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 slotCurrentChanged(int current, int previous);
 434     virtual void slotSelectionChanged(const KItemSet &current, const KItemSet &previous);
 435
 436 private Q_SLOTS:
 437     void slotAnimationFinished(QGraphicsWidget *widget, KItemListViewAnimation::AnimationType type);
 438
 439     void slotRubberBandPosChanged();
 440     void slotRubberBandActivationChanged(bool active);
 441
 442     /**
 443      * Is invoked if the column-width of one role in the header has
 444      * been changed by the user. The automatic resizing of columns
 445      * will be turned off as soon as this method has been called at
 446      * least once.
 447      */
 448     void slotHeaderColumnWidthChanged(const QByteArray &role, qreal currentWidth, qreal previousWidth);
 449
 450     void slotSidePaddingChanged(qreal width);
 451
 452     /**
 453      * Is invoked if a column has been moved by the user. Applies
 454      * the moved role to the view.
 455      */
 456     void slotHeaderColumnMoved(const QByteArray &role, int currentIndex, int previousIndex);
 457
 458     /**
 459      * Triggers the autoscrolling if autoScroll() is enabled by checking the
 460      * current mouse position. If the mouse position is within the autoscroll
 461      * margins a timer will be started that periodically triggers the autoscrolling.
 462      */
 463     void triggerAutoScrolling();
 464
 465     /**
 466      * Is invoked if the geometry of the parent-widget from a group-header has been
 467      * changed. The x-position and width of the group-header gets adjusted to assure
 468      * that it always spans the whole width even during temporary transitions of the
 469      * parent widget.
 470      */
 471     void slotGeometryOfGroupHeaderParentChanged();
 472
 473     void slotRoleEditingCanceled(int index, const QByteArray &role, const QVariant &value);
 474     void slotRoleEditingFinished(int index, const QByteArray &role, const QVariant &value);
 475
 476 private:
 477     enum LayoutAnimationHint { NoAnimation, Animation };
 478
 479     enum SizeType { LayouterSize, ItemSize };
 480
 481     void setController(KItemListController *controller);
 482     void setModel(KItemModelBase *model);
 483
 484     KItemListRubberBand *rubberBand() const;
 485
 486     void doLayout(LayoutAnimationHint hint, int changedIndex = 0, int changedCount = 0);
 487
 488     /**
 489      * Helper method for doLayout: Returns a list of items that can be reused for the visible
 490      * area. Invisible group headers get recycled. The reusable items are items that are
 491      * invisible. If the animation hint is 'Animation' then items that are currently animated
 492      * won't be reused. Reusing items is faster in comparison to deleting invisible
 493      * items and creating a new instance for visible items.
 494      */
 495     QList<int> recycleInvisibleItems(int firstVisibleIndex, int lastVisibleIndex, LayoutAnimationHint hint);
 496
 497     /**
 498      * Helper method for doLayout: Starts a moving-animation for the widget to the given
 499      * new position. The moving-animation is only started if the new position is within
 500      * the same row or column, otherwise the create-animation is used instead.
 501      * @return True if the moving-animation has been applied.
 502      */
 503     bool moveWidget(KItemListWidget *widget, const QPointF &newPos);
 504
 505     void emitOffsetChanges();
 506
 507     KItemListWidget *createWidget(int index);
 508     void recycleWidget(KItemListWidget *widget);
 509
 510     /**
 511      * Changes the index of the widget to \a index and assures a consistent
 512      * update for m_visibleItems and m_visibleCells. The cell-information
 513      * for the new index will not be updated and be initialized as empty cell.
 514      */
 515     void setWidgetIndex(KItemListWidget *widget, int index);
 516
 517     /**
 518      * Changes the index of the widget to \a index. In opposite to
 519      * setWidgetIndex() the cell-information for the widget gets updated.
 520      * This update gives doLayout() the chance to animate the moving
 521      * of the item visually (see moveWidget()).
 522      */
 523     void moveWidgetToIndex(KItemListWidget *widget, int index);
 524
 525     /**
 526      * Helper method for prepareLayoutForIncreasedItemCount().
 527      */
 528     void setLayouterSize(const QSizeF &size, SizeType sizeType);
 529
 530     /**
 531      * Helper method for createWidget() and setWidgetIndex() to update the properties
 532      * of the itemlist widget.
 533      */
 534     void updateWidgetProperties(KItemListWidget *widget, int index);
 535
 536     /**
 537      * Helper method for updateWidgetPropertes() to create or update
 538      * the itemlist group-header.
 539      */
 540     void updateGroupHeaderForWidget(KItemListWidget *widget);
 541
 542     /**
 543      * Updates the position and size of the group-header that belongs
 544      * to the itemlist widget \a widget. The given widget must represent
 545      * the first item of a group.
 546      */
 547     void updateGroupHeaderLayout(KItemListWidget *widget);
 548
 549     /**
 550      * Recycles the group-header for the widget.
 551      */
 552     void recycleGroupHeaderForWidget(KItemListWidget *widget);
 553
 554     /**
 555      * Helper method for slotGroupedSortingChanged(), slotSortOrderChanged()
 556      * and slotSortRoleChanged(): Iterates through all visible items and updates
 557      * the group-header widgets.
 558      */
 559     void updateVisibleGroupHeaders();
 560
 561     /**
 562      * @return Index for the item in the list returned by KItemModelBase::groups()
 563      *         that represents the group where the item with the index \a index
 564      *         belongs to. -1 is returned if no groups are available.
 565      */
 566     int groupIndexForItem(int index) const;
 567
 568     /**
 569      * Updates the alternate background for all visible items.
 570      * @see updateAlternateBackgroundForWidget()
 571      */
 572     void updateAlternateBackgrounds();
 573
 574     /**
 575      * Updates the alternateBackground-property of the widget dependent
 576      * on the state of useAlternateBackgrounds() and the grouping state.
 577      */
 578     void updateAlternateBackgroundForWidget(KItemListWidget *widget);
 579
 580     /**
 581      * @return True if alternate backgrounds should be used for the items.
 582      *         This is the case if an empty item-size is given and if there
 583      *         is more than one visible role.
 584      */
 585     bool useAlternateBackgrounds() const;
 586
 587     /**
 588      * @param itemRanges Items that must be checked for getting the widths of columns.
 589      * @return           The preferred width of the column of each visible role. The width will
 590      *                   be respected if the width of the item size is <= 0 (see
 591      *                   KItemListView::setItemSize()). Per default an empty hash
 592      *                   is returned.
 593      */
 594     QHash<QByteArray, qreal> preferredColumnWidths(const KItemRangeList &itemRanges) const;
 595
 596     /**
 597      * Applies the column-widths from m_headerWidget to the layout
 598      * of the view.
 599      */
 600     void applyColumnWidthsFromHeader();
 601
 602     /**
 603      * Applies the column-widths from m_headerWidget to \a widget.
 604      */
 605     void updateWidgetColumnWidths(KItemListWidget *widget);
 606
 607     /**
 608      * Updates the preferred column-widths of m_groupHeaderWidget by
 609      * invoking KItemListView::columnWidths().
 610      */
 611     void updatePreferredColumnWidths(const KItemRangeList &itemRanges);
 612
 613     /**
 614      * Convenience method for
 615      * updatePreferredColumnWidths(KItemRangeList() << KItemRange(0, m_model->count()).
 616      */
 617     void updatePreferredColumnWidths();
 618
 619     /**
 620      * Resizes the column-widths of m_headerWidget based on the preferred widths
 621      * and the available view-size.
 622      */
 623     void applyAutomaticColumnWidths();
 624
 625     /**
 626      * @return Sum of the widths of all columns.
 627      */
 628     qreal columnWidthsSum() const;
 629
 630     /**
 631      * @return Boundaries of the header. An empty rectangle is returned
 632      *         if no header is shown.
 633      */
 634     QRectF headerBoundaries() const;
 635
 636     /**
 637      * @return True if the number of columns or rows will be changed when applying
 638      *         the new grid- and item-size. Used to determine whether an animation
 639      *         should be done when applying the new layout.
 640      */
 641     bool changesItemGridLayout(const QSizeF &newGridSize, const QSizeF &newItemSize, const QSizeF &newItemMargin) const;
 642
 643     /**
 644      * @param changedItemCount Number of inserted  or removed items.
 645      * @return                 True if the inserting or removing of items should be animated.
 646      *                         No animation should be done if the number of items is too large
 647      *                         to provide a pleasant animation.
 648      */
 649     bool animateChangedItemCount(int changedItemCount) const;
 650
 651     /**
 652      * @return True if a scrollbar for the given scroll-orientation is required
 653      *         when using a size of \p size for the view. Calling the method is rather
 654      *         expansive as a temporary relayout needs to be done.
 655      */
 656     bool scrollBarRequired(const QSizeF &size) const;
 657
 658     /**
 659      * Shows a drop-indicator between items dependent on the given
 660      * cursor position. The cursor position is relative to the upper left
 661      * edge of the view.
 662      * @return Index of the item where the dropping is done. An index of -1
 663      *         indicates that the item has been dropped after the last item.
 664      */
 665     int showDropIndicator(const QPointF &pos);
 666     void hideDropIndicator();
 667
 668     /**
 669      * Applies the height of the group header to the layouter. The height
 670      * depends on the used scroll orientation.
 671      */
 672     void updateGroupHeaderHeight();
 673
 674     /**
 675      * Updates the siblings-information for all visible items that are inside
 676      * the range of \p firstIndex and \p lastIndex. If firstIndex or lastIndex
 677      * is smaller than 0, the siblings-information for all visible items gets
 678      * updated.
 679      * @see KItemListWidget::setSiblingsInformation()
 680      */
 681     void updateSiblingsInformation(int firstIndex = -1, int lastIndex = -1);
 682
 683     /**
 684      * Helper method for updateExpansionIndicators().
 685      * @return True if the item with the index \a index has a sibling successor
 686      *         (= the item is not the last item of the current hierarchy).
 687      */
 688     bool hasSiblingSuccessor(int index) const;
 689
 690     /**
 691      * Helper method for slotRoleEditingCanceled() and slotRoleEditingFinished().
 692      * Disconnects the two Signals "roleEditingCanceled" and
 693      * "roleEditingFinished"
 694      */
 695     void disconnectRoleEditingSignals(int index);
 696
 697     /**
 698      * Helper function for triggerAutoScrolling().
 699      * @param pos    Logical position of the mouse relative to the range.
 700      * @param range  Range of the visible area.
 701      * @param oldInc Previous increment. Is used to assure that the increment
 702      *               increases only gradually.
 703      * @return Scroll increment that should be added to the offset().
 704      *         As soon as \a pos is inside the autoscroll-margin a
 705      *         value != 0 will be returned.
 706      */
 707     static int calculateAutoScrollingIncrement(int pos, int range, int oldInc);
 708
 709     /**
 710      * Helper functions for changesItemCount().
 711      * @return The number of items that fit into the available size by
 712      *         respecting the size of the item and the margin between the items.
 713      */
 714     static int itemsPerSize(qreal size, qreal itemSize, qreal itemMargin);
 715
 716 private:
 717     bool m_enabledSelectionToggles;
 718     bool m_grouped;
 719     bool m_highlightEntireRow;
 720     bool m_alternateBackgrounds;
 721     bool m_supportsItemExpanding;
 722     bool m_editingRole;
 723     int m_activeTransactions; // Counter for beginTransaction()/endTransaction()
 724     LayoutAnimationHint m_endTransactionAnimationHint;
 725
 726     QSizeF m_itemSize;
 727     KItemListController *m_controller;
 728     KItemModelBase *m_model;
 729     QList<QByteArray> m_visibleRoles;
 730     mutable KItemListWidgetCreatorBase *m_widgetCreator;
 731     mutable KItemListGroupHeaderCreatorBase *m_groupHeaderCreator;
 732 #ifndef QT_NO_ACCESSIBILITY
 733     /** The object that will be the parent of this classes QAccessibleInterface. */
 734     KItemListContainerAccessible *m_accessibleParent = nullptr;
 735 #endif
 736     KItemListStyleOption m_styleOption;
 737
 738     QHash<int, KItemListWidget *> m_visibleItems;
 739     QHash<KItemListWidget *, KItemListGroupHeader *> m_visibleGroups;
 740
 741     struct Cell {
 742         Cell()
 743             : column(-1)
 744             , row(-1)
 745         {
 746         }
 747         Cell(int c, int r)
 748             : column(c)
 749             , row(r)
 750         {
 751         }
 752         int column;
 753         int row;
 754     };
 755     QHash<int, Cell> m_visibleCells;
 756
 757     int m_scrollBarExtent;
 758     KItemListViewLayouter *m_layouter;
 759     KItemListViewAnimation *m_animation;
 760
 761     qreal m_oldScrollOffset;
 762     qreal m_oldMaximumScrollOffset;
 763     qreal m_oldItemOffset;
 764     qreal m_oldMaximumItemOffset;
 765
 766     bool m_skipAutoScrollForRubberBand;
 767     KItemListRubberBand *m_rubberBand;
 768     KItemListRubberBand *m_tapAndHoldIndicator;
 769
 770     QPointF m_mousePos;
 771     int m_autoScrollIncrement;
 772     QTimer *m_autoScrollTimer;
 773
 774     KItemListHeader *m_header;
 775     KItemListHeaderWidget *m_headerWidget;
 776
 777     QPropertyAnimation *m_indicatorAnimation;
 778
 779     // When dragging items into the view where the sort-role of the model
 780     // is empty, a visual indicator should be shown during dragging where
 781     // the dropping will happen. This indicator is specified by an index
 782     // of the item. -1 means that no indicator will be shown at all.
 783     // The m_dropIndicator is set by the KItemListController
 784     // by KItemListView::showDropIndicator() and KItemListView::hideDropIndicator().
 785     QRectF m_dropIndicator;
 786
 787     QList<QVariantAnimation *> m_rubberBandAnimations;
 788
 789     KItemListSizeHintResolver *m_sizeHintResolver;
 790
 791     friend class KItemListContainer; // Accesses scrollBarRequired()
 792     friend class KItemListHeader; // Accesses m_headerWidget
 793     friend class KItemListController;
 794     friend class KItemListControllerTest;
 795     friend class KItemListViewAccessible;
 796     friend class KItemListAccessibleCell;
 797 };
 798
 799 /**
 800  * Allows to do a fast logical creation and deletion of QGraphicsWidgets
 801  * by recycling existing QGraphicsWidgets instances. Is used by
 802  * KItemListWidgetCreatorBase and KItemListGroupHeaderCreatorBase.
 803  * @internal
 804  */
 805 class DOLPHIN_EXPORT KItemListCreatorBase
 806 {
 807 public:
 808     virtual ~KItemListCreatorBase();
 809
 810 protected:
 811     void addCreatedWidget(QGraphicsWidget *widget);
 812     void pushRecycleableWidget(QGraphicsWidget *widget);
 813     QGraphicsWidget *popRecycleableWidget();
 814
 815 private:
 816     QSet<QGraphicsWidget *> m_createdWidgets;
 817     QList<QGraphicsWidget *> m_recycleableWidgets;
 818 };
 819
 820 /**
 821  * @brief Base class for creating KItemListWidgets.
 822  *
 823  * It is recommended that applications simply use the KItemListWidgetCreator-template class.
 824  * For a custom implementation the methods create(), itemSizeHint() and preferredColumnWith()
 825  * must be reimplemented. The intention of the widget creator is to prevent repetitive and
 826  * expensive instantiations and deletions of KItemListWidgets by recycling existing widget
 827  * instances.
 828  */
 829 class DOLPHIN_EXPORT KItemListWidgetCreatorBase : public KItemListCreatorBase
 830 {
 831 public:
 832     ~KItemListWidgetCreatorBase() override;
 833
 834     virtual KItemListWidget *create(KItemListView *view) = 0;
 835
 836     virtual void recycle(KItemListWidget *widget);
 837
 838     virtual void calculateItemSizeHints(QVector<std::pair<qreal, bool>> &logicalHeightHints, qreal &logicalWidthHint, const KItemListView *view) const = 0;
 839
 840     virtual qreal preferredRoleColumnWidth(const QByteArray &role, int index, const KItemListView *view) const = 0;
 841 };
 842
 843 /**
 844  * @brief Template class for creating KItemListWidgets.
 845  */
 846 template<class T>
 847 class KItemListWidgetCreator : public KItemListWidgetCreatorBase
 848 {
 849 public:
 850     KItemListWidgetCreator();
 851     ~KItemListWidgetCreator() override;
 852
 853     KItemListWidget *create(KItemListView *view) override;
 854
 855     void calculateItemSizeHints(QVector<std::pair<qreal, bool>> &logicalHeightHints, qreal &logicalWidthHint, const KItemListView *view) const override;
 856
 857     qreal preferredRoleColumnWidth(const QByteArray &role, int index, const KItemListView *view) const override;
 858
 859 private:
 860     KItemListWidgetInformant *m_informant;
 861 };
 862
 863 template<class T>
 864 KItemListWidgetCreator<T>::KItemListWidgetCreator()
 865     : m_informant(T::createInformant())
 866 {
 867 }
 868
 869 template<class T>
 870 KItemListWidgetCreator<T>::~KItemListWidgetCreator()
 871 {
 872     delete m_informant;
 873 }
 874
 875 template<class T>
 876 KItemListWidget *KItemListWidgetCreator<T>::create(KItemListView *view)
 877 {
 878     KItemListWidget *widget = static_cast<KItemListWidget *>(popRecycleableWidget());
 879     if (!widget) {
 880         widget = new T(m_informant, view);
 881         addCreatedWidget(widget);
 882     }
 883     widget->setParentItem(view);
 884     return widget;
 885 }
 886
 887 template<class T>
 888 void KItemListWidgetCreator<T>::calculateItemSizeHints(QVector<std::pair<qreal, bool>> &logicalHeightHints,
 889                                                        qreal &logicalWidthHint,
 890                                                        const KItemListView *view) const
 891 {
 892     return m_informant->calculateItemSizeHints(logicalHeightHints, logicalWidthHint, view);
 893 }
 894
 895 template<class T>
 896 qreal KItemListWidgetCreator<T>::preferredRoleColumnWidth(const QByteArray &role, int index, const KItemListView *view) const
 897 {
 898     return m_informant->preferredRoleColumnWidth(role, index, view);
 899 }
 900
 901 /**
 902  * @brief Base class for creating KItemListGroupHeaders.
 903  *
 904  * It is recommended that applications simply use the KItemListGroupHeaderCreator-template class.
 905  * For a custom implementation the methods create() and recycle() must be reimplemented.
 906  * The intention of the group-header creator is to prevent repetitive and expensive instantiations and
 907  * deletions of KItemListGroupHeaders by recycling existing header instances.
 908  */
 909 class DOLPHIN_EXPORT KItemListGroupHeaderCreatorBase : public KItemListCreatorBase
 910 {
 911 public:
 912     ~KItemListGroupHeaderCreatorBase() override;
 913     virtual KItemListGroupHeader *create(KItemListView *view) = 0;
 914     virtual void recycle(KItemListGroupHeader *header);
 915 };
 916
 917 template<class T>
 918 class KItemListGroupHeaderCreator : public KItemListGroupHeaderCreatorBase
 919 {
 920 public:
 921     ~KItemListGroupHeaderCreator() override;
 922     KItemListGroupHeader *create(KItemListView *view) override;
 923 };
 924
 925 template<class T>
 926 KItemListGroupHeaderCreator<T>::~KItemListGroupHeaderCreator()
 927 {
 928 }
 929
 930 template<class T>
 931 KItemListGroupHeader *KItemListGroupHeaderCreator<T>::create(KItemListView *view)
 932 {
 933     KItemListGroupHeader *widget = static_cast<KItemListGroupHeader *>(popRecycleableWidget());
 934     if (!widget) {
 935         widget = new T(view);
 936         addCreatedWidget(widget);
 937     }
 938     return widget;
 939 }
 940
 941 #endif