Buffer changes received during layout()

Otherwise, changes received by a view during layout() may
override the changes that are currently being processed.

Change-Id: Iabc4db682f85ceb7d04c3f7442fb6c98ebdb94f1
Reviewed-by: Andrew den Exter <andrew.den-exter@nokia.com>

diff --git a/src/quick/items/qquickitemview.cpp b/src/quick/items/qquickitemview.cpp
index 0d95500..209d30a 100644 (file)
--- a/src/quick/items/qquickitemview.cpp
+++ b/src/quick/items/qquickitemview.cpp
@@ -186,6 +186,18 @@ void QQuickItemViewChangeSet::applyChanges(const QQuickChangeSet &changeSet)
     }
 }
 
+void QQuickItemViewChangeSet::applyBufferedChanges(const QQuickItemViewChangeSet &other)
+{
+    if (!other.hasPendingChanges())
+        return;
+
+    pendingChanges.apply(other.pendingChanges);
+    itemCount = other.itemCount;
+    newCurrentIndex = other.newCurrentIndex;
+    currentChanged = other.currentChanged;
+    currentRemoved = other.currentRemoved;
+}
+
 void QQuickItemViewChangeSet::prepare(int currentIndex, int count)
 {
     if (active)
@@ -1044,8 +1056,17 @@ void QQuickItemView::modelUpdated(const QQuickChangeSet &changeSet, bool reset)
             polish();
         }
     } else {
-        d->currentChanges.prepare(d->currentIndex, d->itemCount);
-        d->currentChanges.applyChanges(changeSet);
+        if (d->disableLayout) {
+            d->bufferedChanges.prepare(d->currentIndex, d->itemCount);
+            d->bufferedChanges.applyChanges(changeSet);
+        } else {
+            if (d->bufferedChanges.hasPendingChanges()) {
+                d->currentChanges.applyBufferedChanges(d->bufferedChanges);
+                d->bufferedChanges.reset();
+            }
+            d->currentChanges.prepare(d->currentIndex, d->itemCount);
+            d->currentChanges.applyChanges(changeSet);
+        }
         polish();
     }
 }
@@ -1756,11 +1777,16 @@ void QQuickItemViewPrivate::layout()
 bool QQuickItemViewPrivate::applyModelChanges(ChangeResult *totalInsertionResult, ChangeResult *totalRemovalResult)
 {
     Q_Q(QQuickItemView);
-    if (!q->isComponentComplete() || (!currentChanges.hasPendingChanges() && !runDelayedRemoveTransition) || disableLayout)
+    if (!q->isComponentComplete() || (!currentChanges.hasPendingChanges() && !bufferedChanges.hasPendingChanges() && !runDelayedRemoveTransition) || disableLayout)
         return false;
 
     disableLayout = true;
 
+    if (bufferedChanges.hasPendingChanges()) {
+        currentChanges.applyBufferedChanges(bufferedChanges);
+        bufferedChanges.reset();
+    }
+
     updateUnrequestedIndexes();
     moveReason = QQuickItemViewPrivate::Other;
 

diff --git a/src/quick/items/qquickitemview_p_p.h b/src/quick/items/qquickitemview_p_p.h
index 7516761..e352c46 100644 (file)
--- a/src/quick/items/qquickitemview_p_p.h
+++ b/src/quick/items/qquickitemview_p_p.h
@@ -107,6 +107,8 @@ public:
 
     void applyChanges(const QQuickChangeSet &changeSet);
 
+    void applyBufferedChanges(const QQuickItemViewChangeSet &other);
+
     int itemCount;
     int newCurrentIndex;
     QQuickChangeSet pendingChanges;
@@ -245,6 +247,7 @@ public:
     int requestedIndex;
     FxViewItem *requestedItem;
     QQuickItemViewChangeSet currentChanges;
+    QQuickItemViewChangeSet bufferedChanges;
 
     QQmlComponent *highlightComponent;
     FxViewItem *highlight;

diff --git a/tests/auto/quick/qquicklistview/data/destroyItemOnCreation.qml b/tests/auto/quick/qquicklistview/data/destroyItemOnCreation.qml
new file mode 100644 (file)
index 0000000..12f43b0
--- /dev/null
+++ b/tests/auto/quick/qquicklistview/data/destroyItemOnCreation.qml
@@ -0,0 +1,37 @@
+import QtQuick 2.0
+
+Rectangle {
+    id: root
+
+    width: 240
+    height: 320
+
+    property int createdIndex: -1
+
+    Component {
+        id: myDelegate
+
+        Rectangle {
+            id: wrapper
+            width: 240; height: 20
+            objectName: "wrapper"
+
+            Text { text: index }
+
+            Component.onCompleted: {
+                root.createdIndex = index
+                ListView.view.model.removeItem(index)
+            }
+        }
+    }
+
+    ListView {
+        id: list
+        objectName: "list"
+        focus: true
+        width: 240
+        height: 320
+        delegate: myDelegate
+        model: testModel
+    }
+}

diff --git a/tests/auto/quick/qquicklistview/tst_qquicklistview.cpp b/tests/auto/quick/qquicklistview/tst_qquicklistview.cpp
index 461a6b6..1218d3c 100644 (file)
--- a/tests/auto/quick/qquicklistview/tst_qquicklistview.cpp
+++ b/tests/auto/quick/qquicklistview/tst_qquicklistview.cpp
@@ -189,6 +189,7 @@ private slots:
     void multipleDisplaced();
 
     void flickBeyondBounds();
+    void destroyItemOnCreation();
 
 private:
     template <class T> void items(const QUrl &source, bool forceLayout);
@@ -6245,6 +6246,32 @@ void tst_QQuickListView::flickBeyondBounds()
     delete canvas;
 }
 
+void tst_QQuickListView::destroyItemOnCreation()
+{
+    QmlListModel model;
+    QQuickView *canvas = createView();
+    canvas->rootContext()->setContextProperty("testModel", &model);
+
+    canvas->setSource(testFileUrl("destroyItemOnCreation.qml"));
+    canvas->show();
+    qApp->processEvents();
+
+    QQuickListView *listview = findItem<QQuickListView>(canvas->rootObject(), "list");
+    QVERIFY(listview != 0);
+
+    QQuickItem *contentItem = listview->contentItem();
+    QVERIFY(contentItem != 0);
+    QTRY_COMPARE(QQuickItemPrivate::get(listview)->polishScheduled, false);
+
+    QCOMPARE(canvas->rootObject()->property("createdIndex").toInt(), -1);
+    model.addItem("new item", "");
+    QTRY_COMPARE(canvas->rootObject()->property("createdIndex").toInt(), 0);
+
+    QTRY_COMPARE(findItems<QQuickItem>(contentItem, "wrapper").count(), 0);
+    QCOMPARE(model.count(), 0);
+
+    delete canvas;
+}
 
 QTEST_MAIN(tst_QQuickListView)
 

diff --git a/tests/auto/quick/shared/viewtestutil.h b/tests/auto/quick/shared/viewtestutil.h
index 6ab754c..06efd9c 100644 (file)
--- a/tests/auto/quick/shared/viewtestutil.h
+++ b/tests/auto/quick/shared/viewtestutil.h
@@ -97,8 +97,8 @@ namespace QQuickViewTestUtil
         void insertItem(int index, const QString &name, const QString &number);
         void insertItems(int index, const QList<QPair<QString, QString> > &items);
 
-        void removeItem(int index);
-        void removeItems(int index, int count);
+        Q_INVOKABLE void removeItem(int index);
+        Q_INVOKABLE void removeItems(int index, int count);
 
         void moveItem(int from, int to);
         void moveItems(int from, int to, int count);