Fixes: NB#207822, SceneWindow is relocated too much.

RevBy: Michael Hasselmann, Hannu Koivisto
Details: Give MSceneWindowScroller the currently planned position when querying new one.

7 files changed, 15 insertions, 8 deletions

diff --git a/src/corelib/core/mabstractscroller.h b/src/corelib/core/mabstractscroller.h
index 3b183691..12cafa57 100644
--- a/src/corelib/core/mabstractscroller.h
+++ b/src/corelib/core/mabstractscroller.h
@@ -54,10 +54,12 @@ public:
      *  \param widget The scrollable widget in question.
      *  \param targetRect Target rectangle of the area of interest, in local widget coordinates.
      *  \param originPoint Current position (top left) of the area to be moved to targetRect, in local widget coordinates.
+     *  \param currentOffset The amount that \a widget is already planned to be scrolled but not yet applied.
      */
     virtual QPoint queryScrollingAmount(const QGraphicsWidget *widget,
                                         const QRect &targetRect,
-                                        const QPoint &originPoint) = 0;
+                                        const QPoint &originPoint,
+                                        const QPoint &currentOffset) = 0;
 
     //! \brief Scrolls the contents of given \a widget by the amount of \a contentsOffset.
     virtual void applyScrolling(QGraphicsWidget *widget, const QPoint &contentsOffset) = 0;
diff --git a/src/corelib/core/mpannableviewportscroller.cpp b/src/corelib/core/mpannableviewportscroller.cpp
index 844c472e..be854ec4 100644
--- a/src/corelib/core/mpannableviewportscroller.cpp
+++ b/src/corelib/core/mpannableviewportscroller.cpp
@@ -23,7 +23,8 @@
 
 QPoint MPannableViewportScroller::queryScrollingAmount(const QGraphicsWidget *widget,
                                                        const QRect &targetRect,
-                                                       const QPoint &originPoint)
+                                                       const QPoint &originPoint,
+                                                       const QPoint &)
 {
     const MPannableViewport *viewport = static_cast<const MPannableViewport *>(widget);
 
diff --git a/src/corelib/core/mpannableviewportscroller.h b/src/corelib/core/mpannableviewportscroller.h
index 6263a49c..aaac86fc 100644
--- a/src/corelib/core/mpannableviewportscroller.h
+++ b/src/corelib/core/mpannableviewportscroller.h
@@ -29,7 +29,8 @@ class MPannableViewportScroller : public MAbstractScroller
 public:
     virtual QPoint queryScrollingAmount(const QGraphicsWidget *widget,
                                         const QRect &targetRect,
-                                        const QPoint &originPoint);
+                                        const QPoint &originPoint,
+                                        const QPoint &currentOffset);
     virtual void applyScrolling(QGraphicsWidget *widget, const QPoint &contentsOffset);
     virtual void restoreScrolling(QGraphicsWidget *widget);
 };
diff --git a/src/corelib/core/mscenewindowscroller.cpp b/src/corelib/core/mscenewindowscroller.cpp
index 44bebc9b..783900f2 100644
--- a/src/corelib/core/mscenewindowscroller.cpp
+++ b/src/corelib/core/mscenewindowscroller.cpp
@@ -25,7 +25,8 @@
 
 QPoint MSceneWindowScroller::queryScrollingAmount(const QGraphicsWidget *widget,
                                                   const QRect &targetRect,
-                                                  const QPoint &originPoint)
+                                                  const QPoint &originPoint,
+                                                  const QPoint &currentOffset)
 {
     const MSceneWindow *sceneWindow = static_cast<const MSceneWindow *>(widget);
 
@@ -35,7 +36,7 @@ QPoint MSceneWindowScroller::queryScrollingAmount(const QGraphicsWidget *widget,
     const QRect sceneRect(QRect(QPoint(), sceneWindow->sceneManager()->visibleSceneSize(M::Landscape)));
     const QRect mappedSceneRect(sceneWindow->mapRectFromScene(sceneRect).toRect());
 
-    const int distanceFromBottom = mappedSceneRect.bottom() - sceneWindow->rect().toRect().bottom();
+    const int distanceFromBottom = (mappedSceneRect.bottom() - currentOffset.y()) - sceneWindow->rect().toRect().bottom();
 
     // Negative offset increases distance from bottom.
     const QPoint offset(targetRect.topLeft() - originPoint);
diff --git a/src/corelib/core/mscenewindowscroller.h b/src/corelib/core/mscenewindowscroller.h
index 4e263d39..1a433feb 100644
--- a/src/corelib/core/mscenewindowscroller.h
+++ b/src/corelib/core/mscenewindowscroller.h
@@ -42,7 +42,8 @@ signals:
 public:
     virtual QPoint queryScrollingAmount(const QGraphicsWidget *widget,
                                         const QRect &targetRect,
-                                        const QPoint &originPoint);
+                                        const QPoint &originPoint,
+                                        const QPoint &currentOffset);
     virtual void applyScrolling(QGraphicsWidget *widget, const QPoint &contentsOffset);
     virtual void restoreScrolling(QGraphicsWidget *widget);
 };
diff --git a/src/corelib/core/mscrollchain.cpp b/src/corelib/core/mscrollchain.cpp
index b49bf98a..a292ec32 100644
--- a/src/corelib/core/mscrollchain.cpp
+++ b/src/corelib/core/mscrollchain.cpp
@@ -228,7 +228,7 @@ MScrollChain::ScrollChainItem::ScrollChainItem(QSharedPointer<MAbstractScroller>
 void MScrollChain::ScrollChainItem::calculateScrolling(const QRect &targetRect,
                                                        const QPoint &originPoint)
 {
-    contentsTranslation += scroller->queryScrollingAmount(widget, targetRect, originPoint);
+    contentsTranslation += scroller->queryScrollingAmount(widget, targetRect, originPoint, contentsTranslation);
 }
 
 void MScrollChain::ScrollChainItem::applyScrolling()
diff --git a/tests/ut_mscrollchain/ut_mscrollchain.cpp b/tests/ut_mscrollchain/ut_mscrollchain.cpp
index 2c50cbcf..193f9dc0 100644
--- a/tests/ut_mscrollchain/ut_mscrollchain.cpp
+++ b/tests/ut_mscrollchain/ut_mscrollchain.cpp
@@ -78,7 +78,8 @@ public:
 
     virtual QPoint queryScrollingAmount(const QGraphicsWidget *widget,
                                         const QRect &targetRect,
-                                        const QPoint &originPoint)
+                                        const QPoint &originPoint,
+                                        const QPoint &)
     {
         const QRect boundaries(widget->boundingRect().toRect());