added backnavigation and qrc

LenaPi/models/NavigationListModel.cpp

@@ -18,5 +18,27 @@ void NavigationListModel::setModelItems(QList<NavigationItemModel *> list)
     for(const auto& item : list){
         mItems.append(item);
     }
+
+    if(mItems.isEmpty()){
+        mIsBackVisible = false;
+    } else{
+        mIsBackVisible = !list.at(0)->getParentItem()->isRoot();
+    }
+
     emit modelItemsChanged();
 }
+
+bool NavigationListModel::isBackVisible()
+{
+    return mIsBackVisible;
+}
+
+void NavigationListModel::navigateBack()
+{
+    if(!mIsBackVisible || mItems.isEmpty()) return;
+
+    auto item = qobject_cast<NavigationItemModel*>(mItems.at(0));
+    if(!item || item->getParentItem()->isRoot()) return;
+
+    setModelItems(item->getParentItem()->getSiblings());
+}