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 slotCurrentChanged(int current, int previous);
 445     virtual void slotSelectionChanged(const KItemSet &current, const KItemSet &previous);
 446
 447 private Q_SLOTS:
 448     void slotAnimationFinished(QGraphicsWidget *widget, KItemListViewAnimation::AnimationType type);
 449
 450     void slotRubberBandPosChanged();
 451     void slotRubberBandActivationChanged(bool active);
 452
 453     /**
 454      * Is invoked if the column-width of one role in the header has
 455      * been changed by the user. The automatic resizing of columns
 456      * will be turned off as soon as this method has been called at
 457      * least once.
 458      */
 459     void slotHeaderColumnWidthChanged(const QByteArray &role, qreal currentWidth, qreal previousWidth);
 460
 461     void slotSidePaddingChanged(qreal width);
 462
 463     /**
 464      * Is invoked if a column has been moved by the user. Applies
 465      * the moved role to the view.
 466      */
 467     void slotHeaderColumnMoved(const QByteArray &role, int currentIndex, int previousIndex);
 468
 469     /**
 470      * Triggers the autoscrolling if autoScroll() is enabled by checking the
 471      * current mouse position. If the mouse position is within the autoscroll
 472      * margins a timer will be started that periodically triggers the autoscrolling.
 473      */
 474     void triggerAutoScrolling();
 475
 476     /**
 477      * Is invoked if the geometry of the parent-widget from a group-header has been
 478      * changed. The x-position and width of the group-header gets adjusted to assure
 479      * that it always spans the whole width even during temporary transitions of the
 480      * parent widget.
 481      */
 482     void slotGeometryOfGroupHeaderParentChanged();
 483
 484     void slotRoleEditingCanceled(int index, const QByteArray &role, const QVariant &value);
 485     void slotRoleEditingFinished(int index, const QByteArray &role, const QVariant &value);
 486
 487 private:
 488     enum LayoutAnimationHint { NoAnimation, Animation };
 489
 490     enum SizeType { LayouterSize, ItemSize };
 491
 492     void setController(KItemListController *controller);
 493     void setModel(KItemModelBase *model);
 494
 495     KItemListRubberBand *rubberBand() const;
 496
 497     void doLayout(LayoutAnimationHint hint, int changedIndex = 0, int changedCount = 0);
 498
 499     /**
 500      * Helper method for doLayout: Returns a list of items that can be reused for the visible
 501      * area. Invisible group headers get recycled. The reusable items are items that are
 502      * invisible. If the animation hint is 'Animation' then items that are currently animated
 503      * won't be reused. Reusing items is faster in comparison to deleting invisible
 504      * items and creating a new instance for visible items.
 505      */
 506     QList<int> recycleInvisibleItems(int firstVisibleIndex, int lastVisibleIndex, LayoutAnimationHint hint);
 507
 508     /**
 509      * Helper method for doLayout: Starts a moving-animation for the widget to the given
 510      * new position. The moving-animation is only started if the new position is within
 511      * the same row or column, otherwise the create-animation is used instead.
 512      * @return True if the moving-animation has been applied.
 513      */
 514     bool moveWidget(KItemListWidget *widget, const QPointF &newPos);
 515
 516     void emitOffsetChanges();
 517
 518     KItemListWidget *createWidget(int index);
 519     void recycleWidget(KItemListWidget *widget);
 520
 521     /**
 522      * Changes the index of the widget to \a index and assures a consistent
 523      * update for m_visibleItems and m_visibleCells. The cell-information
 524      * for the new index will not be updated and be initialized as empty cell.
 525      */
 526     void setWidgetIndex(KItemListWidget *widget, int index);
 527
 528     /**
 529      * Changes the index of the widget to \a index. In opposite to
 530      * setWidgetIndex() the cell-information for the widget gets updated.
 531      * This update gives doLayout() the chance to animate the moving
 532      * of the item visually (see moveWidget()).
 533      */
 534     void moveWidgetToIndex(KItemListWidget *widget, int index);
 535
 536     /**
 537      * Helper method for prepareLayoutForIncreasedItemCount().
 538      */
 539     void setLayouterSize(const QSizeF &size, SizeType sizeType);
 540
 541     /**
 542      * Helper method for createWidget() and setWidgetIndex() to update the properties
 543      * of the itemlist widget.
 544      */
 545     void updateWidgetProperties(KItemListWidget *widget, int index);
 546
 547     /**
 548      * Helper method for updateWidgetPropertes() to create or update
 549      * the itemlist group-header.
 550      */
 551     void updateGroupHeaderForWidget(KItemListWidget *widget);
 552
 553     /**
 554      * Updates the position and size of the group-header that belongs
 555      * to the itemlist widget \a widget. The given widget must represent
 556      * the first item of a group.
 557      */
 558     void updateGroupHeaderLayout(KItemListWidget *widget);
 559
 560     /**
 561      * Recycles the group-header for the widget.
 562      */
 563     void recycleGroupHeaderForWidget(KItemListWidget *widget);
 564
 565     /**
 566      * Helper method for slotGroupedSortingChanged(), slotSortOrderChanged()
 567      * and slotSortRoleChanged(): Iterates through all visible items and updates
 568      * the group-header widgets.
 569      */
 570     void updateVisibleGroupHeaders();
 571
 572     /**
 573      * @return Index for the item in the list returned by KItemModelBase::groups()
 574      *         that represents the group where the item with the index \a index
 575      *         belongs to. -1 is returned if no groups are available.
 576      */
 577     int groupIndexForItem(int index) const;
 578
 579     /**
 580      * Updates the alternate background for all visible items.
 581      * @see updateAlternateBackgroundForWidget()
 582      */
 583     void updateAlternateBackgrounds();
 584
 585     /**
 586      * Updates the alternateBackground-property of the widget dependent
 587      * on the state of useAlternateBackgrounds() and the grouping state.
 588      */
 589     void updateAlternateBackgroundForWidget(KItemListWidget *widget);
 590
 591     /**
 592      * @return True if alternate backgrounds should be used for the items.
 593      *         This is the case if an empty item-size is given and if there
 594      *         is more than one visible role.
 595      */
 596     bool useAlternateBackgrounds() const;
 597
 598     /**
 599      * @param itemRanges Items that must be checked for getting the widths of columns.
 600      * @return           The preferred width of the column of each visible role. The width will
 601      *                   be respected if the width of the item size is <= 0 (see
 602      *                   KItemListView::setItemSize()). Per default an empty hash
 603      *                   is returned.
 604      */
 605     QHash<QByteArray, qreal> preferredColumnWidths(const KItemRangeList &itemRanges) const;
 606
 607     /**
 608      * Applies the column-widths from m_headerWidget to the layout
 609      * of the view.
 610      */
 611     void applyColumnWidthsFromHeader();
 612
 613     /**
 614      * Applies the column-widths from m_headerWidget to \a widget.
 615      */
 616     void updateWidgetColumnWidths(KItemListWidget *widget);
 617
 618     /**
 619      * Updates the preferred column-widths of m_groupHeaderWidget by
 620      * invoking KItemListView::columnWidths().
 621      */
 622     void updatePreferredColumnWidths(const KItemRangeList &itemRanges);
 623
 624     /**
 625      * Convenience method for
 626      * updatePreferredColumnWidths(KItemRangeList() << KItemRange(0, m_model->count()).
 627      */
 628     void updatePreferredColumnWidths();
 629
 630     /**
 631      * Resizes the column-widths of m_headerWidget based on the preferred widths
 632      * and the available view-size.
 633      */
 634     void applyAutomaticColumnWidths();
 635
 636     /**
 637      * @return Sum of the widths of all columns.
 638      */
 639     qreal columnWidthsSum() const;
 640
 641     /**
 642      * @return Boundaries of the header. An empty rectangle is returned
 643      *         if no header is shown.
 644      */
 645     QRectF headerBoundaries() const;
 646
 647     /**
 648      * @return True if the number of columns or rows will be changed when applying
 649      *         the new grid- and item-size. Used to determine whether an animation
 650      *         should be done when applying the new layout.
 651      */
 652     bool changesItemGridLayout(const QSizeF &newGridSize, const QSizeF &newItemSize, const QSizeF &newItemMargin) const;
 653
 654     /**
 655      * @param changedItemCount Number of inserted  or removed items.
 656      * @return                 True if the inserting or removing of items should be animated.
 657      *                         No animation should be done if the number of items is too large
 658      *                         to provide a pleasant animation.
 659      */
 660     bool animateChangedItemCount(int changedItemCount) const;
 661
 662     /**
 663      * @return True if a scrollbar for the given scroll-orientation is required
 664      *         when using a size of \p size for the view. Calling the method is rather
 665      *         expansive as a temporary relayout needs to be done.
 666      */
 667     bool scrollBarRequired(const QSizeF &size) const;
 668
 669     /**
 670      * Shows a drop-indicator between items dependent on the given
 671      * cursor position. The cursor position is relative to the upper left
 672      * edge of the view.
 673      * @return Index of the item where the dropping is done. An index of -1
 674      *         indicates that the item has been dropped after the last item.
 675      */
 676     int showDropIndicator(const QPointF &pos);
 677     void hideDropIndicator();
 678
 679     /**
 680      * Applies the height of the group header to the layouter. The height
 681      * depends on the used scroll orientation.
 682      */
 683     void updateGroupHeaderHeight();
 684
 685     /**
 686      * Updates the siblings-information for all visible items that are inside
 687      * the range of \p firstIndex and \p lastIndex. If firstIndex or lastIndex
 688      * is smaller than 0, the siblings-information for all visible items gets
 689      * updated.
 690      * @see KItemListWidget::setSiblingsInformation()
 691      */
 692     void updateSiblingsInformation(int firstIndex = -1, int lastIndex = -1);
 693
 694     /**
 695      * Helper method for updateExpansionIndicators().
 696      * @return True if the item with the index \a index has a sibling successor
 697      *         (= the item is not the last item of the current hierarchy).
 698      */
 699     bool hasSiblingSuccessor(int index) const;
 700
 701     /**
 702      * Helper method for slotRoleEditingCanceled() and slotRoleEditingFinished().
 703      * Disconnects the two Signals "roleEditingCanceled" and
 704      * "roleEditingFinished"
 705      */
 706     void disconnectRoleEditingSignals(int index);
 707
 708     /**
 709      * Helper function for triggerAutoScrolling().
 710      * @param pos    Logical position of the mouse relative to the range.
 711      * @param range  Range of the visible area.
 712      * @param oldInc Previous increment. Is used to assure that the increment
 713      *               increases only gradually.
 714      * @return Scroll increment that should be added to the offset().
 715      *         As soon as \a pos is inside the autoscroll-margin a
 716      *         value != 0 will be returned.
 717      */
 718     static int calculateAutoScrollingIncrement(int pos, int range, int oldInc);
 719
 720     /**
 721      * Helper functions for changesItemCount().
 722      * @return The number of items that fit into the available size by
 723      *         respecting the size of the item and the margin between the items.
 724      */
 725     static int itemsPerSize(qreal size, qreal itemSize, qreal itemMargin);
 726
 727 private:
 728     bool m_enabledSelectionToggles;
 729     bool m_grouped;
 730     bool m_highlightEntireRow;
 731     bool m_alternateBackgrounds;
 732     bool m_supportsItemExpanding;
 733     bool m_editingRole;
 734     int m_activeTransactions; // Counter for beginTransaction()/endTransaction()
 735     LayoutAnimationHint m_endTransactionAnimationHint;
 736
 737     QSizeF m_itemSize;
 738     KItemListController *m_controller;
 739     KItemModelBase *m_model;
 740     QList<QByteArray> m_visibleRoles;
 741     mutable KItemListWidgetCreatorBase *m_widgetCreator;
 742     mutable KItemListGroupHeaderCreatorBase *m_groupHeaderCreator;
 743 #ifndef QT_NO_ACCESSIBILITY
 744     /** The object that will be the parent of this classes QAccessibleInterface. */
 745     KItemListContainerAccessible *m_accessibleParent = nullptr;
 746 #endif
 747     KItemListStyleOption m_styleOption;
 748
 749     QHash<int, KItemListWidget *> m_visibleItems;
 750     QHash<KItemListWidget *, KItemListGroupHeader *> m_visibleGroups;
 751
 752     struct Cell {
 753         Cell()
 754             : column(-1)
 755             , row(-1)
 756         {
 757         }
 758         Cell(int c, int r)
 759             : column(c)
 760             , row(r)
 761         {
 762         }
 763         int column;
 764         int row;
 765     };
 766     QHash<int, Cell> m_visibleCells;
 767
 768     int m_scrollBarExtent;
 769     KItemListViewLayouter *m_layouter;
 770     KItemListViewAnimation *m_animation;
 771
 772     qreal m_oldScrollOffset;
 773     qreal m_oldMaximumScrollOffset;
 774     qreal m_oldItemOffset;
 775     qreal m_oldMaximumItemOffset;
 776
 777     bool m_skipAutoScrollForRubberBand;
 778     KItemListRubberBand *m_rubberBand;
 779     KItemListRubberBand *m_tapAndHoldIndicator;
 780
 781     QPointF m_mousePos;
 782     int m_autoScrollIncrement;
 783     QTimer *m_autoScrollTimer;
 784
 785     KItemListHeader *m_header;
 786     KItemListHeaderWidget *m_headerWidget;
 787
 788     QPropertyAnimation *m_indicatorAnimation;
 789
 790     int m_statusBarOffset;
 791
 792     // When dragging items into the view where the sort-role of the model
 793     // is empty, a visual indicator should be shown during dragging where
 794     // the dropping will happen. This indicator is specified by an index
 795     // of the item. -1 means that no indicator will be shown at all.
 796     // The m_dropIndicator is set by the KItemListController
 797     // by KItemListView::showDropIndicator() and KItemListView::hideDropIndicator().
 798     QRectF m_dropIndicator;
 799
 800     QList<QVariantAnimation *> m_rubberBandAnimations;
 801
 802     KItemListSizeHintResolver *m_sizeHintResolver;
 803
 804     friend class KItemListContainer; // Accesses scrollBarRequired()
 805     friend class KItemListHeader; // Accesses m_headerWidget
 806     friend class KItemListController;
 807     friend class KItemListControllerTest;
 808     friend class KItemListViewAccessible;
 809     friend class KItemListDelegateAccessible;
 810
 811     friend class DolphinMainWindowTest;
 812 };
 813
 814 /**
 815  * Allows to do a fast logical creation and deletion of QGraphicsWidgets
 816  * by recycling existing QGraphicsWidgets instances. Is used by
 817  * KItemListWidgetCreatorBase and KItemListGroupHeaderCreatorBase.
 818  * @internal
 819  */
 820 class DOLPHIN_EXPORT KItemListCreatorBase
 821 {
 822 public:
 823     virtual ~KItemListCreatorBase();
 824
 825 protected:
 826     void addCreatedWidget(QGraphicsWidget *widget);
 827     void pushRecycleableWidget(QGraphicsWidget *widget);
 828     QGraphicsWidget *popRecycleableWidget();
 829
 830 private:
 831     QSet<QGraphicsWidget *> m_createdWidgets;
 832     QList<QGraphicsWidget *> m_recycleableWidgets;
 833 };
 834
 835 /**
 836  * @brief Base class for creating KItemListWidgets.
 837  *
 838  * It is recommended that applications simply use the KItemListWidgetCreator-template class.
 839  * For a custom implementation the methods create(), itemSizeHint() and preferredColumnWith()
 840  * must be reimplemented. The intention of the widget creator is to prevent repetitive and
 841  * expensive instantiations and deletions of KItemListWidgets by recycling existing widget
 842  * instances.
 843  */
 844 class DOLPHIN_EXPORT KItemListWidgetCreatorBase : public KItemListCreatorBase
 845 {
 846 public:
 847     ~KItemListWidgetCreatorBase() override;
 848
 849     virtual KItemListWidget *create(KItemListView *view) = 0;
 850
 851     virtual void recycle(KItemListWidget *widget);
 852
 853     virtual void calculateItemSizeHints(QVector<std::pair<qreal, bool>> &logicalHeightHints, qreal &logicalWidthHint, const KItemListView *view) const = 0;
 854
 855     virtual qreal preferredRoleColumnWidth(const QByteArray &role, int index, const KItemListView *view) const = 0;
 856 };
 857
 858 /**
 859  * @brief Template class for creating KItemListWidgets.
 860  */
 861 template<class T>
 862 class KItemListWidgetCreator : public KItemListWidgetCreatorBase
 863 {
 864 public:
 865     KItemListWidgetCreator();
 866     ~KItemListWidgetCreator() override;
 867
 868     KItemListWidget *create(KItemListView *view) override;
 869
 870     void calculateItemSizeHints(QVector<std::pair<qreal, bool>> &logicalHeightHints, qreal &logicalWidthHint, const KItemListView *view) const override;
 871
 872     qreal preferredRoleColumnWidth(const QByteArray &role, int index, const KItemListView *view) const override;
 873
 874 private:
 875     KItemListWidgetInformant *m_informant;
 876 };
 877
 878 template<class T>
 879 KItemListWidgetCreator<T>::KItemListWidgetCreator()
 880     : m_informant(T::createInformant())
 881 {
 882 }
 883
 884 template<class T>
 885 KItemListWidgetCreator<T>::~KItemListWidgetCreator()
 886 {
 887     delete m_informant;
 888 }
 889
 890 template<class T>
 891 KItemListWidget *KItemListWidgetCreator<T>::create(KItemListView *view)
 892 {
 893     KItemListWidget *widget = static_cast<KItemListWidget *>(popRecycleableWidget());
 894     if (!widget) {
 895         widget = new T(m_informant, view);
 896         addCreatedWidget(widget);
 897     }
 898     widget->setParentItem(view);
 899     return widget;
 900 }
 901
 902 template<class T>
 903 void KItemListWidgetCreator<T>::calculateItemSizeHints(QVector<std::pair<qreal, bool>> &logicalHeightHints,
 904                                                        qreal &logicalWidthHint,
 905                                                        const KItemListView *view) const
 906 {
 907     return m_informant->calculateItemSizeHints(logicalHeightHints, logicalWidthHint, view);
 908 }
 909
 910 template<class T>
 911 qreal KItemListWidgetCreator<T>::preferredRoleColumnWidth(const QByteArray &role, int index, const KItemListView *view) const
 912 {
 913     return m_informant->preferredRoleColumnWidth(role, index, view);
 914 }
 915
 916 /**
 917  * @brief Base class for creating KItemListGroupHeaders.
 918  *
 919  * It is recommended that applications simply use the KItemListGroupHeaderCreator-template class.
 920  * For a custom implementation the methods create() and recycle() must be reimplemented.
 921  * The intention of the group-header creator is to prevent repetitive and expensive instantiations and
 922  * deletions of KItemListGroupHeaders by recycling existing header instances.
 923  */
 924 class DOLPHIN_EXPORT KItemListGroupHeaderCreatorBase : public KItemListCreatorBase
 925 {
 926 public:
 927     ~KItemListGroupHeaderCreatorBase() override;
 928     virtual KItemListGroupHeader *create(KItemListView *view) = 0;
 929     virtual void recycle(KItemListGroupHeader *header);
 930 };
 931
 932 template<class T>
 933 class KItemListGroupHeaderCreator : public KItemListGroupHeaderCreatorBase
 934 {
 935 public:
 936     ~KItemListGroupHeaderCreator() override;
 937     KItemListGroupHeader *create(KItemListView *view) override;
 938 };
 939
 940 template<class T>
 941 KItemListGroupHeaderCreator<T>::~KItemListGroupHeaderCreator()
 942 {
 943 }
 944
 945 template<class T>
 946 KItemListGroupHeader *KItemListGroupHeaderCreator<T>::create(KItemListView *view)
 947 {
 948     KItemListGroupHeader *widget = static_cast<KItemListGroupHeader *>(popRecycleableWidget());
 949     if (!widget) {
 950         widget = new T(view);
 951         addCreatedWidget(widget);
 952     }
 953     return widget;
 954 }
 955
 956 #endif