Fix lockup in views due to endless polish loop.

It was possible to cause an endless polish loop in some rare cases.
Eliminate all calls to polish() within existing polish() code paths.

Cleanup delegate creation and cancelling in the cacheBuffer area.

Adjust first item position correctly when inserting/removing before
visibleItems list.

Change-Id: I508a2e6de8cb09d904466cbf5fb6b5dfd1e89c49
Reviewed-by: Bea Lam <bea.lam@nokia.com>

1 files changed, 13 insertions, 5 deletions

diff --git a/src/quick/items/qquickitemview_p_p.h b/src/quick/items/qquickitemview_p_p.h
index a2dd963dd2..52463afaaa 100644
--- a/src/quick/items/qquickitemview_p_p.h
+++ b/src/quick/items/qquickitemview_p_p.h
@@ -104,9 +104,18 @@ public:
         qreal sizeChangesBeforeVisiblePos;
         qreal sizeChangesAfterVisiblePos;
         bool changedFirstItem;
+        int changeBeforeVisible;
 
         ChangeResult(const QDeclarativeNullableValue<qreal> &p)
-            : visiblePos(p), sizeChangesBeforeVisiblePos(0), sizeChangesAfterVisiblePos(0), changedFirstItem(false) {}
+            : visiblePos(p), sizeChangesBeforeVisiblePos(0), sizeChangesAfterVisiblePos(0),
+            changedFirstItem(false), changeBeforeVisible(0) {}
+
+        void reset() {
+            sizeChangesBeforeVisiblePos = 0.0;
+            sizeChangesAfterVisiblePos = 0.0;
+            changedFirstItem = false;
+            changeBeforeVisible = 0;
+        }
     };
 
     enum BufferMode { NoBuffer = 0x00, BufferBefore = 0x01, BufferAfter = 0x02 };
@@ -130,7 +139,7 @@ public:
     void regenerate();
     void layout();
     void refill();
-    void refill(qreal from, qreal to, bool doBuffer = false);
+    void refill(qreal from, qreal to);
     void mirrorChange();
 
     FxViewItem *createItem(int modelIndex, bool asynchronous = false);
@@ -149,7 +158,7 @@ public:
     bool applyModelChanges();
     bool applyRemovalChange(const QDeclarativeChangeSet::Remove &removal, ChangeResult *changeResult, int *removedCount);
     void repositionFirstItem(FxViewItem *prevVisibleItemsFirst, qreal prevVisibleItemsFirstPos,
-            FxViewItem *prevFirstVisible, const ChangeResult &insertionResult, const ChangeResult &removalResult);
+            FxViewItem *prevFirstVisible, ChangeResult *insertionResult, ChangeResult *removalResult);
 
     void checkVisible() const;
 
@@ -197,7 +206,6 @@ public:
 
     bool ownModel : 1;
     bool wrap : 1;
-    bool deferredRelease : 1;
     bool inApplyModelChanges : 1;
     bool inViewportMoved : 1;
     bool forceLayout : 1;
@@ -240,7 +248,7 @@ protected:
     virtual FxViewItem *newViewItem(int index, QQuickItem *item) = 0;
     virtual void repositionPackageItemAt(QQuickItem *item, int index) = 0;
     virtual void resetFirstItemPosition(qreal pos = 0.0) = 0;
-    virtual void adjustFirstItem(qreal forwards, qreal backwards) = 0;
+    virtual void adjustFirstItem(qreal forwards, qreal backwards, int changeBeforeVisible) = 0;
 
     virtual void layoutVisibleItems(int fromModelIndex = 0) = 0;
     virtual void changedVisibleIndex(int newIndex) = 0;