Righ-to-left support for GridView and ListView

GridView and ListView can now be laid out right-to-left. The
behaviour should be identical and mirrored to the oridinary behaviour.

Change-Id: I8e55c5f88358042caa5201712ef239cd67628172
Task-number: QTBUG-15877
Reviewed-by: Joona Petrell

1 files changed, 417 insertions, 118 deletions

diff --git a/src/declarative/graphicsitems/qdeclarativegridview.cpp b/src/declarative/graphicsitems/qdeclarativegridview.cpp
index 7e7889c..39fa8e8 100644
--- a/src/declarative/graphicsitems/qdeclarativegridview.cpp
+++ b/src/declarative/graphicsitems/qdeclarativegridview.cpp
@@ -68,19 +68,60 @@ public:
     }
     ~FxGridItem() {}
 
-    qreal rowPos() const { return (view->flow() == QDeclarativeGridView::LeftToRight ? item->y() : item->x()); }
-    qreal colPos() const { return (view->flow() == QDeclarativeGridView::LeftToRight ? item->x() : item->y()); }
+    qreal rowPos() const {
+        qreal rowPos = 0;
+        if (view->flow() == QDeclarativeGridView::LeftToRight) {
+            rowPos = item->y();
+        } else {
+            if (view->layoutDirection() == Qt::LeftToRight)
+                rowPos = item->x();
+            else
+                rowPos = -view->cellWidth()-item->x();
+        }
+        return rowPos;
+    }
+    qreal colPos() const {
+        qreal colPos = 0;
+        if (view->flow() == QDeclarativeGridView::LeftToRight) {
+            if (view->layoutDirection() == Qt::LeftToRight) {
+                colPos = item->x();
+            } else {
+                int colSize = view->cellWidth();
+                int columns = view->width()/colSize;
+                colPos = colSize * (columns-1) - item->x();
+            }
+        } else {
+            colPos = item->y();
+        }
+
+        return colPos;
+    }
+
     qreal endRowPos() const {
-        return view->flow() == QDeclarativeGridView::LeftToRight
-                                ? item->y() + view->cellHeight() - 1
-                                : item->x() + view->cellWidth() - 1;
+        if (view->flow() == QDeclarativeGridView::LeftToRight) {
+            return item->y() + view->cellHeight() - 1;
+        } else {
+            if (view->layoutDirection() == Qt::LeftToRight)
+                return item->x() + view->cellWidth() - 1;
+            else
+                return -item->x() - 1;
+        }
     }
     void setPosition(qreal col, qreal row) {
-        if (view->flow() == QDeclarativeGridView::LeftToRight) {
-            item->setPos(QPointF(col, row));
+        if (view->layoutDirection() == Qt::LeftToRight) {
+            if (view->flow() == QDeclarativeGridView::LeftToRight)
+                item->setPos(QPointF(col, row));
+            else
+                item->setPos(QPointF(row, col));
         } else {
-            item->setPos(QPointF(row, col));
+            if (view->flow() == QDeclarativeGridView::LeftToRight) {
+                int columns = view->width()/view->cellWidth();
+                item->setPos(QPointF((view->cellWidth() * (columns-1) - col), row));
+            } else {
+                item->setPos(QPointF(-view->cellWidth()-row, col));
+            }
         }
+
     }
     bool contains(int x, int y) const {
         return (x >= item->x() && x < item->x() + view->cellWidth() &&
@@ -101,10 +142,12 @@ class QDeclarativeGridViewPrivate : public QDeclarativeFlickablePrivate
 
 public:
     QDeclarativeGridViewPrivate()
-    : currentItem(0), flow(QDeclarativeGridView::LeftToRight)
+    : currentItem(0), layoutDirection(Qt::LeftToRight), flow(QDeclarativeGridView::LeftToRight)
     , visibleIndex(0) , currentIndex(-1)
     , cellWidth(100), cellHeight(100), columns(1), requestedIndex(-1), itemCount(0)
-    , highlightRangeStart(0), highlightRangeEnd(0), highlightRange(QDeclarativeGridView::NoHighlightRange)
+    , highlightRangeStart(0), highlightRangeEnd(0)
+    , highlightRangeStartValid(false), highlightRangeEndValid(false)
+    , highlightRange(QDeclarativeGridView::NoHighlightRange)
     , highlightComponent(0), highlight(0), trackedItem(0)
     , moveReason(Other), buffer(0), highlightXAnimator(0), highlightYAnimator(0)
     , highlightMoveDuration(150)
@@ -144,35 +187,54 @@ public:
         return 0;
     }
 
+    bool isRightToLeftTopToBottom() const {
+        return flow == QDeclarativeGridView::TopToBottom && layoutDirection == Qt::RightToLeft;
+    }
+
     qreal position() const {
         Q_Q(const QDeclarativeGridView);
         return flow == QDeclarativeGridView::LeftToRight ? q->contentY() : q->contentX();
     }
     void setPosition(qreal pos) {
         Q_Q(QDeclarativeGridView);
-        if (flow == QDeclarativeGridView::LeftToRight)
+        if (flow == QDeclarativeGridView::LeftToRight) {
             q->QDeclarativeFlickable::setContentY(pos);
-        else
-            q->QDeclarativeFlickable::setContentX(pos);
+            q->QDeclarativeFlickable::setContentX(0);
+        } else {
+            if (layoutDirection == Qt::LeftToRight)
+                q->QDeclarativeFlickable::setContentX(pos);
+            else
+                q->QDeclarativeFlickable::setContentX(-pos-size());
+            q->QDeclarativeFlickable::setContentY(0);
+        }
     }
     int size() const {
         Q_Q(const QDeclarativeGridView);
         return flow == QDeclarativeGridView::LeftToRight ? q->height() : q->width();
     }
-    qreal startPosition() const {
+    qreal originPosition() const {
         qreal pos = 0;
         if (!visibleItems.isEmpty())
             pos = visibleItems.first()->rowPos() - visibleIndex / columns * rowSize();
         return pos;
     }
 
-    qreal endPosition() const {
+    qreal lastPosition() const {
         qreal pos = 0;
         if (model && model->count())
             pos = rowPosAt(model->count() - 1) + rowSize();
         return pos;
     }
 
+    qreal startPosition() const {
+        return isRightToLeftTopToBottom() ? -lastPosition()+1 : originPosition();
+    }
+
+    qreal endPosition() const {
+        return isRightToLeftTopToBottom() ? -originPosition()+1 : lastPosition();
+
+    }
+
     bool isValid() const {
         return model && model->count() && model->isValid();
     }
@@ -227,7 +289,7 @@ public:
     }
 
     FxGridItem *firstVisibleItem() const {
-        const qreal pos = position();
+        const qreal pos = isRightToLeftTopToBottom() ? -position()-size() : position();
         for (int i = 0; i < visibleItems.count(); ++i) {
             FxGridItem *item = visibleItems.at(i);
             if (item->index != -1 && item->endRowPos() > pos)
@@ -237,15 +299,12 @@ public:
     }
 
     int lastVisibleIndex() const {
-        int lastIndex = -1;
-        for (int i = visibleItems.count()-1; i >= 0; --i) {
-            FxGridItem *gridItem = visibleItems.at(i);
-            if (gridItem->index != -1) {
-                lastIndex = gridItem->index;
-                break;
-            }
+        for (int i = 0; i < visibleItems.count(); ++i) {
+            FxGridItem *item = visibleItems.at(i);
+            if (item->index != -1)
+                return item->index;
         }
-        return lastIndex;
+        return -1;
     }
 
     // Map a model index to visibleItems list index.
@@ -271,8 +330,15 @@ public:
             pos += rowSize()/2;
             snapPos = visibleItems.first()->rowPos() - visibleIndex / columns * rowSize();
             snapPos = pos - fmodf(pos - snapPos, qreal(rowSize()));
-            qreal maxExtent = flow == QDeclarativeGridView::LeftToRight ? -q->maxYExtent() : -q->maxXExtent();
-            qreal minExtent = flow == QDeclarativeGridView::LeftToRight ? -q->minYExtent() : -q->minXExtent();
+            qreal maxExtent;
+            qreal minExtent;
+            if (isRightToLeftTopToBottom()) {
+                maxExtent = q->minXExtent();
+                minExtent = q->maxXExtent();
+            } else {
+                maxExtent = flow == QDeclarativeGridView::LeftToRight ? -q->maxYExtent() : -q->maxXExtent();
+                minExtent = flow == QDeclarativeGridView::LeftToRight ? -q->minYExtent() : -q->minXExtent();
+            }
             if (snapPos > maxExtent)
                 snapPos = maxExtent;
             if (snapPos < minExtent)
@@ -363,6 +429,7 @@ public:
     QList<FxGridItem*> visibleItems;
     QHash<QDeclarativeItem*,int> unrequestedItems;
     FxGridItem *currentItem;
+    Qt::LayoutDirection layoutDirection;
     QDeclarativeGridView::Flow flow;
     int visibleIndex;
     int currentIndex;
@@ -373,6 +440,8 @@ public:
     int itemCount;
     qreal highlightRangeStart;
     qreal highlightRangeEnd;
+    bool highlightRangeStartValid;
+    bool highlightRangeEndValid;
     QDeclarativeGridView::HighlightRangeMode highlightRange;
     QDeclarativeComponent *highlightComponent;
     FxGridItem *highlight;
@@ -554,7 +623,7 @@ void QDeclarativeGridViewPrivate::refill(qreal from, qreal to, bool doBuffer)
     if (!lazyRelease || !changed || deferredRelease) { // avoid destroying items in the same frame that we create
         while (visibleItems.count() > 1
                && (item = visibleItems.first())
-                    && item->endRowPos() < bufferFrom - rowSize()*(item->colPos()/colSize()+1)/(columns+1)) {
+                    && item->rowPos()+rowSize()-1 < bufferFrom - rowSize()*(item->colPos()/colSize()+1)/(columns+1)) {
             if (item->attached->delayRemove())
                 break;
 //            qDebug() << "refill: remove first" << visibleIndex << "top end pos" << item->endRowPos();
@@ -596,12 +665,14 @@ void QDeclarativeGridViewPrivate::refill(qreal from, qreal to, bool doBuffer)
 void QDeclarativeGridViewPrivate::updateGrid()
 {
     Q_Q(QDeclarativeGridView);
+
     columns = (int)qMax((flow == QDeclarativeGridView::LeftToRight ? q->width() : q->height()) / colSize(), qreal(1.));
     if (isValid()) {
         if (flow == QDeclarativeGridView::LeftToRight)
             q->setContentHeight(endPosition() - startPosition());
         else
-            q->setContentWidth(endPosition() - startPosition());
+            q->setContentWidth(lastPosition() - originPosition());
+        setPosition(0);
     }
 }
 
@@ -626,7 +697,7 @@ void QDeclarativeGridViewPrivate::layout()
         qreal rowPos = visibleItems.first()->rowPos();
         qreal colPos = visibleItems.first()->colPos();
         int col = visibleIndex % columns;
-        if (colPos != col * colSize()) {
+        if (colPos != col * colSize() || isRightToLeftTopToBottom()) {
             colPos = col * colSize();
             visibleItems.first()->setPosition(colPos, rowPos);
         }
@@ -669,10 +740,14 @@ void QDeclarativeGridViewPrivate::updateUnrequestedPositions()
 {
     QHash<QDeclarativeItem*,int>::const_iterator it;
     for (it = unrequestedItems.begin(); it != unrequestedItems.end(); ++it) {
+        QDeclarativeItem *item = it.key();
         if (flow == QDeclarativeGridView::LeftToRight) {
-            it.key()->setPos(QPointF(colPosAt(*it), rowPosAt(*it)));
+            item->setPos(QPointF(colPosAt(*it), rowPosAt(*it)));
         } else {
-            it.key()->setPos(QPointF(rowPosAt(*it), colPosAt(*it)));
+            if (isRightToLeftTopToBottom())
+                item->setPos(QPointF(-rowPosAt(*it)-item->width(), colPosAt(*it)));
+            else
+                item->setPos(QPointF(rowPosAt(*it), (columns-1)*colSize()-colPosAt(*it)));
         }
     }
 }
@@ -837,23 +912,30 @@ void QDeclarativeGridViewPrivate::updateFooter()
         }
     }
     if (footer) {
+        qreal colOffset = 0;
+        qreal rowOffset;
+        if (isRightToLeftTopToBottom()) {
+            rowOffset = footer->item->width()-cellWidth;
+        } else {
+            rowOffset = 0;
+            if (layoutDirection == Qt::RightToLeft)
+                colOffset = footer->item->width()-cellWidth;
+        }
         if (visibleItems.count()) {
-            qreal endPos = endPosition();
+            qreal endPos = lastPosition();
             if (lastVisibleIndex() == model->count()-1) {
-                footer->setPosition(0, endPos);
+                footer->setPosition(colOffset, endPos + rowOffset);
             } else {
-                qreal visiblePos = position() + q->height();
-                if (endPos <= visiblePos || footer->endRowPos() < endPos)
-                    footer->setPosition(0, endPos);
+                qreal visiblePos = isRightToLeftTopToBottom() ? -position() : position() + size();
+                if (endPos <= visiblePos || footer->endRowPos() < endPos + rowOffset)
+                    footer->setPosition(colOffset, endPos + rowOffset);
             }
         } else {
             qreal endPos = 0;
             if (header) {
-                endPos += flow == QDeclarativeGridView::LeftToRight
-                                   ? header->item->height()
-                                   : header->item->width();
+                endPos += flow == QDeclarativeGridView::LeftToRight ? header->item->height() : header->item->width();
             }
-            footer->setPosition(0, endPos);
+            footer->setPosition(colOffset, endPos);
         }
     }
 }
@@ -883,16 +965,27 @@ void QDeclarativeGridViewPrivate::updateHeader()
         }
     }
     if (header) {
+        qreal colOffset = 0;
+        qreal rowOffset;
+        if (isRightToLeftTopToBottom()) {
+            rowOffset = -cellWidth;
+        } else {
+            rowOffset = -headerSize();
+            if (layoutDirection == Qt::RightToLeft)
+                colOffset = header->item->width()-cellWidth;
+        }
         if (visibleItems.count()) {
-            qreal startPos = startPosition();
+            qreal startPos = originPosition();
             if (visibleIndex == 0) {
-                header->setPosition(0, startPos - headerSize());
+                header->setPosition(colOffset, startPos + rowOffset);
             } else {
-                if (position() <= startPos || header->rowPos() > startPos - headerSize())
-                    header->setPosition(0, startPos - headerSize());
+                qreal tempPos = isRightToLeftTopToBottom() ? -position()-size() : position();
+                qreal headerPos = isRightToLeftTopToBottom() ? header->rowPos() + cellWidth - headerSize() : header->rowPos();
+                if (tempPos <= startPos || headerPos > startPos + rowOffset)
+                    header->setPosition(colOffset, startPos + rowOffset);
             }
         } else {
-            header->setPosition(0, 0);
+            header->setPosition(colOffset, 0);
         }
     }
 }
@@ -915,21 +1008,44 @@ void QDeclarativeGridViewPrivate::fixup(AxisData &data, qreal minExtent, qreal m
     int oldDuration = fixupDuration;
     fixupDuration = moveReason == Mouse ? fixupDuration : 0;
 
+    qreal highlightStart;
+    qreal highlightEnd;
+    qreal viewPos;
+    if (isRightToLeftTopToBottom()) {
+        // Handle Right-To-Left exceptions
+        viewPos = -position()-size();
+        highlightStart = highlightRangeStartValid ? size()-highlightRangeEnd : highlightRangeStart;
+        highlightEnd = highlightRangeEndValid ? size()-highlightRangeStart : highlightRangeEnd;
+    } else {
+        viewPos = position();
+        highlightStart = highlightRangeStart;
+        highlightEnd = highlightRangeEnd;
+    }
+
     if (snapMode != QDeclarativeGridView::NoSnap) {
-        FxGridItem *topItem = snapItemAt(position()+highlightRangeStart);
-        FxGridItem *bottomItem = snapItemAt(position()+highlightRangeEnd);
+        qreal tempPosition = isRightToLeftTopToBottom() ? -position()-size() : position();
+        FxGridItem *topItem = snapItemAt(tempPosition+highlightStart);
+        FxGridItem *bottomItem = snapItemAt(tempPosition+highlightEnd);
         qreal pos;
         if (topItem && bottomItem && haveHighlightRange && highlightRange == QDeclarativeGridView::StrictlyEnforceRange) {
-            qreal topPos = qMin(topItem->rowPos() - highlightRangeStart, -maxExtent);
-            qreal bottomPos = qMax(bottomItem->rowPos() - highlightRangeEnd, -minExtent);
+            qreal topPos = qMin(topItem->rowPos() - highlightStart, -maxExtent);
+            qreal bottomPos = qMax(bottomItem->rowPos() - highlightEnd, -minExtent);
             pos = qAbs(data.move + topPos) < qAbs(data.move + bottomPos) ? topPos : bottomPos;
         } else if (topItem) {
-            if (topItem->index == 0 && header && position()+highlightRangeStart < header->rowPos()+headerSize()/2)
-                pos = header->rowPos() - highlightRangeStart;
-            else
-                pos = qMax(qMin(topItem->rowPos() - highlightRangeStart, -maxExtent), -minExtent);
+            qreal headerPos = isRightToLeftTopToBottom() ? header->rowPos() + cellWidth - headerSize() : header->rowPos();
+            if (topItem->index == 0 && header && tempPosition+highlightStart < headerPos+headerSize()/2) {
+                pos = isRightToLeftTopToBottom() ? - headerPos + highlightStart - size() : headerPos - highlightStart;
+            } else {
+                if (isRightToLeftTopToBottom())
+                    pos = qMax(qMin(-topItem->rowPos() + highlightStart - size(), -maxExtent), -minExtent);
+                else
+                    pos = qMax(qMin(topItem->rowPos() - highlightStart, -maxExtent), -minExtent);
+            }
         } else if (bottomItem) {
-            pos = qMax(qMin(bottomItem->rowPos() - highlightRangeStart, -maxExtent), -minExtent);
+            if (isRightToLeftTopToBottom())
+                pos = qMax(qMin(-bottomItem->rowPos() + highlightStart - size(), -maxExtent), -minExtent);
+            else
+                pos = qMax(qMin(bottomItem->rowPos() - highlightStart, -maxExtent), -minExtent);
         } else {
             QDeclarativeFlickablePrivate::fixup(data, minExtent, maxExtent);
             fixupDuration = oldDuration;
@@ -938,12 +1054,15 @@ void QDeclarativeGridViewPrivate::fixup(AxisData &data, qreal minExtent, qreal m
         if (currentItem && haveHighlightRange && highlightRange == QDeclarativeGridView::StrictlyEnforceRange) {
             updateHighlight();
             qreal currPos = currentItem->rowPos();
-            if (pos < currPos + rowSize() - highlightRangeEnd)
-                pos = currPos + rowSize() - highlightRangeEnd;
-            if (pos > currPos - highlightRangeStart)
-                pos = currPos - highlightRangeStart;
+            if (isRightToLeftTopToBottom())
+                pos = -pos-size(); // Transform Pos if required
+            if (pos < currPos + rowSize() - highlightEnd)
+                pos = currPos + rowSize() - highlightEnd;
+            if (pos > currPos - highlightStart)
+                pos = currPos - highlightStart;
+            if (isRightToLeftTopToBottom())
+                pos = -pos-size(); // Untransform
         }
-
         qreal dist = qAbs(data.move + pos);
         if (dist > 0) {
             timeline.reset(data.move);
@@ -957,12 +1076,12 @@ void QDeclarativeGridViewPrivate::fixup(AxisData &data, qreal minExtent, qreal m
         if (currentItem) {
             updateHighlight();
             qreal pos = currentItem->rowPos();
-            qreal viewPos = position();
-            if (viewPos < pos + rowSize() - highlightRangeEnd)
-                viewPos = pos + rowSize() - highlightRangeEnd;
-            if (viewPos > pos - highlightRangeStart)
-                viewPos = pos - highlightRangeStart;
-
+            if (viewPos < pos + rowSize() - highlightEnd)
+                viewPos = pos + rowSize() - highlightEnd;
+            if (viewPos > pos - highlightStart)
+                viewPos = pos - highlightStart;
+            if (isRightToLeftTopToBottom())
+                viewPos = -viewPos-size();
             timeline.reset(data.move);
             if (viewPos != position()) {
                 if (fixupDuration)
@@ -989,12 +1108,14 @@ void QDeclarativeGridViewPrivate::flick(AxisData &data, qreal minExtent, qreal m
         return;
     }
     qreal maxDistance = 0;
-    // -ve velocity means list is moving up
+    qreal dataValue = isRightToLeftTopToBottom() ? -data.move.value()+size() : data.move.value();
+    // -ve velocity means list is moving up/left
     if (velocity > 0) {
         if (data.move.value() < minExtent) {
             if (snapMode == QDeclarativeGridView::SnapOneRow) {
-                if (FxGridItem *item = firstVisibleItem())
-                    maxDistance = qAbs(item->rowPos() + data.move.value());
+                if (FxGridItem *item = firstVisibleItem()) {
+                    maxDistance = qAbs(item->rowPos() + dataValue);
+                }
             } else {
                 maxDistance = qAbs(minExtent - data.move.value());
             }
@@ -1004,8 +1125,8 @@ void QDeclarativeGridViewPrivate::flick(AxisData &data, qreal minExtent, qreal m
     } else {
         if (data.move.value() > maxExtent) {
             if (snapMode == QDeclarativeGridView::SnapOneRow) {
-                qreal pos = snapPosAt(-data.move.value()) + rowSize();
-                maxDistance = qAbs(pos + data.move.value());
+                qreal pos = snapPosAt(-dataValue) + (isRightToLeftTopToBottom() ? 0 : rowSize());
+                maxDistance = qAbs(pos + dataValue);
             } else {
                 maxDistance = qAbs(maxExtent - data.move.value());
             }
@@ -1013,7 +1134,10 @@ void QDeclarativeGridViewPrivate::flick(AxisData &data, qreal minExtent, qreal m
         if (snapMode == QDeclarativeGridView::NoSnap && highlightRange != QDeclarativeGridView::StrictlyEnforceRange)
             data.flickTarget = maxExtent;
     }
+
     bool overShoot = boundsBehavior == QDeclarativeFlickable::DragAndOvershootBounds;
+    qreal highlightStart = isRightToLeftTopToBottom() && highlightRangeStartValid ? size()-highlightRangeEnd : highlightRangeStart;
+
     if (maxDistance > 0 || overShoot) {
         // This mode requires the grid to stop exactly on a row boundary.
         qreal v = velocity;
@@ -1032,7 +1156,9 @@ void QDeclarativeGridViewPrivate::flick(AxisData &data, qreal minExtent, qreal m
             dist = qMin(dist, maxDistance);
             if (v > 0)
                 dist = -dist;
-            data.flickTarget = -snapPosAt(-(data.move.value() - highlightRangeStart) + dist) + highlightRangeStart;
+            qreal distTemp = isRightToLeftTopToBottom() ? -dist : dist;
+            data.flickTarget = -snapPosAt(-(dataValue - highlightStart) + distTemp) + highlightStart;
+            data.flickTarget = isRightToLeftTopToBottom() ? -data.flickTarget+size() : data.flickTarget;
             qreal adjDist = -data.flickTarget + data.move.value();
             if (qAbs(adjDist) > qAbs(dist)) {
                 // Prevent painfully slow flicking - adjust velocity to suit flickDeceleration
@@ -1224,6 +1350,13 @@ QVariant QDeclarativeGridView::model() const
     return d->modelVariant;
 }
 
+// For internal use
+int QDeclarativeGridView::modelCount() const
+{
+    Q_D(const QDeclarativeGridView);
+    return d->model->count();
+}
+
 void QDeclarativeGridView::setModel(const QVariant &model)
 {
     Q_D(QDeclarativeGridView);
@@ -1549,6 +1682,7 @@ qreal QDeclarativeGridView::preferredHighlightBegin() const
 void QDeclarativeGridView::setPreferredHighlightBegin(qreal start)
 {
     Q_D(QDeclarativeGridView);
+    d->highlightRangeStartValid = true;
     if (d->highlightRangeStart == start)
         return;
     d->highlightRangeStart = start;
@@ -1556,6 +1690,16 @@ void QDeclarativeGridView::setPreferredHighlightBegin(qreal start)
     emit preferredHighlightBeginChanged();
 }
 
+void QDeclarativeGridView::resetPreferredHighlightBegin()
+{
+    Q_D(QDeclarativeGridView);
+    d->highlightRangeStartValid = false;
+    if (d->highlightRangeStart == 0)
+        return;
+    d->highlightRangeStart = 0;
+    emit preferredHighlightBeginChanged();
+}
+
 qreal QDeclarativeGridView::preferredHighlightEnd() const
 {
     Q_D(const QDeclarativeGridView);
@@ -1565,6 +1709,7 @@ qreal QDeclarativeGridView::preferredHighlightEnd() const
 void QDeclarativeGridView::setPreferredHighlightEnd(qreal end)
 {
     Q_D(QDeclarativeGridView);
+    d->highlightRangeEndValid = true;
     if (d->highlightRangeEnd == end)
         return;
     d->highlightRangeEnd = end;
@@ -1572,6 +1717,16 @@ void QDeclarativeGridView::setPreferredHighlightEnd(qreal end)
     emit preferredHighlightEndChanged();
 }
 
+void QDeclarativeGridView::resetPreferredHighlightEnd()
+{
+    Q_D(QDeclarativeGridView);
+    d->highlightRangeEndValid = false;
+    if (d->highlightRangeEnd == 0)
+        return;
+    d->highlightRangeEnd = 0;
+    emit preferredHighlightEndChanged();
+}
+
 QDeclarativeGridView::HighlightRangeMode QDeclarativeGridView::highlightRangeMode() const
 {
     Q_D(const QDeclarativeGridView);
@@ -1588,6 +1743,43 @@ void QDeclarativeGridView::setHighlightRangeMode(HighlightRangeMode mode)
     emit highlightRangeModeChanged();
 }
 
+/*!
+  \qmlproperty enumeration GridView::layoutDirection
+  This property holds the layout direction of the grid.
+
+    Possible values:
+
+  \list
+  \o Qt.LeftToRight (default) - Items will be laid out starting in the top, left corner. The flow is
+  dependent on the \l GridView::flow property.
+  \o Qt.RightToLeft - Items will be laid out starting in the top, right corner. The flow is dependent
+  on the \l GridView:flow property.
+  \endlist
+
+  \bold Note: If GridView::flow is set to GridView.LeftToRight, this is not to be confused if
+  GridView::layoutDirection is set to Qt.RightToLeft. The GridView.LeftToRight flow value simply
+  indicates that the flow is horizontal.
+
+*/
+
+Qt::LayoutDirection QDeclarativeGridView::layoutDirection() const
+{
+    Q_D(const QDeclarativeGridView);
+    return d->layoutDirection;
+}
+
+void QDeclarativeGridView::setLayoutDirection(Qt::LayoutDirection layoutDirection)
+{
+    Q_D(QDeclarativeGridView);
+    if (d->layoutDirection != layoutDirection) {
+        d->layoutDirection = layoutDirection;
+        d->clear();
+        d->updateGrid();
+        refill();
+        d->updateCurrent(d->currentIndex);
+        emit layoutDirectionChanged();
+    }
+}
 
 /*!
   \qmlproperty enumeration GridView::flow
@@ -1890,11 +2082,23 @@ void QDeclarativeGridView::viewportMoved()
         if (d->haveHighlightRange && d->highlightRange == StrictlyEnforceRange && d->highlight) {
             // reposition highlight
             qreal pos = d->highlight->rowPos();
-            qreal viewPos = d->position();
-            if (pos > viewPos + d->highlightRangeEnd - d->rowSize())
-                pos = viewPos + d->highlightRangeEnd - d->rowSize();
-            if (pos < viewPos + d->highlightRangeStart)
-                pos = viewPos + d->highlightRangeStart;
+            qreal viewPos;
+            qreal highlightStart;
+            qreal highlightEnd;
+            if (d->isRightToLeftTopToBottom()) {
+                highlightStart = d->highlightRangeStartValid ? d->size()-d->highlightRangeEnd : d->highlightRangeStart;
+                highlightEnd = d->highlightRangeEndValid ? d->size()-d->highlightRangeStart : d->highlightRangeEnd;
+                viewPos = -d->position()-d->size();
+            } else {
+                highlightStart = d->highlightRangeStart;
+                highlightEnd = d->highlightRangeEnd;
+                viewPos = d->position();
+            }
+            if (pos > viewPos + highlightEnd - d->rowSize())
+                pos = viewPos + highlightEnd - d->rowSize();
+            if (pos < viewPos + highlightStart)
+                pos = viewPos + highlightStart;
+
             d->highlight->setPosition(d->highlight->colPos(), qRound(pos));
 
             // update current index
@@ -1956,11 +2160,27 @@ qreal QDeclarativeGridView::minXExtent() const
     if (d->flow == QDeclarativeGridView::LeftToRight)
         return QDeclarativeFlickable::minXExtent();
     qreal extent = -d->startPosition();
-    if (d->header && d->visibleItems.count())
-        extent += d->header->item->width();
+    qreal highlightStart;
+    qreal highlightEnd;
+    qreal endPositionFirstItem;
+    if (d->isRightToLeftTopToBottom()) {
+        endPositionFirstItem = d->rowPosAt(d->model->count()-1);
+        highlightStart = d->highlightRangeStartValid
+                ? d->highlightRangeStart - (d->lastPosition()-endPositionFirstItem)
+                : d->size() - (d->lastPosition()-endPositionFirstItem);
+        highlightEnd = d->highlightRangeEndValid ? d->highlightRangeEnd : d->size();
+        if (d->footer && d->visibleItems.count())
+            extent += d->footer->item->width();
+    } else {
+        endPositionFirstItem = d->rowPosAt(0)+d->rowSize();
+        highlightStart = d->highlightRangeStart;
+        highlightEnd = d->highlightRangeEnd;
+        if (d->header && d->visibleItems.count())
+            extent += d->header->item->width();
+    }
     if (d->haveHighlightRange && d->highlightRange == StrictlyEnforceRange) {
-        extent += d->highlightRangeStart;
-        extent = qMax(extent, -(d->rowPosAt(0) + d->rowSize() - d->highlightRangeEnd));
+        extent += highlightStart;
+        extent = qMax(extent, -(endPositionFirstItem - highlightEnd));
     }
     return extent;
 }
@@ -1973,15 +2193,36 @@ qreal QDeclarativeGridView::maxXExtent() const
     qreal extent;
     if (!d->model || !d->model->count()) {
         extent = 0;
-    } if (d->haveHighlightRange && d->highlightRange == StrictlyEnforceRange) {
-        extent = -(d->rowPosAt(d->model->count()-1) - d->highlightRangeStart);
-        if (d->highlightRangeEnd != d->highlightRangeStart)
-            extent = qMin(extent, -(d->endPosition() - d->highlightRangeEnd + 1));
+    }
+    qreal highlightStart;
+    qreal highlightEnd;
+    qreal lastItemPosition;
+    if (d->isRightToLeftTopToBottom()){
+        highlightStart = d->highlightRangeStartValid ? d->highlightRangeEnd : d->size();
+        highlightEnd = d->highlightRangeEndValid ? d->highlightRangeStart : d->size();
+        lastItemPosition = d->endPosition();
+    } else {
+        highlightStart = d->highlightRangeStart;
+        highlightEnd = d->highlightRangeEnd;
+        lastItemPosition = d->rowPosAt(d->model->count()-1);
+    }
+    if (d->haveHighlightRange && d->highlightRange == StrictlyEnforceRange) {
+        extent = -(lastItemPosition - highlightStart);
+        if (highlightEnd != highlightStart)
+            extent = d->isRightToLeftTopToBottom()
+                    ? qMax(extent, -(d->endPosition() - highlightEnd + 1))
+                    : qMin(extent, -(d->endPosition() - highlightEnd + 1));
     } else {
         extent = -(d->endPosition() - width());
     }
-    if (d->footer)
-        extent -= d->footer->item->width();
+    if (d->isRightToLeftTopToBottom()) {
+        if (d->header)
+            extent -= d->header->item->width();
+    } else {
+        if (d->footer)
+            extent -= d->footer->item->width();
+    }
+
     const qreal minX = minXExtent();
     if (extent > minX)
         extent = minX;
@@ -2094,15 +2335,30 @@ void QDeclarativeGridView::moveCurrentIndexLeft()
     const int count = d->model ? d->model->count() : 0;
     if (!count)
         return;
-    if (d->flow == QDeclarativeGridView::LeftToRight) {
-        if (currentIndex() > 0 || d->wrap) {
-            int index = currentIndex() - 1;
-            setCurrentIndex((index >= 0 && index < count) ? index : count-1);
+
+    if (d->layoutDirection == Qt::LeftToRight) {
+        if (d->flow == QDeclarativeGridView::LeftToRight) {
+            if (currentIndex() > 0 || d->wrap) {
+                int index = currentIndex() - 1;
+                setCurrentIndex((index >= 0 && index < count) ? index : count-1);
+            }
+        } else {
+            if (currentIndex() >= d->columns || d->wrap) {
+                int index = currentIndex() - d->columns;
+                setCurrentIndex((index >= 0 && index < count) ? index : count-1);
+            }
         }
     } else {
-        if (currentIndex() >= d->columns || d->wrap) {
-            int index = currentIndex() - d->columns;
-            setCurrentIndex((index >= 0 && index < count) ? index : count-1);
+        if (d->flow == QDeclarativeGridView::LeftToRight) {
+            if (currentIndex() < count - 1 || d->wrap) {
+                int index = currentIndex() + 1;
+                setCurrentIndex((index >= 0 && index < count) ? index : 0);
+            }
+        } else {
+            if (currentIndex() < count - d->columns || d->wrap) {
+                int index = currentIndex() + d->columns;
+                setCurrentIndex((index >= 0 && index < count) ? index : 0);
+            }
         }
     }
 }
@@ -2122,15 +2378,30 @@ void QDeclarativeGridView::moveCurrentIndexRight()
     const int count = d->model ? d->model->count() : 0;
     if (!count)
         return;
-    if (d->flow == QDeclarativeGridView::LeftToRight) {
-        if (currentIndex() < count - 1 || d->wrap) {
-            int index = currentIndex() + 1;
-            setCurrentIndex((index >= 0 && index < count) ? index : 0);
+
+    if (d->layoutDirection == Qt::LeftToRight) {
+        if (d->flow == QDeclarativeGridView::LeftToRight) {
+            if (currentIndex() < count - 1 || d->wrap) {
+                int index = currentIndex() + 1;
+                setCurrentIndex((index >= 0 && index < count) ? index : 0);
+            }
+        } else {
+            if (currentIndex() < count - d->columns || d->wrap) {
+                int index = currentIndex()+d->columns;
+                setCurrentIndex((index >= 0 && index < count) ? index : 0);
+            }
         }
     } else {
-        if (currentIndex() < count - d->columns || d->wrap) {
-            int index = currentIndex()+d->columns;
-            setCurrentIndex((index >= 0 && index < count) ? index : 0);
+        if (d->flow == QDeclarativeGridView::LeftToRight) {
+            if (currentIndex() > 0 || d->wrap) {
+                int index = currentIndex() - 1;
+                setCurrentIndex((index >= 0 && index < count) ? index : count-1);
+            }
+        } else {
+            if (currentIndex() >= d->columns || d->wrap) {
+                int index = currentIndex() - d->columns;
+                setCurrentIndex((index >= 0 && index < count) ? index : count-1);
+            }
         }
     }
 }
@@ -2147,16 +2418,24 @@ void QDeclarativeGridViewPrivate::positionViewAtIndex(int index, int mode)
 
     if (layoutScheduled)
         layout();
-    qreal pos = position();
+    qreal pos = isRightToLeftTopToBottom() ? -position() - size() : position();
     FxGridItem *item = visibleItem(idx);
-    qreal maxExtent = flow == QDeclarativeGridView::LeftToRight ? -q->maxYExtent() : -q->maxXExtent();
+    qreal maxExtent;
+    if (flow == QDeclarativeGridView::LeftToRight)
+        maxExtent = -q->maxYExtent();
+    else
+        maxExtent = isRightToLeftTopToBottom() ? q->minXExtent()-size() : -q->maxXExtent();
+
     if (!item) {
         int itemPos = rowPosAt(idx);
         // save the currently visible items in case any of them end up visible again
         QList<FxGridItem*> oldVisible = visibleItems;
         visibleItems.clear();
         visibleIndex = idx - idx % columns;
-        maxExtent = flow == QDeclarativeGridView::LeftToRight ? -q->maxYExtent() : -q->maxXExtent();
+        if (flow == QDeclarativeGridView::LeftToRight)
+            maxExtent = -q->maxYExtent();
+        else
+            maxExtent = isRightToLeftTopToBottom() ? q->minXExtent()-size() : -q->maxXExtent();
         setPosition(qMin(qreal(itemPos), maxExtent));
         // now release the reference to all the old visible items.
         for (int i = 0; i < oldVisible.count(); ++i)
@@ -2197,8 +2476,13 @@ void QDeclarativeGridViewPrivate::positionViewAtIndex(int index, int mode)
             if (itemPos < pos)
                 pos = itemPos;
         }
+
         pos = qMin(pos, maxExtent);
-        qreal minExtent = flow == QDeclarativeGridView::LeftToRight ? -q->minYExtent() : -q->minXExtent();
+        qreal minExtent;
+        if (flow == QDeclarativeGridView::LeftToRight)
+            minExtent = -q->minYExtent();
+        else
+            minExtent = isRightToLeftTopToBottom() ? q->maxXExtent()-size() : -q->minXExtent();
         pos = qMax(pos, minExtent);
         moveReason = QDeclarativeGridViewPrivate::Other;
         q->cancelFlick();
@@ -2337,32 +2621,43 @@ void QDeclarativeGridView::trackedPositionChanged()
         return;
     if (d->moveReason == QDeclarativeGridViewPrivate::SetIndex) {
         const qreal trackedPos = d->trackedItem->rowPos();
-        const qreal viewPos = d->position();
+        qreal viewPos;
+        qreal highlightStart;
+        qreal highlightEnd;
+        if (d->isRightToLeftTopToBottom()) {
+            viewPos = -d->position()-d->size();
+            highlightStart = d->highlightRangeStartValid ? d->size()-d->highlightRangeEnd : d->highlightRangeStart;
+            highlightEnd = d->highlightRangeEndValid ? d->size()-d->highlightRangeStart : d->highlightRangeEnd;
+        } else {
+            viewPos = d->position();
+            highlightStart = d->highlightRangeStart;
+            highlightEnd = d->highlightRangeEnd;
+        }
         qreal pos = viewPos;
         if (d->haveHighlightRange) {
             if (d->highlightRange == StrictlyEnforceRange) {
-                if (trackedPos > pos + d->highlightRangeEnd - d->rowSize())
-                    pos = trackedPos - d->highlightRangeEnd + d->rowSize();
-                if (trackedPos < pos + d->highlightRangeStart)
-                    pos = trackedPos - d->highlightRangeStart;
+                if (trackedPos > pos + highlightEnd - d->rowSize())
+                    pos = trackedPos - highlightEnd + d->rowSize();
+                if (trackedPos < pos + highlightStart)
+                    pos = trackedPos - highlightStart;
             } else {
-                if (trackedPos < d->startPosition() + d->highlightRangeStart) {
+                if (trackedPos < d->startPosition() + highlightStart) {
                     pos = d->startPosition();
-                } else if (d->trackedItem->endRowPos() > d->endPosition() - d->size() + d->highlightRangeEnd) {
+                } else if (d->trackedItem->endRowPos() > d->endPosition() - d->size() + highlightEnd) {
                     pos = d->endPosition() - d->size() + 1;
                     if (pos < d->startPosition())
                         pos = d->startPosition();
                 } else {
-                    if (trackedPos < viewPos + d->highlightRangeStart) {
-                        pos = trackedPos - d->highlightRangeStart;
-                    } else if (trackedPos > viewPos + d->highlightRangeEnd - d->rowSize()) {
-                        pos = trackedPos - d->highlightRangeEnd + d->rowSize();
+                    if (trackedPos < viewPos + highlightStart) {
+                        pos = trackedPos - highlightStart;
+                    } else if (trackedPos > viewPos + highlightEnd - d->rowSize()) {
+                        pos = trackedPos - highlightEnd + d->rowSize();
                     }
                 }
             }
         } else {
             if (trackedPos < viewPos && d->currentItem->rowPos() < viewPos) {
-                pos = d->currentItem->rowPos() < trackedPos ? trackedPos : d->currentItem->rowPos();
+                pos = qMax(trackedPos, d->currentItem->rowPos());
             } else if (d->trackedItem->endRowPos() >= viewPos + d->size()
                 && d->currentItem->endRowPos() >= viewPos + d->size()) {
                 if (d->trackedItem->endRowPos() <= d->currentItem->endRowPos()) {
@@ -2430,7 +2725,8 @@ void QDeclarativeGridView::itemsInserted(int modelIndex, int count)
         modelIndex = d->visibleIndex;
     }
 
-    int to = d->buffer+d->position()+d->size()-1;
+    qreal tempPos = d->isRightToLeftTopToBottom() ? -d->position()-d->size() : d->position();
+    int to = d->buffer+tempPos+d->size()-1;
     int colPos = 0;
     int rowPos = 0;
     if (d->visibleItems.count()) {
@@ -2756,7 +3052,10 @@ void QDeclarativeGridView::animStopped()
 void QDeclarativeGridView::refill()
 {
     Q_D(QDeclarativeGridView);
-    d->refill(d->position(), d->position()+d->size()-1);
+    if (d->isRightToLeftTopToBottom())
+        d->refill(-d->position()-d->size()+1, -d->position());
+    else
+        d->refill(d->position(), d->position()+d->size()-1);
 }