src/kitemviews/kitemlistview.h

   1 /***************************************************************************
   2  *   Copyright (C) 2011 by Peter Penz <peter.penz19@gmail.com>             *
   3  *                                                                         *
   4  *   Based on the Itemviews NG project from Trolltech Labs:                *
   5  *   http://qt.gitorious.org/qt-labs/itemviews-ng                          *
   6  *                                                                         *
   7  *   This program is free software; you can redistribute it and/or modify  *
   8  *   it under the terms of the GNU General Public License as published by  *
   9  *   the Free Software Foundation; either version 2 of the License, or     *
  10  *   (at your option) any later version.                                   *
  11  *                                                                         *
  12  *   This program is distributed in the hope that it will be useful,       *
  13  *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
  14  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
  15  *   GNU General Public License for more details.                          *
  16  *                                                                         *
  17  *   You should have received a copy of the GNU General Public License     *
  18  *   along with this program; if not, write to the                         *
  19  *   Free Software Foundation, Inc.,                                       *
  20  *   51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA            *
  21  ***************************************************************************/
  22
  23 #ifndef KITEMLISTVIEW_H
  24 #define KITEMLISTVIEW_H
  25
  26 #include "dolphin_export.h"
  27
  28 #include <kitemviews/kstandarditemlistgroupheader.h>
  29 #include <kitemviews/kitemliststyleoption.h>
  30 #include <kitemviews/kitemlistwidget.h>
  31 #include <kitemviews/kitemmodelbase.h>
  32 #include <kitemviews/private/kitemlistviewanimation.h>
  33 #include <QGraphicsWidget>
  34 #include <QSet>
  35
  36 class KItemListController;
  37 class KItemListGroupHeaderCreatorBase;
  38 class KItemListHeader;
  39 class KItemListHeaderWidget;
  40 class KItemListSizeHintResolver;
  41 class KItemListRubberBand;
  42 class KItemListViewAnimation;
  43 class KItemListViewLayouter;
  44 class KItemListWidget;
  45 class KItemListWidgetInformant;
  46 class KItemListWidgetCreatorBase;
  47 class QTimer;
  48
  49 /**
  50  * @brief Represents the view of an item-list.
  51  *
  52  * The view is responsible for showing the items of the model within
  53  * a GraphicsItem. Each visible item is represented by a KItemListWidget.
  54  *
  55  * The created view must be applied to the KItemListController with
  56  * KItemListController::setView() or with the constructor of
  57  * KItemListController.
  58  *
  59  * @see KItemListWidget
  60  * @see KItemModelBase
  61  */
  62 class DOLPHIN_EXPORT KItemListView : public QGraphicsWidget
  63 {
  64     Q_OBJECT
  65
  66     Q_PROPERTY(qreal scrollOffset READ scrollOffset WRITE setScrollOffset)
  67     Q_PROPERTY(qreal itemOffset READ itemOffset WRITE setItemOffset)
  68
  69 public:
  70     KItemListView(QGraphicsWidget* parent = 0);
  71     virtual ~KItemListView();
  72
  73     /**
  74      * Offset of the scrollbar that represents the scroll-orientation
  75      * (see setScrollOrientation()).
  76      */
  77     void setScrollOffset(qreal offset);
  78     qreal scrollOffset() const;
  79
  80     qreal maximumScrollOffset() const;
  81
  82     /**
  83      * Offset related to an item, that does not fit into the available
  84      * size of the listview. If the scroll-orientation is vertical
  85      * the item-offset describes the offset of the horizontal axe, if
  86      * the scroll-orientation is horizontal the item-offset describes
  87      * the offset of the vertical axe.
  88      */
  89     void setItemOffset(qreal scrollOffset);
  90     qreal itemOffset() const;
  91
  92     qreal maximumItemOffset() const;
  93
  94     int maximumVisibleItems() const;
  95
  96     void setVisibleRoles(const QList<QByteArray>& roles);
  97     QList<QByteArray> visibleRoles() const;
  98
  99     /**
 100      * If set to true an automatic scrolling is done as soon as the
 101      * mouse is moved near the borders of the view. Per default
 102      * the automatic scrolling is turned off.
 103      */
 104     void setAutoScroll(bool enabled);
 105     bool autoScroll() const;
 106
 107     /**
 108      * If set to true selection-toggles will be shown when hovering
 109      * an item. Per default the selection-toggles are disabled.
 110      */
 111     void setEnabledSelectionToggles(bool enabled);
 112     bool enabledSelectionToggles() const;
 113
 114     /**
 115      * @return Controller of the item-list. The controller gets
 116      *         initialized by KItemListController::setView() and will
 117      *         result in calling KItemListController::onControllerChanged().
 118      */
 119     KItemListController* controller() const;
 120
 121     /**
 122      * @return Model of the item-list. The model gets
 123      *         initialized by KItemListController::setModel() and will
 124      *         result in calling KItemListController::onModelChanged().
 125      */
 126     KItemModelBase* model() const;
 127
 128     /**
 129      * Sets the creator that creates a widget showing the
 130      * content of one model-item. Usually it is sufficient
 131      * to implement a custom widget X derived from KItemListWidget and
 132      * set the creator by:
 133      * <code>
 134      * itemListView->setWidgetCreator(new KItemListWidgetCreator<X>());
 135      * </code>
 136      * The ownership of the widget creator is transferred to
 137      * the item-list view.
 138      **/
 139     void setWidgetCreator(KItemListWidgetCreatorBase* widgetCreator);
 140     KItemListWidgetCreatorBase* widgetCreator() const;
 141
 142     /**
 143      * Sets the creator that creates a group header. Usually it is sufficient
 144      * to implement a custom header widget X derived from KItemListGroupHeader and
 145      * set the creator by:
 146      * <code>
 147      * itemListView->setGroupHeaderCreator(new KItemListGroupHeaderCreator<X>());
 148      * </code>
 149      * The ownership of the gropup header creator is transferred to
 150      * the item-list view.
 151      **/
 152     void setGroupHeaderCreator(KItemListGroupHeaderCreatorBase* groupHeaderCreator);
 153     KItemListGroupHeaderCreatorBase* groupHeaderCreator() const;
 154
 155     /**
 156      * @return The basic size of all items. The size of an item may be larger than
 157      *         the basic size (see KItemListView::itemRect()).
 158      */
 159     QSizeF itemSize() const;
 160
 161     /**
 162      * @return The size hint of all items. It is provided by the KItemListSizeHintResolver.
 163      */
 164     QSizeF itemSizeHint() const;
 165
 166     const KItemListStyleOption& styleOption() const;
 167
 168     virtual void setGeometry(const QRectF& rect) Q_DECL_OVERRIDE;
 169
 170     /**
 171      * @return The page step which should be used by the vertical scroll bar.
 172      *         This is the height of the view except for the header widget.
 173      */
 174     qreal verticalPageStep() const;
 175
 176     /**
 177      * @return Index of the item that is below the point \a pos.
 178      *         The position is relative to the upper right of
 179      *         the visible area. Only (at least partly) visible
 180      *         items are considered. -1 is returned if no item is
 181      *         below the position.
 182      */
 183     int itemAt(const QPointF& pos) const;
 184     bool isAboveSelectionToggle(int index, const QPointF& pos) const;
 185     bool isAboveExpansionToggle(int index, const QPointF& pos) const;
 186
 187     /**
 188      * @return Index of the first item that is at least partly visible.
 189      *         -1 is returned if the model contains no items.
 190      */
 191     int firstVisibleIndex() const;
 192
 193     /**
 194      * @return Index of the last item that is at least partly visible.
 195      *         -1 is returned if the model contains no items.
 196      */
 197     int lastVisibleIndex() const;
 198
 199     /**
 200      * @return Calculates the required size for all items in the model.
 201      *         It might be larger than KItemListView::itemSize().
 202      *         In this case the layout grid will be stretched to assure an
 203      *         unclipped item.
 204      *         NOTE: the logical height (width) is actually the
 205      *         width (height) if the scroll orientation is Qt::Vertical!
 206      */
 207     void calculateItemSizeHints(QVector<qreal>& logicalHeightHints, qreal& logicalWidthHint) const;
 208
 209     /**
 210      * If set to true, items having child-items can be expanded to show the child-items as
 211      * part of the view. Per default the expanding of items is is disabled. If expanding of
 212      * items is enabled, the methods KItemModelBase::setExpanded(), KItemModelBase::isExpanded(),
 213      * KItemModelBase::isExpandable() and KItemModelBase::expandedParentsCount()
 214      * must be reimplemented. The view-implementation
 215      * has to take care itself how to visually represent the expanded items provided
 216      * by the model.
 217      */
 218     void setSupportsItemExpanding(bool supportsExpanding);
 219     bool supportsItemExpanding() const;
 220
 221     /**
 222      * @return The rectangle of the item relative to the top/left of
 223      *         the currently visible area (see KItemListView::offset()).
 224      */
 225     QRectF itemRect(int index) const;
 226
 227     /**
 228      * @return The context rectangle of the item relative to the top/left of
 229      *         the currently visible area (see KItemListView::offset()). The
 230      *         context rectangle is defined by by the united rectangle of
 231      *         the icon rectangle and the text rectangle (see KItemListWidget::iconRect()
 232      *         and KItemListWidget::textRect()) and is useful as reference for e.g. aligning
 233      *         a tooltip or a context-menu for an item. Note that a context rectangle will
 234      *         only be returned for (at least partly) visible items. An empty rectangle will
 235      *         be returned for fully invisible items.
 236      */
 237     QRectF itemContextRect(int index) const;
 238
 239     /**
 240      * Scrolls to the item with the index \a index so that the item
 241      * will be fully visible.
 242      */
 243     void scrollToItem(int index);
 244
 245     /**
 246      * If several properties of KItemListView are changed synchronously, it is
 247      * recommended to encapsulate the calls between beginTransaction() and endTransaction().
 248      * This prevents unnecessary and expensive layout-calculations.
 249      */
 250     void beginTransaction();
 251
 252     /**
 253      * Counterpart to beginTransaction(). The layout changes will only be animated if
 254      * all property changes between beginTransaction() and endTransaction() support
 255      * animations.
 256      */
 257     void endTransaction();
 258
 259     bool isTransactionActive() const;
 260
 261     /**
 262      * Turns on the header if \p visible is true. Per default the
 263      * header is not visible. Usually the header is turned on when
 264      * showing a classic "table-view" to describe the shown columns.
 265      */
 266     void setHeaderVisible(bool visible);
 267     bool isHeaderVisible() const;
 268
 269     /**
 270      * @return Header of the list. The header is also available if it is not shown
 271      *         (see KItemListView::setHeaderShown()).
 272      */
 273     KItemListHeader* header() const;
 274
 275     /**
 276      * @return Pixmap that is used for a drag operation based on the
 277      *         items given by \a indexes.
 278      */
 279     virtual QPixmap createDragPixmap(const KItemSet& indexes) const;
 280
 281     /**
 282      * Lets the user edit the role \a role for item with the index \a index.
 283      */
 284     void editRole(int index, const QByteArray& role);
 285
 286     virtual void paint(QPainter* painter, const QStyleOptionGraphicsItem* option, QWidget* widget = 0) Q_DECL_OVERRIDE;
 287
 288 signals:
 289     void scrollOrientationChanged(Qt::Orientation current, Qt::Orientation previous);
 290     void scrollOffsetChanged(qreal current, qreal previous);
 291     void maximumScrollOffsetChanged(qreal current, qreal previous);
 292     void itemOffsetChanged(qreal current, qreal previous);
 293     void maximumItemOffsetChanged(qreal current, qreal previous);
 294     void scrollTo(qreal newOffset);
 295
 296     /**
 297      * Is emitted if the user has changed the sort order by clicking on a
 298      * header item (see KItemListView::setHeaderShown()). The sort order
 299      * of the model has already been adjusted to
 300      * the current sort order. Note that no signal will be emitted if the
 301      * sort order of the model has been changed without user interaction.
 302      */
 303     void sortOrderChanged(Qt::SortOrder current, Qt::SortOrder previous);
 304
 305     /**
 306      * Is emitted if the user has changed the sort role by clicking on a
 307      * header item (see KItemListView::setHeaderShown()). The sort role
 308      * of the model has already been adjusted to
 309      * the current sort role. Note that no signal will be emitted if the
 310      * sort role of the model has been changed without user interaction.
 311      */
 312     void sortRoleChanged(const QByteArray& current, const QByteArray& previous);
 313
 314     /**
 315      * Is emitted if the user has changed the visible roles by moving a header
 316      * item (see KItemListView::setHeaderShown()). Note that no signal will be
 317      * emitted if the roles have been changed without user interaction by
 318      * KItemListView::setVisibleRoles().
 319      */
 320     void visibleRolesChanged(const QList<QByteArray>& current, const QList<QByteArray>& previous);
 321
 322     void roleEditingCanceled(int index, const QByteArray& role, const QVariant& value);
 323     void roleEditingFinished(int index, const QByteArray& role, const QVariant& value);
 324
 325 protected:
 326     virtual QVariant itemChange(GraphicsItemChange change, const QVariant &value) Q_DECL_OVERRIDE;
 327     void setItemSize(const QSizeF& size);
 328     void setStyleOption(const KItemListStyleOption& option);
 329
 330     /**
 331      * If the scroll-orientation is vertical, the items are ordered
 332      * from top to bottom (= default setting). If the scroll-orientation
 333      * is horizontal, the items are ordered from left to right.
 334      */
 335     void setScrollOrientation(Qt::Orientation orientation);
 336     Qt::Orientation scrollOrientation() const;
 337
 338     /**
 339      * Factory method for creating a default widget-creator. The method will be used
 340      * in case if setWidgetCreator() has not been set by the application.
 341      * @return New instance of the widget-creator that should be used per
 342      *         default.
 343      */
 344     virtual KItemListWidgetCreatorBase* defaultWidgetCreator() const;
 345
 346     /**
 347      * Factory method for creating a default group-header-creator. The method will be used
 348      * in case if setGroupHeaderCreator() has not been set by the application.
 349      * @return New instance of the group-header-creator that should be used per
 350      *         default.
 351      */
 352     virtual KItemListGroupHeaderCreatorBase* defaultGroupHeaderCreator() const;
 353
 354     /**
 355      * Is called when creating a new KItemListWidget instance and allows derived
 356      * classes to do a custom initialization.
 357      */
 358     virtual void initializeItemListWidget(KItemListWidget* item);
 359
 360     /**
 361      * @return True if at least one of the changed roles \p changedRoles might result
 362      *         in the need to update the item-size hint (see KItemListView::itemSizeHint()).
 363      *         Per default true is returned which means on each role-change of existing items
 364      *         the item-size hints are recalculated. For performance reasons it is recommended
 365      *         to return false in case if a role-change will not result in a changed
 366      *         item-size hint.
 367      */
 368     virtual bool itemSizeHintUpdateRequired(const QSet<QByteArray>& changedRoles) const;
 369
 370     virtual void onControllerChanged(KItemListController* current, KItemListController* previous);
 371     virtual void onModelChanged(KItemModelBase* current, KItemModelBase* previous);
 372
 373     virtual void onScrollOrientationChanged(Qt::Orientation current, Qt::Orientation previous);
 374     virtual void onItemSizeChanged(const QSizeF& current, const QSizeF& previous);
 375     virtual void onScrollOffsetChanged(qreal current, qreal previous);
 376     virtual void onVisibleRolesChanged(const QList<QByteArray>& current, const QList<QByteArray>& previous);
 377     virtual void onStyleOptionChanged(const KItemListStyleOption& current, const KItemListStyleOption& previous);
 378     virtual void onSupportsItemExpandingChanged(bool supportsExpanding);
 379
 380     virtual void onTransactionBegin();
 381     virtual void onTransactionEnd();
 382
 383     virtual bool event(QEvent* event) Q_DECL_OVERRIDE;
 384     virtual void mousePressEvent(QGraphicsSceneMouseEvent* event) Q_DECL_OVERRIDE;
 385     virtual void mouseMoveEvent(QGraphicsSceneMouseEvent* event) Q_DECL_OVERRIDE;
 386     virtual void dragEnterEvent(QGraphicsSceneDragDropEvent* event) Q_DECL_OVERRIDE;
 387     virtual void dragMoveEvent(QGraphicsSceneDragDropEvent* event) Q_DECL_OVERRIDE;
 388     virtual void dragLeaveEvent(QGraphicsSceneDragDropEvent* event) Q_DECL_OVERRIDE;
 389     virtual void dropEvent(QGraphicsSceneDragDropEvent* event) Q_DECL_OVERRIDE;
 390
 391     QList<KItemListWidget*> visibleItemListWidgets() const;
 392
 393     virtual void updateFont();
 394     virtual void updatePalette();
 395
 396 protected slots:
 397     virtual void slotItemsInserted(const KItemRangeList& itemRanges);
 398     virtual void slotItemsRemoved(const KItemRangeList& itemRanges);
 399     virtual void slotItemsMoved(const KItemRange& itemRange, const QList<int>& movedToIndexes);
 400     virtual void slotItemsChanged(const KItemRangeList& itemRanges,
 401                                   const QSet<QByteArray>& roles);
 402     virtual void slotGroupsChanged();
 403
 404     virtual void slotGroupedSortingChanged(bool current);
 405     virtual void slotSortOrderChanged(Qt::SortOrder current, Qt::SortOrder previous);
 406     virtual void slotSortRoleChanged(const QByteArray& current, const QByteArray& previous);
 407     virtual void slotCurrentChanged(int current, int previous);
 408     virtual void slotSelectionChanged(const KItemSet& current, const KItemSet& previous);
 409
 410 private slots:
 411     void slotAnimationFinished(QGraphicsWidget* widget,
 412                                KItemListViewAnimation::AnimationType type);
 413     void slotLayoutTimerFinished();
 414
 415     void slotRubberBandPosChanged();
 416     void slotRubberBandActivationChanged(bool active);
 417
 418     /**
 419      * Is invoked if the column-width of one role in the header has
 420      * been changed by the user. The automatic resizing of columns
 421      * will be turned off as soon as this method has been called at
 422      * least once.
 423      */
 424     void slotHeaderColumnWidthChanged(const QByteArray& role,
 425                                       qreal currentWidth,
 426                                       qreal previousWidth);
 427
 428     /**
 429      * Is invoked if a column has been moved by the user. Applies
 430      * the moved role to the view.
 431      */
 432     void slotHeaderColumnMoved(const QByteArray& role,
 433                                int currentIndex,
 434                                int previousIndex);
 435
 436     /**
 437      * Triggers the autoscrolling if autoScroll() is enabled by checking the
 438      * current mouse position. If the mouse position is within the autoscroll
 439      * margins a timer will be started that periodically triggers the autoscrolling.
 440      */
 441     void triggerAutoScrolling();
 442
 443     /**
 444      * Is invoked if the geometry of the parent-widget from a group-header has been
 445      * changed. The x-position and width of the group-header gets adjusted to assure
 446      * that it always spans the whole width even during temporary transitions of the
 447      * parent widget.
 448      */
 449     void slotGeometryOfGroupHeaderParentChanged();
 450
 451     void slotRoleEditingCanceled(int index, const QByteArray& role, const QVariant& value);
 452     void slotRoleEditingFinished(int index, const QByteArray& role, const QVariant& value);
 453
 454 private:
 455     enum LayoutAnimationHint
 456     {
 457         NoAnimation,
 458         Animation
 459     };
 460
 461     enum SizeType
 462     {
 463         LayouterSize,
 464         ItemSize
 465     };
 466
 467     void setController(KItemListController* controller);
 468     void setModel(KItemModelBase* model);
 469
 470     KItemListRubberBand* rubberBand() const;
 471
 472     void doLayout(LayoutAnimationHint hint, int changedIndex = 0, int changedCount = 0);
 473
 474     /**
 475      * Helper method for doLayout: Returns a list of items that can be reused for the visible
 476      * area. Invisible group headers get recycled. The reusable items are items that are
 477      * invisible. If the animation hint is 'Animation' then items that are currently animated
 478      * won't be reused. Reusing items is faster in comparison to deleting invisible
 479      * items and creating a new instance for visible items.
 480      */
 481     QList<int> recycleInvisibleItems(int firstVisibleIndex,
 482                                      int lastVisibleIndex,
 483                                      LayoutAnimationHint hint);
 484
 485     /**
 486      * Helper method for doLayout: Starts a moving-animation for the widget to the given
 487      * new position. The moving-animation is only started if the new position is within
 488      * the same row or column, otherwise the create-animation is used instead.
 489      * @return True if the moving-animation has been applied.
 490      */
 491     bool moveWidget(KItemListWidget* widget, const QPointF& newPos);
 492
 493     void emitOffsetChanges();
 494
 495     KItemListWidget* createWidget(int index);
 496     void recycleWidget(KItemListWidget* widget);
 497
 498     /**
 499      * Changes the index of the widget to \a index and assures a consistent
 500      * update for m_visibleItems and m_visibleCells. The cell-information
 501      * for the new index will not be updated and be initialized as empty cell.
 502      */
 503     void setWidgetIndex(KItemListWidget* widget, int index);
 504
 505     /**
 506      * Changes the index of the widget to \a index. In opposite to
 507      * setWidgetIndex() the cell-information for the widget gets updated.
 508      * This update gives doLayout() the chance to animate the moving
 509      * of the item visually (see moveWidget()).
 510      */
 511     void moveWidgetToIndex(KItemListWidget* widget, int index);
 512
 513     /**
 514      * Helper method for prepareLayoutForIncreasedItemCount().
 515      */
 516     void setLayouterSize(const QSizeF& size, SizeType sizeType);
 517
 518     /**
 519      * Helper method for createWidget() and setWidgetIndex() to update the properties
 520      * of the itemlist widget.
 521      */
 522     void updateWidgetProperties(KItemListWidget* widget, int index);
 523
 524     /**
 525      * Helper method for updateWidgetPropertes() to create or update
 526      * the itemlist group-header.
 527      */
 528     void updateGroupHeaderForWidget(KItemListWidget* widget);
 529
 530     /**
 531      * Updates the position and size of the group-header that belongs
 532      * to the itemlist widget \a widget. The given widget must represent
 533      * the first item of a group.
 534      */
 535     void updateGroupHeaderLayout(KItemListWidget* widget);
 536
 537     /**
 538      * Recycles the group-header for the widget.
 539      */
 540     void recycleGroupHeaderForWidget(KItemListWidget* widget);
 541
 542     /**
 543      * Helper method for slotGroupedSortingChanged(), slotSortOrderChanged()
 544      * and slotSortRoleChanged(): Iterates through all visible items and updates
 545      * the group-header widgets.
 546      */
 547     void updateVisibleGroupHeaders();
 548
 549     /**
 550      * @return Index for the item in the list returned by KItemModelBase::groups()
 551      *         that represents the group where the item with the index \a index
 552      *         belongs to. -1 is returned if no groups are available.
 553      */
 554     int groupIndexForItem(int index) const;
 555
 556     /**
 557      * Updates the alternate background for all visible items.
 558      * @see updateAlternateBackgroundForWidget()
 559      */
 560     void updateAlternateBackgrounds();
 561
 562     /**
 563      * Updates the alternateBackground-property of the widget dependent
 564      * on the state of useAlternateBackgrounds() and the grouping state.
 565      */
 566     void updateAlternateBackgroundForWidget(KItemListWidget* widget);
 567
 568     /**
 569      * @return True if alternate backgrounds should be used for the items.
 570      *         This is the case if an empty item-size is given and if there
 571      *         is more than one visible role.
 572      */
 573     bool useAlternateBackgrounds() const;
 574
 575     /**
 576      * @param itemRanges Items that must be checked for getting the widths of columns.
 577      * @return           The preferred width of the column of each visible role. The width will
 578      *                   be respected if the width of the item size is <= 0 (see
 579      *                   KItemListView::setItemSize()). Per default an empty hash
 580      *                   is returned.
 581      */
 582     QHash<QByteArray, qreal> preferredColumnWidths(const KItemRangeList& itemRanges) const;
 583
 584     /**
 585      * Applies the column-widths from m_headerWidget to the layout
 586      * of the view.
 587      */
 588     void applyColumnWidthsFromHeader();
 589
 590     /**
 591      * Applies the column-widths from m_headerWidget to \a widget.
 592      */
 593     void updateWidgetColumnWidths(KItemListWidget* widget);
 594
 595     /**
 596      * Updates the preferred column-widths of m_groupHeaderWidget by
 597      * invoking KItemListView::columnWidths().
 598      */
 599     void updatePreferredColumnWidths(const KItemRangeList& itemRanges);
 600
 601     /**
 602      * Convenience method for
 603      * updatePreferredColumnWidths(KItemRangeList() << KItemRange(0, m_model->count()).
 604      */
 605     void updatePreferredColumnWidths();
 606
 607     /**
 608      * Resizes the column-widths of m_headerWidget based on the preferred widths
 609      * and the vailable view-size.
 610      */
 611     void applyAutomaticColumnWidths();
 612
 613     /**
 614      * @return Sum of the widths of all columns.
 615      */
 616     qreal columnWidthsSum() const;
 617
 618     /**
 619      * @return Boundaries of the header. An empty rectangle is returned
 620      *         if no header is shown.
 621      */
 622     QRectF headerBoundaries() const;
 623
 624     /**
 625      * @return True if the number of columns or rows will be changed when applying
 626      *         the new grid- and item-size. Used to determine whether an animation
 627      *         should be done when applying the new layout.
 628      */
 629     bool changesItemGridLayout(const QSizeF& newGridSize,
 630                                const QSizeF& newItemSize,
 631                                const QSizeF& newItemMargin) const;
 632
 633     /**
 634      * @param changedItemCount Number of inserted  or removed items.
 635      * @return                 True if the inserting or removing of items should be animated.
 636      *                         No animation should be done if the number of items is too large
 637      *                         to provide a pleasant animation.
 638      */
 639     bool animateChangedItemCount(int changedItemCount) const;
 640
 641     /**
 642      * @return True if a scrollbar for the given scroll-orientation is required
 643      *         when using a size of \p size for the view. Calling the method is rather
 644      *         expansive as a temporary relayout needs to be done.
 645      */
 646     bool scrollBarRequired(const QSizeF& size) const;
 647
 648     /**
 649      * Shows a drop-indicator between items dependent on the given
 650      * cursor position. The cursor position is relative to the upper left
 651      * edge of the view.
 652      * @return Index of the item where the dropping is done. An index of -1
 653      *         indicates that the item has been dropped after the last item.
 654      */
 655     int showDropIndicator(const QPointF& pos);
 656     void hideDropIndicator();
 657
 658     /**
 659      * Applies the height of the group header to the layouter. The height
 660      * depends on the used scroll orientation.
 661      */
 662     void updateGroupHeaderHeight();
 663
 664     /**
 665      * Updates the siblings-information for all visible items that are inside
 666      * the range of \p firstIndex and \p lastIndex. If firstIndex or lastIndex
 667      * is smaller than 0, the siblings-information for all visible items gets
 668      * updated.
 669      * @see KItemListWidget::setSiblingsInformation()
 670      */
 671     void updateSiblingsInformation(int firstIndex = -1, int lastIndex = -1);
 672
 673     /**
 674      * Helper method for updateExpansionIndicators().
 675      * @return True if the item with the index \a index has a sibling successor
 676      *         (= the item is not the last item of the current hierarchy).
 677      */
 678     bool hasSiblingSuccessor(int index) const;
 679
 680     /**
 681      * Helper method for slotRoleEditingCanceled() and slotRoleEditingFinished().
 682      * Disconnects the two Signals "roleEditingCanceled" and
 683      * "roleEditingFinished"
 684      */
 685     void disconnectRoleEditingSignals(int index);
 686
 687     /**
 688      * Helper function for triggerAutoScrolling().
 689      * @param pos    Logical position of the mouse relative to the range.
 690      * @param range  Range of the visible area.
 691      * @param oldInc Previous increment. Is used to assure that the increment
 692      *               increases only gradually.
 693      * @return Scroll increment that should be added to the offset().
 694      *         As soon as \a pos is inside the autoscroll-margin a
 695      *         value != 0 will be returned.
 696      */
 697     static int calculateAutoScrollingIncrement(int pos, int range, int oldInc);
 698
 699     /**
 700      * Helper functions for changesItemCount().
 701      * @return The number of items that fit into the available size by
 702      *         respecting the size of the item and the margin between the items.
 703      */
 704     static int itemsPerSize(qreal size, qreal itemSize, qreal itemMargin);
 705
 706 private:
 707     bool m_enabledSelectionToggles;
 708     bool m_grouped;
 709     bool m_supportsItemExpanding;
 710     bool m_editingRole;
 711     int m_activeTransactions; // Counter for beginTransaction()/endTransaction()
 712     LayoutAnimationHint m_endTransactionAnimationHint;
 713
 714     QSizeF m_itemSize;
 715     KItemListController* m_controller;
 716     KItemModelBase* m_model;
 717     QList<QByteArray> m_visibleRoles;
 718     mutable KItemListWidgetCreatorBase* m_widgetCreator;
 719     mutable KItemListGroupHeaderCreatorBase* m_groupHeaderCreator;
 720     KItemListStyleOption m_styleOption;
 721
 722     QHash<int, KItemListWidget*> m_visibleItems;
 723     QHash<KItemListWidget*, KItemListGroupHeader*> m_visibleGroups;
 724
 725     struct Cell
 726     {
 727         Cell() : column(-1), row(-1) {}
 728         Cell(int c, int r) : column(c), row(r) {}
 729         int column;
 730         int row;
 731     };
 732     QHash<int, Cell> m_visibleCells;
 733
 734     int m_scrollBarExtent;
 735     KItemListSizeHintResolver* m_sizeHintResolver;
 736     KItemListViewLayouter* m_layouter;
 737     KItemListViewAnimation* m_animation;
 738
 739     QTimer* m_layoutTimer; // Triggers an asynchronous doLayout() call.
 740     qreal m_oldScrollOffset;
 741     qreal m_oldMaximumScrollOffset;
 742     qreal m_oldItemOffset;
 743     qreal m_oldMaximumItemOffset;
 744
 745     bool m_skipAutoScrollForRubberBand;
 746     KItemListRubberBand* m_rubberBand;
 747
 748     QPointF m_mousePos;
 749     int m_autoScrollIncrement;
 750     QTimer* m_autoScrollTimer;
 751
 752     KItemListHeader* m_header;
 753     KItemListHeaderWidget* m_headerWidget;
 754
 755     // When dragging items into the view where the sort-role of the model
 756     // is empty, a visual indicator should be shown during dragging where
 757     // the dropping will happen. This indicator is specified by an index
 758     // of the item. -1 means that no indicator will be shown at all.
 759     // The m_dropIndicator is set by the KItemListController
 760     // by KItemListView::showDropIndicator() and KItemListView::hideDropIndicator().
 761     QRectF m_dropIndicator;
 762
 763     friend class KItemListContainer; // Accesses scrollBarRequired()
 764     friend class KItemListHeader;    // Accesses m_headerWidget
 765     friend class KItemListController;
 766     friend class KItemListControllerTest;
 767     friend class KItemListViewAccessible;
 768     friend class KItemListAccessibleCell;
 769 };
 770
 771 /**
 772  * Allows to do a fast logical creation and deletion of QGraphicsWidgets
 773  * by recycling existing QGraphicsWidgets instances. Is used by
 774  * KItemListWidgetCreatorBase and KItemListGroupHeaderCreatorBase.
 775  * @internal
 776  */
 777 class DOLPHIN_EXPORT KItemListCreatorBase
 778 {
 779 public:
 780     virtual ~KItemListCreatorBase();
 781
 782 protected:
 783     void addCreatedWidget(QGraphicsWidget* widget);
 784     void pushRecycleableWidget(QGraphicsWidget* widget);
 785     QGraphicsWidget* popRecycleableWidget();
 786
 787 private:
 788     QSet<QGraphicsWidget*> m_createdWidgets;
 789     QList<QGraphicsWidget*> m_recycleableWidgets;
 790 };
 791
 792 /**
 793  * @brief Base class for creating KItemListWidgets.
 794  *
 795  * It is recommended that applications simply use the KItemListWidgetCreator-template class.
 796  * For a custom implementation the methods create(), itemSizeHint() and preferredColumnWith()
 797  * must be reimplemented. The intention of the widget creator is to prevent repetitive and
 798  * expensive instantiations and deletions of KItemListWidgets by recycling existing widget
 799  * instances.
 800  */
 801 class DOLPHIN_EXPORT KItemListWidgetCreatorBase : public KItemListCreatorBase
 802 {
 803 public:
 804     virtual ~KItemListWidgetCreatorBase();
 805
 806     virtual KItemListWidget* create(KItemListView* view) = 0;
 807
 808     virtual void recycle(KItemListWidget* widget);
 809
 810     virtual void calculateItemSizeHints(QVector<qreal>& logicalHeightHints, qreal& logicalWidthHint, const KItemListView* view) const = 0;
 811
 812     virtual qreal preferredRoleColumnWidth(const QByteArray& role,
 813                                            int index,
 814                                            const KItemListView* view) const = 0;
 815 };
 816
 817 /**
 818  * @brief Template class for creating KItemListWidgets.
 819  */
 820 template <class T>
 821 class KItemListWidgetCreator : public KItemListWidgetCreatorBase
 822 {
 823 public:
 824     KItemListWidgetCreator();
 825     virtual ~KItemListWidgetCreator();
 826
 827     virtual KItemListWidget* create(KItemListView* view);
 828
 829     virtual void calculateItemSizeHints(QVector<qreal>& logicalHeightHints, qreal& logicalWidthHint, const KItemListView* view) const;
 830
 831     virtual qreal preferredRoleColumnWidth(const QByteArray& role,
 832                                            int index,
 833                                            const KItemListView* view) const;
 834 private:
 835     KItemListWidgetInformant* m_informant;
 836 };
 837
 838 template <class T>
 839 KItemListWidgetCreator<T>::KItemListWidgetCreator() :
 840     m_informant(T::createInformant())
 841 {
 842 }
 843
 844 template <class T>
 845 KItemListWidgetCreator<T>::~KItemListWidgetCreator()
 846 {
 847     delete m_informant;
 848 }
 849
 850 template <class T>
 851 KItemListWidget* KItemListWidgetCreator<T>::create(KItemListView* view)
 852 {
 853     KItemListWidget* widget = static_cast<KItemListWidget*>(popRecycleableWidget());
 854     if (!widget) {
 855         widget = new T(m_informant, view);
 856         addCreatedWidget(widget);
 857     }
 858     return widget;
 859 }
 860
 861 template<class T>
 862 void KItemListWidgetCreator<T>::calculateItemSizeHints(QVector<qreal>& logicalHeightHints, qreal& logicalWidthHint, const KItemListView* view) const
 863 {
 864     return m_informant->calculateItemSizeHints(logicalHeightHints, logicalWidthHint, view);
 865 }
 866
 867 template<class T>
 868 qreal KItemListWidgetCreator<T>::preferredRoleColumnWidth(const QByteArray& role,
 869                                                           int index,
 870                                                           const KItemListView* view) const
 871 {
 872     return m_informant->preferredRoleColumnWidth(role, index, view);
 873 }
 874
 875 /**
 876  * @brief Base class for creating KItemListGroupHeaders.
 877  *
 878  * It is recommended that applications simply use the KItemListGroupHeaderCreator-template class.
 879  * For a custom implementation the methods create() and recyle() must be reimplemented.
 880  * The intention of the group-header creator is to prevent repetitive and expensive instantiations and
 881  * deletions of KItemListGroupHeaders by recycling existing header instances.
 882  */
 883 class DOLPHIN_EXPORT KItemListGroupHeaderCreatorBase : public KItemListCreatorBase
 884 {
 885 public:
 886     virtual ~KItemListGroupHeaderCreatorBase();
 887     virtual KItemListGroupHeader* create(KItemListView* view) = 0;
 888     virtual void recycle(KItemListGroupHeader* header);
 889 };
 890
 891 template <class T>
 892 class KItemListGroupHeaderCreator : public KItemListGroupHeaderCreatorBase
 893 {
 894 public:
 895     virtual ~KItemListGroupHeaderCreator();
 896     virtual KItemListGroupHeader* create(KItemListView* view);
 897 };
 898
 899 template <class T>
 900 KItemListGroupHeaderCreator<T>::~KItemListGroupHeaderCreator()
 901 {
 902 }
 903
 904 template <class T>
 905 KItemListGroupHeader* KItemListGroupHeaderCreator<T>::create(KItemListView* view)
 906 {
 907     KItemListGroupHeader* widget = static_cast<KItemListGroupHeader*>(popRecycleableWidget());
 908     if (!widget) {
 909         widget = new T(view);
 910         addCreatedWidget(widget);
 911     }
 912     return widget;
 913 }
 914
 915 #endif