QmlDesigner: Promote visibility changes of item library items

Change-Id: Ie4b70a2785fbd9199a81ffaf879f521431aa609d
Reviewed-by: Tim Jenssen <tim.jenssen@digia.com>

share/qtcreator/qmldesigner/itemLibraryQmlSources/ItemsView.qml

@@ -112,6 +112,7 @@ ScrollView {
                         Repeater {
                             model: sectionEntries
                             delegate: ItemDelegate {
+                                visible: itemVisible
                                 width: styleConstants.cellWidth + itemGrid.flexibleWidth
                                 height: styleConstants.cellHeight
                             }

src/plugins/qmldesigner/components/itemlibrary/itemlibrarysection.cpp

@@ -91,7 +91,7 @@ bool ItemLibrarySection::updateSectionVisibility(const QString &searchText, bool
         if (itemVisible)
             haveVisibleItems = true;
     }
-
+    if (changed)
         m_sectionEntries.resetModel();
 
     emit sectionEntriesChanged();

src/plugins/qmldesigner/components/itemlibrary/itemlibrarysectionmodel.cpp

@@ -90,8 +90,7 @@ const QList<ItemLibraryItem *> &ItemLibrarySectionModel::items() const
 
 void ItemLibrarySectionModel::resetModel()
 {
-    beginResetModel();
-    endResetModel();
+    emit dataChanged(QModelIndex(), QModelIndex());
 }
 
 void ItemLibrarySectionModel::addRoleNames()