diff --git a/src/kitemviews/kitemlistview.cpp b/src/kitemviews/kitemlistview.cpp
index 222a29cf5..281258898 100644
--- a/src/kitemviews/kitemlistview.cpp
+++ b/src/kitemviews/kitemlistview.cpp
@@ -459,9 +459,9 @@ int KItemListView::lastVisibleIndex() const
     return m_layouter->lastVisibleIndex();
 }
 
-void KItemListView::calculateItemSizeHints(QVector<QSizeF>& sizeHints) const
+void KItemListView::calculateItemSizeHints(QVector<qreal>& logicalHeightHints, qreal& logicalWidthHint) const
 {
-    widgetCreator()->calculateItemSizeHints(sizeHints, this);
+    widgetCreator()->calculateItemSizeHints(logicalHeightHints, logicalWidthHint, this);
 }
 
 void KItemListView::setSupportsItemExpanding(bool supportsExpanding)
diff --git a/src/kitemviews/kitemlistview.h b/src/kitemviews/kitemlistview.h
index 8a522a686..cf6f27c03 100644
--- a/src/kitemviews/kitemlistview.h
+++ b/src/kitemviews/kitemlistview.h
@@ -194,12 +194,14 @@ public:
     int lastVisibleIndex() const;
 
     /**
-     * @return Required size for all items in the model.
-     *         The returned value might be larger than KItemListView::itemSize().
+     * @return Calculates the required size for all items in the model.
+     *         It might be larger than KItemListView::itemSize().
      *         In this case the layout grid will be stretched to assure an
      *         unclipped item.
+     *         NOTE: the logical height (width) is actually the
+     *         width (height) if the scroll orientation is Qt::Vertical!
      */
-    void calculateItemSizeHints(QVector<QSizeF>& sizeHints) const;
+    void calculateItemSizeHints(QVector<qreal>& logicalHeightHints, qreal& logicalWidthHint) const;
 
     /**
      * If set to true, items having child-items can be expanded to show the child-items as
@@ -805,7 +807,7 @@ public:
 
     virtual void recycle(KItemListWidget* widget);
 
-    virtual void calculateItemSizeHints(QVector<QSizeF>& sizeHints, const KItemListView* view) const = 0;
+    virtual void calculateItemSizeHints(QVector<qreal>& logicalHeightHints, qreal& logicalWidthHint, const KItemListView* view) const = 0;
 
     virtual qreal preferredRoleColumnWidth(const QByteArray& role,
                                            int index,
@@ -824,7 +826,7 @@ public:
 
     virtual KItemListWidget* create(KItemListView* view);
 
-    virtual void calculateItemSizeHints(QVector<QSizeF>& sizeHints, const KItemListView* view) const;
+    virtual void calculateItemSizeHints(QVector<qreal>& logicalHeightHints, qreal& logicalWidthHint, const KItemListView* view) const;
 
     virtual qreal preferredRoleColumnWidth(const QByteArray& role,
                                            int index,
@@ -857,9 +859,9 @@ KItemListWidget* KItemListWidgetCreator<T>::create(KItemListView* view)
 }
 
 template<class T>
-void KItemListWidgetCreator<T>::calculateItemSizeHints(QVector<QSizeF>& sizeHints, const KItemListView* view) const
+void KItemListWidgetCreator<T>::calculateItemSizeHints(QVector<qreal>& logicalHeightHints, qreal& logicalWidthHint, const KItemListView* view) const
 {
-    return m_informant->calculateItemSizeHints(sizeHints, view);
+    return m_informant->calculateItemSizeHints(logicalHeightHints, logicalWidthHint, view);
 }
 
 template<class T>
diff --git a/src/kitemviews/kitemlistwidget.h b/src/kitemviews/kitemlistwidget.h
index cfb9155eb..a06bb5c9c 100644
--- a/src/kitemviews/kitemlistwidget.h
+++ b/src/kitemviews/kitemlistwidget.h
@@ -49,7 +49,7 @@ public:
     KItemListWidgetInformant();
     virtual ~KItemListWidgetInformant();
 
-    virtual void calculateItemSizeHints(QVector<QSizeF>& sizeHints, const KItemListView* view) const = 0;
+    virtual void calculateItemSizeHints(QVector<qreal>& logicalHeightHints, qreal& logicalWidthHint, const KItemListView* view) const = 0;
 
     virtual qreal preferredRoleColumnWidth(const QByteArray& role,
                                            int index,
diff --git a/src/kitemviews/kstandarditemlistwidget.cpp b/src/kitemviews/kstandarditemlistwidget.cpp
index 037226997..e0375480e 100644
--- a/src/kitemviews/kstandarditemlistwidget.cpp
+++ b/src/kitemviews/kstandarditemlistwidget.cpp
@@ -55,19 +55,19 @@ KStandardItemListWidgetInformant::~KStandardItemListWidgetInformant()
 {
 }
 
-void KStandardItemListWidgetInformant::calculateItemSizeHints(QVector<QSizeF>& sizeHints, const KItemListView* view) const
+void KStandardItemListWidgetInformant::calculateItemSizeHints(QVector<qreal>& logicalHeightHints, qreal& logicalWidthHint, const KItemListView* view) const
 {
     switch (static_cast<const KStandardItemListView*>(view)->itemLayout()) {
     case KStandardItemListWidget::IconsLayout:
-        calculateIconsLayoutItemSizeHints(sizeHints, view);
+        calculateIconsLayoutItemSizeHints(logicalHeightHints, logicalWidthHint, view);
         break;
 
     case KStandardItemListWidget::CompactLayout:
-        calculateCompactLayoutItemSizeHints(sizeHints, view);
+        calculateCompactLayoutItemSizeHints(logicalHeightHints, logicalWidthHint, view);
         break;
 
     case KStandardItemListWidget::DetailsLayout:
-        calculateDetailsLayoutItemSizeHints(sizeHints, view);
+        calculateDetailsLayoutItemSizeHints(logicalHeightHints, logicalWidthHint, view);
         break;
 
     default:
@@ -138,7 +138,7 @@ QFont KStandardItemListWidgetInformant::customizedFontForLinks(const QFont& base
     return baseFont;
 }
 
-void KStandardItemListWidgetInformant::calculateIconsLayoutItemSizeHints(QVector<QSizeF>& sizeHints, const KItemListView* view) const
+void KStandardItemListWidgetInformant::calculateIconsLayoutItemSizeHints(QVector<qreal>& logicalHeightHints, qreal& logicalWidthHint, const KItemListView* view) const
 {
     const KItemListStyleOption& option = view->styleOption();
     const QFont& normalFont = option.font;
@@ -154,8 +154,8 @@ void KStandardItemListWidgetInformant::calculateIconsLayoutItemSizeHints(QVector
     QTextOption textOption(Qt::AlignHCenter);
     textOption.setWrapMode(QTextOption::WrapAtWordBoundaryOrAnywhere);
 
-    for (int index = 0; index < sizeHints.count(); ++index) {
-        if (!sizeHints.at(index).isEmpty()) {
+    for (int index = 0; index < logicalHeightHints.count(); ++index) {
+        if (logicalHeightHints.at(index) > 0.0) {
             continue;
         }
 
@@ -186,11 +186,13 @@ void KStandardItemListWidgetInformant::calculateIconsLayoutItemSizeHints(QVector
         // Add one line for each additional information
         textHeight += additionalRolesSpacing;
 
-        sizeHints[index] = QSizeF(itemWidth, textHeight + spacingAndIconHeight);
+        logicalHeightHints[index] = textHeight + spacingAndIconHeight;
     }
+
+    logicalWidthHint = itemWidth;
 }
 
-void KStandardItemListWidgetInformant::calculateCompactLayoutItemSizeHints(QVector<QSizeF>& sizeHints, const KItemListView* view) const
+void KStandardItemListWidgetInformant::calculateCompactLayoutItemSizeHints(QVector<qreal>& logicalHeightHints, qreal& logicalWidthHint, const KItemListView* view) const
 {
     const KItemListStyleOption& option = view->styleOption();
     const QFontMetrics& normalFontMetrics = option.fontMetrics;
@@ -204,8 +206,8 @@ void KStandardItemListWidgetInformant::calculateCompactLayoutItemSizeHints(QVect
 
     const QFontMetrics linkFontMetrics(customizedFontForLinks(option.font));
 
-    for (int index = 0; index < sizeHints.count(); ++index) {
-        if (!sizeHints.at(index).isEmpty()) {
+    for (int index = 0; index < logicalHeightHints.count(); ++index) {
+        if (logicalHeightHints.at(index) > 0.0) {
             continue;
         }
 
@@ -232,22 +234,18 @@ void KStandardItemListWidgetInformant::calculateCompactLayoutItemSizeHints(QVect
             width = maxWidth;
         }
 
-        sizeHints[index] = QSizeF(width, height);
+        logicalHeightHints[index] = width;
     }
+
+    logicalWidthHint = height;
 }
 
-void KStandardItemListWidgetInformant::calculateDetailsLayoutItemSizeHints(QVector<QSizeF>& sizeHints, const KItemListView* view) const
+void KStandardItemListWidgetInformant::calculateDetailsLayoutItemSizeHints(QVector<qreal>& logicalHeightHints, qreal& logicalWidthHint, const KItemListView* view) const
 {
     const KItemListStyleOption& option = view->styleOption();
     const qreal height = option.padding * 2 + qMax(option.iconSize, option.fontMetrics.height());
-
-    for (int index = 0; index < sizeHints.count(); ++index) {
-        if (!sizeHints.at(index).isEmpty()) {
-            continue;
-        }
-
-        sizeHints[index] = QSizeF(-1, height);
-    }
+    logicalHeightHints.fill(height);
+    logicalWidthHint = -1.0;
 }
 
 KStandardItemListWidget::KStandardItemListWidget(KItemListWidgetInformant* informant, QGraphicsItem* parent) :
diff --git a/src/kitemviews/kstandarditemlistwidget.h b/src/kitemviews/kstandarditemlistwidget.h
index ba426d054..4f7a9136e 100644
--- a/src/kitemviews/kstandarditemlistwidget.h
+++ b/src/kitemviews/kstandarditemlistwidget.h
@@ -38,7 +38,7 @@ public:
     KStandardItemListWidgetInformant();
     virtual ~KStandardItemListWidgetInformant();
 
-    virtual void calculateItemSizeHints(QVector<QSizeF>& sizeHints, const KItemListView* view) const;
+    virtual void calculateItemSizeHints(QVector<qreal>& logicalHeightHints, qreal& logicalWidthHint, const KItemListView* view) const;
 
     virtual qreal preferredRoleColumnWidth(const QByteArray& role,
                                            int index,
@@ -73,9 +73,9 @@ protected:
     */
     virtual QFont customizedFontForLinks(const QFont& baseFont) const;
 
-    void calculateIconsLayoutItemSizeHints(QVector<QSizeF>& sizeHints, const KItemListView* view) const;
-    void calculateCompactLayoutItemSizeHints(QVector<QSizeF>& sizeHints, const KItemListView* view) const;
-    void calculateDetailsLayoutItemSizeHints(QVector<QSizeF>& sizeHints, const KItemListView* view) const;
+    void calculateIconsLayoutItemSizeHints(QVector<qreal>& logicalHeightHints, qreal& logicalWidthHint, const KItemListView* view) const;
+    void calculateCompactLayoutItemSizeHints(QVector<qreal>& logicalHeightHints, qreal& logicalWidthHint, const KItemListView* view) const;
+    void calculateDetailsLayoutItemSizeHints(QVector<qreal>& logicalHeightHints, qreal& logicalWidthHint, const KItemListView* view) const;
 
     friend class KStandardItemListWidget; // Accesses roleText()
 };
diff --git a/src/kitemviews/private/kitemlistsizehintresolver.cpp b/src/kitemviews/private/kitemlistsizehintresolver.cpp
index 029beddf9..1d8067026 100644
--- a/src/kitemviews/private/kitemlistsizehintresolver.cpp
+++ b/src/kitemviews/private/kitemlistsizehintresolver.cpp
@@ -23,7 +23,8 @@
 
 KItemListSizeHintResolver::KItemListSizeHintResolver(const KItemListView* itemListView) :
     m_itemListView(itemListView),
-    m_sizeHintCache(),
+    m_logicalHeightHintCache(),
+    m_logicalWidthHint(0.0),
     m_needsResolving(false)
 {
 }
@@ -35,7 +36,7 @@ KItemListSizeHintResolver::~KItemListSizeHintResolver()
 QSizeF KItemListSizeHintResolver::sizeHint(int index)
 {
     updateCache();
-    return m_sizeHintCache.at(index);
+    return QSizeF(m_logicalWidthHint, m_logicalHeightHintCache.at(index));
 }
 
 void KItemListSizeHintResolver::itemsInserted(const KItemRangeList& itemRanges)
@@ -45,15 +46,15 @@ void KItemListSizeHintResolver::itemsInserted(const KItemRangeList& itemRanges)
         insertedCount += range.count;
     }
 
-    const int currentCount = m_sizeHintCache.count();
-    m_sizeHintCache.reserve(currentCount + insertedCount);
+    const int currentCount = m_logicalHeightHintCache.count();
+    m_logicalHeightHintCache.reserve(currentCount + insertedCount);
 
     // We build the new list from the end to the beginning to mimize the
     // number of moves.
-    m_sizeHintCache.insert(m_sizeHintCache.end(), insertedCount, QSizeF());
+    m_logicalHeightHintCache.insert(m_logicalHeightHintCache.end(), insertedCount, 0.0);
 
     int sourceIndex = currentCount - 1;
-    int targetIndex = m_sizeHintCache.count() - 1;
+    int targetIndex = m_logicalHeightHintCache.count() - 1;
     int itemsToInsertBeforeCurrentRange = insertedCount;
 
     for (int rangeIndex = itemRanges.count() - 1; rangeIndex >= 0; --rangeIndex) {
@@ -62,33 +63,33 @@ void KItemListSizeHintResolver::itemsInserted(const KItemRangeList& itemRanges)
 
         // First: move all existing items that must be put behind 'range'.
         while (targetIndex >= itemsToInsertBeforeCurrentRange + range.index + range.count) {
-            m_sizeHintCache[targetIndex] = m_sizeHintCache[sourceIndex];
+            m_logicalHeightHintCache[targetIndex] = m_logicalHeightHintCache[sourceIndex];
             --sourceIndex;
             --targetIndex;
         }
 
         // Then: insert QSizeF() for the items which are inserted into 'range'.
         while (targetIndex >= itemsToInsertBeforeCurrentRange + range.index) {
-            m_sizeHintCache[targetIndex] = QSizeF();
+            m_logicalHeightHintCache[targetIndex] = 0.0;
             --targetIndex;
         }
     }
 
     m_needsResolving = true;
 
-    Q_ASSERT(m_sizeHintCache.count() == m_itemListView->model()->count());
+    Q_ASSERT(m_logicalHeightHintCache.count() == m_itemListView->model()->count());
 }
 
 void KItemListSizeHintResolver::itemsRemoved(const KItemRangeList& itemRanges)
 {
-    const QVector<QSizeF>::iterator begin = m_sizeHintCache.begin();
-    const QVector<QSizeF>::iterator end = m_sizeHintCache.end();
+    const QVector<qreal>::iterator begin = m_logicalHeightHintCache.begin();
+    const QVector<qreal>::iterator end = m_logicalHeightHintCache.end();
 
     KItemRangeList::const_iterator rangeIt = itemRanges.constBegin();
     const KItemRangeList::const_iterator rangeEnd = itemRanges.constEnd();
 
-    QVector<QSizeF>::iterator destIt = begin + rangeIt->index;
-    QVector<QSizeF>::iterator srcIt = destIt + rangeIt->count;
+    QVector<qreal>::iterator destIt = begin + rangeIt->index;
+    QVector<qreal>::iterator srcIt = destIt + rangeIt->count;
 
     ++rangeIt;
 
@@ -104,33 +105,33 @@ void KItemListSizeHintResolver::itemsRemoved(const KItemRangeList& itemRanges)
         }
     }
 
-    m_sizeHintCache.erase(destIt, end);
+    m_logicalHeightHintCache.erase(destIt, end);
 
     // Note that the cache size might temporarily not match the model size if
     // this function is called from KItemListView::setModel() to empty the cache.
-    if (!m_sizeHintCache.isEmpty() && m_itemListView->model()) {
-        Q_ASSERT(m_sizeHintCache.count() == m_itemListView->model()->count());
+    if (!m_logicalHeightHintCache.isEmpty() && m_itemListView->model()) {
+        Q_ASSERT(m_logicalHeightHintCache.count() == m_itemListView->model()->count());
     }
 }
 
 void KItemListSizeHintResolver::itemsMoved(const KItemRange& range, const QList<int>& movedToIndexes)
 {
-    QVector<QSizeF> newSizeHintCache(m_sizeHintCache);
+    QVector<qreal> newLogicalHeightHintCache(m_logicalHeightHintCache);
 
     const int movedRangeEnd = range.index + range.count;
     for (int i = range.index; i < movedRangeEnd; ++i) {
         const int newIndex = movedToIndexes.at(i - range.index);
-        newSizeHintCache[newIndex] = m_sizeHintCache.at(i);
+        newLogicalHeightHintCache[newIndex] = m_logicalHeightHintCache.at(i);
     }
 
-    m_sizeHintCache = newSizeHintCache;
+    m_logicalHeightHintCache = newLogicalHeightHintCache;
 }
 
 void KItemListSizeHintResolver::itemsChanged(int index, int count, const QSet<QByteArray>& roles)
 {
     Q_UNUSED(roles);
     while (count) {
-        m_sizeHintCache[index] = QSizeF();
+        m_logicalHeightHintCache[index] = 0.0;
         ++index;
         --count;
     }
@@ -140,14 +141,14 @@ void KItemListSizeHintResolver::itemsChanged(int index, int count, const QSet<QB
 
 void KItemListSizeHintResolver::clearCache()
 {
-    m_sizeHintCache.fill(QSizeF());
+    m_logicalHeightHintCache.fill(0.0);
     m_needsResolving = true;
 }
 
 void KItemListSizeHintResolver::updateCache()
 {
     if (m_needsResolving) {
-        m_itemListView->calculateItemSizeHints(m_sizeHintCache);
+        m_itemListView->calculateItemSizeHints(m_logicalHeightHintCache, m_logicalWidthHint);
         m_needsResolving = false;
     }
 }
diff --git a/src/kitemviews/private/kitemlistsizehintresolver.h b/src/kitemviews/private/kitemlistsizehintresolver.h
index 86580bf7b..a0ad033f3 100644
--- a/src/kitemviews/private/kitemlistsizehintresolver.h
+++ b/src/kitemviews/private/kitemlistsizehintresolver.h
@@ -48,7 +48,8 @@ public:
 
 private:
     const KItemListView* m_itemListView;
-    mutable QVector<QSizeF> m_sizeHintCache;
+    mutable QVector<qreal> m_logicalHeightHintCache;
+    mutable qreal m_logicalWidthHint;
     bool m_needsResolving;
 };
 
diff --git a/src/kitemviews/private/kitemlistviewlayouter.cpp b/src/kitemviews/private/kitemlistviewlayouter.cpp
index 9da5384d4..04325c7d0 100644
--- a/src/kitemviews/private/kitemlistviewlayouter.cpp
+++ b/src/kitemviews/private/kitemlistviewlayouter.cpp
@@ -239,6 +239,7 @@ QRectF KItemListViewLayouter::itemRect(int index) const
         // to get the physical horizontal direction
         QPointF pos(y, x);
         pos.rx() -= m_scrollOffset;
+        sizeHint.transpose();
         return QRectF(pos, sizeHint);
     }
 
@@ -282,7 +283,9 @@ QRectF KItemListViewLayouter::groupHeaderRect(int index) const
                 break;
             }
 
-            const qreal itemWidth = m_sizeHintResolver->sizeHint(index).width();
+            const qreal itemWidth = (m_scrollOrientation == Qt::Vertical)
+                                     ? m_sizeHintResolver->sizeHint(index).width()
+                                     : m_sizeHintResolver->sizeHint(index).height();
 
             if (itemWidth > headerWidth) {
                 headerWidth = itemWidth;
@@ -461,7 +464,7 @@ void KItemListViewLayouter::doLayout()
             while (index < itemCount && column < m_columnCount) {
                 qreal requiredItemHeight = itemSize.height();
                 const QSizeF sizeHint = m_sizeHintResolver->sizeHint(index);
-                const qreal sizeHintHeight = horizontalScrolling ? sizeHint.width() : sizeHint.height();
+                const qreal sizeHintHeight = sizeHint.height();
                 if (sizeHintHeight > requiredItemHeight) {
                     requiredItemHeight = sizeHintHeight;
                 }