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 The line step which should be used for the scroll by mouse wheel.
 180      */
 181     virtual qreal scrollSingleStep() const;
 182
 183     /**
 184      * @return Index of the item that is below the point \a pos.
 185      *         The position is relative to the upper right of
 186      *         the visible area. Only (at least partly) visible
 187      *         items are considered. std::nullopt is returned if
 188      *         no item is below the position.
 189      */
 190     std::optional<int> itemAt(const QPointF &pos) const;
 191     bool isAboveSelectionToggle(int index, const QPointF &pos) const;
 192     bool isAboveExpansionToggle(int index, const QPointF &pos) const;
 193     bool isAboveText(int index, const QPointF &pos) const;
 194
 195     /**
 196      * @return Index of the first item that is at least partly visible.
 197      *         -1 is returned if the model contains no items.
 198      */
 199     int firstVisibleIndex() const;
 200
 201     /**
 202      * @return Index of the last item that is at least partly visible.
 203      *         -1 is returned if the model contains no items.
 204      */
 205     int lastVisibleIndex() const;
 206
 207     /**
 208      * Calculates the required size for all items in the model.
 209      * It might be larger than KItemListView::itemSize().
 210      * In this case the layout grid will be stretched to assure an
 211      * unclipped item.
 212      *
 213      * @note the logical height (width) is actually the
 214      * width (height) if the scroll orientation is Qt::Vertical!
 215      */
 216     void calculateItemSizeHints(QVector<std::pair<qreal, bool>> &logicalHeightHints, qreal &logicalWidthHint) const;
 217
 218     /**
 219      * If set to true, items having child-items can be expanded to show the child-items as
 220      * part of the view. Per default the expanding of items is disabled. If expanding of
 221      * items is enabled, the methods KItemModelBase::setExpanded(), KItemModelBase::isExpanded(),
 222      * KItemModelBase::isExpandable() and KItemModelBase::expandedParentsCount()
 223      * must be reimplemented. The view-implementation
 224      * has to take care itself how to visually represent the expanded items provided
 225      * by the model.
 226      */
 227     void setSupportsItemExpanding(bool supportsExpanding);
 228     bool supportsItemExpanding() const;
 229
 230     void setHighlightEntireRow(bool highlightEntireRow);
 231     bool highlightEntireRow() const;
 232
 233     void setAlternateBackgrounds(bool alternate);
 234     bool alternateBackgrounds() const;
 235
 236     /**
 237      * @return The rectangle of the item relative to the top/left of
 238      *         the currently visible area (see KItemListView::offset()).
 239      */
 240     QRectF itemRect(int index) const;
 241
 242     /**
 243      * @return The context rectangle of the item relative to the top/left of
 244      *         the currently visible area (see KItemListView::offset()). The
 245      *         context rectangle is defined by the united rectangle of
 246      *         the icon rectangle and the text rectangle (see KItemListWidget::iconRect()
 247      *         and KItemListWidget::textRect()) and is useful as reference for e.g. aligning
 248      *         a tooltip or a context-menu for an item. Note that a context rectangle will
 249      *         only be returned for (at least partly) visible items. An empty rectangle will
 250      *         be returned for fully invisible items.
 251      */
 252     QRectF itemContextRect(int index) const;
 253
 254     /**
 255      * @return Whether or not the name of the file has been elided. At present this will
 256      *         only ever be true when in icons view.
 257      */
 258     bool isElided(int index) const;
 259
 260     /**
 261      * Scrolls to the item with the index \a index so that the item
 262      * will be fully visible. The item is positioned within the view
 263      * as specified by \a viewItemPosition.
 264      */
 265     void scrollToItem(int index, ViewItemPosition viewItemPosition = ViewItemPosition::Nearest);
 266
 267     /**
 268      * If several properties of KItemListView are changed synchronously, it is
 269      * recommended to encapsulate the calls between beginTransaction() and endTransaction().
 270      * This prevents unnecessary and expensive layout-calculations.
 271      */
 272     void beginTransaction();
 273
 274     /**
 275      * Counterpart to beginTransaction(). The layout changes will only be animated if
 276      * all property changes between beginTransaction() and endTransaction() support
 277      * animations.
 278      */
 279     void endTransaction();
 280
 281     bool isTransactionActive() const;
 282
 283     /**
 284      * Turns on the header if \p visible is true. Per default the
 285      * header is not visible. Usually the header is turned on when
 286      * showing a classic "table-view" to describe the shown columns.
 287      */
 288     void setHeaderVisible(bool visible);
 289     bool isHeaderVisible() const;
 290
 291     /**
 292      * @return Header of the list. The header is also available if it is not shown
 293      *         (see KItemListView::setHeaderShown()).
 294      */
 295     KItemListHeader *header() const;
 296
 297     /**
 298      * @return Pixmap that is used for a drag operation based on the
 299      *         items given by \a indexes.
 300      */
 301     virtual QPixmap createDragPixmap(const KItemSet &indexes) const;
 302
 303     /**
 304      * Lets the user edit the role \a role for item with the index \a index.
 305      */
 306     void editRole(int index, const QByteArray &role);
 307
 308     void paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget = nullptr) override;
 309
 310     /**
 311      * Set the bottom offset for moving the view so that the small overlayed statusbar
 312      * won't cover any items by accident.
 313      */
 314     void setStatusBarOffset(int offset);
 315
 316 Q_SIGNALS:
 317     void scrollOrientationChanged(Qt::Orientation current, Qt::Orientation previous);
 318     void scrollOffsetChanged(qreal current, qreal previous);
 319     void maximumScrollOffsetChanged(qreal current, qreal previous);
 320     void itemOffsetChanged(qreal current, qreal previous);
 321     void maximumItemOffsetChanged(qreal current, qreal previous);
 322     void scrollTo(qreal newOffset);
 323
 324     /**
 325      * Is emitted if the user has changed the sort order by clicking on a
 326      * header item (see KItemListView::setHeaderShown()). The sort order
 327      * of the model has already been adjusted to
 328      * the current sort order. Note that no signal will be emitted if the
 329      * sort order of the model has been changed without user interaction.
 330      */
 331     void sortOrderChanged(Qt::SortOrder current, Qt::SortOrder previous);
 332
 333     /**
 334      * Is emitted if the user has changed the sort role by clicking on a
 335      * header item (see KItemListView::setHeaderShown()). The sort role
 336      * of the model has already been adjusted to
 337      * the current sort role. Note that no signal will be emitted if the
 338      * sort role of the model has been changed without user interaction.
 339      */
 340     void sortRoleChanged(const QByteArray &current, const QByteArray &previous);
 341
 342     /**
 343      * Is emitted if the user has changed the visible roles by moving a header
 344      * item (see KItemListView::setHeaderShown()). Note that no signal will be
 345      * emitted if the roles have been changed without user interaction by
 346      * KItemListView::setVisibleRoles().
 347      */
 348     void visibleRolesChanged(const QList<QByteArray> &current, const QList<QByteArray> &previous);
 349
 350     void roleEditingCanceled(int index, const QByteArray &role, const QVariant &value);
 351     void roleEditingFinished(int index, const QByteArray &role, const QVariant &value);
 352
 353     /**
 354      * Emitted once scrolling has finished, or immediately if no scrolling was necessary
 355      * to get item in view in scrollToItem.
 356      */
 357     void scrollingStopped();
 358
 359     void columnHovered(int roleIndex);
 360     void columnUnHovered(int roleIndex);
 361
 362 protected:
 363     QVariant itemChange(GraphicsItemChange change, const QVariant &value) override;
 364     void setItemSize(const QSizeF &size);
 365     void setStyleOption(const KItemListStyleOption &option);
 366
 367     /**
 368      * If the scroll-orientation is vertical, the items are ordered
 369      * from top to bottom (= default setting). If the scroll-orientation
 370      * is horizontal, the items are ordered from left to right.
 371      */
 372     void setScrollOrientation(Qt::Orientation orientation);
 373     Qt::Orientation scrollOrientation() const;
 374
 375     /**
 376      * Factory method for creating a default widget-creator. The method will be used
 377      * in case if setWidgetCreator() has not been set by the application.
 378      * @return New instance of the widget-creator that should be used per
 379      *         default.
 380      */
 381     virtual KItemListWidgetCreatorBase *defaultWidgetCreator() const;
 382
 383     /**
 384      * Factory method for creating a default group-header-creator. The method will be used
 385      * in case if setGroupHeaderCreator() has not been set by the application.
 386      * @return New instance of the group-header-creator that should be used per
 387      *         default.
 388      */
 389     virtual KItemListGroupHeaderCreatorBase *defaultGroupHeaderCreator() const;
 390
 391     /**
 392      * Is called when creating a new KItemListWidget instance and allows derived
 393      * classes to do a custom initialization.
 394      */
 395     virtual void initializeItemListWidget(KItemListWidget *item);
 396
 397     /**
 398      * @return True if at least one of the changed roles \p changedRoles might result
 399      *         in the need to update the item-size hint (see KItemListView::itemSizeHint()).
 400      *         Per default true is returned which means on each role-change of existing items
 401      *         the item-size hints are recalculated. For performance reasons it is recommended
 402      *         to return false in case if a role-change will not result in a changed
 403      *         item-size hint.
 404      */
 405     virtual bool itemSizeHintUpdateRequired(const QSet<QByteArray> &changedRoles) const;
 406
 407     virtual void onControllerChanged(KItemListController *current, KItemListController *previous);
 408     virtual void onModelChanged(KItemModelBase *current, KItemModelBase *previous);
 409
 410     virtual void onScrollOrientationChanged(Qt::Orientation current, Qt::Orientation previous);
 411     virtual void onItemSizeChanged(const QSizeF &current, const QSizeF &previous);
 412     virtual void onScrollOffsetChanged(qreal current, qreal previous);
 413     virtual void onVisibleRolesChanged(const QList<QByteArray> &current, const QList<QByteArray> &previous);
 414     virtual void onStyleOptionChanged(const KItemListStyleOption &current, const KItemListStyleOption &previous);
 415     virtual void onHighlightEntireRowChanged(bool highlightEntireRow);
 416     virtual void onSupportsItemExpandingChanged(bool supportsExpanding);
 417
 418     virtual void onTransactionBegin();
 419     virtual void onTransactionEnd();
 420
 421     bool event(QEvent *event) override;
 422     void mousePressEvent(QGraphicsSceneMouseEvent *event) override;
 423     void mouseMoveEvent(QGraphicsSceneMouseEvent *event) override;
 424     void dragEnterEvent(QGraphicsSceneDragDropEvent *event) override;
 425     void dragMoveEvent(QGraphicsSceneDragDropEvent *event) override;
 426     void dragLeaveEvent(QGraphicsSceneDragDropEvent *event) override;
 427     void dropEvent(QGraphicsSceneDragDropEvent *event) override;
 428
 429     QList<KItemListWidget *> visibleItemListWidgets() const;
 430
 431     virtual void updateFont();
 432     virtual void updatePalette();
 433
 434 protected Q_SLOTS:
 435     virtual void slotItemsInserted(const KItemRangeList &itemRanges);
 436     virtual void slotItemsRemoved(const KItemRangeList &itemRanges);
 437     virtual void slotItemsMoved(const KItemRange &itemRange, const QList<int> &movedToIndexes);
 438     virtual void slotItemsChanged(const KItemRangeList &itemRanges, const QSet<QByteArray> &roles);
 439     virtual void slotGroupsChanged();
 440
 441     virtual void slotGroupedSortingChanged(bool current);
 442     virtual void slotSortOrderChanged(Qt::SortOrder current, Qt::SortOrder previous);
 443     virtual void slotSortRoleChanged(const QByteArray &current, const QByteArray &previous);
 444     virtual void slotGroupOrderChanged(Qt::SortOrder current, Qt::SortOrder previous);
 445     virtual void slotGroupRoleChanged(const QByteArray &current, const QByteArray &previous);
 446     virtual void slotCurrentChanged(int current, int previous);
 447     virtual void slotSelectionChanged(const KItemSet &current, const KItemSet &previous);
 448
 449 private Q_SLOTS:
 450     void slotAnimationFinished(QGraphicsWidget *widget, KItemListViewAnimation::AnimationType type);
 451
 452     void slotRubberBandPosChanged();
 453     void slotRubberBandActivationChanged(bool active);
 454
 455     /**
 456      * Is invoked if the column-width of one role in the header has
 457      * been changed by the user. The automatic resizing of columns
 458      * will be turned off as soon as this method has been called at
 459      * least once.
 460      */
 461     void slotHeaderColumnWidthChanged(const QByteArray &role, qreal currentWidth, qreal previousWidth);
 462
 463     void slotSidePaddingChanged(qreal width);
 464
 465     /**
 466      * Is invoked if a column has been moved by the user. Applies
 467      * the moved role to the view.
 468      */
 469     void slotHeaderColumnMoved(const QByteArray &role, int currentIndex, int previousIndex);
 470
 471     /**
 472      * Triggers the autoscrolling if autoScroll() is enabled by checking the
 473      * current mouse position. If the mouse position is within the autoscroll
 474      * margins a timer will be started that periodically triggers the autoscrolling.
 475      */
 476     void triggerAutoScrolling();
 477
 478     /**
 479      * Is invoked if the geometry of the parent-widget from a group-header has been
 480      * changed. The x-position and width of the group-header gets adjusted to assure
 481      * that it always spans the whole width even during temporary transitions of the
 482      * parent widget.
 483      */
 484     void slotGeometryOfGroupHeaderParentChanged();
 485
 486     void slotRoleEditingCanceled(int index, const QByteArray &role, const QVariant &value);
 487     void slotRoleEditingFinished(int index, const QByteArray &role, const QVariant &value);
 488
 489 private:
 490     enum LayoutAnimationHint { NoAnimation, Animation };
 491
 492     enum SizeType { LayouterSize, ItemSize };
 493
 494     void setController(KItemListController *controller);
 495     void setModel(KItemModelBase *model);
 496
 497     KItemListRubberBand *rubberBand() const;
 498
 499     void doLayout(LayoutAnimationHint hint, int changedIndex = 0, int changedCount = 0);
 500
 501     /**
 502      * Helper method for doLayout: Returns a list of items that can be reused for the visible
 503      * area. Invisible group headers get recycled. The reusable items are items that are
 504      * invisible. If the animation hint is 'Animation' then items that are currently animated
 505      * won't be reused. Reusing items is faster in comparison to deleting invisible
 506      * items and creating a new instance for visible items.
 507      */
 508     QList<int> recycleInvisibleItems(int firstVisibleIndex, int lastVisibleIndex, LayoutAnimationHint hint);
 509
 510     /**
 511      * Helper method for doLayout: Starts a moving-animation for the widget to the given
 512      * new position. The moving-animation is only started if the new position is within
 513      * the same row or column, otherwise the create-animation is used instead.
 514      * @return True if the moving-animation has been applied.
 515      */
 516     bool moveWidget(KItemListWidget *widget, const QPointF &newPos);
 517
 518     void emitOffsetChanges();
 519
 520     KItemListWidget *createWidget(int index);
 521     void recycleWidget(KItemListWidget *widget);
 522
 523     /**
 524      * Changes the index of the widget to \a index and assures a consistent
 525      * update for m_visibleItems and m_visibleCells. The cell-information
 526      * for the new index will not be updated and be initialized as empty cell.
 527      */
 528     void setWidgetIndex(KItemListWidget *widget, int index);
 529
 530     /**
 531      * Changes the index of the widget to \a index. In opposite to
 532      * setWidgetIndex() the cell-information for the widget gets updated.
 533      * This update gives doLayout() the chance to animate the moving
 534      * of the item visually (see moveWidget()).
 535      */
 536     void moveWidgetToIndex(KItemListWidget *widget, int index);
 537
 538     /**
 539      * Helper method for prepareLayoutForIncreasedItemCount().
 540      */
 541     void setLayouterSize(const QSizeF &size, SizeType sizeType);
 542
 543     /**
 544      * Helper method for createWidget() and setWidgetIndex() to update the properties
 545      * of the itemlist widget.
 546      */
 547     void updateWidgetProperties(KItemListWidget *widget, int index);
 548
 549     /**
 550      * Helper method for updateWidgetPropertes() to create or update
 551      * the itemlist group-header.
 552      */
 553     void updateGroupHeaderForWidget(KItemListWidget *widget);
 554
 555     /**
 556      * Updates the position and size of the group-header that belongs
 557      * to the itemlist widget \a widget. The given widget must represent
 558      * the first item of a group.
 559      */
 560     void updateGroupHeaderLayout(KItemListWidget *widget);
 561
 562     /**
 563      * Recycles the group-header for the widget.
 564      */
 565     void recycleGroupHeaderForWidget(KItemListWidget *widget);
 566
 567     /**
 568      * Helper method for slotGroupedSortingChanged(), slotSortOrderChanged(),
 569      * slotSortRoleChanged(), slotGroupOrderChanged() and slotGroupRoleChanged():
 570      * Iterates through all visible items and updates
 571      * the group-header widgets.
 572      */
 573     void updateVisibleGroupHeaders();
 574
 575     /**
 576      * @return Index for the item in the list returned by KItemModelBase::groups()
 577      *         that represents the group where the item with the index \a index
 578      *         belongs to. -1 is returned if no groups are available.
 579      */
 580     int groupIndexForItem(int index) const;
 581
 582     /**
 583      * Updates the alternate background for all visible items.
 584      * @see updateAlternateBackgroundForWidget()
 585      */
 586     void updateAlternateBackgrounds();
 587
 588     /**
 589      * Updates the alternateBackground-property of the widget dependent
 590      * on the state of useAlternateBackgrounds() and the grouping state.
 591      */
 592     void updateAlternateBackgroundForWidget(KItemListWidget *widget);
 593
 594     /**
 595      * @return True if alternate backgrounds should be used for the items.
 596      *         This is the case if an empty item-size is given and if there
 597      *         is more than one visible role.
 598      */
 599     bool useAlternateBackgrounds() const;
 600
 601     /**
 602      * @param itemRanges Items that must be checked for getting the widths of columns.
 603      * @return           The preferred width of the column of each visible role. The width will
 604      *                   be respected if the width of the item size is <= 0 (see
 605      *                   KItemListView::setItemSize()). Per default an empty hash
 606      *                   is returned.
 607      */
 608     QHash<QByteArray, qreal> preferredColumnWidths(const KItemRangeList &itemRanges) const;
 609
 610     /**
 611      * Applies the column-widths from m_headerWidget to the layout
 612      * of the view.
 613      */
 614     void applyColumnWidthsFromHeader();
 615
 616     /**
 617      * Applies the column-widths from m_headerWidget to \a widget.
 618      */
 619     void updateWidgetColumnWidths(KItemListWidget *widget);
 620
 621     /**
 622      * Updates the preferred column-widths of m_groupHeaderWidget by
 623      * invoking KItemListView::columnWidths().
 624      */
 625     void updatePreferredColumnWidths(const KItemRangeList &itemRanges);
 626
 627     /**
 628      * Convenience method for
 629      * updatePreferredColumnWidths(KItemRangeList() << KItemRange(0, m_model->count()).
 630      */
 631     void updatePreferredColumnWidths();
 632
 633     /**
 634      * Resizes the column-widths of m_headerWidget based on the preferred widths
 635      * and the available view-size.
 636      */
 637     void applyAutomaticColumnWidths();
 638
 639     /**
 640      * @return Sum of the widths of all columns.
 641      */
 642     qreal columnWidthsSum() const;
 643
 644     /**
 645      * @return Boundaries of the header. An empty rectangle is returned
 646      *         if no header is shown.
 647      */
 648     QRectF headerBoundaries() const;
 649
 650     /**
 651      * @return True if the number of columns or rows will be changed when applying
 652      *         the new grid- and item-size. Used to determine whether an animation
 653      *         should be done when applying the new layout.
 654      */
 655     bool changesItemGridLayout(const QSizeF &newGridSize, const QSizeF &newItemSize, const QSizeF &newItemMargin) const;
 656
 657     /**
 658      * @param changedItemCount Number of inserted  or removed items.
 659      * @return                 True if the inserting or removing of items should be animated.
 660      *                         No animation should be done if the number of items is too large
 661      *                         to provide a pleasant animation.
 662      */
 663     bool animateChangedItemCount(int changedItemCount) const;
 664
 665     /**
 666      * @return True if a scrollbar for the given scroll-orientation is required
 667      *         when using a size of \p size for the view. Calling the method is rather
 668      *         expansive as a temporary relayout needs to be done.
 669      */
 670     bool scrollBarRequired(const QSizeF &size) const;
 671
 672     /**
 673      * Shows a drop-indicator between items dependent on the given
 674      * cursor position. The cursor position is relative to the upper left
 675      * edge of the view.
 676      * @return Index of the item where the dropping is done. An index of -1
 677      *         indicates that the item has been dropped after the last item.
 678      */
 679     int showDropIndicator(const QPointF &pos);
 680     void hideDropIndicator();
 681
 682     /**
 683      * Applies the height of the group header to the layouter. The height
 684      * depends on the used scroll orientation.
 685      */
 686     void updateGroupHeaderHeight();
 687
 688     /**
 689      * Updates the siblings-information for all visible items that are inside
 690      * the range of \p firstIndex and \p lastIndex. If firstIndex or lastIndex
 691      * is smaller than 0, the siblings-information for all visible items gets
 692      * updated.
 693      * @see KItemListWidget::setSiblingsInformation()
 694      */
 695     void updateSiblingsInformation(int firstIndex = -1, int lastIndex = -1);
 696
 697     /**
 698      * Helper method for updateExpansionIndicators().
 699      * @return True if the item with the index \a index has a sibling successor
 700      *         (= the item is not the last item of the current hierarchy).
 701      */
 702     bool hasSiblingSuccessor(int index) const;
 703
 704     /**
 705      * Helper method for slotRoleEditingCanceled() and slotRoleEditingFinished().
 706      * Disconnects the two Signals "roleEditingCanceled" and
 707      * "roleEditingFinished"
 708      */
 709     void disconnectRoleEditingSignals(int index);
 710
 711     /**
 712      * Helper function for triggerAutoScrolling().
 713      * @param pos    Logical position of the mouse relative to the range.
 714      * @param range  Range of the visible area.
 715      * @param oldInc Previous increment. Is used to assure that the increment
 716      *               increases only gradually.
 717      * @return Scroll increment that should be added to the offset().
 718      *         As soon as \a pos is inside the autoscroll-margin a
 719      *         value != 0 will be returned.
 720      */
 721     static int calculateAutoScrollingIncrement(int pos, int range, int oldInc);
 722
 723     /**
 724      * Helper functions for changesItemCount().
 725      * @return The number of items that fit into the available size by
 726      *         respecting the size of the item and the margin between the items.
 727      */
 728     static int itemsPerSize(qreal size, qreal itemSize, qreal itemMargin);
 729
 730 private:
 731     bool m_enabledSelectionToggles;
 732     bool m_grouped;
 733     bool m_highlightEntireRow;
 734     bool m_alternateBackgrounds;
 735     bool m_supportsItemExpanding;
 736     bool m_editingRole;
 737     int m_activeTransactions; // Counter for beginTransaction()/endTransaction()
 738     LayoutAnimationHint m_endTransactionAnimationHint;
 739
 740     QSizeF m_itemSize;
 741     KItemListController *m_controller;
 742     KItemModelBase *m_model;
 743     QList<QByteArray> m_visibleRoles;
 744     mutable KItemListWidgetCreatorBase *m_widgetCreator;
 745     mutable KItemListGroupHeaderCreatorBase *m_groupHeaderCreator;
 746 #ifndef QT_NO_ACCESSIBILITY
 747     /** The object that will be the parent of this classes QAccessibleInterface. */
 748     KItemListContainerAccessible *m_accessibleParent = nullptr;
 749 #endif
 750     KItemListStyleOption m_styleOption;
 751
 752     QHash<int, KItemListWidget *> m_visibleItems;
 753     QHash<KItemListWidget *, KItemListGroupHeader *> m_visibleGroups;
 754
 755     struct Cell {
 756         Cell()
 757             : column(-1)
 758             , row(-1)
 759         {
 760         }
 761         Cell(int c, int r)
 762             : column(c)
 763             , row(r)
 764         {
 765         }
 766         int column;
 767         int row;
 768     };
 769     QHash<int, Cell> m_visibleCells;
 770
 771     int m_scrollBarExtent;
 772     KItemListViewLayouter *m_layouter;
 773     KItemListViewAnimation *m_animation;
 774
 775     qreal m_oldScrollOffset;
 776     qreal m_oldMaximumScrollOffset;
 777     qreal m_oldItemOffset;
 778     qreal m_oldMaximumItemOffset;
 779
 780     bool m_skipAutoScrollForRubberBand;
 781     KItemListRubberBand *m_rubberBand;
 782     KItemListRubberBand *m_tapAndHoldIndicator;
 783
 784     QPointF m_mousePos;
 785     int m_autoScrollIncrement;
 786     QTimer *m_autoScrollTimer;
 787
 788     KItemListHeader *m_header;
 789     KItemListHeaderWidget *m_headerWidget;
 790
 791     QPropertyAnimation *m_indicatorAnimation;
 792
 793     int m_statusBarOffset;
 794
 795     // When dragging items into the view where the sort-role of the model
 796     // is empty, a visual indicator should be shown during dragging where
 797     // the dropping will happen. This indicator is specified by an index
 798     // of the item. -1 means that no indicator will be shown at all.
 799     // The m_dropIndicator is set by the KItemListController
 800     // by KItemListView::showDropIndicator() and KItemListView::hideDropIndicator().
 801     QRectF m_dropIndicator;
 802
 803     QList<QVariantAnimation *> m_rubberBandAnimations;
 804
 805     KItemListSizeHintResolver *m_sizeHintResolver;
 806
 807     friend class KItemListContainer; // Accesses scrollBarRequired()
 808     friend class KItemListHeader; // Accesses m_headerWidget
 809     friend class KItemListController;
 810     friend class KItemListControllerTest;
 811     friend class KItemListViewAccessible;
 812     friend class KItemListDelegateAccessible;
 813
 814     friend class DolphinMainWindowTest;
 815 };
 816
 817 /**
 818  * Allows to do a fast logical creation and deletion of QGraphicsWidgets
 819  * by recycling existing QGraphicsWidgets instances. Is used by
 820  * KItemListWidgetCreatorBase and KItemListGroupHeaderCreatorBase.
 821  * @internal
 822  */
 823 class DOLPHIN_EXPORT KItemListCreatorBase
 824 {
 825 public:
 826     virtual ~KItemListCreatorBase();
 827
 828 protected:
 829     void addCreatedWidget(QGraphicsWidget *widget);
 830     void pushRecycleableWidget(QGraphicsWidget *widget);
 831     QGraphicsWidget *popRecycleableWidget();
 832
 833 private:
 834     QSet<QGraphicsWidget *> m_createdWidgets;
 835     QList<QGraphicsWidget *> m_recycleableWidgets;
 836 };
 837
 838 /**
 839  * @brief Base class for creating KItemListWidgets.
 840  *
 841  * It is recommended that applications simply use the KItemListWidgetCreator-template class.
 842  * For a custom implementation the methods create(), itemSizeHint() and preferredColumnWith()
 843  * must be reimplemented. The intention of the widget creator is to prevent repetitive and
 844  * expensive instantiations and deletions of KItemListWidgets by recycling existing widget
 845  * instances.
 846  */
 847 class DOLPHIN_EXPORT KItemListWidgetCreatorBase : public KItemListCreatorBase
 848 {
 849 public:
 850     ~KItemListWidgetCreatorBase() override;
 851
 852     virtual KItemListWidget *create(KItemListView *view) = 0;
 853
 854     virtual void recycle(KItemListWidget *widget);
 855
 856     virtual void calculateItemSizeHints(QVector<std::pair<qreal, bool>> &logicalHeightHints, qreal &logicalWidthHint, const KItemListView *view) const = 0;
 857
 858     virtual qreal preferredRoleColumnWidth(const QByteArray &role, int index, const KItemListView *view) const = 0;
 859 };
 860
 861 /**
 862  * @brief Template class for creating KItemListWidgets.
 863  */
 864 template<class T>
 865 class KItemListWidgetCreator : public KItemListWidgetCreatorBase
 866 {
 867 public:
 868     KItemListWidgetCreator();
 869     ~KItemListWidgetCreator() override;
 870
 871     KItemListWidget *create(KItemListView *view) override;
 872
 873     void calculateItemSizeHints(QVector<std::pair<qreal, bool>> &logicalHeightHints, qreal &logicalWidthHint, const KItemListView *view) const override;
 874
 875     qreal preferredRoleColumnWidth(const QByteArray &role, int index, const KItemListView *view) const override;
 876
 877 private:
 878     KItemListWidgetInformant *m_informant;
 879 };
 880
 881 template<class T>
 882 KItemListWidgetCreator<T>::KItemListWidgetCreator()
 883     : m_informant(T::createInformant())
 884 {
 885 }
 886
 887 template<class T>
 888 KItemListWidgetCreator<T>::~KItemListWidgetCreator()
 889 {
 890     delete m_informant;
 891 }
 892
 893 template<class T>
 894 KItemListWidget *KItemListWidgetCreator<T>::create(KItemListView *view)
 895 {
 896     KItemListWidget *widget = static_cast<KItemListWidget *>(popRecycleableWidget());
 897     if (!widget) {
 898         widget = new T(m_informant, view);
 899         addCreatedWidget(widget);
 900     }
 901     widget->setParentItem(view);
 902     return widget;
 903 }
 904
 905 template<class T>
 906 void KItemListWidgetCreator<T>::calculateItemSizeHints(QVector<std::pair<qreal, bool>> &logicalHeightHints,
 907                                                        qreal &logicalWidthHint,
 908                                                        const KItemListView *view) const
 909 {
 910     return m_informant->calculateItemSizeHints(logicalHeightHints, logicalWidthHint, view);
 911 }
 912
 913 template<class T>
 914 qreal KItemListWidgetCreator<T>::preferredRoleColumnWidth(const QByteArray &role, int index, const KItemListView *view) const
 915 {
 916     return m_informant->preferredRoleColumnWidth(role, index, view);
 917 }
 918
 919 /**
 920  * @brief Base class for creating KItemListGroupHeaders.
 921  *
 922  * It is recommended that applications simply use the KItemListGroupHeaderCreator-template class.
 923  * For a custom implementation the methods create() and recycle() must be reimplemented.
 924  * The intention of the group-header creator is to prevent repetitive and expensive instantiations and
 925  * deletions of KItemListGroupHeaders by recycling existing header instances.
 926  */
 927 class DOLPHIN_EXPORT KItemListGroupHeaderCreatorBase : public KItemListCreatorBase
 928 {
 929 public:
 930     ~KItemListGroupHeaderCreatorBase() override;
 931     virtual KItemListGroupHeader *create(KItemListView *view) = 0;
 932     virtual void recycle(KItemListGroupHeader *header);
 933 };
 934
 935 template<class T>
 936 class KItemListGroupHeaderCreator : public KItemListGroupHeaderCreatorBase
 937 {
 938 public:
 939     ~KItemListGroupHeaderCreator() override;
 940     KItemListGroupHeader *create(KItemListView *view) override;
 941 };
 942
 943 template<class T>
 944 KItemListGroupHeaderCreator<T>::~KItemListGroupHeaderCreator()
 945 {
 946 }
 947
 948 template<class T>
 949 KItemListGroupHeader *KItemListGroupHeaderCreator<T>::create(KItemListView *view)
 950 {
 951     KItemListGroupHeader *widget = static_cast<KItemListGroupHeader *>(popRecycleableWidget());
 952     if (!widget) {
 953         widget = new T(view);
 954         addCreatedWidget(widget);
 955     }
 956     return widget;
 957 }
 958
 959 #endif