7 files changed, 172 insertions, 77 deletions

diff --git a/src/kitemviews/kfileitemlistview.cpp b/src/kitemviews/kfileitemlistview.cpp
index 25f7738bf..27ef7fdb5 100644
--- a/src/kitemviews/kfileitemlistview.cpp
+++ b/src/kitemviews/kfileitemlistview.cpp
@@ -324,9 +324,6 @@ void KFileItemListView::initializeItemListWidget(KItemListWidget* item)
     case DetailsLayout: fileItemListWidget->setLayout(KFileItemListWidget::DetailsLayout); break;
     default:            Q_ASSERT(false); break;
     }
-
-    fileItemListWidget->setAlternatingBackgroundColors(m_itemLayout == DetailsLayout &&
-                                                       visibleRoles().count() > 1);
 }
 
 bool KFileItemListView::itemSizeHintUpdateRequired(const QSet<QByteArray>& changedRoles) const
@@ -379,20 +376,9 @@ void KFileItemListView::onScrollOffsetChanged(qreal current, qreal previous)
 
 void KFileItemListView::onVisibleRolesChanged(const QList<QByteArray>& current, const QList<QByteArray>& previous)
 {
+    Q_UNUSED(current);
+    Q_UNUSED(previous);
     applyRolesToModel();
-
-    if (m_itemLayout == DetailsLayout) {
-        // Only enable the alternating background colors if more than one role
-        // is visible
-        const int previousCount = previous.count();
-        const int currentCount = current.count();
-        if ((previousCount <= 1 && currentCount > 1) || (previousCount > 1 && currentCount <= 1)) {
-            const bool enabled = (currentCount > 1);
-            foreach (KItemListWidget* widget, visibleItemListWidgets()) {
-                widget->setAlternatingBackgroundColors(enabled);
-            }
-        }
-    }
 }
 
 void KFileItemListView::onStyleOptionChanged(const KItemListStyleOption& current, const KItemListStyleOption& previous)
diff --git a/src/kitemviews/kitemlistview.cpp b/src/kitemviews/kitemlistview.cpp
index 907bf624d..527436725 100644
--- a/src/kitemviews/kitemlistview.cpp
+++ b/src/kitemviews/kitemlistview.cpp
@@ -156,9 +156,24 @@ void KItemListView::setItemSize(const QSizeF& itemSize)
     const bool animate = !changesItemGridLayout(m_layouter->size(),
                                                 itemSize,
                                                 m_layouter->itemMargin());
-    
+
+    const bool updateAlternateBackgrounds = (m_visibleRoles.count() > 1) &&
+                                            (( m_itemSize.isEmpty() && !itemSize.isEmpty()) ||
+                                             (!m_itemSize.isEmpty() && itemSize.isEmpty()));
+
     m_itemSize = itemSize;
 
+    if (updateAlternateBackgrounds) {
+        // For an empty item size alternate backgrounds are drawn if more than
+        // one role is shown. Assure that the backgrounds for visible items are
+        // updated when changing the size in this context.
+        QHashIterator<int, KItemListWidget*> it(m_visibleItems);
+        while (it.hasNext()) {
+            it.next();
+            updateAlternateBackgroundForWidget(it.value());
+        }
+    }
+
     if (itemSize.isEmpty()) {
         updateVisibleRolesSizes();
     } else {
@@ -238,12 +253,19 @@ void KItemListView::setVisibleRoles(const QList<QByteArray>& roles)
     const QList<QByteArray> previousRoles = m_visibleRoles;
     m_visibleRoles = roles;
 
+    const bool updateAlternateBackgrounds = m_itemSize.isEmpty() &&
+                                            ((roles.count() > 1 && previousRoles.count() <= 1) ||
+                                             (roles.count() <= 1 && previousRoles.count() > 1));
+
     QHashIterator<int, KItemListWidget*> it(m_visibleItems);
     while (it.hasNext()) {
         it.next();
         KItemListWidget* widget = it.value();
         widget->setVisibleRoles(roles);
         widget->setVisibleRolesSizes(m_stretchedVisibleRolesSizes);
+        if (updateAlternateBackgrounds) {
+            updateAlternateBackgroundForWidget(widget);
+        }
     }
 
     m_sizeHintResolver->clearCache();
@@ -785,9 +807,6 @@ void KItemListView::slotItemsInserted(const KItemRangeList& itemRanges)
         beginTransaction();
     }
 
-    // Important: Don't read any m_layouter-property inside the for-loop in case if
-    // multiple ranges are given! m_layouter accesses m_sizeHintResolver which is
-    // updated in each loop-cycle and has only a consistent state after the loop.
     m_layouter->markAsDirty();
 
     int previouslyInsertedCount = 0;
@@ -823,11 +842,12 @@ void KItemListView::slotItemsInserted(const KItemRangeList& itemRanges)
         for (int i = itemsToMove.count() - 1; i >= 0; --i) {
             KItemListWidget* widget = m_visibleItems.value(itemsToMove[i]);
             Q_ASSERT(widget);
+            const int newIndex = widget->index() + count;
             if (hasMultipleRanges) {
-                setWidgetIndex(widget, widget->index() + count);
+                setWidgetIndex(widget, newIndex);
             } else {
                 // Try to animate the moving of the item
-                moveWidgetToIndex(widget, widget->index() + count);
+                moveWidgetToIndex(widget, newIndex);
             }
         }
 
@@ -861,6 +881,12 @@ void KItemListView::slotItemsInserted(const KItemRangeList& itemRanges)
     }
 
     if (hasMultipleRanges) {
+#ifndef QT_NO_DEBUG
+        // Important: Don't read any m_layouter-property inside the for-loop in case if
+        // multiple ranges are given! m_layouter accesses m_sizeHintResolver which is
+        // updated in each loop-cycle and has only a consistent state after the loop.
+        Q_ASSERT(m_layouter->isDirty());
+#endif
         m_endTransactionAnimationHint = NoAnimation;
         endTransaction();
         updateSiblingsInformation();
@@ -876,9 +902,6 @@ void KItemListView::slotItemsRemoved(const KItemRangeList& itemRanges)
         beginTransaction();
     }
 
-    // Important: Don't read any m_layouter-property inside the for-loop in case if
-    // multiple ranges are given! m_layouter accesses m_sizeHintResolver which is
-    // updated in each loop-cycle and has only a consistent state after the loop.
     m_layouter->markAsDirty();
 
     for (int i = itemRanges.count() - 1; i >= 0; --i) {
@@ -959,6 +982,12 @@ void KItemListView::slotItemsRemoved(const KItemRangeList& itemRanges)
     }
 
     if (hasMultipleRanges) {
+#ifndef QT_NO_DEBUG
+        // Important: Don't read any m_layouter-property inside the for-loop in case if
+        // multiple ranges are given! m_layouter accesses m_sizeHintResolver which is
+        // updated in each loop-cycle and has only a consistent state after the loop.
+        Q_ASSERT(m_layouter->isDirty());
+#endif
         m_endTransactionAnimationHint = NoAnimation;
         endTransaction();
         updateSiblingsInformation();
@@ -981,9 +1010,6 @@ void KItemListView::slotItemsMoved(const KItemRange& itemRange, const QList<int>
         KItemListWidget* widget = m_visibleItems.value(index);
         if (widget) {
             updateWidgetProperties(widget, index);
-            if (m_grouped) {
-                updateGroupHeaderForWidget(widget);
-            }
             initializeItemListWidget(widget);
         }
     }
@@ -1048,6 +1074,17 @@ void KItemListView::slotGroupedSortingChanged(bool current)
         Q_ASSERT(m_visibleGroups.isEmpty());
     }
 
+    if (useAlternateBackgrounds()) {
+        // Changing the group mode requires to update the alternate backgrounds
+        // as with the enabled group mode the altering is done on base of the first
+        // group item.
+        QHashIterator<int, KItemListWidget*> it(m_visibleItems);
+        while (it.hasNext()) {
+            it.next();
+            updateAlternateBackgroundForWidget(it.value());
+        }
+    }
+
     doLayout(NoAnimation);
 }
 
@@ -1077,13 +1114,11 @@ void KItemListView::slotCurrentChanged(int current, int previous)
 
     KItemListWidget* previousWidget = m_visibleItems.value(previous, 0);
     if (previousWidget) {
-        Q_ASSERT(previousWidget->isCurrent());
         previousWidget->setCurrent(false);
     }
 
     KItemListWidget* currentWidget = m_visibleItems.value(current, 0);
     if (currentWidget) {
-        Q_ASSERT(!currentWidget->isCurrent());
         currentWidget->setCurrent(true);
     }
 }
@@ -1406,10 +1441,8 @@ void KItemListView::doLayout(LayoutAnimationHint hint, int changedIndex, int cha
                 const int oldIndex = reusableItems.takeLast();
                 widget = m_visibleItems.value(oldIndex);
                 setWidgetIndex(widget, i);
-
-                if (m_grouped) {
-                    updateGroupHeaderForWidget(widget);
-                }
+                updateWidgetProperties(widget, i);
+                initializeItemListWidget(widget);
             } else {
                 // No reusable KItemListWidget instance is available, create a new one
                 widget = createWidget(i);
@@ -1626,14 +1659,9 @@ KItemListWidget* KItemListView::createWidget(int index)
     KItemListWidget* widget = m_widgetCreator->create(this);
     widget->setFlag(QGraphicsItem::ItemStacksBehindParent);
 
-    updateWidgetProperties(widget, index);
     m_visibleItems.insert(index, widget);
     m_visibleCells.insert(index, Cell());
-
-    if (m_grouped) {
-        updateGroupHeaderForWidget(widget);
-    }
-
+    updateWidgetProperties(widget, index);
     initializeItemListWidget(widget);
     return widget;
 }
@@ -1654,16 +1682,13 @@ void KItemListView::recycleWidget(KItemListWidget* widget)
 void KItemListView::setWidgetIndex(KItemListWidget* widget, int index)
 {
     const int oldIndex = widget->index();
-
     m_visibleItems.remove(oldIndex);
     m_visibleCells.remove(oldIndex);
 
-    updateWidgetProperties(widget, index);
-
     m_visibleItems.insert(index, widget);
     m_visibleCells.insert(index, Cell());
 
-    initializeItemListWidget(widget);
+    widget->setIndex(index);
 }
 
 void KItemListView::moveWidgetToIndex(KItemListWidget* widget, int index)
@@ -1701,11 +1726,15 @@ void KItemListView::updateWidgetProperties(KItemListWidget* widget, int index)
     widget->setCurrent(index == selectionManager->currentItem());
     widget->setSelected(selectionManager->isSelected(index));
     widget->setHovered(false);
-    widget->setAlternatingBackgroundColors(false);
     widget->setEnabledSelectionToggle(enabledSelectionToggles());
     widget->setIndex(index);
     widget->setData(m_model->data(index));
     widget->setSiblingsInformation(QBitArray());
+    updateAlternateBackgroundForWidget(widget);
+
+    if (m_grouped) {
+        updateGroupHeaderForWidget(widget);
+    }
 }
 
 void KItemListView::updateGroupHeaderForWidget(KItemListWidget* widget)
@@ -1734,21 +1763,9 @@ void KItemListView::updateGroupHeaderForWidget(KItemListWidget* widget)
     }
     Q_ASSERT(groupHeader->parentItem() == widget);
 
-    // Determine the shown data for the header by doing a binary
-    // search in the groups-list
-    int min = 0;
-    int max = groups.count() - 1;
-    int mid = 0;
-    do {
-        mid = (min + max) / 2;
-        if (index > groups.at(mid).first) {
-            min = mid + 1;
-        } else {
-            max = mid - 1;
-        }
-    } while (groups.at(mid).first != index && min <= max);
-
-    groupHeader->setData(groups.at(mid).second);
+    const int groupIndex = groupIndexForItem(index);
+    Q_ASSERT(groupIndex >= 0);
+    groupHeader->setData(groups.at(groupIndex).second);
     groupHeader->setRole(model()->sortRole());
     groupHeader->setStyleOption(m_styleOption);
     groupHeader->setScrollOrientation(scrollOrientation());
@@ -1803,6 +1820,60 @@ void KItemListView::updateVisibleGroupHeaders()
     }
 }
 
+int KItemListView::groupIndexForItem(int index) const
+{
+    Q_ASSERT(m_grouped);
+
+    const QList<QPair<int, QVariant> > groups = model()->groups();
+    if (groups.isEmpty()) {
+        return -1;
+    }
+
+    int min = 0;
+    int max = groups.count() - 1;
+    int mid = 0;
+    do {
+        mid = (min + max) / 2;
+        if (index > groups[mid].first) {
+            min = mid + 1;
+        } else {
+            max = mid - 1;
+        }
+    } while (groups[mid].first != index && min <= max);
+
+    if (min > max) {
+        while (groups[mid].first > index && mid > 0) {
+            --mid;
+        }
+    }
+
+    return mid;
+}
+
+void KItemListView::updateAlternateBackgroundForWidget(KItemListWidget* widget)
+{
+    bool enabled = useAlternateBackgrounds();
+    if (enabled) {
+        const int index = widget->index();
+        enabled = (index & 0x1) > 0;
+        if (m_grouped) {
+            const int groupIndex = groupIndexForItem(index);
+            if (groupIndex >= 0) {
+                const QList<QPair<int, QVariant> > groups = model()->groups();
+                const int indexOfFirstGroupItem = groups[groupIndex].first;
+                const int relativeIndex = index - indexOfFirstGroupItem;
+                enabled = (relativeIndex & 0x1) == 0;
+            }
+        }
+    }
+    widget->setAlternateBackground(enabled);
+}
+
+bool KItemListView::useAlternateBackgrounds() const
+{
+    return m_itemSize.isEmpty() && m_visibleRoles.count() > 1;
+}
+
 QHash<QByteArray, qreal> KItemListView::headerRolesWidths() const
 {
     QHash<QByteArray, qreal> rolesWidths;
diff --git a/src/kitemviews/kitemlistview.h b/src/kitemviews/kitemlistview.h
index d524dbdf4..17b7b8880 100644
--- a/src/kitemviews/kitemlistview.h
+++ b/src/kitemviews/kitemlistview.h
@@ -396,14 +396,15 @@ private:
     void recycleWidget(KItemListWidget* widget);
 
     /**
-     * Changes the index of the widget to \a index. The cell-information
-     * for the widget gets reset and will be updated in the next doLayout().
+     * Changes the index of the widget to \a index and assures a consistent
+     * update for m_visibleItems and m_visibleCells. The cell-information
+     * for the new index will not be updated and be initialized as empty cell.
      */
     void setWidgetIndex(KItemListWidget* widget, int index);
 
     /**
      * Changes the index of the widget to \a index. In opposite to
-     * setWidgetIndex() the cell-information of the widget gets updated.
+     * setWidgetIndex() the cell-information for the widget gets updated.
      * This update gives doLayout() the chance to animate the moving
      * of the item visually (see moveWidget()).
      */
@@ -421,7 +422,7 @@ private:
     void updateWidgetProperties(KItemListWidget* widget, int index);
 
     /**
-     * Helper method for createWidget() and setWidgetIndex() to create or update
+     * Helper method for updateWidgetPropertes() to create or update
      * the itemlist group-header.
      */
     void updateGroupHeaderForWidget(KItemListWidget* widget);
@@ -446,6 +447,26 @@ private:
     void updateVisibleGroupHeaders();
 
     /**
+     * @return Index for the item in the list returned by KItemModelBase::groups()
+     *         that represents the group where the item with the index \a index
+     *         belongs to. -1 is returned if no groups are available.
+     */
+    int groupIndexForItem(int index) const;
+
+    /**
+     * Updates the alternateBackground-property of the widget dependent
+     * on the state of useAlternateBackgrounds() and the grouping state.
+     */
+    void updateAlternateBackgroundForWidget(KItemListWidget* widget);
+
+    /**
+     * @return True if alternate backgrounds should be used for the items.
+     *         This is the case if an empty item-size is given and if there
+     *         is more than one visible role.
+     */
+    bool useAlternateBackgrounds() const;
+
+    /**
      * @return The widths of each visible role that is shown in the KItemListHeader.
      */
     QHash<QByteArray, qreal> headerRolesWidths() const;
diff --git a/src/kitemviews/kitemlistviewlayouter.cpp b/src/kitemviews/kitemlistviewlayouter.cpp
index 744914929..d8b5796ec 100644
--- a/src/kitemviews/kitemlistviewlayouter.cpp
+++ b/src/kitemviews/kitemlistviewlayouter.cpp
@@ -340,6 +340,14 @@ void KItemListViewLayouter::markAsDirty()
     m_dirty = true;
 }
 
+
+#ifndef QT_NO_DEBUG
+    bool KItemListViewLayouter::isDirty()
+    {
+        return m_dirty;
+    }
+#endif
+
 void KItemListViewLayouter::doLayout()
 {
     if (m_dirty) {
diff --git a/src/kitemviews/kitemlistviewlayouter_p.h b/src/kitemviews/kitemlistviewlayouter_p.h
index 017f520fe..0d7c0d040 100644
--- a/src/kitemviews/kitemlistviewlayouter_p.h
+++ b/src/kitemviews/kitemlistviewlayouter_p.h
@@ -139,6 +139,15 @@ public:
 
     void markAsDirty();
 
+#ifndef QT_NO_DEBUG
+    /**
+     * @return True if the layouter has been marked as dirty and hence has
+     *         not called yet doLayout(). Is enabled only in the debugging
+     *         mode, as it is not useful to check the dirty state otherwise.
+     */
+    bool isDirty();
+#endif
+
 private:
     void doLayout();
     void updateVisibleIndexes();
diff --git a/src/kitemviews/kitemlistwidget.cpp b/src/kitemviews/kitemlistwidget.cpp
index 94eed6840..9d58a283e 100644
--- a/src/kitemviews/kitemlistwidget.cpp
+++ b/src/kitemviews/kitemlistwidget.cpp
@@ -40,7 +40,7 @@ KItemListWidget::KItemListWidget(QGraphicsItem* parent) :
     m_selected(false),
     m_current(false),
     m_hovered(false),
-    m_alternatingBackgroundColors(false),
+    m_alternateBackground(false),
     m_enabledSelectionToggle(false),
     m_data(),
     m_visibleRoles(),
@@ -105,7 +105,7 @@ void KItemListWidget::paint(QPainter* painter, const QStyleOptionGraphicsItem* o
 {
     Q_UNUSED(option);
 
-    if (m_alternatingBackgroundColors && (m_index & 0x1)) {
+    if (m_alternateBackground) {
         const QColor backgroundColor = m_styleOption.palette.color(QPalette::AlternateBase);
         const QRectF backgroundRect(0, 0, size().width(), size().height());
         painter->fillRect(backgroundRect, backgroundColor);
@@ -276,18 +276,18 @@ bool KItemListWidget::isHovered() const
     return m_hovered;
 }
 
-void KItemListWidget::setAlternatingBackgroundColors(bool enable)
+void KItemListWidget::setAlternateBackground(bool enable)
 {
-    if (m_alternatingBackgroundColors != enable) {
-        m_alternatingBackgroundColors = enable;
-        alternatingBackgroundColorsChanged(enable);
+    if (m_alternateBackground != enable) {
+        m_alternateBackground = enable;
+        alternateBackgroundChanged(enable);
         update();
     }
 }
 
-bool KItemListWidget::alternatingBackgroundColors() const
+bool KItemListWidget::alternateBackground() const
 {
-    return m_alternatingBackgroundColors;
+    return m_alternateBackground;
 }
 
 void KItemListWidget::setEnabledSelectionToggle(bool enable)
@@ -381,7 +381,7 @@ void KItemListWidget::hoveredChanged(bool hovered)
     Q_UNUSED(hovered);
 }
 
-void KItemListWidget::alternatingBackgroundColorsChanged(bool enabled)
+void KItemListWidget::alternateBackgroundChanged(bool enabled)
 {
     Q_UNUSED(enabled);
 }
diff --git a/src/kitemviews/kitemlistwidget.h b/src/kitemviews/kitemlistwidget.h
index 20efa7c94..84bd15fa5 100644
--- a/src/kitemviews/kitemlistwidget.h
+++ b/src/kitemviews/kitemlistwidget.h
@@ -82,8 +82,8 @@ public:
     void setHovered(bool hovered);
     bool isHovered() const;
 
-    void setAlternatingBackgroundColors(bool enable);
-    bool alternatingBackgroundColors() const;
+    void setAlternateBackground(bool enable);
+    bool alternateBackground() const;
 
     void setEnabledSelectionToggle(bool enabled);
     bool enabledSelectionToggle() const;
@@ -138,7 +138,7 @@ protected:
     virtual void currentChanged(bool current);
     virtual void selectedChanged(bool selected);
     virtual void hoveredChanged(bool hovered);
-    virtual void alternatingBackgroundColorsChanged(bool enabled);
+    virtual void alternateBackgroundChanged(bool enabled);
     virtual void siblingsInformationChanged(const QBitArray& current, const QBitArray& previous);
     virtual void resizeEvent(QGraphicsSceneResizeEvent* event);    
 
@@ -164,7 +164,7 @@ private:
     bool m_selected;
     bool m_current;
     bool m_hovered;
-    bool m_alternatingBackgroundColors;
+    bool m_alternateBackground;
     bool m_enabledSelectionToggle;
     QHash<QByteArray, QVariant> m_data;
     QList<QByteArray> m_visibleRoles;