[app] Added positionViewAtIndex method to BooksListWatcher

It allows to avoid binding loops

app/src/BooksListWatcher.cpp

@@ -38,6 +38,7 @@
 #define LISTVIEW_CONTENT_X              "contentX"
 #define LISTVIEW_CONTENT_Y              "contentY"
 #define LISTVIEW_INDEX_AT               "indexAt"
+#define LISTVIEW_POSITION_VIEW_AT_INDEX "positionViewAtIndex"
 
 BooksListWatcher::BooksListWatcher(QObject* aParent) :
     QObject(aParent),
@@ -45,6 +46,8 @@ BooksListWatcher::BooksListWatcher(QObject* aParent) :
     iContentX(0),
     iContentY(0),
     iListView(NULL),
+    iCenterMode(-1),
+    iPositionIsChanging(false),
     iResizeTimer(new QTimer(this))
 {
     iResizeTimer->setSingleShot(true);
@@ -58,6 +61,7 @@ void BooksListWatcher::setListView(QQuickItem* aView)
         const QSize oldSize(iSize);
         if (iListView) iListView->disconnect(this);
         iListView = aView;
+        iCenterMode = -1;
         if (iListView) {
             connect(iListView,
                 SIGNAL(widthChanged()),
@@ -110,6 +114,38 @@ qreal BooksListWatcher::getRealProperty(const char *name, qreal defaultValue)
     return defaultValue;
 }
 
+void BooksListWatcher::positionViewAtIndex(int aIndex)
+{
+    if (iListView) {
+        HDEBUG(aIndex);
+        if (iCenterMode < 0) {
+            bool ok = false;
+            const QMetaObject* metaObject = iListView->metaObject();
+            if (metaObject) {
+                int index = metaObject->indexOfEnumerator("PositionMode");
+                if (index >= 0) {
+                    QMetaEnum metaEnum = metaObject->enumerator(index);
+                    int value = metaEnum.keyToValue("Center", &ok);
+                    if (ok) {
+                        iCenterMode = value;
+                        HDEBUG("Center =" << iCenterMode);
+                    }
+                }
+            }
+            HASSERT(ok);
+            if (!ok) {
+                // This is what it normally is
+                iCenterMode = 1;
+            }
+        }
+        iPositionIsChanging = true;
+        QMetaObject::invokeMethod(iListView, LISTVIEW_POSITION_VIEW_AT_INDEX,
+            Q_ARG(int,aIndex), Q_ARG(int,iCenterMode));
+        iPositionIsChanging = false;
+        updateCurrentIndex();
+    }
+}
+
 qreal BooksListWatcher::contentX()
 {
     return getRealProperty(LISTVIEW_CONTENT_X);
@@ -193,18 +229,24 @@ void BooksListWatcher::onContentXChanged()
 {
     HASSERT(sender() == iListView);
     iContentX = contentX();
-    updateCurrentIndex();
+    if (!iPositionIsChanging) {
+        updateCurrentIndex();
+    }
 }
 
 void BooksListWatcher::onContentYChanged()
 {
     HASSERT(sender() == iListView);
     iContentY = contentY();
-    updateCurrentIndex();
+    if (!iPositionIsChanging) {
+        updateCurrentIndex();
+    }
 }
 
 void BooksListWatcher::onContentSizeChanged()
 {
     HASSERT(sender() == iListView);
-    updateCurrentIndex();
+    if (!iPositionIsChanging) {
+        updateCurrentIndex();
+    }
 }

app/src/BooksListWatcher.h

@@ -59,6 +59,8 @@ public:
     QQuickItem* listView() const { return iListView; }
     void setListView(QQuickItem* aView);
 
+    Q_INVOKABLE void positionViewAtIndex(int aIndex);
+
 private:
     qreal contentX();
     qreal contentY();
@@ -88,6 +90,8 @@ private:
     qreal iContentX;
     qreal iContentY;
     QQuickItem* iListView;
+    int iCenterMode;
+    bool iPositionIsChanging;
     QTimer* iResizeTimer;
 };