 799     friend class KItemListAccessibleCell;
 800 };
 801
 802 /**
 803  * Allows to do a fast logical creation and deletion of QGraphicsWidgets
 804  * by recycling existing QGraphicsWidgets instances. Is used by
 805  * KItemListWidgetCreatorBase and KItemListGroupHeaderCreatorBase.
 806  * @internal
 807  */
 808 class DOLPHIN_EXPORT KItemListCreatorBase
 809 {
 810 public:
 811     virtual ~KItemListCreatorBase();
 812
 813 protected:
 814     void addCreatedWidget(QGraphicsWidget *widget);
 815     void pushRecycleableWidget(QGraphicsWidget *widget);
 816     QGraphicsWidget *popRecycleableWidget();
 817
 818 private:
 819     QSet<QGraphicsWidget *> m_createdWidgets;
 820     QList<QGraphicsWidget *> m_recycleableWidgets;
 821 };
 822
 823 /**
 824  * @brief Base class for creating KItemListWidgets.
 825  *
 826  * It is recommended that applications simply use the KItemListWidgetCreator-template class.
 827  * For a custom implementation the methods create(), itemSizeHint() and preferredColumnWith()
 828  * must be reimplemented. The intention of the widget creator is to prevent repetitive and
 829  * expensive instantiations and deletions of KItemListWidgets by recycling existing widget
 830  * instances.
 831  */
 832 class DOLPHIN_EXPORT KItemListWidgetCreatorBase : public KItemListCreatorBase
 833 {
 834 public:
 835     ~KItemListWidgetCreatorBase() override;
 836
 837     virtual KItemListWidget *create(KItemListView *view) = 0;
 838
 839     virtual void recycle(KItemListWidget *widget);
 840
 841     virtual void calculateItemSizeHints(QVector<std::pair<qreal, bool>> &logicalHeightHints, qreal &logicalWidthHint, const KItemListView *view) const = 0;
 842
 843     virtual qreal preferredRoleColumnWidth(const QByteArray &role, int index, const KItemListView *view) const = 0;
 844 };
 845
 846 /**
 847  * @brief Template class for creating KItemListWidgets.
 848  */
 849 template<class T>
 850 class KItemListWidgetCreator : public KItemListWidgetCreatorBase
 851 {
 852 public:
 853     KItemListWidgetCreator();
 854     ~KItemListWidgetCreator() override;
 855
 856     KItemListWidget *create(KItemListView *view) override;
 857
 858     void calculateItemSizeHints(QVector<std::pair<qreal, bool>> &logicalHeightHints, qreal &logicalWidthHint, const KItemListView *view) const override;
 859
 860     qreal preferredRoleColumnWidth(const QByteArray &role, int index, const KItemListView *view) const override;
 861
 862 private:
 863     KItemListWidgetInformant *m_informant;
 864 };
 865
 866 template<class T>
 867 KItemListWidgetCreator<T>::KItemListWidgetCreator()
 868     : m_informant(T::createInformant())
 869 {
 870 }
 871
 872 template<class T>
 873 KItemListWidgetCreator<T>::~KItemListWidgetCreator()
 874 {
 875     delete m_informant;
 876 }
 877
 878 template<class T>
 879 KItemListWidget *KItemListWidgetCreator<T>::create(KItemListView *view)
 880 {
 881     KItemListWidget *widget = static_cast<KItemListWidget *>(popRecycleableWidget());
 882     if (!widget) {
 883         widget = new T(m_informant, view);
 884         addCreatedWidget(widget);
 885     }
 886     widget->setParentItem(view);
 887     return widget;
 888 }
 889
 890 template<class T>
 891 void KItemListWidgetCreator<T>::calculateItemSizeHints(QVector<std::pair<qreal, bool>> &logicalHeightHints,
 892                                                        qreal &logicalWidthHint,
 893                                                        const KItemListView *view) const
 894 {
 895     return m_informant->calculateItemSizeHints(logicalHeightHints, logicalWidthHint, view);
 896 }
 897
 898 template<class T>
 899 qreal KItemListWidgetCreator<T>::preferredRoleColumnWidth(const QByteArray &role, int index, const KItemListView *view) const
 900 {
 901     return m_informant->preferredRoleColumnWidth(role, index, view);
 902 }
 903
 904 /**
 905  * @brief Base class for creating KItemListGroupHeaders.
 906  *
 907  * It is recommended that applications simply use the KItemListGroupHeaderCreator-template class.
 908  * For a custom implementation the methods create() and recycle() must be reimplemented.
 909  * The intention of the group-header creator is to prevent repetitive and expensive instantiations and
 910  * deletions of KItemListGroupHeaders by recycling existing header instances.
 911  */
 912 class DOLPHIN_EXPORT KItemListGroupHeaderCreatorBase : public KItemListCreatorBase
 913 {
 914 public:
 915     ~KItemListGroupHeaderCreatorBase() override;
 916     virtual KItemListGroupHeader *create(KItemListView *view) = 0;
 917     virtual void recycle(KItemListGroupHeader *header);
 918 };
 919
 920 template<class T>
 921 class KItemListGroupHeaderCreator : public KItemListGroupHeaderCreatorBase
 922 {
 923 public:
 924     ~KItemListGroupHeaderCreator() override;
 925     KItemListGroupHeader *create(KItemListView *view) override;
 926 };
 927
 928 template<class T>
 929 KItemListGroupHeaderCreator<T>::~KItemListGroupHeaderCreator()
 930 {
 931 }
 932
 933 template<class T>
 934 KItemListGroupHeader *KItemListGroupHeaderCreator<T>::create(KItemListView *view)
 935 {
 936     KItemListGroupHeader *widget = static_cast<KItemListGroupHeader *>(popRecycleableWidget());
 937     if (!widget) {
 938         widget = new T(view);
 939         addCreatedWidget(widget);
 940     }
 941     return widget;
 942 }
 943
 944 #endif